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Revision 1.282 by root, Tue Aug 11 01:18:27 2009 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
		6	and POE are various supported event loops/environments.
6		7
7	=head1 SYNOPSIS	8	=head1 SYNOPSIS
8		9
9	use AnyEvent;	10	use AnyEvent;
10		11
		12	# file descriptor readable
11	my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { ... });	13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
12		14
		15	# one-shot or repeating timers
13	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
14	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
15		18
16	print AnyEvent->now; # prints current event loop time	19	print AnyEvent->now; # prints current event loop time
17	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
18		21
		22	# POSIX signal
19	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });	23	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
20		24
		25	# child process exit
21	my $w = AnyEvent->child (pid => $pid, cb => sub {	26	my $w = AnyEvent->child (pid => $pid, cb => sub {
22	my ($pid, $status) = @_;	27	my ($pid, $status) = @_;
23	...	28	...
24	});	29	});
		30
		31	# called when event loop idle (if applicable)
		32	my $w = AnyEvent->idle (cb => sub { ... });
25		33
26	my $w = AnyEvent->condvar; # stores whether a condition was flagged	34	my $w = AnyEvent->condvar; # stores whether a condition was flagged
27	$w->send; # wake up current and all future recv's	35	$w->send; # wake up current and all future recv's
28	$w->recv; # enters "main loop" till $condvar gets ->send	36	$w->recv; # enters "main loop" till $condvar gets ->send
29	# use a condvar in callback mode:	37	# use a condvar in callback mode:
…		…
32	=head1 INTRODUCTION/TUTORIAL	40	=head1 INTRODUCTION/TUTORIAL
33		41
34	This manpage is mainly a reference manual. If you are interested	42	This manpage is mainly a reference manual. If you are interested
35	in a tutorial or some gentle introduction, have a look at the	43	in a tutorial or some gentle introduction, have a look at the
36	L<AnyEvent::Intro> manpage.	44	L<AnyEvent::Intro> manpage.
		45
		46	=head1 SUPPORT
		47
		48	There is a mailinglist for discussing all things AnyEvent, and an IRC
		49	channel, too.
		50
		51	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
		52	Repository>, at L<http://anyevent.schmorp.de>, for more info.
37		53
38	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	54	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
39		55
40	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	56	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
41	nowadays. So what is different about AnyEvent?	57	nowadays. So what is different about AnyEvent?
…		…
137	These watchers are normal Perl objects with normal Perl lifetime. After	153	These watchers are normal Perl objects with normal Perl lifetime. After
138	creating a watcher it will immediately "watch" for events and invoke the	154	creating a watcher it will immediately "watch" for events and invoke the
139	callback when the event occurs (of course, only when the event model	155	callback when the event occurs (of course, only when the event model
140	is in control).	156	is in control).
141		157
		158	Note that B<callbacks must not permanently change global variables>
		159	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
		160	callbacks must not C<die> >>. The former is good programming practise in
		161	Perl and the latter stems from the fact that exception handling differs
		162	widely between event loops.
		163
142	To disable the watcher you have to destroy it (e.g. by setting the	164	To disable the watcher you have to destroy it (e.g. by setting the
143	variable you store it in to C<undef> or otherwise deleting all references	165	variable you store it in to C<undef> or otherwise deleting all references
144	to it).	166	to it).
145		167
146	All watchers are created by calling a method on the C<AnyEvent> class.	168	All watchers are created by calling a method on the C<AnyEvent> class.
…		…
159	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
160	declared.	182	declared.
161		183
162	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
163		185
		186	$w = AnyEvent->io (
		187	fh => <filehandle_or_fileno>,
		188	poll => <"r" or "w">,
		189	cb => <callback>,
		190	);
		191
164	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
165	with the following mandatory key-value pairs as arguments:	193	with the following mandatory key-value pairs as arguments:
166		194
167	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events	195	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
168	(AnyEvent might or might not keep a reference to this file handle). C<poll>	196	for events (AnyEvent might or might not keep a reference to this file
		197	handle). Note that only file handles pointing to things for which
		198	non-blocking operation makes sense are allowed. This includes sockets,
		199	most character devices, pipes, fifos and so on, but not for example files
		200	or block devices.
		201
169	must be a string that is either C<r> or C<w>, which creates a watcher	202	C<poll> must be a string that is either C<r> or C<w>, which creates a
170	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the	203	watcher waiting for "r"eadable or "w"ritable events, respectively.
		204
171	callback to invoke each time the file handle becomes ready.	205	C<cb> is the callback to invoke each time the file handle becomes ready.
172		206
173	Although the callback might get passed parameters, their value and	207	Although the callback might get passed parameters, their value and
174	presence is undefined and you cannot rely on them. Portable AnyEvent	208	presence is undefined and you cannot rely on them. Portable AnyEvent
175	callbacks cannot use arguments passed to I/O watcher callbacks.	209	callbacks cannot use arguments passed to I/O watcher callbacks.
176		210
…		…
191	undef $w;	225	undef $w;
192	});	226	});
193		227
194	=head2 TIME WATCHERS	228	=head2 TIME WATCHERS
195		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
196	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 >>
197	method with the following mandatory arguments:	239	method with the following mandatory arguments:
198		240
199	C<after> specifies after how many seconds (fractional values are	241	C<after> specifies after how many seconds (fractional values are
200	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
…		…
308	In either case, if you care (and in most cases, you don't), then you	350	In either case, if you care (and in most cases, you don't), then you
309	can get whatever behaviour you want with any event loop, by taking the	351	can get whatever behaviour you want with any event loop, by taking the
310	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
311	account.	353	account.
312		354
		355	=item AnyEvent->now_update
		356
		357	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache
		358	the current time for each loop iteration (see the discussion of L<<
		359	AnyEvent->now >>, above).
		360
		361	When a callback runs for a long time (or when the process sleeps), then
		362	this "current" time will differ substantially from the real time, which
		363	might affect timers and time-outs.
		364
		365	When this is the case, you can call this method, which will update the
		366	event loop's idea of "current time".
		367
		368	Note that updating the time I<might> cause some events to be handled.
		369
313	=back	370	=back
314		371
315	=head2 SIGNAL WATCHERS	372	=head2 SIGNAL WATCHERS
		373
		374	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
316		375
317	You can watch for signals using a signal watcher, C<signal> is the signal	376	You can watch for signals using a signal watcher, C<signal> is the signal
318	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	377	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
319	callback to be invoked whenever a signal occurs.	378	callback to be invoked whenever a signal occurs.
320		379
…		…
326	invocation, and callback invocation will be synchronous. Synchronous means	385	invocation, and callback invocation will be synchronous. Synchronous means
327	that it might take a while until the signal gets handled by the process,	386	that it might take a while until the signal gets handled by the process,
328	but it is guaranteed not to interrupt any other callbacks.	387	but it is guaranteed not to interrupt any other callbacks.
329		388
330	The main advantage of using these watchers is that you can share a signal	389	The main advantage of using these watchers is that you can share a signal
331	between multiple watchers.	390	between multiple watchers, and AnyEvent will ensure that signals will not
		391	interrupt your program at bad times.
332		392
333	This watcher might use C<%SIG>, so programs overwriting those signals	393	This watcher might use C<%SIG> (depending on the event loop used),
334	directly will likely not work correctly.	394	so programs overwriting those signals directly will likely not work
		395	correctly.
335		396
336	Example: exit on SIGINT	397	Example: exit on SIGINT
337		398
338	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
339		400
		401	=head3 Signal Races, Delays and Workarounds
		402
		403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		404	callbacks to signals in a generic way, which is a pity, as you cannot
		405	do race-free signal handling in perl, requiring C libraries for
		406	this. AnyEvent will try to do it's best, which means in some cases,
		407	signals will be delayed. The maximum time a signal might be delayed is
		408	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
		409	variable can be changed only before the first signal watcher is created,
		410	and should be left alone otherwise. This variable determines how often
		411	AnyEvent polls for signals (in case a wake-up was missed). Higher values
		412	will cause fewer spurious wake-ups, which is better for power and CPU
		413	saving.
		414
		415	All these problems can be avoided by installing the optional
		416	L<Async::Interrupt> module, which works with most event loops. It will not
		417	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		418	(and not with L<POE> currently, as POE does it's own workaround with
		419	one-second latency). For those, you just have to suffer the delays.
		420
340	=head2 CHILD PROCESS WATCHERS	421	=head2 CHILD PROCESS WATCHERS
341		422
		423	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		424
342	You can also watch on a child process exit and catch its exit status.	425	You can also watch on a child process exit and catch its exit status.
343		426
344	The child process is specified by the C<pid> argument (if set to C<0>, it	427	The child process is specified by the C<pid> argument (one some backends,
345	watches for any child process exit). The watcher will triggered only when	428	using C<0> watches for any child process exit, on others this will
346	the child process has finished and an exit status is available, not on	429	croak). The watcher will be triggered only when the child process has
347	any trace events (stopped/continued).	430	finished and an exit status is available, not on any trace events
		431	(stopped/continued).
348		432
349	The callback will be called with the pid and exit status (as returned by	433	The callback will be called with the pid and exit status (as returned by
350	waitpid), so unlike other watcher types, you I<can> rely on child watcher	434	waitpid), so unlike other watcher types, you I<can> rely on child watcher
351	callback arguments.	435	callback arguments.
352		436
…		…
357		441
358	There is a slight catch to child watchers, however: you usually start them	442	There is a slight catch to child watchers, however: you usually start them
359	I<after> the child process was created, and this means the process could	443	I<after> the child process was created, and this means the process could
360	have exited already (and no SIGCHLD will be sent anymore).	444	have exited already (and no SIGCHLD will be sent anymore).
361		445
362	Not all event models handle this correctly (POE doesn't), but even for	446	Not all event models handle this correctly (neither POE nor IO::Async do,
		447	see their AnyEvent::Impl manpages for details), but even for event models
363	event models that I<do> handle this correctly, they usually need to be	448	that I<do> handle this correctly, they usually need to be loaded before
364	loaded before the process exits (i.e. before you fork in the first place).	449	the process exits (i.e. before you fork in the first place). AnyEvent's
		450	pure perl event loop handles all cases correctly regardless of when you
		451	start the watcher.
365		452
366	This means you cannot create a child watcher as the very first thing in an	453	This means you cannot create a child watcher as the very first
367	AnyEvent program, you I<have> to create at least one watcher before you	454	thing in an AnyEvent program, you I<have> to create at least one
368	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	455	watcher before you C<fork> the child (alternatively, you can call
		456	C<AnyEvent::detect>).
		457
		458	As most event loops do not support waiting for child events, they will be
		459	emulated by AnyEvent in most cases, in which the latency and race problems
		460	mentioned in the description of signal watchers apply.
369		461
370	Example: fork a process and wait for it	462	Example: fork a process and wait for it
371		463
372	my $done = AnyEvent->condvar;	464	my $done = AnyEvent->condvar;
373		465
…		…
383	);	475	);
384		476
385	# do something else, then wait for process exit	477	# do something else, then wait for process exit
386	$done->recv;	478	$done->recv;
387		479
		480	=head2 IDLE WATCHERS
		481
		482	$w = AnyEvent->idle (cb => <callback>);
		483
		484	Sometimes there is a need to do something, but it is not so important
		485	to do it instantly, but only when there is nothing better to do. This
		486	"nothing better to do" is usually defined to be "no other events need
		487	attention by the event loop".
		488
		489	Idle watchers ideally get invoked when the event loop has nothing
		490	better to do, just before it would block the process to wait for new
		491	events. Instead of blocking, the idle watcher is invoked.
		492
		493	Most event loops unfortunately do not really support idle watchers (only
		494	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
		495	will simply call the callback "from time to time".
		496
		497	Example: read lines from STDIN, but only process them when the
		498	program is otherwise idle:
		499
		500	my @lines; # read data
		501	my $idle_w;
		502	my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		503	push @lines, scalar <STDIN>;
		504
		505	# start an idle watcher, if not already done
		506	$idle_w ||= AnyEvent->idle (cb => sub {
		507	# handle only one line, when there are lines left
		508	if (my $line = shift @lines) {
		509	print "handled when idle: $line";
		510	} else {
		511	# otherwise disable the idle watcher again
		512	undef $idle_w;
		513	}
		514	});
		515	});
		516
388	=head2 CONDITION VARIABLES	517	=head2 CONDITION VARIABLES
		518
		519	$cv = AnyEvent->condvar;
		520
		521	$cv->send (<list>);
		522	my @res = $cv->recv;
389		523
390	If you are familiar with some event loops you will know that all of them	524	If you are familiar with some event loops you will know that all of them
391	require you to run some blocking "loop", "run" or similar function that	525	require you to run some blocking "loop", "run" or similar function that
392	will actively watch for new events and call your callbacks.	526	will actively watch for new events and call your callbacks.
393		527
394	AnyEvent is different, it expects somebody else to run the event loop and	528	AnyEvent is slightly different: it expects somebody else to run the event
395	will only block when necessary (usually when told by the user).	529	loop and will only block when necessary (usually when told by the user).
396		530
397	The instrument to do that is called a "condition variable", so called	531	The instrument to do that is called a "condition variable", so called
398	because they represent a condition that must become true.	532	because they represent a condition that must become true.
399		533
		534	Now is probably a good time to look at the examples further below.
		535
400	Condition variables can be created by calling the C<< AnyEvent->condvar	536	Condition variables can be created by calling the C<< AnyEvent->condvar
401	>> method, usually without arguments. The only argument pair allowed is	537	>> method, usually without arguments. The only argument pair allowed is
402
403	C<cb>, which specifies a callback to be called when the condition variable	538	C<cb>, which specifies a callback to be called when the condition variable
404	becomes true, with the condition variable as the first argument (but not	539	becomes true, with the condition variable as the first argument (but not
405	the results).	540	the results).
406		541
407	After creation, the condition variable is "false" until it becomes "true"	542	After creation, the condition variable is "false" until it becomes "true"
…		…
412	Condition variables are similar to callbacks, except that you can	547	Condition variables are similar to callbacks, except that you can
413	optionally wait for them. They can also be called merge points - points	548	optionally wait for them. They can also be called merge points - points
414	in time where multiple outstanding events have been processed. And yet	549	in time where multiple outstanding events have been processed. And yet
415	another way to call them is transactions - each condition variable can be	550	another way to call them is transactions - each condition variable can be
416	used to represent a transaction, which finishes at some point and delivers	551	used to represent a transaction, which finishes at some point and delivers
417	a result.	552	a result. And yet some people know them as "futures" - a promise to
		553	compute/deliver something that you can wait for.
418		554
419	Condition variables are very useful to signal that something has finished,	555	Condition variables are very useful to signal that something has finished,
420	for example, if you write a module that does asynchronous http requests,	556	for example, if you write a module that does asynchronous http requests,
421	then a condition variable would be the ideal candidate to signal the	557	then a condition variable would be the ideal candidate to signal the
422	availability of results. The user can either act when the callback is	558	availability of results. The user can either act when the callback is
…		…
456	after => 1,	592	after => 1,
457	cb => sub { $result_ready->send },	593	cb => sub { $result_ready->send },
458	);	594	);
459		595
460	# this "blocks" (while handling events) till the callback	596	# this "blocks" (while handling events) till the callback
461	# calls send	597	# calls -<send
462	$result_ready->recv;	598	$result_ready->recv;
463		599
464	Example: wait for a timer, but take advantage of the fact that	600	Example: wait for a timer, but take advantage of the fact that condition
465	condition variables are also code references.	601	variables are also callable directly.
466		602
467	my $done = AnyEvent->condvar;	603	my $done = AnyEvent->condvar;
468	my $delay = AnyEvent->timer (after => 5, cb => $done);	604	my $delay = AnyEvent->timer (after => 5, cb => $done);
469	$done->recv;	605	$done->recv;
470		606
…		…
476		612
477	...	613	...
478		614
479	my @info = $couchdb->info->recv;	615	my @info = $couchdb->info->recv;
480		616
481	And this is how you would just ste a callback to be called whenever the	617	And this is how you would just set a callback to be called whenever the
482	results are available:	618	results are available:
483		619
484	$couchdb->info->cb (sub {	620	$couchdb->info->cb (sub {
485	my @info = $_[0]->recv;	621	my @info = $_[0]->recv;
486	});	622	});
…		…
504	immediately from within send.	640	immediately from within send.
505		641
506	Any arguments passed to the C<send> call will be returned by all	642	Any arguments passed to the C<send> call will be returned by all
507	future C<< ->recv >> calls.	643	future C<< ->recv >> calls.
508		644
509	Condition variables are overloaded so one can call them directly	645	Condition variables are overloaded so one can call them directly (as if
510	(as a code reference). Calling them directly is the same as calling	646	they were a code reference). Calling them directly is the same as calling
511	C<send>. Note, however, that many C-based event loops do not handle	647	C<send>.
512	overloading, so as tempting as it may be, passing a condition variable
513	instead of a callback does not work. Both the pure perl and EV loops
514	support overloading, however, as well as all functions that use perl to
515	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
516	example).
517		648
518	=item $cv->croak ($error)	649	=item $cv->croak ($error)
519		650
520	Similar to send, but causes all call's to C<< ->recv >> to invoke	651	Similar to send, but causes all call's to C<< ->recv >> to invoke
521	C<Carp::croak> with the given error message/object/scalar.	652	C<Carp::croak> with the given error message/object/scalar.
522		653
523	This can be used to signal any errors to the condition variable	654	This can be used to signal any errors to the condition variable
524	user/consumer.	655	user/consumer. Doing it this way instead of calling C<croak> directly
		656	delays the error detetcion, but has the overwhelmign advantage that it
		657	diagnoses the error at the place where the result is expected, and not
		658	deep in some event clalback without connection to the actual code causing
		659	the problem.
525		660
526	=item $cv->begin ([group callback])	661	=item $cv->begin ([group callback])
527		662
528	=item $cv->end	663	=item $cv->end
529
530	These two methods are EXPERIMENTAL and MIGHT CHANGE.
531		664
532	These two methods can be used to combine many transactions/events into	665	These two methods can be used to combine many transactions/events into
533	one. For example, a function that pings many hosts in parallel might want	666	one. For example, a function that pings many hosts in parallel might want
534	to use a condition variable for the whole process.	667	to use a condition variable for the whole process.
535		668
536	Every call to C<< ->begin >> will increment a counter, and every call to	669	Every call to C<< ->begin >> will increment a counter, and every call to
537	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	670	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
538	>>, the (last) callback passed to C<begin> will be executed. That callback	671	>>, the (last) callback passed to C<begin> will be executed, passing the
539	is I<supposed> to call C<< ->send >>, but that is not required. If no	672	condvar as first argument. That callback is I<supposed> to call C<< ->send
540	callback was set, C<send> will be called without any arguments.	673	>>, but that is not required. If no group callback was set, C<send> will
		674	be called without any arguments.
541		675
542	Let's clarify this with the ping example:	676	You can think of C<< $cv->send >> giving you an OR condition (one call
		677	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		678	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		679
		680	Let's start with a simple example: you have two I/O watchers (for example,
		681	STDOUT and STDERR for a program), and you want to wait for both streams to
		682	close before activating a condvar:
543		683
544	my $cv = AnyEvent->condvar;	684	my $cv = AnyEvent->condvar;
545		685
		686	$cv->begin; # first watcher
		687	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		688	defined sysread $fh1, my $buf, 4096
		689	or $cv->end;
		690	});
		691
		692	$cv->begin; # second watcher
		693	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		694	defined sysread $fh2, my $buf, 4096
		695	or $cv->end;
		696	});
		697
		698	$cv->recv;
		699
		700	This works because for every event source (EOF on file handle), there is
		701	one call to C<begin>, so the condvar waits for all calls to C<end> before
		702	sending.
		703
		704	The ping example mentioned above is slightly more complicated, as the
		705	there are results to be passwd back, and the number of tasks that are
		706	begung can potentially be zero:
		707
		708	my $cv = AnyEvent->condvar;
		709
546	my %result;	710	my %result;
547	$cv->begin (sub { $cv->send (\%result) });	711	$cv->begin (sub { shift->send (\%result) });
548		712
549	for my $host (@list_of_hosts) {	713	for my $host (@list_of_hosts) {
550	$cv->begin;	714	$cv->begin;
551	ping_host_then_call_callback $host, sub {	715	ping_host_then_call_callback $host, sub {
552	$result{$host} = ...;	716	$result{$host} = ...;
…		…
567	loop, which serves two important purposes: first, it sets the callback	731	loop, which serves two important purposes: first, it sets the callback
568	to be called once the counter reaches C<0>, and second, it ensures that	732	to be called once the counter reaches C<0>, and second, it ensures that
569	C<send> is called even when C<no> hosts are being pinged (the loop	733	C<send> is called even when C<no> hosts are being pinged (the loop
570	doesn't execute once).	734	doesn't execute once).
571		735
572	This is the general pattern when you "fan out" into multiple subrequests:	736	This is the general pattern when you "fan out" into multiple (but
573	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	737	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
574	is called at least once, and then, for each subrequest you start, call	738	the callback and ensure C<end> is called at least once, and then, for each
575	C<begin> and for each subrequest you finish, call C<end>.	739	subrequest you start, call C<begin> and for each subrequest you finish,
		740	call C<end>.
576		741
577	=back	742	=back
578		743
579	=head3 METHODS FOR CONSUMERS	744	=head3 METHODS FOR CONSUMERS
580		745
…		…
596	function will call C<croak>.	761	function will call C<croak>.
597		762
598	In list context, all parameters passed to C<send> will be returned,	763	In list context, all parameters passed to C<send> will be returned,
599	in scalar context only the first one will be returned.	764	in scalar context only the first one will be returned.
600		765
		766	Note that doing a blocking wait in a callback is not supported by any
		767	event loop, that is, recursive invocation of a blocking C<< ->recv
		768	>> is not allowed, and the C<recv> call will C<croak> if such a
		769	condition is detected. This condition can be slightly loosened by using
		770	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		771	any thread that doesn't run the event loop itself.
		772
601	Not all event models support a blocking wait - some die in that case	773	Not all event models support a blocking wait - some die in that case
602	(programs might want to do that to stay interactive), so I<if you are	774	(programs might want to do that to stay interactive), so I<if you are
603	using this from a module, never require a blocking wait>, but let the	775	using this from a module, never require a blocking wait>. Instead, let the
604	caller decide whether the call will block or not (for example, by coupling	776	caller decide whether the call will block or not (for example, by coupling
605	condition variables with some kind of request results and supporting	777	condition variables with some kind of request results and supporting
606	callbacks so the caller knows that getting the result will not block,	778	callbacks so the caller knows that getting the result will not block,
607	while still supporting blocking waits if the caller so desires).	779	while still supporting blocking waits if the caller so desires).
608		780
609	Another reason I<never> to C<< ->recv >> in a module is that you cannot
610	sensibly have two C<< ->recv >>'s in parallel, as that would require
611	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
612	can supply.
613
614	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
615	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
616	versions and also integrates coroutines into AnyEvent, making blocking
617	C<< ->recv >> calls perfectly safe as long as they are done from another
618	coroutine (one that doesn't run the event loop).
619
620	You can ensure that C<< -recv >> never blocks by setting a callback and	781	You can ensure that C<< -recv >> never blocks by setting a callback and
621	only calling C<< ->recv >> from within that callback (or at a later	782	only calling C<< ->recv >> from within that callback (or at a later
622	time). This will work even when the event loop does not support blocking	783	time). This will work even when the event loop does not support blocking
623	waits otherwise.	784	waits otherwise.
624		785
…		…
630	=item $cb = $cv->cb ($cb->($cv))	791	=item $cb = $cv->cb ($cb->($cv))
631		792
632	This is a mutator function that returns the callback set and optionally	793	This is a mutator function that returns the callback set and optionally
633	replaces it before doing so.	794	replaces it before doing so.
634		795
635	The callback will be called when the condition becomes "true", i.e. when	796	The callback will be called when the condition becomes (or already was)
636	C<send> or C<croak> are called, with the only argument being the condition	797	"true", i.e. when C<send> or C<croak> are called (or were called), with
637	variable itself. Calling C<recv> inside the callback or at any later time	798	the only argument being the condition variable itself. Calling C<recv>
638	is guaranteed not to block.	799	inside the callback or at any later time is guaranteed not to block.
639		800
640	=back	801	=back
641		802
		803	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		804
		805	The available backend classes are (every class has its own manpage):
		806
		807	=over 4
		808
		809	=item Backends that are autoprobed when no other event loop can be found.
		810
		811	EV is the preferred backend when no other event loop seems to be in
		812	use. If EV is not installed, then AnyEvent will fall back to its own
		813	pure-perl implementation, which is available everywhere as it comes with
		814	AnyEvent itself.
		815
		816	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		817	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		818
		819	=item Backends that are transparently being picked up when they are used.
		820
		821	These will be used when they are currently loaded when the first watcher
		822	is created, in which case it is assumed that the application is using
		823	them. This means that AnyEvent will automatically pick the right backend
		824	when the main program loads an event module before anything starts to
		825	create watchers. Nothing special needs to be done by the main program.
		826
		827	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		828	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		829	AnyEvent::Impl::Tk based on Tk, very broken.
		830	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		831	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		832	AnyEvent::Impl::Irssi used when running within irssi.
		833
		834	=item Backends with special needs.
		835
		836	Qt requires the Qt::Application to be instantiated first, but will
		837	otherwise be picked up automatically. As long as the main program
		838	instantiates the application before any AnyEvent watchers are created,
		839	everything should just work.
		840
		841	AnyEvent::Impl::Qt based on Qt.
		842
		843	Support for IO::Async can only be partial, as it is too broken and
		844	architecturally limited to even support the AnyEvent API. It also
		845	is the only event loop that needs the loop to be set explicitly, so
		846	it can only be used by a main program knowing about AnyEvent. See
		847	L<AnyEvent::Impl::Async> for the gory details.
		848
		849	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		850
		851	=item Event loops that are indirectly supported via other backends.
		852
		853	Some event loops can be supported via other modules:
		854
		855	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		856
		857	B<WxWidgets> has no support for watching file handles. However, you can
		858	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		859	polls 20 times per second, which was considered to be too horrible to even
		860	consider for AnyEvent.
		861
		862	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		863	backend, so it can be supported through POE.
		864
		865	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		866	load L<POE> when detecting them, in the hope that POE will pick them up,
		867	in which case everything will be automatic.
		868
		869	=back
		870
642	=head1 GLOBAL VARIABLES AND FUNCTIONS	871	=head1 GLOBAL VARIABLES AND FUNCTIONS
643		872
		873	These are not normally required to use AnyEvent, but can be useful to
		874	write AnyEvent extension modules.
		875
644	=over 4	876	=over 4
645		877
646	=item $AnyEvent::MODEL	878	=item $AnyEvent::MODEL
647		879
648	Contains C<undef> until the first watcher is being created. Then it	880	Contains C<undef> until the first watcher is being created, before the
		881	backend has been autodetected.
		882
649	contains the event model that is being used, which is the name of the	883	Afterwards it contains the event model that is being used, which is the
650	Perl class implementing the model. This class is usually one of the	884	name of the Perl class implementing the model. This class is usually one
651	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	885	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
652	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	886	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
653		887	will be C<urxvt::anyevent>).
654	The known classes so far are:
655
656	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
657	AnyEvent::Impl::Event based on Event, second best choice.
658	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
659	AnyEvent::Impl::Glib based on Glib, third-best choice.
660	AnyEvent::Impl::Tk based on Tk, very bad choice.
661	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
662	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
663	AnyEvent::Impl::POE based on POE, not generic enough for full support.
664
665	There is no support for WxWidgets, as WxWidgets has no support for
666	watching file handles. However, you can use WxWidgets through the
667	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
668	second, which was considered to be too horrible to even consider for
669	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
670	it's adaptor.
671
672	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
673	autodetecting them.
674		888
675	=item AnyEvent::detect	889	=item AnyEvent::detect
676		890
677	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	891	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
678	if necessary. You should only call this function right before you would	892	if necessary. You should only call this function right before you would
679	have created an AnyEvent watcher anyway, that is, as late as possible at	893	have created an AnyEvent watcher anyway, that is, as late as possible at
680	runtime.	894	runtime, and not e.g. while initialising of your module.
		895
		896	If you need to do some initialisation before AnyEvent watchers are
		897	created, use C<post_detect>.
681		898
682	=item $guard = AnyEvent::post_detect { BLOCK }	899	=item $guard = AnyEvent::post_detect { BLOCK }
683		900
684	Arranges for the code block to be executed as soon as the event model is	901	Arranges for the code block to be executed as soon as the event model is
685	autodetected (or immediately if this has already happened).	902	autodetected (or immediately if this has already happened).
686		903
		904	The block will be executed I<after> the actual backend has been detected
		905	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		906	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		907	other initialisations - see the sources of L<AnyEvent::Strict> or
		908	L<AnyEvent::AIO> to see how this is used.
		909
		910	The most common usage is to create some global watchers, without forcing
		911	event module detection too early, for example, L<AnyEvent::AIO> creates
		912	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		913	avoid autodetecting the event module at load time.
		914
687	If called in scalar or list context, then it creates and returns an object	915	If called in scalar or list context, then it creates and returns an object
688	that automatically removes the callback again when it is destroyed. See	916	that automatically removes the callback again when it is destroyed (or
		917	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
689	L<Coro::BDB> for a case where this is useful.	918	a case where this is useful.
		919
		920	Example: Create a watcher for the IO::AIO module and store it in
		921	C<$WATCHER>. Only do so after the event loop is initialised, though.
		922
		923	our WATCHER;
		924
		925	my $guard = AnyEvent::post_detect {
		926	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		927	};
		928
		929	# the ||= is important in case post_detect immediately runs the block,
		930	# as to not clobber the newly-created watcher. assigning both watcher and
		931	# post_detect guard to the same variable has the advantage of users being
		932	# able to just C<undef $WATCHER> if the watcher causes them grief.
		933
		934	$WATCHER ||= $guard;
690		935
691	=item @AnyEvent::post_detect	936	=item @AnyEvent::post_detect
692		937
693	If there are any code references in this array (you can C<push> to it	938	If there are any code references in this array (you can C<push> to it
694	before or after loading AnyEvent), then they will called directly after	939	before or after loading AnyEvent), then they will called directly after
695	the event loop has been chosen.	940	the event loop has been chosen.
696		941
697	You should check C<$AnyEvent::MODEL> before adding to this array, though:	942	You should check C<$AnyEvent::MODEL> before adding to this array, though:
698	if it contains a true value then the event loop has already been detected,	943	if it is defined then the event loop has already been detected, and the
699	and the array will be ignored.	944	array will be ignored.
700		945
701	Best use C<AnyEvent::post_detect { BLOCK }> instead.	946	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		947	it,as it takes care of these details.
		948
		949	This variable is mainly useful for modules that can do something useful
		950	when AnyEvent is used and thus want to know when it is initialised, but do
		951	not need to even load it by default. This array provides the means to hook
		952	into AnyEvent passively, without loading it.
702		953
703	=back	954	=back
704		955
705	=head1 WHAT TO DO IN A MODULE	956	=head1 WHAT TO DO IN A MODULE
706		957
…		…
761		1012
762		1013
763	=head1 OTHER MODULES	1014	=head1 OTHER MODULES
764		1015
765	The following is a non-exhaustive list of additional modules that use	1016	The following is a non-exhaustive list of additional modules that use
766	AnyEvent and can therefore be mixed easily with other AnyEvent modules	1017	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
767	in the same program. Some of the modules come with AnyEvent, some are	1018	modules and other event loops in the same program. Some of the modules
768	available via CPAN.	1019	come with AnyEvent, most are available via CPAN.
769		1020
770	=over 4	1021	=over 4
771		1022
772	=item L<AnyEvent::Util>	1023	=item L<AnyEvent::Util>
773		1024
…		…
782		1033
783	=item L<AnyEvent::Handle>	1034	=item L<AnyEvent::Handle>
784		1035
785	Provide read and write buffers, manages watchers for reads and writes,	1036	Provide read and write buffers, manages watchers for reads and writes,
786	supports raw and formatted I/O, I/O queued and fully transparent and	1037	supports raw and formatted I/O, I/O queued and fully transparent and
787	non-blocking SSL/TLS.	1038	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
788		1039
789	=item L<AnyEvent::DNS>	1040	=item L<AnyEvent::DNS>
790		1041
791	Provides rich asynchronous DNS resolver capabilities.	1042	Provides rich asynchronous DNS resolver capabilities.
792		1043
…		…
820		1071
821	=item L<AnyEvent::GPSD>	1072	=item L<AnyEvent::GPSD>
822		1073
823	A non-blocking interface to gpsd, a daemon delivering GPS information.	1074	A non-blocking interface to gpsd, a daemon delivering GPS information.
824		1075
		1076	=item L<AnyEvent::IRC>
		1077
		1078	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1079
		1080	=item L<AnyEvent::XMPP>
		1081
		1082	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1083	Net::XMPP2>.
		1084
825	=item L<AnyEvent::IGS>	1085	=item L<AnyEvent::IGS>
826		1086
827	A non-blocking interface to the Internet Go Server protocol (used by	1087	A non-blocking interface to the Internet Go Server protocol (used by
828	L<App::IGS>).	1088	L<App::IGS>).
829		1089
830	=item L<AnyEvent::IRC>
831
832	AnyEvent based IRC client module family (replacing the older Net::IRC3).
833
834	=item L<Net::XMPP2>
835
836	AnyEvent based XMPP (Jabber protocol) module family.
837
838	=item L<Net::FCP>	1090	=item L<Net::FCP>
839		1091
840	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1092	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
841	of AnyEvent.	1093	of AnyEvent.
842		1094
…		…
846		1098
847	=item L<Coro>	1099	=item L<Coro>
848		1100
849	Has special support for AnyEvent via L<Coro::AnyEvent>.	1101	Has special support for AnyEvent via L<Coro::AnyEvent>.
850		1102
851	=item L<IO::Lambda>
852
853	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
854
855	=back	1103	=back
856		1104
857	=cut	1105	=cut
858		1106
859	package AnyEvent;	1107	package AnyEvent;
860		1108
		1109	# basically a tuned-down version of common::sense
		1110	sub common_sense {
861	no warnings;	1111	# no warnings
		1112	${^WARNING_BITS} ^= ${^WARNING_BITS};
862	use strict qw(vars subs);	1113	# use strict vars subs
		1114	$^H |= 0x00000600;
		1115	}
863		1116
		1117	BEGIN { AnyEvent::common_sense }
		1118
864	use Carp;	1119	use Carp ();
865		1120
866	our $VERSION = 4.3;	1121	our $VERSION = '5.1';
867	our $MODEL;	1122	our $MODEL;
868		1123
869	our $AUTOLOAD;	1124	our $AUTOLOAD;
870	our @ISA;	1125	our @ISA;
871		1126
872	our @REGISTRY;	1127	our @REGISTRY;
873		1128
874	our $WIN32;	1129	our $WIN32;
875		1130
		1131	our $VERBOSE;
		1132
876	BEGIN {	1133	BEGIN {
877	my $win32 = ! ! ($^O =~ /mswin32/i);	1134	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
878	eval "sub WIN32(){ $win32 }";	1135	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
879	}
880		1136
		1137	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1138	if ${^TAINT};
		1139
881	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1140	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1141
		1142	}
		1143
		1144	our $MAX_SIGNAL_LATENCY = 10;
882		1145
883	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1146	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
884		1147
885	{	1148	{
886	my $idx;	1149	my $idx;
…		…
888	for reverse split /\s*,\s*/,	1151	for reverse split /\s*,\s*/,
889	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1152	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
890	}	1153	}
891		1154
892	my @models = (	1155	my @models = (
893	[EV:: => AnyEvent::Impl::EV::],	1156	[EV:: => AnyEvent::Impl::EV:: , 1],
894	[Event:: => AnyEvent::Impl::Event::],
895	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1157	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
896	# everything below here will not be autoprobed	1158	# everything below here will not (normally) be autoprobed
897	# as the pureperl backend should work everywhere	1159	# as the pureperl backend should work everywhere
898	# and is usually faster	1160	# and is usually faster
		1161	[Event:: => AnyEvent::Impl::Event::, 1],
		1162	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1163	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1164	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
899	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1165	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
900	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
901	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
902	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1166	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
903	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1167	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
904	[Wx:: => AnyEvent::Impl::POE::],	1168	[Wx:: => AnyEvent::Impl::POE::],
905	[Prima:: => AnyEvent::Impl::POE::],	1169	[Prima:: => AnyEvent::Impl::POE::],
		1170	# IO::Async is just too broken - we would need workarounds for its
		1171	# byzantine signal and broken child handling, among others.
		1172	# IO::Async is rather hard to detect, as it doesn't have any
		1173	# obvious default class.
		1174	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1175	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1176	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1177	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
906	);	1178	);
907		1179
908	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	1180	our %method = map +($_ => 1),
		1181	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
909		1182
910	our @post_detect;	1183	our @post_detect;
911		1184
912	sub post_detect(&) {	1185	sub post_detect(&) {
913	my ($cb) = @_;	1186	my ($cb) = @_;
914		1187
915	if ($MODEL) {	1188	if ($MODEL) {
916	$cb->();	1189	$cb->();
917		1190
918	1	1191	undef
919	} else {	1192	} else {
920	push @post_detect, $cb;	1193	push @post_detect, $cb;
921		1194
922	defined wantarray	1195	defined wantarray
923	? bless \$cb, "AnyEvent::Util::PostDetect"	1196	? bless \$cb, "AnyEvent::Util::postdetect"
924	: ()	1197	: ()
925	}	1198	}
926	}	1199	}
927		1200
928	sub AnyEvent::Util::PostDetect::DESTROY {	1201	sub AnyEvent::Util::postdetect::DESTROY {
929	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1202	@post_detect = grep $_ != ${$_[0]}, @post_detect;
930	}	1203	}
931		1204
932	sub detect() {	1205	sub detect() {
933	unless ($MODEL) {	1206	unless ($MODEL) {
934	no strict 'refs';
935	local $SIG{__DIE__};	1207	local $SIG{__DIE__};
936		1208
937	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1209	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
938	my $model = "AnyEvent::Impl::$1";	1210	my $model = "AnyEvent::Impl::$1";
939	if (eval "require $model") {	1211	if (eval "require $model") {
940	$MODEL = $model;	1212	$MODEL = $model;
941	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1213	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
942	} else {	1214	} else {
943	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1215	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
944	}	1216	}
945	}	1217	}
946		1218
947	# check for already loaded models	1219	# check for already loaded models
948	unless ($MODEL) {	1220	unless ($MODEL) {
949	for (@REGISTRY, @models) {	1221	for (@REGISTRY, @models) {
950	my ($package, $model) = @$_;	1222	my ($package, $model) = @$_;
951	if (${"$package\::VERSION"} > 0) {	1223	if (${"$package\::VERSION"} > 0) {
952	if (eval "require $model") {	1224	if (eval "require $model") {
953	$MODEL = $model;	1225	$MODEL = $model;
954	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1226	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
955	last;	1227	last;
956	}	1228	}
957	}	1229	}
958	}	1230	}
959		1231
960	unless ($MODEL) {	1232	unless ($MODEL) {
961	# try to load a model	1233	# try to autoload a model
962
963	for (@REGISTRY, @models) {	1234	for (@REGISTRY, @models) {
964	my ($package, $model) = @$_;	1235	my ($package, $model, $autoload) = @$_;
		1236	if (
		1237	$autoload
965	if (eval "require $package"	1238	and eval "require $package"
966	and ${"$package\::VERSION"} > 0	1239	and ${"$package\::VERSION"} > 0
967	and eval "require $model") {	1240	and eval "require $model"
		1241	) {
968	$MODEL = $model;	1242	$MODEL = $model;
969	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1243	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
970	last;	1244	last;
971	}	1245	}
972	}	1246	}
973		1247
974	$MODEL	1248	$MODEL
975	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1249	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
976	}	1250	}
977	}	1251	}
978		1252
979	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1253	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
980		1254
…		…
990		1264
991	sub AUTOLOAD {	1265	sub AUTOLOAD {
992	(my $func = $AUTOLOAD) =~ s/.*://;	1266	(my $func = $AUTOLOAD) =~ s/.*://;
993		1267
994	$method{$func}	1268	$method{$func}
995	or croak "$func: not a valid method for AnyEvent objects";	1269	or Carp::croak "$func: not a valid method for AnyEvent objects";
996		1270
997	detect unless $MODEL;	1271	detect unless $MODEL;
998		1272
999	my $class = shift;	1273	my $class = shift;
1000	$class->$func (@_);	1274	$class->$func (@_);
1001	}	1275	}
1002		1276
1003	# utility function to dup a filehandle. this is used by many backends	1277	# utility function to dup a filehandle. this is used by many backends
1004	# to support binding more than one watcher per filehandle (they usually	1278	# to support binding more than one watcher per filehandle (they usually
1005	# allow only one watcher per fd, so we dup it to get a different one).	1279	# allow only one watcher per fd, so we dup it to get a different one).
1006	sub _dupfh($$$$) {	1280	sub _dupfh($$;$$) {
1007	my ($poll, $fh, $r, $w) = @_;	1281	my ($poll, $fh, $r, $w) = @_;
1008		1282
1009	require Fcntl;
1010
1011	# cygwin requires the fh mode to be matching, unix doesn't	1283	# cygwin requires the fh mode to be matching, unix doesn't
1012	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1284	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1013	: $poll eq "w" ? ($w, ">")
1014	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1015		1285
1016	open my $fh2, "$mode&" . fileno $fh	1286	open my $fh2, $mode, $fh
1017	or die "cannot dup() filehandle: $!";	1287	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1018		1288
1019	# we assume CLOEXEC is already set by perl in all important cases	1289	# we assume CLOEXEC is already set by perl in all important cases
1020		1290
1021	($fh2, $rw)	1291	($fh2, $rw)
1022	}	1292	}
1023		1293
		1294	=head1 SIMPLIFIED AE API
		1295
		1296	Starting with version 5.0, AnyEvent officially supports a second, much
		1297	simpler, API that is designed to reduce the calling, typing and memory
		1298	overhead.
		1299
		1300	See the L<AE> manpage for details.
		1301
		1302	=cut
		1303
		1304	package AE;
		1305
		1306	our $VERSION = $AnyEvent::VERSION;
		1307
		1308	sub io($$$) {
		1309	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1310	}
		1311
		1312	sub timer($$$) {
		1313	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1314	}
		1315
		1316	sub signal($$) {
		1317	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1318	}
		1319
		1320	sub child($$) {
		1321	AnyEvent->child (pid => $_[0], cb => $_[1])
		1322	}
		1323
		1324	sub idle($) {
		1325	AnyEvent->idle (cb => $_[0])
		1326	}
		1327
		1328	sub cv(;&) {
		1329	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1330	}
		1331
		1332	sub now() {
		1333	AnyEvent->now
		1334	}
		1335
		1336	sub now_update() {
		1337	AnyEvent->now_update
		1338	}
		1339
		1340	sub time() {
		1341	AnyEvent->time
		1342	}
		1343
1024	package AnyEvent::Base;	1344	package AnyEvent::Base;
1025		1345
1026	# default implementation for now and time	1346	# default implementations for many methods
1027		1347
1028	BEGIN {	1348	sub _time {
		1349	# probe for availability of Time::HiRes
1029	if (eval "use Time::HiRes (); time (); 1") {	1350	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1351	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1030	*_time = \&Time::HiRes::time;	1352	*_time = \&Time::HiRes::time;
1031	# if (eval "use POSIX (); (POSIX::times())...	1353	# if (eval "use POSIX (); (POSIX::times())...
1032	} else {	1354	} else {
		1355	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1033	*_time = sub { time }; # epic fail	1356	*_time = sub { time }; # epic fail
1034	}	1357	}
		1358
		1359	&_time
1035	}	1360	}
1036		1361
1037	sub time { _time }	1362	sub time { _time }
1038	sub now { _time }	1363	sub now { _time }
		1364	sub now_update { }
1039		1365
1040	# default implementation for ->condvar	1366	# default implementation for ->condvar
1041		1367
1042	sub condvar {	1368	sub condvar {
1043	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1369	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1044	}	1370	}
1045		1371
1046	# default implementation for ->signal	1372	# default implementation for ->signal
1047		1373
1048	our %SIG_CB;	1374	our $HAVE_ASYNC_INTERRUPT;
		1375
		1376	sub _have_async_interrupt() {
		1377	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1378	&& eval "use Async::Interrupt 1.0 (); 1")
		1379	unless defined $HAVE_ASYNC_INTERRUPT;
		1380
		1381	$HAVE_ASYNC_INTERRUPT
		1382	}
		1383
		1384	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1385	our (%SIG_ASY, %SIG_ASY_W);
		1386	our ($SIG_COUNT, $SIG_TW);
		1387
		1388	sub _signal_exec {
		1389	$HAVE_ASYNC_INTERRUPT
		1390	? $SIGPIPE_R->drain
		1391	: sysread $SIGPIPE_R, my $dummy, 9;
		1392
		1393	while (%SIG_EV) {
		1394	for (keys %SIG_EV) {
		1395	delete $SIG_EV{$_};
		1396	$_->() for values %{ $SIG_CB{$_} || {} };
		1397	}
		1398	}
		1399	}
		1400
		1401	# install a dummy wakeup watcher to reduce signal catching latency
		1402	sub _sig_add() {
		1403	unless ($SIG_COUNT++) {
		1404	# try to align timer on a full-second boundary, if possible
		1405	my $NOW = AE::now;
		1406
		1407	$SIG_TW = AE::timer
		1408	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1409	$MAX_SIGNAL_LATENCY,
		1410	sub { } # just for the PERL_ASYNC_CHECK
		1411	;
		1412	}
		1413	}
		1414
		1415	sub _sig_del {
		1416	undef $SIG_TW
		1417	unless --$SIG_COUNT;
		1418	}
		1419
		1420	our $_sig_name_init; $_sig_name_init = sub {
		1421	eval q{ # poor man's autoloading
		1422	undef $_sig_name_init;
		1423
		1424	if (_have_async_interrupt) {
		1425	*sig2num = \&Async::Interrupt::sig2num;
		1426	*sig2name = \&Async::Interrupt::sig2name;
		1427	} else {
		1428	require Config;
		1429
		1430	my %signame2num;
		1431	@signame2num{ split ' ', $Config::Config{sig_name} }
		1432	= split ' ', $Config::Config{sig_num};
		1433
		1434	my @signum2name;
		1435	@signum2name[values %signame2num] = keys %signame2num;
		1436
		1437	*sig2num = sub($) {
		1438	$_[0] > 0 ? shift : $signame2num{+shift}
		1439	};
		1440	*sig2name = sub ($) {
		1441	$_[0] > 0 ? $signum2name[+shift] : shift
		1442	};
		1443	}
		1444	};
		1445	die if $@;
		1446	};
		1447
		1448	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1449	sub sig2name($) { &$_sig_name_init; &sig2name }
1049		1450
1050	sub signal {	1451	sub signal {
		1452	eval q{ # poor man's autoloading {}
		1453	# probe for availability of Async::Interrupt
		1454	if (_have_async_interrupt) {
		1455	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
		1456
		1457	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1458	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
		1459
		1460	} else {
		1461	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1462
		1463	require Fcntl;
		1464
		1465	if (AnyEvent::WIN32) {
		1466	require AnyEvent::Util;
		1467
		1468	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1469	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1470	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1471	} else {
		1472	pipe $SIGPIPE_R, $SIGPIPE_W;
		1473	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1474	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1475
		1476	# not strictly required, as $^F is normally 2, but let's make sure...
		1477	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1478	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1479	}
		1480
		1481	$SIGPIPE_R
		1482	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1483
		1484	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1485	}
		1486
		1487	*signal = sub {
1051	my (undef, %arg) = @_;	1488	my (undef, %arg) = @_;
1052		1489
1053	my $signal = uc $arg{signal}	1490	my $signal = uc $arg{signal}
1054	or Carp::croak "required option 'signal' is missing";	1491	or Carp::croak "required option 'signal' is missing";
1055		1492
		1493	if ($HAVE_ASYNC_INTERRUPT) {
		1494	# async::interrupt
		1495
		1496	$signal = sig2num $signal;
1056	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1497	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1498
		1499	$SIG_ASY{$signal} ||= new Async::Interrupt
		1500	cb => sub { undef $SIG_EV{$signal} },
		1501	signal => $signal,
		1502	pipe => [$SIGPIPE_R->filenos],
		1503	pipe_autodrain => 0,
		1504	;
		1505
		1506	} else {
		1507	# pure perl
		1508
		1509	# AE::Util has been loaded in signal
		1510	$signal = sig2name $signal;
		1511	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1512
1057	$SIG{$signal} ||= sub {	1513	$SIG{$signal} ||= sub {
1058	$_->() for values %{ $SIG_CB{$signal} || {} };	1514	local $!;
		1515	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1516	undef $SIG_EV{$signal};
		1517	};
		1518
		1519	# can't do signal processing without introducing races in pure perl,
		1520	# so limit the signal latency.
		1521	_sig_add;
		1522	}
		1523
		1524	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1525	};
		1526
		1527	*AnyEvent::Base::signal::DESTROY = sub {
		1528	my ($signal, $cb) = @{$_[0]};
		1529
		1530	_sig_del;
		1531
		1532	delete $SIG_CB{$signal}{$cb};
		1533
		1534	$HAVE_ASYNC_INTERRUPT
		1535	? delete $SIG_ASY{$signal}
		1536	: # delete doesn't work with older perls - they then
		1537	# print weird messages, or just unconditionally exit
		1538	# instead of getting the default action.
		1539	undef $SIG{$signal}
		1540	unless keys %{ $SIG_CB{$signal} };
		1541	};
1059	};	1542	};
1060		1543	die if $@;
1061	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1544	&signal
1062	}
1063
1064	sub AnyEvent::Base::Signal::DESTROY {
1065	my ($signal, $cb) = @{$_[0]};
1066
1067	delete $SIG_CB{$signal}{$cb};
1068
1069	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1070	}	1545	}
1071		1546
1072	# default implementation for ->child	1547	# default implementation for ->child
1073		1548
1074	our %PID_CB;	1549	our %PID_CB;
1075	our $CHLD_W;	1550	our $CHLD_W;
1076	our $CHLD_DELAY_W;	1551	our $CHLD_DELAY_W;
1077	our $PID_IDLE;
1078	our $WNOHANG;	1552	our $WNOHANG;
1079		1553
1080	sub _child_wait {	1554	sub _emit_childstatus($$) {
1081	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1555	my (undef, $rpid, $rstatus) = @_;
		1556
		1557	$_->($rpid, $rstatus)
1082	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1558	for values %{ $PID_CB{$rpid} || {} },
1083	(values %{ $PID_CB{0} || {} });	1559	values %{ $PID_CB{0} || {} };
1084	}
1085
1086	undef $PID_IDLE;
1087	}	1560	}
1088		1561
1089	sub _sigchld {	1562	sub _sigchld {
1090	# make sure we deliver these changes "synchronous" with the event loop.	1563	my $pid;
1091	$CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub {	1564
1092	undef $CHLD_DELAY_W;	1565	AnyEvent->_emit_childstatus ($pid, $?)
1093	&_child_wait;	1566	while ($pid = waitpid -1, $WNOHANG) > 0;
1094	});
1095	}	1567	}
1096		1568
1097	sub child {	1569	sub child {
1098	my (undef, %arg) = @_;	1570	my (undef, %arg) = @_;
1099		1571
1100	defined (my $pid = $arg{pid} + 0)	1572	defined (my $pid = $arg{pid} + 0)
1101	or Carp::croak "required option 'pid' is missing";	1573	or Carp::croak "required option 'pid' is missing";
1102		1574
1103	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1575	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1104		1576
1105	unless ($WNOHANG) {	1577	# WNOHANG is almost cetrainly 1 everywhere
		1578	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1579	? 1
1106	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1580	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1107	}
1108		1581
1109	unless ($CHLD_W) {	1582	unless ($CHLD_W) {
1110	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1583	$CHLD_W = AE::signal CHLD => \&_sigchld;
1111	# child could be a zombie already, so make at least one round	1584	# child could be a zombie already, so make at least one round
1112	&_sigchld;	1585	&_sigchld;
1113	}	1586	}
1114		1587
1115	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1588	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1116	}	1589	}
1117		1590
1118	sub AnyEvent::Base::Child::DESTROY {	1591	sub AnyEvent::Base::child::DESTROY {
1119	my ($pid, $cb) = @{$_[0]};	1592	my ($pid, $cb) = @{$_[0]};
1120		1593
1121	delete $PID_CB{$pid}{$cb};	1594	delete $PID_CB{$pid}{$cb};
1122	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1595	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1123		1596
1124	undef $CHLD_W unless keys %PID_CB;	1597	undef $CHLD_W unless keys %PID_CB;
1125	}	1598	}
1126		1599
		1600	# idle emulation is done by simply using a timer, regardless
		1601	# of whether the process is idle or not, and not letting
		1602	# the callback use more than 50% of the time.
		1603	sub idle {
		1604	my (undef, %arg) = @_;
		1605
		1606	my ($cb, $w, $rcb) = $arg{cb};
		1607
		1608	$rcb = sub {
		1609	if ($cb) {
		1610	$w = _time;
		1611	&$cb;
		1612	$w = _time - $w;
		1613
		1614	# never use more then 50% of the time for the idle watcher,
		1615	# within some limits
		1616	$w = 0.0001 if $w < 0.0001;
		1617	$w = 5 if $w > 5;
		1618
		1619	$w = AE::timer $w, 0, $rcb;
		1620	} else {
		1621	# clean up...
		1622	undef $w;
		1623	undef $rcb;
		1624	}
		1625	};
		1626
		1627	$w = AE::timer 0.05, 0, $rcb;
		1628
		1629	bless \\$cb, "AnyEvent::Base::idle"
		1630	}
		1631
		1632	sub AnyEvent::Base::idle::DESTROY {
		1633	undef $${$_[0]};
		1634	}
		1635
1127	package AnyEvent::CondVar;	1636	package AnyEvent::CondVar;
1128		1637
1129	our @ISA = AnyEvent::CondVar::Base::;	1638	our @ISA = AnyEvent::CondVar::Base::;
1130		1639
1131	package AnyEvent::CondVar::Base;	1640	package AnyEvent::CondVar::Base;
1132		1641
1133	use overload	1642	#use overload
1134	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1643	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1135	fallback => 1;	1644	# fallback => 1;
		1645
		1646	# save 300+ kilobytes by dirtily hardcoding overloading
		1647	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1648	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1649	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1650	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1651
		1652	our $WAITING;
1136		1653
1137	sub _send {	1654	sub _send {
1138	# nop	1655	# nop
1139	}	1656	}
1140		1657
…		…
1153	sub ready {	1670	sub ready {
1154	$_[0]{_ae_sent}	1671	$_[0]{_ae_sent}
1155	}	1672	}
1156		1673
1157	sub _wait {	1674	sub _wait {
		1675	$WAITING
		1676	and !$_[0]{_ae_sent}
		1677	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1678
		1679	local $WAITING = 1;
1158	AnyEvent->one_event while !$_[0]{_ae_sent};	1680	AnyEvent->one_event while !$_[0]{_ae_sent};
1159	}	1681	}
1160		1682
1161	sub recv {	1683	sub recv {
1162	$_[0]->_wait;	1684	$_[0]->_wait;
…		…
1164	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1686	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1165	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1687	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1166	}	1688	}
1167		1689
1168	sub cb {	1690	sub cb {
1169	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1691	my $cv = shift;
		1692
		1693	@_
		1694	and $cv->{_ae_cb} = shift
		1695	and $cv->{_ae_sent}
		1696	and (delete $cv->{_ae_cb})->($cv);
		1697
1170	$_[0]{_ae_cb}	1698	$cv->{_ae_cb}
1171	}	1699	}
1172		1700
1173	sub begin {	1701	sub begin {
1174	++$_[0]{_ae_counter};	1702	++$_[0]{_ae_counter};
1175	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1703	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1203	so on.	1731	so on.
1204		1732
1205	=head1 ENVIRONMENT VARIABLES	1733	=head1 ENVIRONMENT VARIABLES
1206		1734
1207	The following environment variables are used by this module or its	1735	The following environment variables are used by this module or its
1208	submodules:	1736	submodules.
		1737
		1738	Note that AnyEvent will remove I<all> environment variables starting with
		1739	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1740	enabled.
1209		1741
1210	=over 4	1742	=over 4
1211		1743
1212	=item C<PERL_ANYEVENT_VERBOSE>	1744	=item C<PERL_ANYEVENT_VERBOSE>
1213		1745
…		…
1220	C<PERL_ANYEVENT_MODEL>.	1752	C<PERL_ANYEVENT_MODEL>.
1221		1753
1222	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1754	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1223	model it chooses.	1755	model it chooses.
1224		1756
		1757	When set to C<8> or higher, then AnyEvent will report extra information on
		1758	which optional modules it loads and how it implements certain features.
		1759
1225	=item C<PERL_ANYEVENT_STRICT>	1760	=item C<PERL_ANYEVENT_STRICT>
1226		1761
1227	AnyEvent does not do much argument checking by default, as thorough	1762	AnyEvent does not do much argument checking by default, as thorough
1228	argument checking is very costly. Setting this variable to a true value	1763	argument checking is very costly. Setting this variable to a true value
1229	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1764	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1230	check the arguments passed to most method calls. If it finds any problems	1765	check the arguments passed to most method calls. If it finds any problems,
1231	it will croak.	1766	it will croak.
1232		1767
1233	In other words, enables "strict" mode.	1768	In other words, enables "strict" mode.
1234		1769
1235	Unlike C<use strict>, it is definitely recommended ot keep it off in	1770	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1236	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1771	>>, it is definitely recommended to keep it off in production. Keeping
1237	developing programs can be very useful, however.	1772	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1773	can be very useful, however.
1238		1774
1239	=item C<PERL_ANYEVENT_MODEL>	1775	=item C<PERL_ANYEVENT_MODEL>
1240		1776
1241	This can be used to specify the event model to be used by AnyEvent, before	1777	This can be used to specify the event model to be used by AnyEvent, before
1242	auto detection and -probing kicks in. It must be a string consisting	1778	auto detection and -probing kicks in. It must be a string consisting
…		…
1263	used, and preference will be given to protocols mentioned earlier in the	1799	used, and preference will be given to protocols mentioned earlier in the
1264	list.	1800	list.
1265		1801
1266	This variable can effectively be used for denial-of-service attacks	1802	This variable can effectively be used for denial-of-service attacks
1267	against local programs (e.g. when setuid), although the impact is likely	1803	against local programs (e.g. when setuid), although the impact is likely
1268	small, as the program has to handle connection errors already-	1804	small, as the program has to handle conenction and other failures anyways.
1269		1805
1270	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,	1806	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1271	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	1807	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1272	- only support IPv4, never try to resolve or contact IPv6	1808	- only support IPv4, never try to resolve or contact IPv6
1273	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	1809	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
…		…
1285		1821
1286	=item C<PERL_ANYEVENT_MAX_FORKS>	1822	=item C<PERL_ANYEVENT_MAX_FORKS>
1287		1823
1288	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1824	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1289	will create in parallel.	1825	will create in parallel.
		1826
		1827	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1828
		1829	The default value for the C<max_outstanding> parameter for the default DNS
		1830	resolver - this is the maximum number of parallel DNS requests that are
		1831	sent to the DNS server.
		1832
		1833	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1834
		1835	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1836	configuration) in the default resolver. When set to the empty string, no
		1837	default config will be used.
		1838
		1839	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1840
		1841	When neither C<ca_file> nor C<ca_path> was specified during
		1842	L<AnyEvent::TLS> context creation, and either of these environment
		1843	variables exist, they will be used to specify CA certificate locations
		1844	instead of a system-dependent default.
		1845
		1846	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1847
		1848	When these are set to C<1>, then the respective modules are not
		1849	loaded. Mostly good for testing AnyEvent itself.
1290		1850
1291	=back	1851	=back
1292		1852
1293	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1853	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1294		1854
…		…
1502	through AnyEvent. The benchmark creates a lot of timers (with a zero	2062	through AnyEvent. The benchmark creates a lot of timers (with a zero
1503	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2063	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1504	which it is), lets them fire exactly once and destroys them again.	2064	which it is), lets them fire exactly once and destroys them again.
1505		2065
1506	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2066	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1507	distribution.	2067	distribution. It uses the L<AE> interface, which makes a real difference
		2068	for the EV and Perl backends only.
1508		2069
1509	=head3 Explanation of the columns	2070	=head3 Explanation of the columns
1510		2071
1511	I<watcher> is the number of event watchers created/destroyed. Since	2072	I<watcher> is the number of event watchers created/destroyed. Since
1512	different event models feature vastly different performances, each event	2073	different event models feature vastly different performances, each event
…		…
1533	watcher.	2094	watcher.
1534		2095
1535	=head3 Results	2096	=head3 Results
1536		2097
1537	name watchers bytes create invoke destroy comment	2098	name watchers bytes create invoke destroy comment
1538	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	2099	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1539	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	2100	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1540	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	2101	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1541	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	2102	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1542	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	2103	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1543	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	2104	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
		2105	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
		2106	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1544	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	2107	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1545	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	2108	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1546	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	2109	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1547	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	2110	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1548		2111
1549	=head3 Discussion	2112	=head3 Discussion
1550		2113
1551	The benchmark does I<not> measure scalability of the event loop very	2114	The benchmark does I<not> measure scalability of the event loop very
1552	well. For example, a select-based event loop (such as the pure perl one)	2115	well. For example, a select-based event loop (such as the pure perl one)
…		…
1564	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2127	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1565	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2128	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1566	cycles with POE.	2129	cycles with POE.
1567		2130
1568	C<EV> is the sole leader regarding speed and memory use, which are both	2131	C<EV> is the sole leader regarding speed and memory use, which are both
1569	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2132	maximal/minimal, respectively. When using the L<AE> API there is zero
		2133	overhead (when going through the AnyEvent API create is about 5-6 times
		2134	slower, with other times being equal, so still uses far less memory than
1570	far less memory than any other event loop and is still faster than Event	2135	any other event loop and is still faster than Event natively).
1571	natively.
1572		2136
1573	The pure perl implementation is hit in a few sweet spots (both the	2137	The pure perl implementation is hit in a few sweet spots (both the
1574	constant timeout and the use of a single fd hit optimisations in the perl	2138	constant timeout and the use of a single fd hit optimisations in the perl
1575	interpreter and the backend itself). Nevertheless this shows that it	2139	interpreter and the backend itself). Nevertheless this shows that it
1576	adds very little overhead in itself. Like any select-based backend its	2140	adds very little overhead in itself. Like any select-based backend its
1577	performance becomes really bad with lots of file descriptors (and few of	2141	performance becomes really bad with lots of file descriptors (and few of
1578	them active), of course, but this was not subject of this benchmark.	2142	them active), of course, but this was not subject of this benchmark.
1579		2143
1580	The C<Event> module has a relatively high setup and callback invocation	2144	The C<Event> module has a relatively high setup and callback invocation
1581	cost, but overall scores in on the third place.	2145	cost, but overall scores in on the third place.
		2146
		2147	C<IO::Async> performs admirably well, about on par with C<Event>, even
		2148	when using its pure perl backend.
1582		2149
1583	C<Glib>'s memory usage is quite a bit higher, but it features a	2150	C<Glib>'s memory usage is quite a bit higher, but it features a
1584	faster callback invocation and overall ends up in the same class as	2151	faster callback invocation and overall ends up in the same class as
1585	C<Event>. However, Glib scales extremely badly, doubling the number of	2152	C<Event>. However, Glib scales extremely badly, doubling the number of
1586	watchers increases the processing time by more than a factor of four,	2153	watchers increases the processing time by more than a factor of four,
…		…
1647	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2214	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1648	(1%) are active. This mirrors the activity of large servers with many	2215	(1%) are active. This mirrors the activity of large servers with many
1649	connections, most of which are idle at any one point in time.	2216	connections, most of which are idle at any one point in time.
1650		2217
1651	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2218	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1652	distribution.	2219	distribution. It uses the L<AE> interface, which makes a real difference
		2220	for the EV and Perl backends only.
1653		2221
1654	=head3 Explanation of the columns	2222	=head3 Explanation of the columns
1655		2223
1656	I<sockets> is the number of sockets, and twice the number of "servers" (as	2224	I<sockets> is the number of sockets, and twice the number of "servers" (as
1657	each server has a read and write socket end).	2225	each server has a read and write socket end).
…		…
1664	it to another server. This includes deleting the old timeout and creating	2232	it to another server. This includes deleting the old timeout and creating
1665	a new one that moves the timeout into the future.	2233	a new one that moves the timeout into the future.
1666		2234
1667	=head3 Results	2235	=head3 Results
1668		2236
1669	name sockets create request	2237	name sockets create request
1670	EV 20000 69.01 11.16	2238	EV 20000 62.66 7.99
1671	Perl 20000 73.32 35.87	2239	Perl 20000 68.32 32.64
1672	Event 20000 212.62 257.32	2240	IOAsync 20000 174.06 101.15 epoll
1673	Glib 20000 651.16 1896.30	2241	IOAsync 20000 174.67 610.84 poll
		2242	Event 20000 202.69 242.91
		2243	Glib 20000 557.01 1689.52
1674	POE 20000 349.67 12317.24 uses POE::Loop::Event	2244	POE 20000 341.54 12086.32 uses POE::Loop::Event
1675		2245
1676	=head3 Discussion	2246	=head3 Discussion
1677		2247
1678	This benchmark I<does> measure scalability and overall performance of the	2248	This benchmark I<does> measure scalability and overall performance of the
1679	particular event loop.	2249	particular event loop.
…		…
1681	EV is again fastest. Since it is using epoll on my system, the setup time	2251	EV is again fastest. Since it is using epoll on my system, the setup time
1682	is relatively high, though.	2252	is relatively high, though.
1683		2253
1684	Perl surprisingly comes second. It is much faster than the C-based event	2254	Perl surprisingly comes second. It is much faster than the C-based event
1685	loops Event and Glib.	2255	loops Event and Glib.
		2256
		2257	IO::Async performs very well when using its epoll backend, and still quite
		2258	good compared to Glib when using its pure perl backend.
1686		2259
1687	Event suffers from high setup time as well (look at its code and you will	2260	Event suffers from high setup time as well (look at its code and you will
1688	understand why). Callback invocation also has a high overhead compared to	2261	understand why). Callback invocation also has a high overhead compared to
1689	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2262	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1690	uses select or poll in basically all documented configurations.	2263	uses select or poll in basically all documented configurations.
…		…
1753	=item * C-based event loops perform very well with small number of	2326	=item * C-based event loops perform very well with small number of
1754	watchers, as the management overhead dominates.	2327	watchers, as the management overhead dominates.
1755		2328
1756	=back	2329	=back
1757		2330
		2331	=head2 THE IO::Lambda BENCHMARK
		2332
		2333	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2334	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2335	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2336	shouldn't come as a surprise to anybody). As such, the benchmark is
		2337	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2338	very optimal. But how would AnyEvent compare when used without the extra
		2339	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2340
		2341	The benchmark itself creates an echo-server, and then, for 500 times,
		2342	connects to the echo server, sends a line, waits for the reply, and then
		2343	creates the next connection. This is a rather bad benchmark, as it doesn't
		2344	test the efficiency of the framework or much non-blocking I/O, but it is a
		2345	benchmark nevertheless.
		2346
		2347	name runtime
		2348	Lambda/select 0.330 sec
		2349	+ optimized 0.122 sec
		2350	Lambda/AnyEvent 0.327 sec
		2351	+ optimized 0.138 sec
		2352	Raw sockets/select 0.077 sec
		2353	POE/select, components 0.662 sec
		2354	POE/select, raw sockets 0.226 sec
		2355	POE/select, optimized 0.404 sec
		2356
		2357	AnyEvent/select/nb 0.085 sec
		2358	AnyEvent/EV/nb 0.068 sec
		2359	+state machine 0.134 sec
		2360
		2361	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2362	benchmarks actually make blocking connects and use 100% blocking I/O,
		2363	defeating the purpose of an event-based solution. All of the newly
		2364	written AnyEvent benchmarks use 100% non-blocking connects (using
		2365	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2366	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2367	generally require a lot more bookkeeping and event handling than blocking
		2368	connects (which involve a single syscall only).
		2369
		2370	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2371	offers similar expressive power as POE and IO::Lambda, using conventional
		2372	Perl syntax. This means that both the echo server and the client are 100%
		2373	non-blocking, further placing it at a disadvantage.
		2374
		2375	As you can see, the AnyEvent + EV combination even beats the
		2376	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2377	backend easily beats IO::Lambda and POE.
		2378
		2379	And even the 100% non-blocking version written using the high-level (and
		2380	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a
		2381	large margin, even though it does all of DNS, tcp-connect and socket I/O
		2382	in a non-blocking way.
		2383
		2384	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2385	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2386	part of the IO::lambda distribution and were used without any changes.
		2387
		2388
		2389	=head1 SIGNALS
		2390
		2391	AnyEvent currently installs handlers for these signals:
		2392
		2393	=over 4
		2394
		2395	=item SIGCHLD
		2396
		2397	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		2398	emulation for event loops that do not support them natively. Also, some
		2399	event loops install a similar handler.
		2400
		2401	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2402	AnyEvent will reset it to default, to avoid losing child exit statuses.
		2403
		2404	=item SIGPIPE
		2405
		2406	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		2407	when AnyEvent gets loaded.
		2408
		2409	The rationale for this is that AnyEvent users usually do not really depend
		2410	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		2411	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		2412	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		2413	some random socket.
		2414
		2415	The rationale for installing a no-op handler as opposed to ignoring it is
		2416	that this way, the handler will be restored to defaults on exec.
		2417
		2418	Feel free to install your own handler, or reset it to defaults.
		2419
		2420	=back
		2421
		2422	=cut
		2423
		2424	undef $SIG{CHLD}
		2425	if $SIG{CHLD} eq 'IGNORE';
		2426
		2427	$SIG{PIPE} = sub { }
		2428	unless defined $SIG{PIPE};
		2429
		2430	=head1 RECOMMENDED/OPTIONAL MODULES
		2431
		2432	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2433	it's built-in modules) are required to use it.
		2434
		2435	That does not mean that AnyEvent won't take advantage of some additional
		2436	modules if they are installed.
		2437
		2438	This section epxlains which additional modules will be used, and how they
		2439	affect AnyEvent's operetion.
		2440
		2441	=over 4
		2442
		2443	=item L<Async::Interrupt>
		2444
		2445	This slightly arcane module is used to implement fast signal handling: To
		2446	my knowledge, there is no way to do completely race-free and quick
		2447	signal handling in pure perl. To ensure that signals still get
		2448	delivered, AnyEvent will start an interval timer to wake up perl (and
		2449	catch the signals) with some delay (default is 10 seconds, look for
		2450	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2451
		2452	If this module is available, then it will be used to implement signal
		2453	catching, which means that signals will not be delayed, and the event loop
		2454	will not be interrupted regularly, which is more efficient (And good for
		2455	battery life on laptops).
		2456
		2457	This affects not just the pure-perl event loop, but also other event loops
		2458	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2459
		2460	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2461	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2462	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2463	does nothing for those backends.
		2464
		2465	=item L<EV>
		2466
		2467	This module isn't really "optional", as it is simply one of the backend
		2468	event loops that AnyEvent can use. However, it is simply the best event
		2469	loop available in terms of features, speed and stability: It supports
		2470	the AnyEvent API optimally, implements all the watcher types in XS, does
		2471	automatic timer adjustments even when no monotonic clock is available,
		2472	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2473	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2474	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2475
		2476	=item L<Guard>
		2477
		2478	The guard module, when used, will be used to implement
		2479	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2480	lot less memory), but otherwise doesn't affect guard operation much. It is
		2481	purely used for performance.
		2482
		2483	=item L<JSON> and L<JSON::XS>
		2484
		2485	This module is required when you want to read or write JSON data via
		2486	L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2487	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2488
		2489	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2490	installed.
		2491
		2492	=item L<Net::SSLeay>
		2493
		2494	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2495	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2496	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2497
		2498	=item L<Time::HiRes>
		2499
		2500	This module is part of perl since release 5.008. It will be used when the
		2501	chosen event library does not come with a timing source on it's own. The
		2502	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2503	try to use a monotonic clock for timing stability.
		2504
		2505	=back
		2506
1758		2507
1759	=head1 FORK	2508	=head1 FORK
1760		2509
1761	Most event libraries are not fork-safe. The ones who are usually are	2510	Most event libraries are not fork-safe. The ones who are usually are
1762	because they rely on inefficient but fork-safe C<select> or C<poll>	2511	because they rely on inefficient but fork-safe C<select> or C<poll>
1763	calls. Only L<EV> is fully fork-aware.	2512	calls. Only L<EV> is fully fork-aware.
1764		2513
1765	If you have to fork, you must either do so I<before> creating your first	2514	If you have to fork, you must either do so I<before> creating your first
1766	watcher OR you must not use AnyEvent at all in the child.	2515	watcher OR you must not use AnyEvent at all in the child OR you must do
		2516	something completely out of the scope of AnyEvent.
1767		2517
1768		2518
1769	=head1 SECURITY CONSIDERATIONS	2519	=head1 SECURITY CONSIDERATIONS
1770		2520
1771	AnyEvent can be forced to load any event model via	2521	AnyEvent can be forced to load any event model via
…		…
1783	use AnyEvent;	2533	use AnyEvent;
1784		2534
1785	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2535	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1786	be used to probe what backend is used and gain other information (which is	2536	be used to probe what backend is used and gain other information (which is
1787	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2537	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1788	$ENV{PERL_ANYEGENT_STRICT}.	2538	$ENV{PERL_ANYEVENT_STRICT}.
		2539
		2540	Note that AnyEvent will remove I<all> environment variables starting with
		2541	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2542	enabled.
1789		2543
1790		2544
1791	=head1 BUGS	2545	=head1 BUGS
1792		2546
1793	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2547	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1794	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	2548	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1795	and check wether the leaks still show up. (Perl 5.10.0 has other annoying	2549	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1796	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as	2550	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
1797	pronounced).	2551	pronounced).
1798		2552
1799		2553
1800	=head1 SEE ALSO	2554	=head1 SEE ALSO
1801		2555
…		…
1805	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2559	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1806		2560
1807	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2561	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1808	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2562	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1809	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2563	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1810	L<AnyEvent::Impl::POE>.	2564	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
1811		2565
1812	Non-blocking file handles, sockets, TCP clients and	2566	Non-blocking file handles, sockets, TCP clients and
1813	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2567	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1814		2568
1815	Asynchronous DNS: L<AnyEvent::DNS>.	2569	Asynchronous DNS: L<AnyEvent::DNS>.
1816		2570
1817	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2571	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2572	L<Coro::Event>,
1818		2573
1819	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2574	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2575	L<AnyEvent::HTTP>.
1820		2576
1821		2577
1822	=head1 AUTHOR	2578	=head1 AUTHOR
1823		2579
1824	Marc Lehmann <schmorp@schmorp.de>	2580	Marc Lehmann <schmorp@schmorp.de>

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