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Revision 1.198 by root, Thu Mar 26 20:17:44 2009 UTC vs.
Revision 1.297 by root, Thu Nov 19 01:55:57 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?
…		…
165	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
166	declared.	182	declared.
167		183
168	=head2 I/O WATCHERS	184	=head2 I/O WATCHERS
169		185
		186	$w = AnyEvent->io (
		187	fh => <filehandle_or_fileno>,
		188	poll => <"r" or "w">,
		189	cb => <callback>,
		190	);
		191
170	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
171	with the following mandatory key-value pairs as arguments:	193	with the following mandatory key-value pairs as arguments:
172		194
173	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
174	(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
175	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
176	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
177	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.
178		206
179	Although the callback might get passed parameters, their value and	207	Although the callback might get passed parameters, their value and
180	presence is undefined and you cannot rely on them. Portable AnyEvent	208	presence is undefined and you cannot rely on them. Portable AnyEvent
181	callbacks cannot use arguments passed to I/O watcher callbacks.	209	callbacks cannot use arguments passed to I/O watcher callbacks.
182		210
…		…
197	undef $w;	225	undef $w;
198	});	226	});
199		227
200	=head2 TIME WATCHERS	228	=head2 TIME WATCHERS
201		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
202	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 >>
203	method with the following mandatory arguments:	239	method with the following mandatory arguments:
204		240
205	C<after> specifies after how many seconds (fractional values are	241	C<after> specifies after how many seconds (fractional values are
206	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
…		…
314	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
315	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
316	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
317	account.	353	account.
318		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	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		369	when mod_perl executes the script, then the event loop will have the wrong
		370	idea about the "current time" (being potentially far in the past, when the
		371	script ran the last time). In that case you should arrange a call to C<<
		372	AnyEvent->now_update >> each time the web server process wakes up again
		373	(e.g. at the start of your script, or in a handler).
		374
		375	Note that updating the time I<might> cause some events to be handled.
		376
319	=back	377	=back
320		378
321	=head2 SIGNAL WATCHERS	379	=head2 SIGNAL WATCHERS
		380
		381	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
322		382
323	You can watch for signals using a signal watcher, C<signal> is the signal	383	You can watch for signals using a signal watcher, C<signal> is the signal
324	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	384	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
325	callback to be invoked whenever a signal occurs.	385	callback to be invoked whenever a signal occurs.
326		386
…		…
332	invocation, and callback invocation will be synchronous. Synchronous means	392	invocation, and callback invocation will be synchronous. Synchronous means
333	that it might take a while until the signal gets handled by the process,	393	that it might take a while until the signal gets handled by the process,
334	but it is guaranteed not to interrupt any other callbacks.	394	but it is guaranteed not to interrupt any other callbacks.
335		395
336	The main advantage of using these watchers is that you can share a signal	396	The main advantage of using these watchers is that you can share a signal
337	between multiple watchers.	397	between multiple watchers, and AnyEvent will ensure that signals will not
		398	interrupt your program at bad times.
338		399
339	This watcher might use C<%SIG>, so programs overwriting those signals	400	This watcher might use C<%SIG> (depending on the event loop used),
340	directly will likely not work correctly.	401	so programs overwriting those signals directly will likely not work
		402	correctly.
341		403
342	Example: exit on SIGINT	404	Example: exit on SIGINT
343		405
344	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	406	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
345		407
		408	=head3 Signal Races, Delays and Workarounds
		409
		410	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
		411	callbacks to signals in a generic way, which is a pity, as you cannot
		412	do race-free signal handling in perl, requiring C libraries for
		413	this. AnyEvent will try to do it's best, which means in some cases,
		414	signals will be delayed. The maximum time a signal might be delayed is
		415	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
		416	variable can be changed only before the first signal watcher is created,
		417	and should be left alone otherwise. This variable determines how often
		418	AnyEvent polls for signals (in case a wake-up was missed). Higher values
		419	will cause fewer spurious wake-ups, which is better for power and CPU
		420	saving.
		421
		422	All these problems can be avoided by installing the optional
		423	L<Async::Interrupt> module, which works with most event loops. It will not
		424	work with inherently broken event loops such as L<Event> or L<Event::Lib>
		425	(and not with L<POE> currently, as POE does it's own workaround with
		426	one-second latency). For those, you just have to suffer the delays.
		427
346	=head2 CHILD PROCESS WATCHERS	428	=head2 CHILD PROCESS WATCHERS
347		429
		430	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		431
348	You can also watch on a child process exit and catch its exit status.	432	You can also watch on a child process exit and catch its exit status.
349		433
350	The child process is specified by the C<pid> argument (if set to C<0>, it	434	The child process is specified by the C<pid> argument (one some backends,
351	watches for any child process exit). The watcher will triggered only when	435	using C<0> watches for any child process exit, on others this will
352	the child process has finished and an exit status is available, not on	436	croak). The watcher will be triggered only when the child process has
353	any trace events (stopped/continued).	437	finished and an exit status is available, not on any trace events
		438	(stopped/continued).
354		439
355	The callback will be called with the pid and exit status (as returned by	440	The callback will be called with the pid and exit status (as returned by
356	waitpid), so unlike other watcher types, you I<can> rely on child watcher	441	waitpid), so unlike other watcher types, you I<can> rely on child watcher
357	callback arguments.	442	callback arguments.
358		443
…		…
363		448
364	There is a slight catch to child watchers, however: you usually start them	449	There is a slight catch to child watchers, however: you usually start them
365	I<after> the child process was created, and this means the process could	450	I<after> the child process was created, and this means the process could
366	have exited already (and no SIGCHLD will be sent anymore).	451	have exited already (and no SIGCHLD will be sent anymore).
367		452
368	Not all event models handle this correctly (POE doesn't), but even for	453	Not all event models handle this correctly (neither POE nor IO::Async do,
		454	see their AnyEvent::Impl manpages for details), but even for event models
369	event models that I<do> handle this correctly, they usually need to be	455	that I<do> handle this correctly, they usually need to be loaded before
370	loaded before the process exits (i.e. before you fork in the first place).	456	the process exits (i.e. before you fork in the first place). AnyEvent's
		457	pure perl event loop handles all cases correctly regardless of when you
		458	start the watcher.
371		459
372	This means you cannot create a child watcher as the very first thing in an	460	This means you cannot create a child watcher as the very first
373	AnyEvent program, you I<have> to create at least one watcher before you	461	thing in an AnyEvent program, you I<have> to create at least one
374	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	462	watcher before you C<fork> the child (alternatively, you can call
		463	C<AnyEvent::detect>).
		464
		465	As most event loops do not support waiting for child events, they will be
		466	emulated by AnyEvent in most cases, in which the latency and race problems
		467	mentioned in the description of signal watchers apply.
375		468
376	Example: fork a process and wait for it	469	Example: fork a process and wait for it
377		470
378	my $done = AnyEvent->condvar;	471	my $done = AnyEvent->condvar;
379		472
…		…
389	);	482	);
390		483
391	# do something else, then wait for process exit	484	# do something else, then wait for process exit
392	$done->recv;	485	$done->recv;
393		486
		487	=head2 IDLE WATCHERS
		488
		489	$w = AnyEvent->idle (cb => <callback>);
		490
		491	Sometimes there is a need to do something, but it is not so important
		492	to do it instantly, but only when there is nothing better to do. This
		493	"nothing better to do" is usually defined to be "no other events need
		494	attention by the event loop".
		495
		496	Idle watchers ideally get invoked when the event loop has nothing
		497	better to do, just before it would block the process to wait for new
		498	events. Instead of blocking, the idle watcher is invoked.
		499
		500	Most event loops unfortunately do not really support idle watchers (only
		501	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
		502	will simply call the callback "from time to time".
		503
		504	Example: read lines from STDIN, but only process them when the
		505	program is otherwise idle:
		506
		507	my @lines; # read data
		508	my $idle_w;
		509	my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		510	push @lines, scalar <STDIN>;
		511
		512	# start an idle watcher, if not already done
		513	$idle_w ||= AnyEvent->idle (cb => sub {
		514	# handle only one line, when there are lines left
		515	if (my $line = shift @lines) {
		516	print "handled when idle: $line";
		517	} else {
		518	# otherwise disable the idle watcher again
		519	undef $idle_w;
		520	}
		521	});
		522	});
		523
394	=head2 CONDITION VARIABLES	524	=head2 CONDITION VARIABLES
		525
		526	$cv = AnyEvent->condvar;
		527
		528	$cv->send (<list>);
		529	my @res = $cv->recv;
395		530
396	If you are familiar with some event loops you will know that all of them	531	If you are familiar with some event loops you will know that all of them
397	require you to run some blocking "loop", "run" or similar function that	532	require you to run some blocking "loop", "run" or similar function that
398	will actively watch for new events and call your callbacks.	533	will actively watch for new events and call your callbacks.
399		534
400	AnyEvent is different, it expects somebody else to run the event loop and	535	AnyEvent is slightly different: it expects somebody else to run the event
401	will only block when necessary (usually when told by the user).	536	loop and will only block when necessary (usually when told by the user).
402		537
403	The instrument to do that is called a "condition variable", so called	538	The instrument to do that is called a "condition variable", so called
404	because they represent a condition that must become true.	539	because they represent a condition that must become true.
405		540
		541	Now is probably a good time to look at the examples further below.
		542
406	Condition variables can be created by calling the C<< AnyEvent->condvar	543	Condition variables can be created by calling the C<< AnyEvent->condvar
407	>> method, usually without arguments. The only argument pair allowed is	544	>> method, usually without arguments. The only argument pair allowed is
408
409	C<cb>, which specifies a callback to be called when the condition variable	545	C<cb>, which specifies a callback to be called when the condition variable
410	becomes true, with the condition variable as the first argument (but not	546	becomes true, with the condition variable as the first argument (but not
411	the results).	547	the results).
412		548
413	After creation, the condition variable is "false" until it becomes "true"	549	After creation, the condition variable is "false" until it becomes "true"
…		…
418	Condition variables are similar to callbacks, except that you can	554	Condition variables are similar to callbacks, except that you can
419	optionally wait for them. They can also be called merge points - points	555	optionally wait for them. They can also be called merge points - points
420	in time where multiple outstanding events have been processed. And yet	556	in time where multiple outstanding events have been processed. And yet
421	another way to call them is transactions - each condition variable can be	557	another way to call them is transactions - each condition variable can be
422	used to represent a transaction, which finishes at some point and delivers	558	used to represent a transaction, which finishes at some point and delivers
423	a result.	559	a result. And yet some people know them as "futures" - a promise to
		560	compute/deliver something that you can wait for.
424		561
425	Condition variables are very useful to signal that something has finished,	562	Condition variables are very useful to signal that something has finished,
426	for example, if you write a module that does asynchronous http requests,	563	for example, if you write a module that does asynchronous http requests,
427	then a condition variable would be the ideal candidate to signal the	564	then a condition variable would be the ideal candidate to signal the
428	availability of results. The user can either act when the callback is	565	availability of results. The user can either act when the callback is
…		…
462	after => 1,	599	after => 1,
463	cb => sub { $result_ready->send },	600	cb => sub { $result_ready->send },
464	);	601	);
465		602
466	# this "blocks" (while handling events) till the callback	603	# this "blocks" (while handling events) till the callback
467	# calls send	604	# calls ->send
468	$result_ready->recv;	605	$result_ready->recv;
469		606
470	Example: wait for a timer, but take advantage of the fact that	607	Example: wait for a timer, but take advantage of the fact that condition
471	condition variables are also code references.	608	variables are also callable directly.
472		609
473	my $done = AnyEvent->condvar;	610	my $done = AnyEvent->condvar;
474	my $delay = AnyEvent->timer (after => 5, cb => $done);	611	my $delay = AnyEvent->timer (after => 5, cb => $done);
475	$done->recv;	612	$done->recv;
476		613
…		…
482		619
483	...	620	...
484		621
485	my @info = $couchdb->info->recv;	622	my @info = $couchdb->info->recv;
486		623
487	And this is how you would just ste a callback to be called whenever the	624	And this is how you would just set a callback to be called whenever the
488	results are available:	625	results are available:
489		626
490	$couchdb->info->cb (sub {	627	$couchdb->info->cb (sub {
491	my @info = $_[0]->recv;	628	my @info = $_[0]->recv;
492	});	629	});
…		…
510	immediately from within send.	647	immediately from within send.
511		648
512	Any arguments passed to the C<send> call will be returned by all	649	Any arguments passed to the C<send> call will be returned by all
513	future C<< ->recv >> calls.	650	future C<< ->recv >> calls.
514		651
515	Condition variables are overloaded so one can call them directly	652	Condition variables are overloaded so one can call them directly (as if
516	(as a code reference). Calling them directly is the same as calling	653	they were a code reference). Calling them directly is the same as calling
517	C<send>. Note, however, that many C-based event loops do not handle	654	C<send>.
518	overloading, so as tempting as it may be, passing a condition variable
519	instead of a callback does not work. Both the pure perl and EV loops
520	support overloading, however, as well as all functions that use perl to
521	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
522	example).
523		655
524	=item $cv->croak ($error)	656	=item $cv->croak ($error)
525		657
526	Similar to send, but causes all call's to C<< ->recv >> to invoke	658	Similar to send, but causes all call's to C<< ->recv >> to invoke
527	C<Carp::croak> with the given error message/object/scalar.	659	C<Carp::croak> with the given error message/object/scalar.
528		660
529	This can be used to signal any errors to the condition variable	661	This can be used to signal any errors to the condition variable
530	user/consumer.	662	user/consumer. Doing it this way instead of calling C<croak> directly
		663	delays the error detetcion, but has the overwhelmign advantage that it
		664	diagnoses the error at the place where the result is expected, and not
		665	deep in some event clalback without connection to the actual code causing
		666	the problem.
531		667
532	=item $cv->begin ([group callback])	668	=item $cv->begin ([group callback])
533		669
534	=item $cv->end	670	=item $cv->end
535
536	These two methods are EXPERIMENTAL and MIGHT CHANGE.
537		671
538	These two methods can be used to combine many transactions/events into	672	These two methods can be used to combine many transactions/events into
539	one. For example, a function that pings many hosts in parallel might want	673	one. For example, a function that pings many hosts in parallel might want
540	to use a condition variable for the whole process.	674	to use a condition variable for the whole process.
541		675
542	Every call to C<< ->begin >> will increment a counter, and every call to	676	Every call to C<< ->begin >> will increment a counter, and every call to
543	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	677	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
544	>>, the (last) callback passed to C<begin> will be executed. That callback	678	>>, the (last) callback passed to C<begin> will be executed, passing the
545	is I<supposed> to call C<< ->send >>, but that is not required. If no	679	condvar as first argument. That callback is I<supposed> to call C<< ->send
546	callback was set, C<send> will be called without any arguments.	680	>>, but that is not required. If no group callback was set, C<send> will
		681	be called without any arguments.
547		682
548	Let's clarify this with the ping example:	683	You can think of C<< $cv->send >> giving you an OR condition (one call
		684	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		685	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		686
		687	Let's start with a simple example: you have two I/O watchers (for example,
		688	STDOUT and STDERR for a program), and you want to wait for both streams to
		689	close before activating a condvar:
549		690
550	my $cv = AnyEvent->condvar;	691	my $cv = AnyEvent->condvar;
551		692
		693	$cv->begin; # first watcher
		694	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		695	defined sysread $fh1, my $buf, 4096
		696	or $cv->end;
		697	});
		698
		699	$cv->begin; # second watcher
		700	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		701	defined sysread $fh2, my $buf, 4096
		702	or $cv->end;
		703	});
		704
		705	$cv->recv;
		706
		707	This works because for every event source (EOF on file handle), there is
		708	one call to C<begin>, so the condvar waits for all calls to C<end> before
		709	sending.
		710
		711	The ping example mentioned above is slightly more complicated, as the
		712	there are results to be passwd back, and the number of tasks that are
		713	begung can potentially be zero:
		714
		715	my $cv = AnyEvent->condvar;
		716
552	my %result;	717	my %result;
553	$cv->begin (sub { $cv->send (\%result) });	718	$cv->begin (sub { shift->send (\%result) });
554		719
555	for my $host (@list_of_hosts) {	720	for my $host (@list_of_hosts) {
556	$cv->begin;	721	$cv->begin;
557	ping_host_then_call_callback $host, sub {	722	ping_host_then_call_callback $host, sub {
558	$result{$host} = ...;	723	$result{$host} = ...;
…		…
573	loop, which serves two important purposes: first, it sets the callback	738	loop, which serves two important purposes: first, it sets the callback
574	to be called once the counter reaches C<0>, and second, it ensures that	739	to be called once the counter reaches C<0>, and second, it ensures that
575	C<send> is called even when C<no> hosts are being pinged (the loop	740	C<send> is called even when C<no> hosts are being pinged (the loop
576	doesn't execute once).	741	doesn't execute once).
577		742
578	This is the general pattern when you "fan out" into multiple subrequests:	743	This is the general pattern when you "fan out" into multiple (but
579	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	744	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
580	is called at least once, and then, for each subrequest you start, call	745	the callback and ensure C<end> is called at least once, and then, for each
581	C<begin> and for each subrequest you finish, call C<end>.	746	subrequest you start, call C<begin> and for each subrequest you finish,
		747	call C<end>.
582		748
583	=back	749	=back
584		750
585	=head3 METHODS FOR CONSUMERS	751	=head3 METHODS FOR CONSUMERS
586		752
…		…
602	function will call C<croak>.	768	function will call C<croak>.
603		769
604	In list context, all parameters passed to C<send> will be returned,	770	In list context, all parameters passed to C<send> will be returned,
605	in scalar context only the first one will be returned.	771	in scalar context only the first one will be returned.
606		772
		773	Note that doing a blocking wait in a callback is not supported by any
		774	event loop, that is, recursive invocation of a blocking C<< ->recv
		775	>> is not allowed, and the C<recv> call will C<croak> if such a
		776	condition is detected. This condition can be slightly loosened by using
		777	L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
		778	any thread that doesn't run the event loop itself.
		779
607	Not all event models support a blocking wait - some die in that case	780	Not all event models support a blocking wait - some die in that case
608	(programs might want to do that to stay interactive), so I<if you are	781	(programs might want to do that to stay interactive), so I<if you are
609	using this from a module, never require a blocking wait>, but let the	782	using this from a module, never require a blocking wait>. Instead, let the
610	caller decide whether the call will block or not (for example, by coupling	783	caller decide whether the call will block or not (for example, by coupling
611	condition variables with some kind of request results and supporting	784	condition variables with some kind of request results and supporting
612	callbacks so the caller knows that getting the result will not block,	785	callbacks so the caller knows that getting the result will not block,
613	while still supporting blocking waits if the caller so desires).	786	while still supporting blocking waits if the caller so desires).
614		787
615	Another reason I<never> to C<< ->recv >> in a module is that you cannot
616	sensibly have two C<< ->recv >>'s in parallel, as that would require
617	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
618	can supply.
619
620	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
621	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
622	versions and also integrates coroutines into AnyEvent, making blocking
623	C<< ->recv >> calls perfectly safe as long as they are done from another
624	coroutine (one that doesn't run the event loop).
625
626	You can ensure that C<< -recv >> never blocks by setting a callback and	788	You can ensure that C<< -recv >> never blocks by setting a callback and
627	only calling C<< ->recv >> from within that callback (or at a later	789	only calling C<< ->recv >> from within that callback (or at a later
628	time). This will work even when the event loop does not support blocking	790	time). This will work even when the event loop does not support blocking
629	waits otherwise.	791	waits otherwise.
630		792
…		…
636	=item $cb = $cv->cb ($cb->($cv))	798	=item $cb = $cv->cb ($cb->($cv))
637		799
638	This is a mutator function that returns the callback set and optionally	800	This is a mutator function that returns the callback set and optionally
639	replaces it before doing so.	801	replaces it before doing so.
640		802
641	The callback will be called when the condition becomes "true", i.e. when	803	The callback will be called when the condition becomes (or already was)
642	C<send> or C<croak> are called, with the only argument being the condition	804	"true", i.e. when C<send> or C<croak> are called (or were called), with
643	variable itself. Calling C<recv> inside the callback or at any later time	805	the only argument being the condition variable itself. Calling C<recv>
644	is guaranteed not to block.	806	inside the callback or at any later time is guaranteed not to block.
645		807
646	=back	808	=back
647		809
		810	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		811
		812	The available backend classes are (every class has its own manpage):
		813
		814	=over 4
		815
		816	=item Backends that are autoprobed when no other event loop can be found.
		817
		818	EV is the preferred backend when no other event loop seems to be in
		819	use. If EV is not installed, then AnyEvent will fall back to its own
		820	pure-perl implementation, which is available everywhere as it comes with
		821	AnyEvent itself.
		822
		823	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		824	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		825
		826	=item Backends that are transparently being picked up when they are used.
		827
		828	These will be used when they are currently loaded when the first watcher
		829	is created, in which case it is assumed that the application is using
		830	them. This means that AnyEvent will automatically pick the right backend
		831	when the main program loads an event module before anything starts to
		832	create watchers. Nothing special needs to be done by the main program.
		833
		834	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		835	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		836	AnyEvent::Impl::Tk based on Tk, very broken.
		837	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		838	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		839	AnyEvent::Impl::Irssi used when running within irssi.
		840
		841	=item Backends with special needs.
		842
		843	Qt requires the Qt::Application to be instantiated first, but will
		844	otherwise be picked up automatically. As long as the main program
		845	instantiates the application before any AnyEvent watchers are created,
		846	everything should just work.
		847
		848	AnyEvent::Impl::Qt based on Qt.
		849
		850	Support for IO::Async can only be partial, as it is too broken and
		851	architecturally limited to even support the AnyEvent API. It also
		852	is the only event loop that needs the loop to be set explicitly, so
		853	it can only be used by a main program knowing about AnyEvent. See
		854	L<AnyEvent::Impl::Async> for the gory details.
		855
		856	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		857
		858	=item Event loops that are indirectly supported via other backends.
		859
		860	Some event loops can be supported via other modules:
		861
		862	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		863
		864	B<WxWidgets> has no support for watching file handles. However, you can
		865	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		866	polls 20 times per second, which was considered to be too horrible to even
		867	consider for AnyEvent.
		868
		869	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		870	backend, so it can be supported through POE.
		871
		872	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		873	load L<POE> when detecting them, in the hope that POE will pick them up,
		874	in which case everything will be automatic.
		875
		876	=back
		877
648	=head1 GLOBAL VARIABLES AND FUNCTIONS	878	=head1 GLOBAL VARIABLES AND FUNCTIONS
649		879
		880	These are not normally required to use AnyEvent, but can be useful to
		881	write AnyEvent extension modules.
		882
650	=over 4	883	=over 4
651		884
652	=item $AnyEvent::MODEL	885	=item $AnyEvent::MODEL
653		886
654	Contains C<undef> until the first watcher is being created. Then it	887	Contains C<undef> until the first watcher is being created, before the
		888	backend has been autodetected.
		889
655	contains the event model that is being used, which is the name of the	890	Afterwards it contains the event model that is being used, which is the
656	Perl class implementing the model. This class is usually one of the	891	name of the Perl class implementing the model. This class is usually one
657	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	892	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
658	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	893	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
659		894	will be C<urxvt::anyevent>).
660	The known classes so far are:
661
662	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
663	AnyEvent::Impl::Event based on Event, second best choice.
664	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
665	AnyEvent::Impl::Glib based on Glib, third-best choice.
666	AnyEvent::Impl::Tk based on Tk, very bad choice.
667	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
668	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
669	AnyEvent::Impl::POE based on POE, not generic enough for full support.
670
671	There is no support for WxWidgets, as WxWidgets has no support for
672	watching file handles. However, you can use WxWidgets through the
673	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
674	second, which was considered to be too horrible to even consider for
675	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
676	it's adaptor.
677
678	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
679	autodetecting them.
680		895
681	=item AnyEvent::detect	896	=item AnyEvent::detect
682		897
683	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	898	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
684	if necessary. You should only call this function right before you would	899	if necessary. You should only call this function right before you would
685	have created an AnyEvent watcher anyway, that is, as late as possible at	900	have created an AnyEvent watcher anyway, that is, as late as possible at
686	runtime.	901	runtime, and not e.g. while initialising of your module.
		902
		903	If you need to do some initialisation before AnyEvent watchers are
		904	created, use C<post_detect>.
687		905
688	=item $guard = AnyEvent::post_detect { BLOCK }	906	=item $guard = AnyEvent::post_detect { BLOCK }
689		907
690	Arranges for the code block to be executed as soon as the event model is	908	Arranges for the code block to be executed as soon as the event model is
691	autodetected (or immediately if this has already happened).	909	autodetected (or immediately if this has already happened).
692		910
		911	The block will be executed I<after> the actual backend has been detected
		912	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		913	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		914	other initialisations - see the sources of L<AnyEvent::Strict> or
		915	L<AnyEvent::AIO> to see how this is used.
		916
		917	The most common usage is to create some global watchers, without forcing
		918	event module detection too early, for example, L<AnyEvent::AIO> creates
		919	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		920	avoid autodetecting the event module at load time.
		921
693	If called in scalar or list context, then it creates and returns an object	922	If called in scalar or list context, then it creates and returns an object
694	that automatically removes the callback again when it is destroyed. See	923	that automatically removes the callback again when it is destroyed (or
		924	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
695	L<Coro::BDB> for a case where this is useful.	925	a case where this is useful.
		926
		927	Example: Create a watcher for the IO::AIO module and store it in
		928	C<$WATCHER>. Only do so after the event loop is initialised, though.
		929
		930	our WATCHER;
		931
		932	my $guard = AnyEvent::post_detect {
		933	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
		934	};
		935
		936	# the ||= is important in case post_detect immediately runs the block,
		937	# as to not clobber the newly-created watcher. assigning both watcher and
		938	# post_detect guard to the same variable has the advantage of users being
		939	# able to just C<undef $WATCHER> if the watcher causes them grief.
		940
		941	$WATCHER ||= $guard;
696		942
697	=item @AnyEvent::post_detect	943	=item @AnyEvent::post_detect
698		944
699	If there are any code references in this array (you can C<push> to it	945	If there are any code references in this array (you can C<push> to it
700	before or after loading AnyEvent), then they will called directly after	946	before or after loading AnyEvent), then they will called directly after
701	the event loop has been chosen.	947	the event loop has been chosen.
702		948
703	You should check C<$AnyEvent::MODEL> before adding to this array, though:	949	You should check C<$AnyEvent::MODEL> before adding to this array, though:
704	if it contains a true value then the event loop has already been detected,	950	if it is defined then the event loop has already been detected, and the
705	and the array will be ignored.	951	array will be ignored.
706		952
707	Best use C<AnyEvent::post_detect { BLOCK }> instead.	953	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		954	it,as it takes care of these details.
		955
		956	This variable is mainly useful for modules that can do something useful
		957	when AnyEvent is used and thus want to know when it is initialised, but do
		958	not need to even load it by default. This array provides the means to hook
		959	into AnyEvent passively, without loading it.
708		960
709	=back	961	=back
710		962
711	=head1 WHAT TO DO IN A MODULE	963	=head1 WHAT TO DO IN A MODULE
712		964
…		…
767		1019
768		1020
769	=head1 OTHER MODULES	1021	=head1 OTHER MODULES
770		1022
771	The following is a non-exhaustive list of additional modules that use	1023	The following is a non-exhaustive list of additional modules that use
772	AnyEvent and can therefore be mixed easily with other AnyEvent modules	1024	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
773	in the same program. Some of the modules come with AnyEvent, some are	1025	modules and other event loops in the same program. Some of the modules
774	available via CPAN.	1026	come with AnyEvent, most are available via CPAN.
775		1027
776	=over 4	1028	=over 4
777		1029
778	=item L<AnyEvent::Util>	1030	=item L<AnyEvent::Util>
779		1031
…		…
788		1040
789	=item L<AnyEvent::Handle>	1041	=item L<AnyEvent::Handle>
790		1042
791	Provide read and write buffers, manages watchers for reads and writes,	1043	Provide read and write buffers, manages watchers for reads and writes,
792	supports raw and formatted I/O, I/O queued and fully transparent and	1044	supports raw and formatted I/O, I/O queued and fully transparent and
793	non-blocking SSL/TLS.	1045	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
794		1046
795	=item L<AnyEvent::DNS>	1047	=item L<AnyEvent::DNS>
796		1048
797	Provides rich asynchronous DNS resolver capabilities.	1049	Provides rich asynchronous DNS resolver capabilities.
798		1050
…		…
826		1078
827	=item L<AnyEvent::GPSD>	1079	=item L<AnyEvent::GPSD>
828		1080
829	A non-blocking interface to gpsd, a daemon delivering GPS information.	1081	A non-blocking interface to gpsd, a daemon delivering GPS information.
830		1082
		1083	=item L<AnyEvent::IRC>
		1084
		1085	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1086
		1087	=item L<AnyEvent::XMPP>
		1088
		1089	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1090	Net::XMPP2>.
		1091
831	=item L<AnyEvent::IGS>	1092	=item L<AnyEvent::IGS>
832		1093
833	A non-blocking interface to the Internet Go Server protocol (used by	1094	A non-blocking interface to the Internet Go Server protocol (used by
834	L<App::IGS>).	1095	L<App::IGS>).
835		1096
836	=item L<AnyEvent::IRC>
837
838	AnyEvent based IRC client module family (replacing the older Net::IRC3).
839
840	=item L<Net::XMPP2>
841
842	AnyEvent based XMPP (Jabber protocol) module family.
843
844	=item L<Net::FCP>	1097	=item L<Net::FCP>
845		1098
846	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1099	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
847	of AnyEvent.	1100	of AnyEvent.
848		1101
…		…
852		1105
853	=item L<Coro>	1106	=item L<Coro>
854		1107
855	Has special support for AnyEvent via L<Coro::AnyEvent>.	1108	Has special support for AnyEvent via L<Coro::AnyEvent>.
856		1109
857	=item L<IO::Lambda>
858
859	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
860
861	=back	1110	=back
862		1111
863	=cut	1112	=cut
864		1113
865	package AnyEvent;	1114	package AnyEvent;
866		1115
867	no warnings;	1116	# basically a tuned-down version of common::sense
		1117	sub common_sense {
		1118	# from common:.sense 1.0
		1119	${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03";
868	use strict qw(vars subs);	1120	# use strict vars subs
		1121	$^H |= 0x00000600;
		1122	}
869		1123
		1124	BEGIN { AnyEvent::common_sense }
		1125
870	use Carp;	1126	use Carp ();
871		1127
872	our $VERSION = 4.341;	1128	our $VERSION = '5.21';
873	our $MODEL;	1129	our $MODEL;
874		1130
875	our $AUTOLOAD;	1131	our $AUTOLOAD;
876	our @ISA;	1132	our @ISA;
877		1133
878	our @REGISTRY;	1134	our @REGISTRY;
879		1135
880	our $WIN32;	1136	our $VERBOSE;
881		1137
882	BEGIN {	1138	BEGIN {
883	my $win32 = ! ! ($^O =~ /mswin32/i);	1139	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
884	eval "sub WIN32(){ $win32 }";	1140	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
885	}
886		1141
		1142	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1143	if ${^TAINT};
		1144
887	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1145	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
		1146
		1147	}
		1148
		1149	our $MAX_SIGNAL_LATENCY = 10;
888		1150
889	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1151	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
890		1152
891	{	1153	{
892	my $idx;	1154	my $idx;
…		…
894	for reverse split /\s*,\s*/,	1156	for reverse split /\s*,\s*/,
895	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1157	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
896	}	1158	}
897		1159
898	my @models = (	1160	my @models = (
899	[EV:: => AnyEvent::Impl::EV::],	1161	[EV:: => AnyEvent::Impl::EV:: , 1],
900	[Event:: => AnyEvent::Impl::Event::],
901	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1162	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
902	# everything below here will not be autoprobed	1163	# everything below here will not (normally) be autoprobed
903	# as the pureperl backend should work everywhere	1164	# as the pureperl backend should work everywhere
904	# and is usually faster	1165	# and is usually faster
		1166	[Event:: => AnyEvent::Impl::Event::, 1],
		1167	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
		1168	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1169	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
905	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1170	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
906	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
907	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
908	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1171	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
909	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1172	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
910	[Wx:: => AnyEvent::Impl::POE::],	1173	[Wx:: => AnyEvent::Impl::POE::],
911	[Prima:: => AnyEvent::Impl::POE::],	1174	[Prima:: => AnyEvent::Impl::POE::],
		1175	# IO::Async is just too broken - we would need workarounds for its
		1176	# byzantine signal and broken child handling, among others.
		1177	# IO::Async is rather hard to detect, as it doesn't have any
		1178	# obvious default class.
		1179	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1180	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1181	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1182	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
912	);	1183	);
913		1184
914	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	1185	our %method = map +($_ => 1),
		1186	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
915		1187
916	our @post_detect;	1188	our @post_detect;
917		1189
918	sub post_detect(&) {	1190	sub post_detect(&) {
919	my ($cb) = @_;	1191	my ($cb) = @_;
920		1192
921	if ($MODEL) {	1193	if ($MODEL) {
922	$cb->();	1194	$cb->();
923		1195
924	1	1196	undef
925	} else {	1197	} else {
926	push @post_detect, $cb;	1198	push @post_detect, $cb;
927		1199
928	defined wantarray	1200	defined wantarray
929	? bless \$cb, "AnyEvent::Util::PostDetect"	1201	? bless \$cb, "AnyEvent::Util::postdetect"
930	: ()	1202	: ()
931	}	1203	}
932	}	1204	}
933		1205
934	sub AnyEvent::Util::PostDetect::DESTROY {	1206	sub AnyEvent::Util::postdetect::DESTROY {
935	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1207	@post_detect = grep $_ != ${$_[0]}, @post_detect;
936	}	1208	}
937		1209
938	sub detect() {	1210	sub detect() {
939	unless ($MODEL) {	1211	unless ($MODEL) {
940	no strict 'refs';
941	local $SIG{__DIE__};	1212	local $SIG{__DIE__};
942		1213
943	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1214	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
944	my $model = "AnyEvent::Impl::$1";	1215	my $model = "AnyEvent::Impl::$1";
945	if (eval "require $model") {	1216	if (eval "require $model") {
946	$MODEL = $model;	1217	$MODEL = $model;
947	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1218	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
948	} else {	1219	} else {
949	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1220	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
950	}	1221	}
951	}	1222	}
952		1223
953	# check for already loaded models	1224	# check for already loaded models
954	unless ($MODEL) {	1225	unless ($MODEL) {
955	for (@REGISTRY, @models) {	1226	for (@REGISTRY, @models) {
956	my ($package, $model) = @$_;	1227	my ($package, $model) = @$_;
957	if (${"$package\::VERSION"} > 0) {	1228	if (${"$package\::VERSION"} > 0) {
958	if (eval "require $model") {	1229	if (eval "require $model") {
959	$MODEL = $model;	1230	$MODEL = $model;
960	warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1;	1231	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
961	last;	1232	last;
962	}	1233	}
963	}	1234	}
964	}	1235	}
965		1236
966	unless ($MODEL) {	1237	unless ($MODEL) {
967	# try to load a model	1238	# try to autoload a model
968
969	for (@REGISTRY, @models) {	1239	for (@REGISTRY, @models) {
970	my ($package, $model) = @$_;	1240	my ($package, $model, $autoload) = @$_;
		1241	if (
		1242	$autoload
971	if (eval "require $package"	1243	and eval "require $package"
972	and ${"$package\::VERSION"} > 0	1244	and ${"$package\::VERSION"} > 0
973	and eval "require $model") {	1245	and eval "require $model"
		1246	) {
974	$MODEL = $model;	1247	$MODEL = $model;
975	warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;	1248	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
976	last;	1249	last;
977	}	1250	}
978	}	1251	}
979		1252
980	$MODEL	1253	$MODEL
981	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1254	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
982	}	1255	}
983	}	1256	}
984		1257
985	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1258	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
986		1259
…		…
996		1269
997	sub AUTOLOAD {	1270	sub AUTOLOAD {
998	(my $func = $AUTOLOAD) =~ s/.*://;	1271	(my $func = $AUTOLOAD) =~ s/.*://;
999		1272
1000	$method{$func}	1273	$method{$func}
1001	or croak "$func: not a valid method for AnyEvent objects";	1274	or Carp::croak "$func: not a valid method for AnyEvent objects";
1002		1275
1003	detect unless $MODEL;	1276	detect unless $MODEL;
1004		1277
1005	my $class = shift;	1278	my $class = shift;
1006	$class->$func (@_);	1279	$class->$func (@_);
1007	}	1280	}
1008		1281
1009	# utility function to dup a filehandle. this is used by many backends	1282	# utility function to dup a filehandle. this is used by many backends
1010	# to support binding more than one watcher per filehandle (they usually	1283	# to support binding more than one watcher per filehandle (they usually
1011	# allow only one watcher per fd, so we dup it to get a different one).	1284	# allow only one watcher per fd, so we dup it to get a different one).
1012	sub _dupfh($$$$) {	1285	sub _dupfh($$;$$) {
1013	my ($poll, $fh, $r, $w) = @_;	1286	my ($poll, $fh, $r, $w) = @_;
1014		1287
1015	# cygwin requires the fh mode to be matching, unix doesn't	1288	# cygwin requires the fh mode to be matching, unix doesn't
1016	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1289	my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1017	: $poll eq "w" ? ($w, ">")
1018	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1019		1290
1020	open my $fh2, "$mode&" . fileno $fh	1291	open my $fh2, $mode, $fh
1021	or die "cannot dup() filehandle: $!";	1292	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1022		1293
1023	# we assume CLOEXEC is already set by perl in all important cases	1294	# we assume CLOEXEC is already set by perl in all important cases
1024		1295
1025	($fh2, $rw)	1296	($fh2, $rw)
1026	}	1297	}
1027		1298
		1299	=head1 SIMPLIFIED AE API
		1300
		1301	Starting with version 5.0, AnyEvent officially supports a second, much
		1302	simpler, API that is designed to reduce the calling, typing and memory
		1303	overhead.
		1304
		1305	See the L<AE> manpage for details.
		1306
		1307	=cut
		1308
		1309	package AE;
		1310
		1311	our $VERSION = $AnyEvent::VERSION;
		1312
		1313	sub io($$$) {
		1314	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1315	}
		1316
		1317	sub timer($$$) {
		1318	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1319	}
		1320
		1321	sub signal($$) {
		1322	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1323	}
		1324
		1325	sub child($$) {
		1326	AnyEvent->child (pid => $_[0], cb => $_[1])
		1327	}
		1328
		1329	sub idle($) {
		1330	AnyEvent->idle (cb => $_[0])
		1331	}
		1332
		1333	sub cv(;&) {
		1334	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1335	}
		1336
		1337	sub now() {
		1338	AnyEvent->now
		1339	}
		1340
		1341	sub now_update() {
		1342	AnyEvent->now_update
		1343	}
		1344
		1345	sub time() {
		1346	AnyEvent->time
		1347	}
		1348
1028	package AnyEvent::Base;	1349	package AnyEvent::Base;
1029		1350
1030	# default implementation for now and time	1351	# default implementations for many methods
1031		1352
1032	BEGIN {	1353	sub _time() {
		1354	# probe for availability of Time::HiRes
1033	if (eval "use Time::HiRes (); time (); 1") {	1355	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1356	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1034	*_time = \&Time::HiRes::time;	1357	*_time = \&Time::HiRes::time;
1035	# if (eval "use POSIX (); (POSIX::times())...	1358	# if (eval "use POSIX (); (POSIX::times())...
1036	} else {	1359	} else {
		1360	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1037	*_time = sub { time }; # epic fail	1361	*_time = sub { time }; # epic fail
1038	}	1362	}
		1363
		1364	&_time
1039	}	1365	}
1040		1366
1041	sub time { _time }	1367	sub time { _time }
1042	sub now { _time }	1368	sub now { _time }
		1369	sub now_update { }
1043		1370
1044	# default implementation for ->condvar	1371	# default implementation for ->condvar
1045		1372
1046	sub condvar {	1373	sub condvar {
1047	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1374	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1048	}	1375	}
1049		1376
1050	# default implementation for ->signal	1377	# default implementation for ->signal
1051		1378
		1379	our $HAVE_ASYNC_INTERRUPT;
		1380
		1381	sub _have_async_interrupt() {
		1382	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
		1383	&& eval "use Async::Interrupt 1.02 (); 1")
		1384	unless defined $HAVE_ASYNC_INTERRUPT;
		1385
		1386	$HAVE_ASYNC_INTERRUPT
		1387	}
		1388
1052	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1389	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1390	our (%SIG_ASY, %SIG_ASY_W);
		1391	our ($SIG_COUNT, $SIG_TW);
1053		1392
1054	sub _signal_exec {	1393	sub _signal_exec {
		1394	$HAVE_ASYNC_INTERRUPT
		1395	? $SIGPIPE_R->drain
1055	sysread $SIGPIPE_R, my $dummy, 4;	1396	: sysread $SIGPIPE_R, (my $dummy), 9;
1056		1397
1057	while (%SIG_EV) {	1398	while (%SIG_EV) {
1058	for (keys %SIG_EV) {	1399	for (keys %SIG_EV) {
1059	delete $SIG_EV{$_};	1400	delete $SIG_EV{$_};
1060	$_->() for values %{ $SIG_CB{$_} || {} };	1401	$_->() for values %{ $SIG_CB{$_} || {} };
1061	}	1402	}
1062	}	1403	}
1063	}	1404	}
1064		1405
		1406	# install a dummy wakeup watcher to reduce signal catching latency
		1407	sub _sig_add() {
		1408	unless ($SIG_COUNT++) {
		1409	# try to align timer on a full-second boundary, if possible
		1410	my $NOW = AE::now;
		1411
		1412	$SIG_TW = AE::timer
		1413	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
		1414	$MAX_SIGNAL_LATENCY,
		1415	sub { } # just for the PERL_ASYNC_CHECK
		1416	;
		1417	}
		1418	}
		1419
		1420	sub _sig_del {
		1421	undef $SIG_TW
		1422	unless --$SIG_COUNT;
		1423	}
		1424
		1425	our $_sig_name_init; $_sig_name_init = sub {
		1426	eval q{ # poor man's autoloading
		1427	undef $_sig_name_init;
		1428
		1429	if (_have_async_interrupt) {
		1430	*sig2num = \&Async::Interrupt::sig2num;
		1431	*sig2name = \&Async::Interrupt::sig2name;
		1432	} else {
		1433	require Config;
		1434
		1435	my %signame2num;
		1436	@signame2num{ split ' ', $Config::Config{sig_name} }
		1437	= split ' ', $Config::Config{sig_num};
		1438
		1439	my @signum2name;
		1440	@signum2name[values %signame2num] = keys %signame2num;
		1441
		1442	*sig2num = sub($) {
		1443	$_[0] > 0 ? shift : $signame2num{+shift}
		1444	};
		1445	*sig2name = sub ($) {
		1446	$_[0] > 0 ? $signum2name[+shift] : shift
		1447	};
		1448	}
		1449	};
		1450	die if $@;
		1451	};
		1452
		1453	sub sig2num ($) { &$_sig_name_init; &sig2num }
		1454	sub sig2name($) { &$_sig_name_init; &sig2name }
		1455
1065	sub signal {	1456	sub signal {
1066	my (undef, %arg) = @_;	1457	eval q{ # poor man's autoloading {}
		1458	# probe for availability of Async::Interrupt
		1459	if (_have_async_interrupt) {
		1460	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1067		1461
1068	unless ($SIGPIPE_R) {	1462	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1069	if (AnyEvent::WIN32) {	1463	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1070	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1464
1071	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1072	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1073	} else {	1465	} else {
1074	pipe $SIGPIPE_R, $SIGPIPE_W;	1466	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1467
1075	require Fcntl;	1468	require Fcntl;
		1469
		1470	if (AnyEvent::WIN32) {
		1471	require AnyEvent::Util;
		1472
		1473	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1474	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1475	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1476	} else {
		1477	pipe $SIGPIPE_R, $SIGPIPE_W;
1076	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1478	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1077	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1479	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1480
		1481	# not strictly required, as $^F is normally 2, but let's make sure...
		1482	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1483	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1484	}
		1485
		1486	$SIGPIPE_R
		1487	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1488
		1489	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1078	}	1490	}
1079		1491
1080	$SIGPIPE_R	1492	*signal = sub {
1081	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1493	my (undef, %arg) = @_;
1082		1494
1083	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1084	}
1085
1086	my $signal = uc $arg{signal}	1495	my $signal = uc $arg{signal}
1087	or Carp::croak "required option 'signal' is missing";	1496	or Carp::croak "required option 'signal' is missing";
1088		1497
		1498	if ($HAVE_ASYNC_INTERRUPT) {
		1499	# async::interrupt
		1500
		1501	$signal = sig2num $signal;
1089	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1502	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1503
		1504	$SIG_ASY{$signal} ||= new Async::Interrupt
		1505	cb => sub { undef $SIG_EV{$signal} },
		1506	signal => $signal,
		1507	pipe => [$SIGPIPE_R->filenos],
		1508	pipe_autodrain => 0,
		1509	;
		1510
		1511	} else {
		1512	# pure perl
		1513
		1514	# AE::Util has been loaded in signal
		1515	$signal = sig2name $signal;
		1516	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1517
1090	$SIG{$signal} ||= sub {	1518	$SIG{$signal} ||= sub {
		1519	local $!;
1091	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1520	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1092	undef $SIG_EV{$signal};	1521	undef $SIG_EV{$signal};
		1522	};
		1523
		1524	# can't do signal processing without introducing races in pure perl,
		1525	# so limit the signal latency.
		1526	_sig_add;
		1527	}
		1528
		1529	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1530	};
		1531
		1532	*AnyEvent::Base::signal::DESTROY = sub {
		1533	my ($signal, $cb) = @{$_[0]};
		1534
		1535	_sig_del;
		1536
		1537	delete $SIG_CB{$signal}{$cb};
		1538
		1539	$HAVE_ASYNC_INTERRUPT
		1540	? delete $SIG_ASY{$signal}
		1541	: # delete doesn't work with older perls - they then
		1542	# print weird messages, or just unconditionally exit
		1543	# instead of getting the default action.
		1544	undef $SIG{$signal}
		1545	unless keys %{ $SIG_CB{$signal} };
		1546	};
1093	};	1547	};
1094		1548	die if $@;
1095	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1549	&signal
1096	}
1097
1098	sub AnyEvent::Base::Signal::DESTROY {
1099	my ($signal, $cb) = @{$_[0]};
1100
1101	delete $SIG_CB{$signal}{$cb};
1102
1103	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1104	}	1550	}
1105		1551
1106	# default implementation for ->child	1552	# default implementation for ->child
1107		1553
1108	our %PID_CB;	1554	our %PID_CB;
1109	our $CHLD_W;	1555	our $CHLD_W;
1110	our $CHLD_DELAY_W;	1556	our $CHLD_DELAY_W;
1111	our $PID_IDLE;
1112	our $WNOHANG;	1557	our $WNOHANG;
1113		1558
1114	sub _child_wait {	1559	sub _emit_childstatus($$) {
1115	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1560	my (undef, $rpid, $rstatus) = @_;
		1561
		1562	$_->($rpid, $rstatus)
1116	$_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),	1563	for values %{ $PID_CB{$rpid} || {} },
1117	(values %{ $PID_CB{0} || {} });	1564	values %{ $PID_CB{0} || {} };
1118	}
1119
1120	undef $PID_IDLE;
1121	}	1565	}
1122		1566
1123	sub _sigchld {	1567	sub _sigchld {
1124	# make sure we deliver these changes "synchronous" with the event loop.	1568	my $pid;
1125	$CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub {	1569
1126	undef $CHLD_DELAY_W;	1570	AnyEvent->_emit_childstatus ($pid, $?)
1127	&_child_wait;	1571	while ($pid = waitpid -1, $WNOHANG) > 0;
1128	});
1129	}	1572	}
1130		1573
1131	sub child {	1574	sub child {
1132	my (undef, %arg) = @_;	1575	my (undef, %arg) = @_;
1133		1576
1134	defined (my $pid = $arg{pid} + 0)	1577	defined (my $pid = $arg{pid} + 0)
1135	or Carp::croak "required option 'pid' is missing";	1578	or Carp::croak "required option 'pid' is missing";
1136		1579
1137	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1580	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1138		1581
1139	unless ($WNOHANG) {	1582	# WNOHANG is almost cetrainly 1 everywhere
		1583	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
		1584	? 1
1140	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;	1585	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1141	}
1142		1586
1143	unless ($CHLD_W) {	1587	unless ($CHLD_W) {
1144	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1588	$CHLD_W = AE::signal CHLD => \&_sigchld;
1145	# child could be a zombie already, so make at least one round	1589	# child could be a zombie already, so make at least one round
1146	&_sigchld;	1590	&_sigchld;
1147	}	1591	}
1148		1592
1149	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1593	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1150	}	1594	}
1151		1595
1152	sub AnyEvent::Base::Child::DESTROY {	1596	sub AnyEvent::Base::child::DESTROY {
1153	my ($pid, $cb) = @{$_[0]};	1597	my ($pid, $cb) = @{$_[0]};
1154		1598
1155	delete $PID_CB{$pid}{$cb};	1599	delete $PID_CB{$pid}{$cb};
1156	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1600	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1157		1601
1158	undef $CHLD_W unless keys %PID_CB;	1602	undef $CHLD_W unless keys %PID_CB;
1159	}	1603	}
1160		1604
		1605	# idle emulation is done by simply using a timer, regardless
		1606	# of whether the process is idle or not, and not letting
		1607	# the callback use more than 50% of the time.
		1608	sub idle {
		1609	my (undef, %arg) = @_;
		1610
		1611	my ($cb, $w, $rcb) = $arg{cb};
		1612
		1613	$rcb = sub {
		1614	if ($cb) {
		1615	$w = _time;
		1616	&$cb;
		1617	$w = _time - $w;
		1618
		1619	# never use more then 50% of the time for the idle watcher,
		1620	# within some limits
		1621	$w = 0.0001 if $w < 0.0001;
		1622	$w = 5 if $w > 5;
		1623
		1624	$w = AE::timer $w, 0, $rcb;
		1625	} else {
		1626	# clean up...
		1627	undef $w;
		1628	undef $rcb;
		1629	}
		1630	};
		1631
		1632	$w = AE::timer 0.05, 0, $rcb;
		1633
		1634	bless \\$cb, "AnyEvent::Base::idle"
		1635	}
		1636
		1637	sub AnyEvent::Base::idle::DESTROY {
		1638	undef $${$_[0]};
		1639	}
		1640
1161	package AnyEvent::CondVar;	1641	package AnyEvent::CondVar;
1162		1642
1163	our @ISA = AnyEvent::CondVar::Base::;	1643	our @ISA = AnyEvent::CondVar::Base::;
1164		1644
1165	package AnyEvent::CondVar::Base;	1645	package AnyEvent::CondVar::Base;
1166		1646
1167	use overload	1647	#use overload
1168	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1648	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1169	fallback => 1;	1649	# fallback => 1;
		1650
		1651	# save 300+ kilobytes by dirtily hardcoding overloading
		1652	${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
		1653	*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
		1654	*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
		1655	${'AnyEvent::CondVar::Base::()'} = 1; # fallback
		1656
		1657	our $WAITING;
1170		1658
1171	sub _send {	1659	sub _send {
1172	# nop	1660	# nop
1173	}	1661	}
1174		1662
…		…
1187	sub ready {	1675	sub ready {
1188	$_[0]{_ae_sent}	1676	$_[0]{_ae_sent}
1189	}	1677	}
1190		1678
1191	sub _wait {	1679	sub _wait {
		1680	$WAITING
		1681	and !$_[0]{_ae_sent}
		1682	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
		1683
		1684	local $WAITING = 1;
1192	AnyEvent->one_event while !$_[0]{_ae_sent};	1685	AnyEvent->one_event while !$_[0]{_ae_sent};
1193	}	1686	}
1194		1687
1195	sub recv {	1688	sub recv {
1196	$_[0]->_wait;	1689	$_[0]->_wait;
…		…
1198	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1691	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1199	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1692	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1200	}	1693	}
1201		1694
1202	sub cb {	1695	sub cb {
1203	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1696	my $cv = shift;
		1697
		1698	@_
		1699	and $cv->{_ae_cb} = shift
		1700	and $cv->{_ae_sent}
		1701	and (delete $cv->{_ae_cb})->($cv);
		1702
1204	$_[0]{_ae_cb}	1703	$cv->{_ae_cb}
1205	}	1704	}
1206		1705
1207	sub begin {	1706	sub begin {
1208	++$_[0]{_ae_counter};	1707	++$_[0]{_ae_counter};
1209	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1708	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1237	so on.	1736	so on.
1238		1737
1239	=head1 ENVIRONMENT VARIABLES	1738	=head1 ENVIRONMENT VARIABLES
1240		1739
1241	The following environment variables are used by this module or its	1740	The following environment variables are used by this module or its
1242	submodules:	1741	submodules.
		1742
		1743	Note that AnyEvent will remove I<all> environment variables starting with
		1744	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1745	enabled.
1243		1746
1244	=over 4	1747	=over 4
1245		1748
1246	=item C<PERL_ANYEVENT_VERBOSE>	1749	=item C<PERL_ANYEVENT_VERBOSE>
1247		1750
…		…
1254	C<PERL_ANYEVENT_MODEL>.	1757	C<PERL_ANYEVENT_MODEL>.
1255		1758
1256	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1759	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1257	model it chooses.	1760	model it chooses.
1258		1761
		1762	When set to C<8> or higher, then AnyEvent will report extra information on
		1763	which optional modules it loads and how it implements certain features.
		1764
1259	=item C<PERL_ANYEVENT_STRICT>	1765	=item C<PERL_ANYEVENT_STRICT>
1260		1766
1261	AnyEvent does not do much argument checking by default, as thorough	1767	AnyEvent does not do much argument checking by default, as thorough
1262	argument checking is very costly. Setting this variable to a true value	1768	argument checking is very costly. Setting this variable to a true value
1263	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1769	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1264	check the arguments passed to most method calls. If it finds any problems	1770	check the arguments passed to most method calls. If it finds any problems,
1265	it will croak.	1771	it will croak.
1266		1772
1267	In other words, enables "strict" mode.	1773	In other words, enables "strict" mode.
1268		1774
1269	Unlike C<use strict>, it is definitely recommended ot keep it off in	1775	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1270	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1776	>>, it is definitely recommended to keep it off in production. Keeping
1271	developing programs can be very useful, however.	1777	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
		1778	can be very useful, however.
1272		1779
1273	=item C<PERL_ANYEVENT_MODEL>	1780	=item C<PERL_ANYEVENT_MODEL>
1274		1781
1275	This can be used to specify the event model to be used by AnyEvent, before	1782	This can be used to specify the event model to be used by AnyEvent, before
1276	auto detection and -probing kicks in. It must be a string consisting	1783	auto detection and -probing kicks in. It must be a string consisting
…		…
1319		1826
1320	=item C<PERL_ANYEVENT_MAX_FORKS>	1827	=item C<PERL_ANYEVENT_MAX_FORKS>
1321		1828
1322	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1829	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1323	will create in parallel.	1830	will create in parallel.
		1831
		1832	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1833
		1834	The default value for the C<max_outstanding> parameter for the default DNS
		1835	resolver - this is the maximum number of parallel DNS requests that are
		1836	sent to the DNS server.
		1837
		1838	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1839
		1840	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1841	configuration) in the default resolver. When set to the empty string, no
		1842	default config will be used.
		1843
		1844	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1845
		1846	When neither C<ca_file> nor C<ca_path> was specified during
		1847	L<AnyEvent::TLS> context creation, and either of these environment
		1848	variables exist, they will be used to specify CA certificate locations
		1849	instead of a system-dependent default.
		1850
		1851	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
		1852
		1853	When these are set to C<1>, then the respective modules are not
		1854	loaded. Mostly good for testing AnyEvent itself.
1324		1855
1325	=back	1856	=back
1326		1857
1327	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1858	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1328		1859
…		…
1386	warn "read: $input\n"; # output what has been read	1917	warn "read: $input\n"; # output what has been read
1387	$cv->send if $input =~ /^q/i; # quit program if /^q/i	1918	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1388	},	1919	},
1389	);	1920	);
1390		1921
1391	my $time_watcher; # can only be used once
1392
1393	sub new_timer {
1394	$timer = AnyEvent->timer (after => 1, cb => sub {	1922	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1395	warn "timeout\n"; # print 'timeout' about every second	1923	warn "timeout\n"; # print 'timeout' at most every second
1396	&new_timer; # and restart the time
1397	});	1924	});
1398	}
1399
1400	new_timer; # create first timer
1401		1925
1402	$cv->recv; # wait until user enters /^q/i	1926	$cv->recv; # wait until user enters /^q/i
1403		1927
1404	=head1 REAL-WORLD EXAMPLE	1928	=head1 REAL-WORLD EXAMPLE
1405		1929
…		…
1536	through AnyEvent. The benchmark creates a lot of timers (with a zero	2060	through AnyEvent. The benchmark creates a lot of timers (with a zero
1537	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2061	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1538	which it is), lets them fire exactly once and destroys them again.	2062	which it is), lets them fire exactly once and destroys them again.
1539		2063
1540	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2064	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1541	distribution.	2065	distribution. It uses the L<AE> interface, which makes a real difference
		2066	for the EV and Perl backends only.
1542		2067
1543	=head3 Explanation of the columns	2068	=head3 Explanation of the columns
1544		2069
1545	I<watcher> is the number of event watchers created/destroyed. Since	2070	I<watcher> is the number of event watchers created/destroyed. Since
1546	different event models feature vastly different performances, each event	2071	different event models feature vastly different performances, each event
…		…
1567	watcher.	2092	watcher.
1568		2093
1569	=head3 Results	2094	=head3 Results
1570		2095
1571	name watchers bytes create invoke destroy comment	2096	name watchers bytes create invoke destroy comment
1572	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2097	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1573	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2098	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1574	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2099	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1575	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2100	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1576	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2101	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1577	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2102	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
		2103	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
		2104	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1578	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2105	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1579	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2106	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1580	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2107	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1581	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2108	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1582		2109
1583	=head3 Discussion	2110	=head3 Discussion
1584		2111
1585	The benchmark does I<not> measure scalability of the event loop very	2112	The benchmark does I<not> measure scalability of the event loop very
1586	well. For example, a select-based event loop (such as the pure perl one)	2113	well. For example, a select-based event loop (such as the pure perl one)
…		…
1598	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2125	benchmark machine, handling an event takes roughly 1600 CPU cycles with
1599	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2126	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1600	cycles with POE.	2127	cycles with POE.
1601		2128
1602	C<EV> is the sole leader regarding speed and memory use, which are both	2129	C<EV> is the sole leader regarding speed and memory use, which are both
1603	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2130	maximal/minimal, respectively. When using the L<AE> API there is zero
		2131	overhead (when going through the AnyEvent API create is about 5-6 times
		2132	slower, with other times being equal, so still uses far less memory than
1604	far less memory than any other event loop and is still faster than Event	2133	any other event loop and is still faster than Event natively).
1605	natively.
1606		2134
1607	The pure perl implementation is hit in a few sweet spots (both the	2135	The pure perl implementation is hit in a few sweet spots (both the
1608	constant timeout and the use of a single fd hit optimisations in the perl	2136	constant timeout and the use of a single fd hit optimisations in the perl
1609	interpreter and the backend itself). Nevertheless this shows that it	2137	interpreter and the backend itself). Nevertheless this shows that it
1610	adds very little overhead in itself. Like any select-based backend its	2138	adds very little overhead in itself. Like any select-based backend its
1611	performance becomes really bad with lots of file descriptors (and few of	2139	performance becomes really bad with lots of file descriptors (and few of
1612	them active), of course, but this was not subject of this benchmark.	2140	them active), of course, but this was not subject of this benchmark.
1613		2141
1614	The C<Event> module has a relatively high setup and callback invocation	2142	The C<Event> module has a relatively high setup and callback invocation
1615	cost, but overall scores in on the third place.	2143	cost, but overall scores in on the third place.
		2144
		2145	C<IO::Async> performs admirably well, about on par with C<Event>, even
		2146	when using its pure perl backend.
1616		2147
1617	C<Glib>'s memory usage is quite a bit higher, but it features a	2148	C<Glib>'s memory usage is quite a bit higher, but it features a
1618	faster callback invocation and overall ends up in the same class as	2149	faster callback invocation and overall ends up in the same class as
1619	C<Event>. However, Glib scales extremely badly, doubling the number of	2150	C<Event>. However, Glib scales extremely badly, doubling the number of
1620	watchers increases the processing time by more than a factor of four,	2151	watchers increases the processing time by more than a factor of four,
…		…
1681	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2212	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1682	(1%) are active. This mirrors the activity of large servers with many	2213	(1%) are active. This mirrors the activity of large servers with many
1683	connections, most of which are idle at any one point in time.	2214	connections, most of which are idle at any one point in time.
1684		2215
1685	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2216	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1686	distribution.	2217	distribution. It uses the L<AE> interface, which makes a real difference
		2218	for the EV and Perl backends only.
1687		2219
1688	=head3 Explanation of the columns	2220	=head3 Explanation of the columns
1689		2221
1690	I<sockets> is the number of sockets, and twice the number of "servers" (as	2222	I<sockets> is the number of sockets, and twice the number of "servers" (as
1691	each server has a read and write socket end).	2223	each server has a read and write socket end).
…		…
1698	it to another server. This includes deleting the old timeout and creating	2230	it to another server. This includes deleting the old timeout and creating
1699	a new one that moves the timeout into the future.	2231	a new one that moves the timeout into the future.
1700		2232
1701	=head3 Results	2233	=head3 Results
1702		2234
1703	name sockets create request	2235	name sockets create request
1704	EV 20000 69.01 11.16	2236	EV 20000 62.66 7.99
1705	Perl 20000 73.32 35.87	2237	Perl 20000 68.32 32.64
1706	Event 20000 212.62 257.32	2238	IOAsync 20000 174.06 101.15 epoll
1707	Glib 20000 651.16 1896.30	2239	IOAsync 20000 174.67 610.84 poll
		2240	Event 20000 202.69 242.91
		2241	Glib 20000 557.01 1689.52
1708	POE 20000 349.67 12317.24 uses POE::Loop::Event	2242	POE 20000 341.54 12086.32 uses POE::Loop::Event
1709		2243
1710	=head3 Discussion	2244	=head3 Discussion
1711		2245
1712	This benchmark I<does> measure scalability and overall performance of the	2246	This benchmark I<does> measure scalability and overall performance of the
1713	particular event loop.	2247	particular event loop.
…		…
1715	EV is again fastest. Since it is using epoll on my system, the setup time	2249	EV is again fastest. Since it is using epoll on my system, the setup time
1716	is relatively high, though.	2250	is relatively high, though.
1717		2251
1718	Perl surprisingly comes second. It is much faster than the C-based event	2252	Perl surprisingly comes second. It is much faster than the C-based event
1719	loops Event and Glib.	2253	loops Event and Glib.
		2254
		2255	IO::Async performs very well when using its epoll backend, and still quite
		2256	good compared to Glib when using its pure perl backend.
1720		2257
1721	Event suffers from high setup time as well (look at its code and you will	2258	Event suffers from high setup time as well (look at its code and you will
1722	understand why). Callback invocation also has a high overhead compared to	2259	understand why). Callback invocation also has a high overhead compared to
1723	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	2260	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1724	uses select or poll in basically all documented configurations.	2261	uses select or poll in basically all documented configurations.
…		…
1787	=item * C-based event loops perform very well with small number of	2324	=item * C-based event loops perform very well with small number of
1788	watchers, as the management overhead dominates.	2325	watchers, as the management overhead dominates.
1789		2326
1790	=back	2327	=back
1791		2328
		2329	=head2 THE IO::Lambda BENCHMARK
		2330
		2331	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2332	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2333	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2334	shouldn't come as a surprise to anybody). As such, the benchmark is
		2335	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2336	very optimal. But how would AnyEvent compare when used without the extra
		2337	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2338
		2339	The benchmark itself creates an echo-server, and then, for 500 times,
		2340	connects to the echo server, sends a line, waits for the reply, and then
		2341	creates the next connection. This is a rather bad benchmark, as it doesn't
		2342	test the efficiency of the framework or much non-blocking I/O, but it is a
		2343	benchmark nevertheless.
		2344
		2345	name runtime
		2346	Lambda/select 0.330 sec
		2347	+ optimized 0.122 sec
		2348	Lambda/AnyEvent 0.327 sec
		2349	+ optimized 0.138 sec
		2350	Raw sockets/select 0.077 sec
		2351	POE/select, components 0.662 sec
		2352	POE/select, raw sockets 0.226 sec
		2353	POE/select, optimized 0.404 sec
		2354
		2355	AnyEvent/select/nb 0.085 sec
		2356	AnyEvent/EV/nb 0.068 sec
		2357	+state machine 0.134 sec
		2358
		2359	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2360	benchmarks actually make blocking connects and use 100% blocking I/O,
		2361	defeating the purpose of an event-based solution. All of the newly
		2362	written AnyEvent benchmarks use 100% non-blocking connects (using
		2363	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2364	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2365	generally require a lot more bookkeeping and event handling than blocking
		2366	connects (which involve a single syscall only).
		2367
		2368	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2369	offers similar expressive power as POE and IO::Lambda, using conventional
		2370	Perl syntax. This means that both the echo server and the client are 100%
		2371	non-blocking, further placing it at a disadvantage.
		2372
		2373	As you can see, the AnyEvent + EV combination even beats the
		2374	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2375	backend easily beats IO::Lambda and POE.
		2376
		2377	And even the 100% non-blocking version written using the high-level (and
		2378	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
		2379	higher level ("unoptimised") abstractions by a large margin, even though
		2380	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
		2381
		2382	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2383	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2384	part of the IO::Lambda distribution and were used without any changes.
		2385
1792		2386
1793	=head1 SIGNALS	2387	=head1 SIGNALS
1794		2388
1795	AnyEvent currently installs handlers for these signals:	2389	AnyEvent currently installs handlers for these signals:
1796		2390
…		…
1799	=item SIGCHLD	2393	=item SIGCHLD
1800		2394
1801	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2395	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1802	emulation for event loops that do not support them natively. Also, some	2396	emulation for event loops that do not support them natively. Also, some
1803	event loops install a similar handler.	2397	event loops install a similar handler.
		2398
		2399	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2400	AnyEvent will reset it to default, to avoid losing child exit statuses.
1804		2401
1805	=item SIGPIPE	2402	=item SIGPIPE
1806		2403
1807	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2404	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1808	when AnyEvent gets loaded.	2405	when AnyEvent gets loaded.
…		…
1820		2417
1821	=back	2418	=back
1822		2419
1823	=cut	2420	=cut
1824		2421
		2422	undef $SIG{CHLD}
		2423	if $SIG{CHLD} eq 'IGNORE';
		2424
1825	$SIG{PIPE} = sub { }	2425	$SIG{PIPE} = sub { }
1826	unless defined $SIG{PIPE};	2426	unless defined $SIG{PIPE};
		2427
		2428	=head1 RECOMMENDED/OPTIONAL MODULES
		2429
		2430	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
		2431	it's built-in modules) are required to use it.
		2432
		2433	That does not mean that AnyEvent won't take advantage of some additional
		2434	modules if they are installed.
		2435
		2436	This section epxlains which additional modules will be used, and how they
		2437	affect AnyEvent's operetion.
		2438
		2439	=over 4
		2440
		2441	=item L<Async::Interrupt>
		2442
		2443	This slightly arcane module is used to implement fast signal handling: To
		2444	my knowledge, there is no way to do completely race-free and quick
		2445	signal handling in pure perl. To ensure that signals still get
		2446	delivered, AnyEvent will start an interval timer to wake up perl (and
		2447	catch the signals) with some delay (default is 10 seconds, look for
		2448	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
		2449
		2450	If this module is available, then it will be used to implement signal
		2451	catching, which means that signals will not be delayed, and the event loop
		2452	will not be interrupted regularly, which is more efficient (And good for
		2453	battery life on laptops).
		2454
		2455	This affects not just the pure-perl event loop, but also other event loops
		2456	that have no signal handling on their own (e.g. Glib, Tk, Qt).
		2457
		2458	Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
		2459	and either employ their own workarounds (POE) or use AnyEvent's workaround
		2460	(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
		2461	does nothing for those backends.
		2462
		2463	=item L<EV>
		2464
		2465	This module isn't really "optional", as it is simply one of the backend
		2466	event loops that AnyEvent can use. However, it is simply the best event
		2467	loop available in terms of features, speed and stability: It supports
		2468	the AnyEvent API optimally, implements all the watcher types in XS, does
		2469	automatic timer adjustments even when no monotonic clock is available,
		2470	can take avdantage of advanced kernel interfaces such as C<epoll> and
		2471	C<kqueue>, and is the fastest backend I<by far>. You can even embed
		2472	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
		2473
		2474	=item L<Guard>
		2475
		2476	The guard module, when used, will be used to implement
		2477	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
		2478	lot less memory), but otherwise doesn't affect guard operation much. It is
		2479	purely used for performance.
		2480
		2481	=item L<JSON> and L<JSON::XS>
		2482
		2483	One of these modules is required when you want to read or write JSON data
		2484	via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
		2485	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
		2486
		2487	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
		2488	installed.
		2489
		2490	=item L<Net::SSLeay>
		2491
		2492	Implementing TLS/SSL in Perl is certainly interesting, but not very
		2493	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
		2494	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
		2495
		2496	=item L<Time::HiRes>
		2497
		2498	This module is part of perl since release 5.008. It will be used when the
		2499	chosen event library does not come with a timing source on it's own. The
		2500	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
		2501	try to use a monotonic clock for timing stability.
		2502
		2503	=back
1827		2504
1828		2505
1829	=head1 FORK	2506	=head1 FORK
1830		2507
1831	Most event libraries are not fork-safe. The ones who are usually are	2508	Most event libraries are not fork-safe. The ones who are usually are
1832	because they rely on inefficient but fork-safe C<select> or C<poll>	2509	because they rely on inefficient but fork-safe C<select> or C<poll>
1833	calls. Only L<EV> is fully fork-aware.	2510	calls. Only L<EV> is fully fork-aware.
1834		2511
1835	If you have to fork, you must either do so I<before> creating your first	2512	If you have to fork, you must either do so I<before> creating your first
1836	watcher OR you must not use AnyEvent at all in the child.	2513	watcher OR you must not use AnyEvent at all in the child OR you must do
		2514	something completely out of the scope of AnyEvent.
1837		2515
1838		2516
1839	=head1 SECURITY CONSIDERATIONS	2517	=head1 SECURITY CONSIDERATIONS
1840		2518
1841	AnyEvent can be forced to load any event model via	2519	AnyEvent can be forced to load any event model via
…		…
1853	use AnyEvent;	2531	use AnyEvent;
1854		2532
1855	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2533	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1856	be used to probe what backend is used and gain other information (which is	2534	be used to probe what backend is used and gain other information (which is
1857	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2535	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1858	$ENV{PERL_ANYEGENT_STRICT}.	2536	$ENV{PERL_ANYEVENT_STRICT}.
		2537
		2538	Note that AnyEvent will remove I<all> environment variables starting with
		2539	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2540	enabled.
1859		2541
1860		2542
1861	=head1 BUGS	2543	=head1 BUGS
1862		2544
1863	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2545	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
…		…
1875	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2557	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1876		2558
1877	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2559	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1878	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2560	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1879	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2561	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1880	L<AnyEvent::Impl::POE>.	2562	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
1881		2563
1882	Non-blocking file handles, sockets, TCP clients and	2564	Non-blocking file handles, sockets, TCP clients and
1883	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2565	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1884		2566
1885	Asynchronous DNS: L<AnyEvent::DNS>.	2567	Asynchronous DNS: L<AnyEvent::DNS>.
1886		2568
1887	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2569	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2570	L<Coro::Event>,
1888		2571
1889	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2572	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2573	L<AnyEvent::HTTP>.
1890		2574
1891		2575
1892	=head1 AUTHOR	2576	=head1 AUTHOR
1893		2577
1894	Marc Lehmann <schmorp@schmorp.de>	2578	Marc Lehmann <schmorp@schmorp.de>

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