[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.180 by root, Sat Sep 6 07:00:45 2008 UTC vs.
Revision 1.238 by root, Thu Jul 16 03:48:33 2009 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - provide framework for multiple event loops
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported
		6	event loops.
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 $condvar gets ->send
29	# use a condvar in callback mode:	37	# use a condvar in callback mode:
137	These watchers are normal Perl objects with normal Perl lifetime. After	145	These watchers are normal Perl objects with normal Perl lifetime. After
138	creating a watcher it will immediately "watch" for events and invoke the	146	creating a watcher it will immediately "watch" for events and invoke the
139	callback when the event occurs (of course, only when the event model	147	callback when the event occurs (of course, only when the event model
140	is in control).	148	is in control).
141		149
		150	Note that B<callbacks must not permanently change global variables>
		151	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
		152	callbacks must not C<die> >>. The former is good programming practise in
		153	Perl and the latter stems from the fact that exception handling differs
		154	widely between event loops.
		155
142	To disable the watcher you have to destroy it (e.g. by setting the	156	To disable the watcher you have to destroy it (e.g. by setting the
143	variable you store it in to C<undef> or otherwise deleting all references	157	variable you store it in to C<undef> or otherwise deleting all references
144	to it).	158	to it).
145		159
146	All watchers are created by calling a method on the C<AnyEvent> class.	160	All watchers are created by calling a method on the C<AnyEvent> class.
…		…
162	=head2 I/O WATCHERS	176	=head2 I/O WATCHERS
163		177
164	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
165	with the following mandatory key-value pairs as arguments:	179	with the following mandatory key-value pairs as arguments:
166		180
167	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events	181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
168	(AnyEvent might or might not keep a reference to this file handle). C<poll>	182	for events (AnyEvent might or might not keep a reference to this file
		183	handle). Note that only file handles pointing to things for which
		184	non-blocking operation makes sense are allowed. This includes sockets,
		185	most character devices, pipes, fifos and so on, but not for example files
		186	or block devices.
		187
169	must be a string that is either C<r> or C<w>, which creates a watcher	188	C<poll> must be a string that is either C<r> or C<w>, which creates a
170	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the	189	watcher waiting for "r"eadable or "w"ritable events, respectively.
		190
171	callback to invoke each time the file handle becomes ready.	191	C<cb> is the callback to invoke each time the file handle becomes ready.
172		192
173	Although the callback might get passed parameters, their value and	193	Although the callback might get passed parameters, their value and
174	presence is undefined and you cannot rely on them. Portable AnyEvent	194	presence is undefined and you cannot rely on them. Portable AnyEvent
175	callbacks cannot use arguments passed to I/O watcher callbacks.	195	callbacks cannot use arguments passed to I/O watcher callbacks.
176		196
…		…
308	In either case, if you care (and in most cases, you don't), then you	328	In either case, if you care (and in most cases, you don't), then you
309	can get whatever behaviour you want with any event loop, by taking the	329	can get whatever behaviour you want with any event loop, by taking the
310	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	330	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
311	account.	331	account.
312		332
		333	=item AnyEvent->now_update
		334
		335	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache
		336	the current time for each loop iteration (see the discussion of L<<
		337	AnyEvent->now >>, above).
		338
		339	When a callback runs for a long time (or when the process sleeps), then
		340	this "current" time will differ substantially from the real time, which
		341	might affect timers and time-outs.
		342
		343	When this is the case, you can call this method, which will update the
		344	event loop's idea of "current time".
		345
		346	Note that updating the time I<might> cause some events to be handled.
		347
313	=back	348	=back
314		349
315	=head2 SIGNAL WATCHERS	350	=head2 SIGNAL WATCHERS
316		351
317	You can watch for signals using a signal watcher, C<signal> is the signal	352	You can watch for signals using a signal watcher, C<signal> is the signal
…		…
340	=head2 CHILD PROCESS WATCHERS	375	=head2 CHILD PROCESS WATCHERS
341		376
342	You can also watch on a child process exit and catch its exit status.	377	You can also watch on a child process exit and catch its exit status.
343		378
344	The child process is specified by the C<pid> argument (if set to C<0>, it	379	The child process is specified by the C<pid> argument (if set to C<0>, it
345	watches for any child process exit). The watcher will trigger as often	380	watches for any child process exit). The watcher will triggered only when
346	as status change for the child are received. This works by installing a	381	the child process has finished and an exit status is available, not on
347	signal handler for C<SIGCHLD>. The callback will be called with the pid	382	any trace events (stopped/continued).
348	and exit status (as returned by waitpid), so unlike other watcher types,	383
349	you I<can> rely on child watcher callback arguments.	384	The callback will be called with the pid and exit status (as returned by
		385	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		386	callback arguments.
		387
		388	This watcher type works by installing a signal handler for C<SIGCHLD>,
		389	and since it cannot be shared, nothing else should use SIGCHLD or reap
		390	random child processes (waiting for specific child processes, e.g. inside
		391	C<system>, is just fine).
350		392
351	There is a slight catch to child watchers, however: you usually start them	393	There is a slight catch to child watchers, however: you usually start them
352	I<after> the child process was created, and this means the process could	394	I<after> the child process was created, and this means the process could
353	have exited already (and no SIGCHLD will be sent anymore).	395	have exited already (and no SIGCHLD will be sent anymore).
354		396
355	Not all event models handle this correctly (POE doesn't), but even for	397	Not all event models handle this correctly (neither POE nor IO::Async do,
		398	see their AnyEvent::Impl manpages for details), but even for event models
356	event models that I<do> handle this correctly, they usually need to be	399	that I<do> handle this correctly, they usually need to be loaded before
357	loaded before the process exits (i.e. before you fork in the first place).	400	the process exits (i.e. before you fork in the first place). AnyEvent's
		401	pure perl event loop handles all cases correctly regardless of when you
		402	start the watcher.
358		403
359	This means you cannot create a child watcher as the very first thing in an	404	This means you cannot create a child watcher as the very first
360	AnyEvent program, you I<have> to create at least one watcher before you	405	thing in an AnyEvent program, you I<have> to create at least one
361	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	406	watcher before you C<fork> the child (alternatively, you can call
		407	C<AnyEvent::detect>).
362		408
363	Example: fork a process and wait for it	409	Example: fork a process and wait for it
364		410
365	my $done = AnyEvent->condvar;	411	my $done = AnyEvent->condvar;
366		412
…		…
376	);	422	);
377		423
378	# do something else, then wait for process exit	424	# do something else, then wait for process exit
379	$done->recv;	425	$done->recv;
380		426
		427	=head2 IDLE WATCHERS
		428
		429	Sometimes there is a need to do something, but it is not so important
		430	to do it instantly, but only when there is nothing better to do. This
		431	"nothing better to do" is usually defined to be "no other events need
		432	attention by the event loop".
		433
		434	Idle watchers ideally get invoked when the event loop has nothing
		435	better to do, just before it would block the process to wait for new
		436	events. Instead of blocking, the idle watcher is invoked.
		437
		438	Most event loops unfortunately do not really support idle watchers (only
		439	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
		440	will simply call the callback "from time to time".
		441
		442	Example: read lines from STDIN, but only process them when the
		443	program is otherwise idle:
		444
		445	my @lines; # read data
		446	my $idle_w;
		447	my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		448	push @lines, scalar <STDIN>;
		449
		450	# start an idle watcher, if not already done
		451	$idle_w \|\|= AnyEvent->idle (cb => sub {
		452	# handle only one line, when there are lines left
		453	if (my $line = shift @lines) {
		454	print "handled when idle: $line";
		455	} else {
		456	# otherwise disable the idle watcher again
		457	undef $idle_w;
		458	}
		459	});
		460	});
		461
381	=head2 CONDITION VARIABLES	462	=head2 CONDITION VARIABLES
382		463
383	If you are familiar with some event loops you will know that all of them	464	If you are familiar with some event loops you will know that all of them
384	require you to run some blocking "loop", "run" or similar function that	465	require you to run some blocking "loop", "run" or similar function that
385	will actively watch for new events and call your callbacks.	466	will actively watch for new events and call your callbacks.
…		…
518		599
519	=item $cv->begin ([group callback])	600	=item $cv->begin ([group callback])
520		601
521	=item $cv->end	602	=item $cv->end
522		603
523	These two methods are EXPERIMENTAL and MIGHT CHANGE.
524
525	These two methods can be used to combine many transactions/events into	604	These two methods can be used to combine many transactions/events into
526	one. For example, a function that pings many hosts in parallel might want	605	one. For example, a function that pings many hosts in parallel might want
527	to use a condition variable for the whole process.	606	to use a condition variable for the whole process.
528		607
529	Every call to C<< ->begin >> will increment a counter, and every call to	608	Every call to C<< ->begin >> will increment a counter, and every call to
530	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	609	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
531	>>, the (last) callback passed to C<begin> will be executed. That callback	610	>>, the (last) callback passed to C<begin> will be executed. That callback
532	is I<supposed> to call C<< ->send >>, but that is not required. If no	611	is I<supposed> to call C<< ->send >>, but that is not required. If no
533	callback was set, C<send> will be called without any arguments.	612	callback was set, C<send> will be called without any arguments.
534		613
535	Let's clarify this with the ping example:	614	You can think of C<< $cv->send >> giving you an OR condition (one call
		615	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
		616	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
		617
		618	Let's start with a simple example: you have two I/O watchers (for example,
		619	STDOUT and STDERR for a program), and you want to wait for both streams to
		620	close before activating a condvar:
		621
		622	my $cv = AnyEvent->condvar;
		623
		624	$cv->begin; # first watcher
		625	my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
		626	defined sysread $fh1, my $buf, 4096
		627	or $cv->end;
		628	});
		629
		630	$cv->begin; # second watcher
		631	my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
		632	defined sysread $fh2, my $buf, 4096
		633	or $cv->end;
		634	});
		635
		636	$cv->recv;
		637
		638	This works because for every event source (EOF on file handle), there is
		639	one call to C<begin>, so the condvar waits for all calls to C<end> before
		640	sending.
		641
		642	The ping example mentioned above is slightly more complicated, as the
		643	there are results to be passwd back, and the number of tasks that are
		644	begung can potentially be zero:
536		645
537	my $cv = AnyEvent->condvar;	646	my $cv = AnyEvent->condvar;
538		647
539	my %result;	648	my %result;
540	$cv->begin (sub { $cv->send (\%result) });	649	$cv->begin (sub { $cv->send (\%result) });
…		…
560	loop, which serves two important purposes: first, it sets the callback	669	loop, which serves two important purposes: first, it sets the callback
561	to be called once the counter reaches C<0>, and second, it ensures that	670	to be called once the counter reaches C<0>, and second, it ensures that
562	C<send> is called even when C<no> hosts are being pinged (the loop	671	C<send> is called even when C<no> hosts are being pinged (the loop
563	doesn't execute once).	672	doesn't execute once).
564		673
565	This is the general pattern when you "fan out" into multiple subrequests:	674	This is the general pattern when you "fan out" into multiple (but
566	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	675	potentially none) subrequests: use an outer C<begin>/C<end> pair to set
567	is called at least once, and then, for each subrequest you start, call	676	the callback and ensure C<end> is called at least once, and then, for each
568	C<begin> and for each subrequest you finish, call C<end>.	677	subrequest you start, call C<begin> and for each subrequest you finish,
		678	call C<end>.
569		679
570	=back	680	=back
571		681
572	=head3 METHODS FOR CONSUMERS	682	=head3 METHODS FOR CONSUMERS
573		683
…		…
630	variable itself. Calling C<recv> inside the callback or at any later time	740	variable itself. Calling C<recv> inside the callback or at any later time
631	is guaranteed not to block.	741	is guaranteed not to block.
632		742
633	=back	743	=back
634		744
		745	=head1 SUPPORTED EVENT LOOPS/BACKENDS
		746
		747	The available backend classes are (every class has its own manpage):
		748
		749	=over 4
		750
		751	=item Backends that are autoprobed when no other event loop can be found.
		752
		753	EV is the preferred backend when no other event loop seems to be in
		754	use. If EV is not installed, then AnyEvent will try Event, and, failing
		755	that, will fall back to its own pure-perl implementation, which is
		756	available everywhere as it comes with AnyEvent itself.
		757
		758	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
		759	AnyEvent::Impl::Event based on Event, very stable, few glitches.
		760	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
		761
		762	=item Backends that are transparently being picked up when they are used.
		763
		764	These will be used when they are currently loaded when the first watcher
		765	is created, in which case it is assumed that the application is using
		766	them. This means that AnyEvent will automatically pick the right backend
		767	when the main program loads an event module before anything starts to
		768	create watchers. Nothing special needs to be done by the main program.
		769
		770	AnyEvent::Impl::Glib based on Glib, slow but very stable.
		771	AnyEvent::Impl::Tk based on Tk, very broken.
		772	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
		773	AnyEvent::Impl::POE based on POE, very slow, some limitations.
		774
		775	=item Backends with special needs.
		776
		777	Qt requires the Qt::Application to be instantiated first, but will
		778	otherwise be picked up automatically. As long as the main program
		779	instantiates the application before any AnyEvent watchers are created,
		780	everything should just work.
		781
		782	AnyEvent::Impl::Qt based on Qt.
		783
		784	Support for IO::Async can only be partial, as it is too broken and
		785	architecturally limited to even support the AnyEvent API. It also
		786	is the only event loop that needs the loop to be set explicitly, so
		787	it can only be used by a main program knowing about AnyEvent. See
		788	L<AnyEvent::Impl::Async> for the gory details.
		789
		790	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
		791
		792	=item Event loops that are indirectly supported via other backends.
		793
		794	Some event loops can be supported via other modules:
		795
		796	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
		797
		798	B<WxWidgets> has no support for watching file handles. However, you can
		799	use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
		800	polls 20 times per second, which was considered to be too horrible to even
		801	consider for AnyEvent.
		802
		803	B<Prima> is not supported as nobody seems to be using it, but it has a POE
		804	backend, so it can be supported through POE.
		805
		806	AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
		807	load L<POE> when detecting them, in the hope that POE will pick them up,
		808	in which case everything will be automatic.
		809
		810	=back
		811
635	=head1 GLOBAL VARIABLES AND FUNCTIONS	812	=head1 GLOBAL VARIABLES AND FUNCTIONS
636		813
		814	These are not normally required to use AnyEvent, but can be useful to
		815	write AnyEvent extension modules.
		816
637	=over 4	817	=over 4
638		818
639	=item $AnyEvent::MODEL	819	=item $AnyEvent::MODEL
640		820
641	Contains C<undef> until the first watcher is being created. Then it	821	Contains C<undef> until the first watcher is being created, before the
		822	backend has been autodetected.
		823
642	contains the event model that is being used, which is the name of the	824	Afterwards it contains the event model that is being used, which is the
643	Perl class implementing the model. This class is usually one of the	825	name of the Perl class implementing the model. This class is usually one
644	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	826	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
645	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	827	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
646		828	will be C<urxvt::anyevent>).
647	The known classes so far are:
648
649	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
650	AnyEvent::Impl::Event based on Event, second best choice.
651	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
652	AnyEvent::Impl::Glib based on Glib, third-best choice.
653	AnyEvent::Impl::Tk based on Tk, very bad choice.
654	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
655	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
656	AnyEvent::Impl::POE based on POE, not generic enough for full support.
657
658	There is no support for WxWidgets, as WxWidgets has no support for
659	watching file handles. However, you can use WxWidgets through the
660	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
661	second, which was considered to be too horrible to even consider for
662	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
663	it's adaptor.
664
665	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
666	autodetecting them.
667		829
668	=item AnyEvent::detect	830	=item AnyEvent::detect
669		831
670	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	832	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
671	if necessary. You should only call this function right before you would	833	if necessary. You should only call this function right before you would
672	have created an AnyEvent watcher anyway, that is, as late as possible at	834	have created an AnyEvent watcher anyway, that is, as late as possible at
673	runtime.	835	runtime, and not e.g. while initialising of your module.
		836
		837	If you need to do some initialisation before AnyEvent watchers are
		838	created, use C<post_detect>.
674		839
675	=item $guard = AnyEvent::post_detect { BLOCK }	840	=item $guard = AnyEvent::post_detect { BLOCK }
676		841
677	Arranges for the code block to be executed as soon as the event model is	842	Arranges for the code block to be executed as soon as the event model is
678	autodetected (or immediately if this has already happened).	843	autodetected (or immediately if this has already happened).
		844
		845	The block will be executed I<after> the actual backend has been detected
		846	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
		847	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
		848	other initialisations - see the sources of L<AnyEvent::Strict> or
		849	L<AnyEvent::AIO> to see how this is used.
		850
		851	The most common usage is to create some global watchers, without forcing
		852	event module detection too early, for example, L<AnyEvent::AIO> creates
		853	and installs the global L<IO::AIO> watcher in a C<post_detect> block to
		854	avoid autodetecting the event module at load time.
679		855
680	If called in scalar or list context, then it creates and returns an object	856	If called in scalar or list context, then it creates and returns an object
681	that automatically removes the callback again when it is destroyed. See	857	that automatically removes the callback again when it is destroyed. See
682	L<Coro::BDB> for a case where this is useful.	858	L<Coro::BDB> for a case where this is useful.
683		859
…		…
686	If there are any code references in this array (you can C<push> to it	862	If there are any code references in this array (you can C<push> to it
687	before or after loading AnyEvent), then they will called directly after	863	before or after loading AnyEvent), then they will called directly after
688	the event loop has been chosen.	864	the event loop has been chosen.
689		865
690	You should check C<$AnyEvent::MODEL> before adding to this array, though:	866	You should check C<$AnyEvent::MODEL> before adding to this array, though:
691	if it contains a true value then the event loop has already been detected,	867	if it is defined then the event loop has already been detected, and the
692	and the array will be ignored.	868	array will be ignored.
693		869
694	Best use C<AnyEvent::post_detect { BLOCK }> instead.	870	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
		871	it,as it takes care of these details.
		872
		873	This variable is mainly useful for modules that can do something useful
		874	when AnyEvent is used and thus want to know when it is initialised, but do
		875	not need to even load it by default. This array provides the means to hook
		876	into AnyEvent passively, without loading it.
695		877
696	=back	878	=back
697		879
698	=head1 WHAT TO DO IN A MODULE	880	=head1 WHAT TO DO IN A MODULE
699		881
…		…
754		936
755		937
756	=head1 OTHER MODULES	938	=head1 OTHER MODULES
757		939
758	The following is a non-exhaustive list of additional modules that use	940	The following is a non-exhaustive list of additional modules that use
759	AnyEvent and can therefore be mixed easily with other AnyEvent modules	941	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
760	in the same program. Some of the modules come with AnyEvent, some are	942	modules and other event loops in the same program. Some of the modules
761	available via CPAN.	943	come with AnyEvent, most are available via CPAN.
762		944
763	=over 4	945	=over 4
764		946
765	=item L<AnyEvent::Util>	947	=item L<AnyEvent::Util>
766		948
…		…
775		957
776	=item L<AnyEvent::Handle>	958	=item L<AnyEvent::Handle>
777		959
778	Provide read and write buffers, manages watchers for reads and writes,	960	Provide read and write buffers, manages watchers for reads and writes,
779	supports raw and formatted I/O, I/O queued and fully transparent and	961	supports raw and formatted I/O, I/O queued and fully transparent and
780	non-blocking SSL/TLS.	962	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
781		963
782	=item L<AnyEvent::DNS>	964	=item L<AnyEvent::DNS>
783		965
784	Provides rich asynchronous DNS resolver capabilities.	966	Provides rich asynchronous DNS resolver capabilities.
785		967
…		…
813		995
814	=item L<AnyEvent::GPSD>	996	=item L<AnyEvent::GPSD>
815		997
816	A non-blocking interface to gpsd, a daemon delivering GPS information.	998	A non-blocking interface to gpsd, a daemon delivering GPS information.
817		999
		1000	=item L<AnyEvent::IRC>
		1001
		1002	AnyEvent based IRC client module family (replacing the older Net::IRC3).
		1003
		1004	=item L<AnyEvent::XMPP>
		1005
		1006	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
		1007	Net::XMPP2>.
		1008
818	=item L<AnyEvent::IGS>	1009	=item L<AnyEvent::IGS>
819		1010
820	A non-blocking interface to the Internet Go Server protocol (used by	1011	A non-blocking interface to the Internet Go Server protocol (used by
821	L<App::IGS>).	1012	L<App::IGS>).
822		1013
823	=item L<Net::IRC3>
824
825	AnyEvent based IRC client module family.
826
827	=item L<Net::XMPP2>
828
829	AnyEvent based XMPP (Jabber protocol) module family.
830
831	=item L<Net::FCP>	1014	=item L<Net::FCP>
832		1015
833	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1016	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
834	of AnyEvent.	1017	of AnyEvent.
835		1018
…		…
839		1022
840	=item L<Coro>	1023	=item L<Coro>
841		1024
842	Has special support for AnyEvent via L<Coro::AnyEvent>.	1025	Has special support for AnyEvent via L<Coro::AnyEvent>.
843		1026
844	=item L<IO::Lambda>
845
846	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
847
848	=back	1027	=back
849		1028
850	=cut	1029	=cut
851		1030
852	package AnyEvent;	1031	package AnyEvent;
…		…
854	no warnings;	1033	no warnings;
855	use strict qw(vars subs);	1034	use strict qw(vars subs);
856		1035
857	use Carp;	1036	use Carp;
858		1037
859	our $VERSION = 4.233;	1038	our $VERSION = 4.82;
860	our $MODEL;	1039	our $MODEL;
861		1040
862	our $AUTOLOAD;	1041	our $AUTOLOAD;
863	our @ISA;	1042	our @ISA;
864		1043
865	our @REGISTRY;	1044	our @REGISTRY;
866		1045
867	our $WIN32;	1046	our $WIN32;
868		1047
869	BEGIN {	1048	BEGIN {
870	my $win32 = ! ! ($^O =~ /mswin32/i);	1049	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
871	eval "sub WIN32(){ $win32 }";	1050	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
		1051
		1052	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1053	if ${^TAINT};
872	}	1054	}
873		1055
874	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1056	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
875		1057
876	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1058	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
…		…
887	[Event:: => AnyEvent::Impl::Event::],	1069	[Event:: => AnyEvent::Impl::Event::],
888	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1070	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
889	# everything below here will not be autoprobed	1071	# everything below here will not be autoprobed
890	# as the pureperl backend should work everywhere	1072	# as the pureperl backend should work everywhere
891	# and is usually faster	1073	# and is usually faster
892	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
893	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1074	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
894	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1075	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1076	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
895	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1077	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
896	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1078	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
897	[Wx:: => AnyEvent::Impl::POE::],	1079	[Wx:: => AnyEvent::Impl::POE::],
898	[Prima:: => AnyEvent::Impl::POE::],	1080	[Prima:: => AnyEvent::Impl::POE::],
		1081	# IO::Async is just too broken - we would need workarounds for its
		1082	# byzantine signal and broken child handling, among others.
		1083	# IO::Async is rather hard to detect, as it doesn't have any
		1084	# obvious default class.
		1085	# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1086	# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1087	# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
899	);	1088	);
900		1089
901	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	1090	our %method = map +($_ => 1),
		1091	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
902		1092
903	our @post_detect;	1093	our @post_detect;
904		1094
905	sub post_detect(&) {	1095	sub post_detect(&) {
906	my ($cb) = @_;	1096	my ($cb) = @_;
…		…
911	1	1101	1
912	} else {	1102	} else {
913	push @post_detect, $cb;	1103	push @post_detect, $cb;
914		1104
915	defined wantarray	1105	defined wantarray
916	? bless \$cb, "AnyEvent::Util::PostDetect"	1106	? bless \$cb, "AnyEvent::Util::postdetect"
917	: ()	1107	: ()
918	}	1108	}
919	}	1109	}
920		1110
921	sub AnyEvent::Util::PostDetect::DESTROY {	1111	sub AnyEvent::Util::postdetect::DESTROY {
922	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1112	@post_detect = grep $_ != ${$_[0]}, @post_detect;
923	}	1113	}
924		1114
925	sub detect() {	1115	sub detect() {
926	unless ($MODEL) {	1116	unless ($MODEL) {
…		…
929		1119
930	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1120	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
931	my $model = "AnyEvent::Impl::$1";	1121	my $model = "AnyEvent::Impl::$1";
932	if (eval "require $model") {	1122	if (eval "require $model") {
933	$MODEL = $model;	1123	$MODEL = $model;
934	warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;	1124	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $verbose > 1;
935	} else {	1125	} else {
936	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1126	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $verbose;
937	}	1127	}
938	}	1128	}
939		1129
940	# check for already loaded models	1130	# check for already loaded models
941	unless ($MODEL) {	1131	unless ($MODEL) {
…		…
963	last;	1153	last;
964	}	1154	}
965	}	1155	}
966		1156
967	$MODEL	1157	$MODEL
968	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1158	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
969	}	1159	}
970	}	1160	}
971		1161
972	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1162	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
973		1163
…		…
994	}	1184	}
995		1185
996	# utility function to dup a filehandle. this is used by many backends	1186	# utility function to dup a filehandle. this is used by many backends
997	# to support binding more than one watcher per filehandle (they usually	1187	# to support binding more than one watcher per filehandle (they usually
998	# allow only one watcher per fd, so we dup it to get a different one).	1188	# allow only one watcher per fd, so we dup it to get a different one).
999	sub _dupfh($$$$) {	1189	sub _dupfh($$;$$) {
1000	my ($poll, $fh, $r, $w) = @_;	1190	my ($poll, $fh, $r, $w) = @_;
1001		1191
1002	require Fcntl;
1003
1004	# cygwin requires the fh mode to be matching, unix doesn't	1192	# cygwin requires the fh mode to be matching, unix doesn't
1005	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1193	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");
1006	: $poll eq "w" ? ($w, ">")
1007	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1008		1194
1009	open my $fh2, "$mode&" . fileno $fh	1195	open my $fh2, "$mode&", $fh
1010	or die "cannot dup() filehandle: $!";	1196	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1011		1197
1012	# we assume CLOEXEC is already set by perl in all important cases	1198	# we assume CLOEXEC is already set by perl in all important cases
1013		1199
1014	($fh2, $rw)	1200	($fh2, $rw)
1015	}	1201	}
1016		1202
1017	package AnyEvent::Base;	1203	package AnyEvent::Base;
1018		1204
1019	# default implementation for now and time	1205	# default implementations for many methods
1020		1206
1021	BEGIN {	1207	BEGIN {
1022	if (eval "use Time::HiRes (); time (); 1") {	1208	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1023	*_time = \&Time::HiRes::time;	1209	*_time = \&Time::HiRes::time;
1024	# if (eval "use POSIX (); (POSIX::times())...	1210	# if (eval "use POSIX (); (POSIX::times())...
1025	} else {	1211	} else {
1026	*_time = \&CORE::time; # epic fail	1212	*_time = sub { time }; # epic fail
1027	}	1213	}
1028	}	1214	}
1029		1215
1030	sub time { _time }	1216	sub time { _time }
1031	sub now { _time }	1217	sub now { _time }
		1218	sub now_update { }
1032		1219
1033	# default implementation for ->condvar	1220	# default implementation for ->condvar
1034		1221
1035	sub condvar {	1222	sub condvar {
1036	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1223	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1037	}	1224	}
1038		1225
1039	# default implementation for ->signal	1226	# default implementation for ->signal
1040		1227
1041	our %SIG_CB;	1228	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1229
		1230	sub _signal_exec {
		1231	sysread $SIGPIPE_R, my $dummy, 4;
		1232
		1233	while (%SIG_EV) {
		1234	for (keys %SIG_EV) {
		1235	delete $SIG_EV{$_};
		1236	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1237	}
		1238	}
		1239	}
1042		1240
1043	sub signal {	1241	sub signal {
1044	my (undef, %arg) = @_;	1242	my (undef, %arg) = @_;
1045		1243
		1244	unless ($SIGPIPE_R) {
		1245	require Fcntl;
		1246
		1247	if (AnyEvent::WIN32) {
		1248	require AnyEvent::Util;
		1249
		1250	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1251	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1252	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1253	} else {
		1254	pipe $SIGPIPE_R, $SIGPIPE_W;
		1255	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1256	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1257
		1258	# not strictly required, as $^F is normally 2, but let's make sure...
		1259	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1260	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1261	}
		1262
		1263	$SIGPIPE_R
		1264	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1265
		1266	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1267	}
		1268
1046	my $signal = uc $arg{signal}	1269	my $signal = uc $arg{signal}
1047	or Carp::croak "required option 'signal' is missing";	1270	or Carp::croak "required option 'signal' is missing";
1048		1271
1049	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1272	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1050	$SIG{$signal} \|\|= sub {	1273	$SIG{$signal} \|\|= sub {
1051	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1274	local $!;
		1275	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1276	undef $SIG_EV{$signal};
1052	};	1277	};
1053		1278
1054	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1279	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1055	}	1280	}
1056		1281
1057	sub AnyEvent::Base::Signal::DESTROY {	1282	sub AnyEvent::Base::signal::DESTROY {
1058	my ($signal, $cb) = @{$_[0]};	1283	my ($signal, $cb) = @{$_[0]};
1059		1284
1060	delete $SIG_CB{$signal}{$cb};	1285	delete $SIG_CB{$signal}{$cb};
1061		1286
		1287	# delete doesn't work with older perls - they then
		1288	# print weird messages, or just unconditionally exit
		1289	# instead of getting the default action.
1062	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1290	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1063	}	1291	}
1064		1292
1065	# default implementation for ->child	1293	# default implementation for ->child
1066		1294
1067	our %PID_CB;	1295	our %PID_CB;
1068	our $CHLD_W;	1296	our $CHLD_W;
1069	our $CHLD_DELAY_W;	1297	our $CHLD_DELAY_W;
1070	our $PID_IDLE;
1071	our $WNOHANG;	1298	our $WNOHANG;
1072		1299
1073	sub _child_wait {	1300	sub _sigchld {
1074	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1301	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1075	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1302	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),
1076	(values %{ $PID_CB{0} \|\| {} });	1303	(values %{ $PID_CB{0} \|\| {} });
1077	}	1304	}
1078
1079	undef $PID_IDLE;
1080	}
1081
1082	sub _sigchld {
1083	# make sure we deliver these changes "synchronous" with the event loop.
1084	$CHLD_DELAY_W \|\|= AnyEvent->timer (after => 0, cb => sub {
1085	undef $CHLD_DELAY_W;
1086	&_child_wait;
1087	});
1088	}	1305	}
1089		1306
1090	sub child {	1307	sub child {
1091	my (undef, %arg) = @_;	1308	my (undef, %arg) = @_;
1092		1309
1093	defined (my $pid = $arg{pid} + 0)	1310	defined (my $pid = $arg{pid} + 0)
1094	or Carp::croak "required option 'pid' is missing";	1311	or Carp::croak "required option 'pid' is missing";
1095		1312
1096	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1313	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1097		1314
1098	unless ($WNOHANG) {
1099	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1315	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1100	}
1101		1316
1102	unless ($CHLD_W) {	1317	unless ($CHLD_W) {
1103	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1318	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1104	# child could be a zombie already, so make at least one round	1319	# child could be a zombie already, so make at least one round
1105	&_sigchld;	1320	&_sigchld;
1106	}	1321	}
1107		1322
1108	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1323	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1109	}	1324	}
1110		1325
1111	sub AnyEvent::Base::Child::DESTROY {	1326	sub AnyEvent::Base::child::DESTROY {
1112	my ($pid, $cb) = @{$_[0]};	1327	my ($pid, $cb) = @{$_[0]};
1113		1328
1114	delete $PID_CB{$pid}{$cb};	1329	delete $PID_CB{$pid}{$cb};
1115	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1330	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1116		1331
1117	undef $CHLD_W unless keys %PID_CB;	1332	undef $CHLD_W unless keys %PID_CB;
		1333	}
		1334
		1335	# idle emulation is done by simply using a timer, regardless
		1336	# of whether the process is idle or not, and not letting
		1337	# the callback use more than 50% of the time.
		1338	sub idle {
		1339	my (undef, %arg) = @_;
		1340
		1341	my ($cb, $w, $rcb) = $arg{cb};
		1342
		1343	$rcb = sub {
		1344	if ($cb) {
		1345	$w = _time;
		1346	&$cb;
		1347	$w = _time - $w;
		1348
		1349	# never use more then 50% of the time for the idle watcher,
		1350	# within some limits
		1351	$w = 0.0001 if $w < 0.0001;
		1352	$w = 5 if $w > 5;
		1353
		1354	$w = AnyEvent->timer (after => $w, cb => $rcb);
		1355	} else {
		1356	# clean up...
		1357	undef $w;
		1358	undef $rcb;
		1359	}
		1360	};
		1361
		1362	$w = AnyEvent->timer (after => 0.05, cb => $rcb);
		1363
		1364	bless \\$cb, "AnyEvent::Base::idle"
		1365	}
		1366
		1367	sub AnyEvent::Base::idle::DESTROY {
		1368	undef $${$_[0]};
1118	}	1369	}
1119		1370
1120	package AnyEvent::CondVar;	1371	package AnyEvent::CondVar;
1121		1372
1122	our @ISA = AnyEvent::CondVar::Base::;	1373	our @ISA = AnyEvent::CondVar::Base::;
…		…
1196	so on.	1447	so on.
1197		1448
1198	=head1 ENVIRONMENT VARIABLES	1449	=head1 ENVIRONMENT VARIABLES
1199		1450
1200	The following environment variables are used by this module or its	1451	The following environment variables are used by this module or its
1201	submodules:	1452	submodules.
		1453
		1454	Note that AnyEvent will remove I<all> environment variables starting with
		1455	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1456	enabled.
1202		1457
1203	=over 4	1458	=over 4
1204		1459
1205	=item C<PERL_ANYEVENT_VERBOSE>	1460	=item C<PERL_ANYEVENT_VERBOSE>
1206		1461
…		…
1218	=item C<PERL_ANYEVENT_STRICT>	1473	=item C<PERL_ANYEVENT_STRICT>
1219		1474
1220	AnyEvent does not do much argument checking by default, as thorough	1475	AnyEvent does not do much argument checking by default, as thorough
1221	argument checking is very costly. Setting this variable to a true value	1476	argument checking is very costly. Setting this variable to a true value
1222	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly	1477	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1223	check the arguments passed to most method calls. If it finds any problems	1478	check the arguments passed to most method calls. If it finds any problems,
1224	it will croak.	1479	it will croak.
1225		1480
1226	In other words, enables "strict" mode.	1481	In other words, enables "strict" mode.
1227		1482
1228	Unlike C<use strict>, it is definitely recommended ot keep it off in	1483	Unlike C<use strict>, it is definitely recommended to keep it off in
1229	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1484	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
1230	developing programs can be very useful, however.	1485	developing programs can be very useful, however.
1231		1486
1232	=item C<PERL_ANYEVENT_MODEL>	1487	=item C<PERL_ANYEVENT_MODEL>
1233		1488
…		…
1256	used, and preference will be given to protocols mentioned earlier in the	1511	used, and preference will be given to protocols mentioned earlier in the
1257	list.	1512	list.
1258		1513
1259	This variable can effectively be used for denial-of-service attacks	1514	This variable can effectively be used for denial-of-service attacks
1260	against local programs (e.g. when setuid), although the impact is likely	1515	against local programs (e.g. when setuid), although the impact is likely
1261	small, as the program has to handle connection errors already-	1516	small, as the program has to handle conenction and other failures anyways.
1262		1517
1263	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,	1518	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1264	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	1519	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1265	- only support IPv4, never try to resolve or contact IPv6	1520	- only support IPv4, never try to resolve or contact IPv6
1266	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	1521	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
…		…
1278		1533
1279	=item C<PERL_ANYEVENT_MAX_FORKS>	1534	=item C<PERL_ANYEVENT_MAX_FORKS>
1280		1535
1281	The maximum number of child processes that C<AnyEvent::Util::fork_call>	1536	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1282	will create in parallel.	1537	will create in parallel.
		1538
		1539	=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
		1540
		1541	The default value for the C<max_outstanding> parameter for the default DNS
		1542	resolver - this is the maximum number of parallel DNS requests that are
		1543	sent to the DNS server.
		1544
		1545	=item C<PERL_ANYEVENT_RESOLV_CONF>
		1546
		1547	The file to use instead of F</etc/resolv.conf> (or OS-specific
		1548	configuration) in the default resolver. When set to the empty string, no
		1549	default config will be used.
		1550
		1551	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
		1552
		1553	When neither C<ca_file> nor C<ca_path> was specified during
		1554	L<AnyEvent::TLS> context creation, and either of these environment
		1555	variables exist, they will be used to specify CA certificate locations
		1556	instead of a system-dependent default.
1283		1557
1284	=back	1558	=back
1285		1559
1286	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1560	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1287		1561
…		…
1526	watcher.	1800	watcher.
1527		1801
1528	=head3 Results	1802	=head3 Results
1529		1803
1530	name watchers bytes create invoke destroy comment	1804	name watchers bytes create invoke destroy comment
1531	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1805	EV/EV 400000 224 0.47 0.35 0.27 EV native interface
1532	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1806	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1533	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1807	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1534	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1808	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1535	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1809	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1536	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1810	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
		1811	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll
		1812	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll
1537	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1813	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1538	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1814	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1539	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1815	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1540	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1816	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1541		1817
1542	=head3 Discussion	1818	=head3 Discussion
1543		1819
1544	The benchmark does I<not> measure scalability of the event loop very	1820	The benchmark does I<not> measure scalability of the event loop very
1545	well. For example, a select-based event loop (such as the pure perl one)	1821	well. For example, a select-based event loop (such as the pure perl one)
…		…
1570	performance becomes really bad with lots of file descriptors (and few of	1846	performance becomes really bad with lots of file descriptors (and few of
1571	them active), of course, but this was not subject of this benchmark.	1847	them active), of course, but this was not subject of this benchmark.
1572		1848
1573	The C<Event> module has a relatively high setup and callback invocation	1849	The C<Event> module has a relatively high setup and callback invocation
1574	cost, but overall scores in on the third place.	1850	cost, but overall scores in on the third place.
		1851
		1852	C<IO::Async> performs admirably well, about on par with C<Event>, even
		1853	when using its pure perl backend.
1575		1854
1576	C<Glib>'s memory usage is quite a bit higher, but it features a	1855	C<Glib>'s memory usage is quite a bit higher, but it features a
1577	faster callback invocation and overall ends up in the same class as	1856	faster callback invocation and overall ends up in the same class as
1578	C<Event>. However, Glib scales extremely badly, doubling the number of	1857	C<Event>. However, Glib scales extremely badly, doubling the number of
1579	watchers increases the processing time by more than a factor of four,	1858	watchers increases the processing time by more than a factor of four,
…		…
1657	it to another server. This includes deleting the old timeout and creating	1936	it to another server. This includes deleting the old timeout and creating
1658	a new one that moves the timeout into the future.	1937	a new one that moves the timeout into the future.
1659		1938
1660	=head3 Results	1939	=head3 Results
1661		1940
1662	name sockets create request	1941	name sockets create request
1663	EV 20000 69.01 11.16	1942	EV 20000 69.01 11.16
1664	Perl 20000 73.32 35.87	1943	Perl 20000 73.32 35.87
		1944	IOAsync 20000 157.00 98.14 epoll
		1945	IOAsync 20000 159.31 616.06 poll
1665	Event 20000 212.62 257.32	1946	Event 20000 212.62 257.32
1666	Glib 20000 651.16 1896.30	1947	Glib 20000 651.16 1896.30
1667	POE 20000 349.67 12317.24 uses POE::Loop::Event	1948	POE 20000 349.67 12317.24 uses POE::Loop::Event
1668		1949
1669	=head3 Discussion	1950	=head3 Discussion
1670		1951
1671	This benchmark I<does> measure scalability and overall performance of the	1952	This benchmark I<does> measure scalability and overall performance of the
1672	particular event loop.	1953	particular event loop.
…		…
1674	EV is again fastest. Since it is using epoll on my system, the setup time	1955	EV is again fastest. Since it is using epoll on my system, the setup time
1675	is relatively high, though.	1956	is relatively high, though.
1676		1957
1677	Perl surprisingly comes second. It is much faster than the C-based event	1958	Perl surprisingly comes second. It is much faster than the C-based event
1678	loops Event and Glib.	1959	loops Event and Glib.
		1960
		1961	IO::Async performs very well when using its epoll backend, and still quite
		1962	good compared to Glib when using its pure perl backend.
1679		1963
1680	Event suffers from high setup time as well (look at its code and you will	1964	Event suffers from high setup time as well (look at its code and you will
1681	understand why). Callback invocation also has a high overhead compared to	1965	understand why). Callback invocation also has a high overhead compared to
1682	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event	1966	the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1683	uses select or poll in basically all documented configurations.	1967	uses select or poll in basically all documented configurations.
…		…
1746	=item * C-based event loops perform very well with small number of	2030	=item * C-based event loops perform very well with small number of
1747	watchers, as the management overhead dominates.	2031	watchers, as the management overhead dominates.
1748		2032
1749	=back	2033	=back
1750		2034
		2035	=head2 THE IO::Lambda BENCHMARK
		2036
		2037	Recently I was told about the benchmark in the IO::Lambda manpage, which
		2038	could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
		2039	simply compares IO::Lambda with POE, and IO::Lambda looks better (which
		2040	shouldn't come as a surprise to anybody). As such, the benchmark is
		2041	fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
		2042	very optimal. But how would AnyEvent compare when used without the extra
		2043	baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
		2044
		2045	The benchmark itself creates an echo-server, and then, for 500 times,
		2046	connects to the echo server, sends a line, waits for the reply, and then
		2047	creates the next connection. This is a rather bad benchmark, as it doesn't
		2048	test the efficiency of the framework or much non-blocking I/O, but it is a
		2049	benchmark nevertheless.
		2050
		2051	name runtime
		2052	Lambda/select 0.330 sec
		2053	+ optimized 0.122 sec
		2054	Lambda/AnyEvent 0.327 sec
		2055	+ optimized 0.138 sec
		2056	Raw sockets/select 0.077 sec
		2057	POE/select, components 0.662 sec
		2058	POE/select, raw sockets 0.226 sec
		2059	POE/select, optimized 0.404 sec
		2060
		2061	AnyEvent/select/nb 0.085 sec
		2062	AnyEvent/EV/nb 0.068 sec
		2063	+state machine 0.134 sec
		2064
		2065	The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
		2066	benchmarks actually make blocking connects and use 100% blocking I/O,
		2067	defeating the purpose of an event-based solution. All of the newly
		2068	written AnyEvent benchmarks use 100% non-blocking connects (using
		2069	AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
		2070	resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
		2071	generally require a lot more bookkeeping and event handling than blocking
		2072	connects (which involve a single syscall only).
		2073
		2074	The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
		2075	offers similar expressive power as POE and IO::Lambda, using conventional
		2076	Perl syntax. This means that both the echo server and the client are 100%
		2077	non-blocking, further placing it at a disadvantage.
		2078
		2079	As you can see, the AnyEvent + EV combination even beats the
		2080	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
		2081	backend easily beats IO::Lambda and POE.
		2082
		2083	And even the 100% non-blocking version written using the high-level (and
		2084	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a
		2085	large margin, even though it does all of DNS, tcp-connect and socket I/O
		2086	in a non-blocking way.
		2087
		2088	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
		2089	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
		2090	part of the IO::lambda distribution and were used without any changes.
		2091
		2092
		2093	=head1 SIGNALS
		2094
		2095	AnyEvent currently installs handlers for these signals:
		2096
		2097	=over 4
		2098
		2099	=item SIGCHLD
		2100
		2101	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		2102	emulation for event loops that do not support them natively. Also, some
		2103	event loops install a similar handler.
		2104
		2105	Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
		2106	AnyEvent will reset it to default, to avoid losing child exit statuses.
		2107
		2108	=item SIGPIPE
		2109
		2110	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		2111	when AnyEvent gets loaded.
		2112
		2113	The rationale for this is that AnyEvent users usually do not really depend
		2114	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		2115	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		2116	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		2117	some random socket.
		2118
		2119	The rationale for installing a no-op handler as opposed to ignoring it is
		2120	that this way, the handler will be restored to defaults on exec.
		2121
		2122	Feel free to install your own handler, or reset it to defaults.
		2123
		2124	=back
		2125
		2126	=cut
		2127
		2128	undef $SIG{CHLD}
		2129	if $SIG{CHLD} eq 'IGNORE';
		2130
		2131	$SIG{PIPE} = sub { }
		2132	unless defined $SIG{PIPE};
1751		2133
1752	=head1 FORK	2134	=head1 FORK
1753		2135
1754	Most event libraries are not fork-safe. The ones who are usually are	2136	Most event libraries are not fork-safe. The ones who are usually are
1755	because they rely on inefficient but fork-safe C<select> or C<poll>	2137	because they rely on inefficient but fork-safe C<select> or C<poll>
…		…
1776	use AnyEvent;	2158	use AnyEvent;
1777		2159
1778	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2160	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1779	be used to probe what backend is used and gain other information (which is	2161	be used to probe what backend is used and gain other information (which is
1780	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and	2162	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1781	$ENV{PERL_ANYEGENT_STRICT}.	2163	$ENV{PERL_ANYEVENT_STRICT}.
		2164
		2165	Note that AnyEvent will remove I<all> environment variables starting with
		2166	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		2167	enabled.
1782		2168
1783		2169
1784	=head1 BUGS	2170	=head1 BUGS
1785		2171
1786	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard	2172	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1787	to work around. If you suffer from memleaks, first upgrade to Perl 5.10	2173	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1788	and check wether the leaks still show up. (Perl 5.10.0 has other annoying	2174	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1789	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as	2175	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
1790	pronounced).	2176	pronounced).
1791		2177
1792		2178
1793	=head1 SEE ALSO	2179	=head1 SEE ALSO
1794		2180
…		…
1798	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2184	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1799		2185
1800	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2186	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1801	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2187	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1802	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2188	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1803	L<AnyEvent::Impl::POE>.	2189	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
1804		2190
1805	Non-blocking file handles, sockets, TCP clients and	2191	Non-blocking file handles, sockets, TCP clients and
1806	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2192	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1807		2193
1808	Asynchronous DNS: L<AnyEvent::DNS>.	2194	Asynchronous DNS: L<AnyEvent::DNS>.
1809		2195
1810	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,	2196	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
		2197	L<Coro::Event>,
1811		2198
1812	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	2199	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
		2200	L<AnyEvent::HTTP>.
1813		2201
1814		2202
1815	=head1 AUTHOR	2203	=head1 AUTHOR
1816		2204
1817	Marc Lehmann <schmorp@schmorp.de>	2205	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.180 by root, Sat Sep 6 07:00:45 2008 UTC vs. Revision 1.238 by root, Thu Jul 16 03:48:33 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.180 by root, Sat Sep 6 07:00:45 2008 UTC vs.
Revision 1.238 by root, Thu Jul 16 03:48:33 2009 UTC