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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.206 by root, Mon Apr 20 14:34:18 2009 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:
168	=head2 I/O WATCHERS	176	=head2 I/O WATCHERS
169		177
170	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
171	with the following mandatory key-value pairs as arguments:	179	with the following mandatory key-value pairs as arguments:
172		180
173	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch	181	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
174	for events (AnyEvent might or might not keep a reference to this file	182	for events (AnyEvent might or might not keep a reference to this file
175	handle). Note that only file handles pointing to things for which	183	handle). Note that only file handles pointing to things for which
176	non-blocking operation makes sense are allowed. This includes sockets,	184	non-blocking operation makes sense are allowed. This includes sockets,
177	most character devices, pipes, fifos and so on, but not for example files	185	most character devices, pipes, fifos and so on, but not for example files
178	or block devices.	186	or block devices.
…		…
384		392
385	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
386	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
387	have exited already (and no SIGCHLD will be sent anymore).	395	have exited already (and no SIGCHLD will be sent anymore).
388		396
389	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
390	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
391	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.
392		403
393	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
394	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
395	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>).
396		408
397	Example: fork a process and wait for it	409	Example: fork a process and wait for it
398		410
399	my $done = AnyEvent->condvar;	411	my $done = AnyEvent->condvar;
400		412
…		…
410	);	422	);
411		423
412	# do something else, then wait for process exit	424	# do something else, then wait for process exit
413	$done->recv;	425	$done->recv;
414		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
415	=head2 CONDITION VARIABLES	462	=head2 CONDITION VARIABLES
416		463
417	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
418	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
419	will actively watch for new events and call your callbacks.	466	will actively watch for new events and call your callbacks.
…		…
552		599
553	=item $cv->begin ([group callback])	600	=item $cv->begin ([group callback])
554		601
555	=item $cv->end	602	=item $cv->end
556		603
557	These two methods are EXPERIMENTAL and MIGHT CHANGE.
558
559	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
560	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
561	to use a condition variable for the whole process.	606	to use a condition variable for the whole process.
562		607
563	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
564	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
565	>>, 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
566	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
567	callback was set, C<send> will be called without any arguments.	612	callback was set, C<send> will be called without any arguments.
568		613
569	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:
570		645
571	my $cv = AnyEvent->condvar;	646	my $cv = AnyEvent->condvar;
572		647
573	my %result;	648	my %result;
574	$cv->begin (sub { $cv->send (\%result) });	649	$cv->begin (sub { $cv->send (\%result) });
…		…
594	loop, which serves two important purposes: first, it sets the callback	669	loop, which serves two important purposes: first, it sets the callback
595	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
596	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
597	doesn't execute once).	672	doesn't execute once).
598		673
599	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
600	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
601	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
602	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>.
603		679
604	=back	680	=back
605		681
606	=head3 METHODS FOR CONSUMERS	682	=head3 METHODS FOR CONSUMERS
607		683
…		…
664	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
665	is guaranteed not to block.	741	is guaranteed not to block.
666		742
667	=back	743	=back
668		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
669	=head1 GLOBAL VARIABLES AND FUNCTIONS	812	=head1 GLOBAL VARIABLES AND FUNCTIONS
670		813
		814	These are not normally required to use AnyEvent, but can be useful to
		815	write AnyEvent extension modules.
		816
671	=over 4	817	=over 4
672		818
673	=item $AnyEvent::MODEL	819	=item $AnyEvent::MODEL
674		820
675	Contains C<undef> until the first watcher is being created. Then it	821	Contains C<undef> until the first watcher is being created, before the
		822	backend has been autodetected.
		823
676	contains the event model that is being used, which is the name of the	824	Afterwards it contains the event model that is being used, which is the
677	Perl class implementing the model. This class is usually one of the	825	name of the Perl class implementing the model. This class is usually one
678	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	826	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
679	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	827	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
680		828	will be C<urxvt::anyevent>).
681	The known classes so far are:
682
683	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
684	AnyEvent::Impl::Event based on Event, second best choice.
685	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
686	AnyEvent::Impl::Glib based on Glib, third-best choice.
687	AnyEvent::Impl::Tk based on Tk, very bad choice.
688	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
689	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
690	AnyEvent::Impl::POE based on POE, not generic enough for full support.
691
692	There is no support for WxWidgets, as WxWidgets has no support for
693	watching file handles. However, you can use WxWidgets through the
694	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
695	second, which was considered to be too horrible to even consider for
696	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
697	it's adaptor.
698
699	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
700	autodetecting them.
701		829
702	=item AnyEvent::detect	830	=item AnyEvent::detect
703		831
704	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	832	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
705	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
706	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
707	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>.
708		839
709	=item $guard = AnyEvent::post_detect { BLOCK }	840	=item $guard = AnyEvent::post_detect { BLOCK }
710		841
711	Arranges for the code block to be executed as soon as the event model is	842	Arranges for the code block to be executed as soon as the event model is
712	autodetected (or immediately if this has already happened).	843	autodetected (or immediately if this has already happened).
		844
		845	The block will be executed I<after> the actual backend has been detected
		846	(C<$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.
713		855
714	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
715	that automatically removes the callback again when it is destroyed. See	857	that automatically removes the callback again when it is destroyed. See
716	L<Coro::BDB> for a case where this is useful.	858	L<Coro::BDB> for a case where this is useful.
717		859
…		…
720	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
721	before or after loading AnyEvent), then they will called directly after	863	before or after loading AnyEvent), then they will called directly after
722	the event loop has been chosen.	864	the event loop has been chosen.
723		865
724	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:
725	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
726	and the array will be ignored.	868	array will be ignored.
727		869
728	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.
729		877
730	=back	878	=back
731		879
732	=head1 WHAT TO DO IN A MODULE	880	=head1 WHAT TO DO IN A MODULE
733		881
…		…
788		936
789		937
790	=head1 OTHER MODULES	938	=head1 OTHER MODULES
791		939
792	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
793	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
794	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
795	available via CPAN.	943	come with AnyEvent, most are available via CPAN.
796		944
797	=over 4	945	=over 4
798		946
799	=item L<AnyEvent::Util>	947	=item L<AnyEvent::Util>
800		948
…		…
809		957
810	=item L<AnyEvent::Handle>	958	=item L<AnyEvent::Handle>
811		959
812	Provide read and write buffers, manages watchers for reads and writes,	960	Provide read and write buffers, manages watchers for reads and writes,
813	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
814	non-blocking SSL/TLS.	962	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
815		963
816	=item L<AnyEvent::DNS>	964	=item L<AnyEvent::DNS>
817		965
818	Provides rich asynchronous DNS resolver capabilities.	966	Provides rich asynchronous DNS resolver capabilities.
819		967
…		…
847		995
848	=item L<AnyEvent::GPSD>	996	=item L<AnyEvent::GPSD>
849		997
850	A non-blocking interface to gpsd, a daemon delivering GPS information.	998	A non-blocking interface to gpsd, a daemon delivering GPS information.
851		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
852	=item L<AnyEvent::IGS>	1009	=item L<AnyEvent::IGS>
853		1010
854	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
855	L<App::IGS>).	1012	L<App::IGS>).
856		1013
857	=item L<AnyEvent::IRC>
858
859	AnyEvent based IRC client module family (replacing the older Net::IRC3).
860
861	=item L<Net::XMPP2>
862
863	AnyEvent based XMPP (Jabber protocol) module family.
864
865	=item L<Net::FCP>	1014	=item L<Net::FCP>
866		1015
867	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1016	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
868	of AnyEvent.	1017	of AnyEvent.
869		1018
…		…
873		1022
874	=item L<Coro>	1023	=item L<Coro>
875		1024
876	Has special support for AnyEvent via L<Coro::AnyEvent>.	1025	Has special support for AnyEvent via L<Coro::AnyEvent>.
877		1026
878	=item L<IO::Lambda>
879
880	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
881
882	=back	1027	=back
883		1028
884	=cut	1029	=cut
885		1030
886	package AnyEvent;	1031	package AnyEvent;
…		…
888	no warnings;	1033	no warnings;
889	use strict qw(vars subs);	1034	use strict qw(vars subs);
890		1035
891	use Carp;	1036	use Carp;
892		1037
893	our $VERSION = 4.352;	1038	our $VERSION = 4.82;
894	our $MODEL;	1039	our $MODEL;
895		1040
896	our $AUTOLOAD;	1041	our $AUTOLOAD;
897	our @ISA;	1042	our @ISA;
898		1043
899	our @REGISTRY;	1044	our @REGISTRY;
900		1045
901	our $WIN32;	1046	our $WIN32;
902		1047
903	BEGIN {	1048	BEGIN {
904	my $win32 = ! ! ($^O =~ /mswin32/i);	1049	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
905	eval "sub WIN32(){ $win32 }";	1050	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
		1051
		1052	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1053	if ${^TAINT};
906	}	1054	}
907		1055
908	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1056	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
909		1057
910	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1058	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
…		…
921	[Event:: => AnyEvent::Impl::Event::],	1069	[Event:: => AnyEvent::Impl::Event::],
922	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1070	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
923	# everything below here will not be autoprobed	1071	# everything below here will not be autoprobed
924	# as the pureperl backend should work everywhere	1072	# as the pureperl backend should work everywhere
925	# and is usually faster	1073	# and is usually faster
926	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
927	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1074	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
928	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1075	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1076	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
929	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1077	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
930	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1078	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
931	[Wx:: => AnyEvent::Impl::POE::],	1079	[Wx:: => AnyEvent::Impl::POE::],
932	[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
933	);	1088	);
934		1089
935	our %method = map +($_ => 1),	1090	our %method = map +($_ => 1),
936	qw(io timer time now now_update signal child condvar one_event DESTROY);	1091	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
937		1092
938	our @post_detect;	1093	our @post_detect;
939		1094
940	sub post_detect(&) {	1095	sub post_detect(&) {
941	my ($cb) = @_;	1096	my ($cb) = @_;
…		…
946	1	1101	1
947	} else {	1102	} else {
948	push @post_detect, $cb;	1103	push @post_detect, $cb;
949		1104
950	defined wantarray	1105	defined wantarray
951	? bless \$cb, "AnyEvent::Util::PostDetect"	1106	? bless \$cb, "AnyEvent::Util::postdetect"
952	: ()	1107	: ()
953	}	1108	}
954	}	1109	}
955		1110
956	sub AnyEvent::Util::PostDetect::DESTROY {	1111	sub AnyEvent::Util::postdetect::DESTROY {
957	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1112	@post_detect = grep $_ != ${$_[0]}, @post_detect;
958	}	1113	}
959		1114
960	sub detect() {	1115	sub detect() {
961	unless ($MODEL) {	1116	unless ($MODEL) {
…		…
964		1119
965	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1120	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
966	my $model = "AnyEvent::Impl::$1";	1121	my $model = "AnyEvent::Impl::$1";
967	if (eval "require $model") {	1122	if (eval "require $model") {
968	$MODEL = $model;	1123	$MODEL = $model;
969	warn "AnyEvent: loaded model '$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 $verbose > 1;
970	} else {	1125	} else {
971	warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;	1126	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $verbose;
972	}	1127	}
973	}	1128	}
974		1129
975	# check for already loaded models	1130	# check for already loaded models
976	unless ($MODEL) {	1131	unless ($MODEL) {
…		…
1029	}	1184	}
1030		1185
1031	# 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
1032	# to support binding more than one watcher per filehandle (they usually	1187	# to support binding more than one watcher per filehandle (they usually
1033	# 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).
1034	sub _dupfh($$$$) {	1189	sub _dupfh($$;$$) {
1035	my ($poll, $fh, $r, $w) = @_;	1190	my ($poll, $fh, $r, $w) = @_;
1036		1191
1037	# cygwin requires the fh mode to be matching, unix doesn't	1192	# cygwin requires the fh mode to be matching, unix doesn't
1038	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1193	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");
1039	: $poll eq "w" ? ($w, ">")
1040	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1041		1194
1042	open my $fh2, "$mode&" . fileno $fh	1195	open my $fh2, "$mode&", $fh
1043	or die "cannot dup() filehandle: $!,";	1196	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1044		1197
1045	# 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
1046		1199
1047	($fh2, $rw)	1200	($fh2, $rw)
1048	}	1201	}
…		…
1050	package AnyEvent::Base;	1203	package AnyEvent::Base;
1051		1204
1052	# default implementations for many methods	1205	# default implementations for many methods
1053		1206
1054	BEGIN {	1207	BEGIN {
1055	if (eval "use Time::HiRes (); time (); 1") {	1208	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1056	*_time = \&Time::HiRes::time;	1209	*_time = \&Time::HiRes::time;
1057	# if (eval "use POSIX (); (POSIX::times())...	1210	# if (eval "use POSIX (); (POSIX::times())...
1058	} else {	1211	} else {
1059	*_time = sub { time }; # epic fail	1212	*_time = sub { time }; # epic fail
1060	}	1213	}
…		…
1065	sub now_update { }	1218	sub now_update { }
1066		1219
1067	# default implementation for ->condvar	1220	# default implementation for ->condvar
1068		1221
1069	sub condvar {	1222	sub condvar {
1070	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1223	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1071	}	1224	}
1072		1225
1073	# default implementation for ->signal	1226	# default implementation for ->signal
1074		1227
1075	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1228	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
…		…
1099	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case	1252	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1100	} else {	1253	} else {
1101	pipe $SIGPIPE_R, $SIGPIPE_W;	1254	pipe $SIGPIPE_R, $SIGPIPE_W;
1102	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1255	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1103	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	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;
1104	}	1261	}
1105		1262
1106	$SIGPIPE_R	1263	$SIGPIPE_R
1107	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1264	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1108
1109	# not strictly required, as $^F is normally 2, but let's make sure...
1110	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1111	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1112		1265
1113	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);	1266	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1114	}	1267	}
1115		1268
1116	my $signal = uc $arg{signal}	1269	my $signal = uc $arg{signal}
…		…
1121	local $!;	1274	local $!;
1122	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1275	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1123	undef $SIG_EV{$signal};	1276	undef $SIG_EV{$signal};
1124	};	1277	};
1125		1278
1126	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1279	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1127	}	1280	}
1128		1281
1129	sub AnyEvent::Base::Signal::DESTROY {	1282	sub AnyEvent::Base::signal::DESTROY {
1130	my ($signal, $cb) = @{$_[0]};	1283	my ($signal, $cb) = @{$_[0]};
1131		1284
1132	delete $SIG_CB{$signal}{$cb};	1285	delete $SIG_CB{$signal}{$cb};
1133		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.
1134	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1290	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1135	}	1291	}
1136		1292
1137	# default implementation for ->child	1293	# default implementation for ->child
1138		1294
1139	our %PID_CB;	1295	our %PID_CB;
1140	our $CHLD_W;	1296	our $CHLD_W;
1141	our $CHLD_DELAY_W;	1297	our $CHLD_DELAY_W;
1142	our $PID_IDLE;
1143	our $WNOHANG;	1298	our $WNOHANG;
1144		1299
1145	sub _child_wait {	1300	sub _sigchld {
1146	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1301	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1147	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1302	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),
1148	(values %{ $PID_CB{0} \|\| {} });	1303	(values %{ $PID_CB{0} \|\| {} });
1149	}	1304	}
1150
1151	undef $PID_IDLE;
1152	}
1153
1154	sub _sigchld {
1155	# make sure we deliver these changes "synchronous" with the event loop.
1156	$CHLD_DELAY_W \|\|= AnyEvent->timer (after => 0, cb => sub {
1157	undef $CHLD_DELAY_W;
1158	&_child_wait;
1159	});
1160	}	1305	}
1161		1306
1162	sub child {	1307	sub child {
1163	my (undef, %arg) = @_;	1308	my (undef, %arg) = @_;
1164		1309
1165	defined (my $pid = $arg{pid} + 0)	1310	defined (my $pid = $arg{pid} + 0)
1166	or Carp::croak "required option 'pid' is missing";	1311	or Carp::croak "required option 'pid' is missing";
1167		1312
1168	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1313	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1169		1314
1170	unless ($WNOHANG) {
1171	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1315	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1172	}
1173		1316
1174	unless ($CHLD_W) {	1317	unless ($CHLD_W) {
1175	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1318	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1176	# 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
1177	&_sigchld;	1320	&_sigchld;
1178	}	1321	}
1179		1322
1180	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1323	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1181	}	1324	}
1182		1325
1183	sub AnyEvent::Base::Child::DESTROY {	1326	sub AnyEvent::Base::child::DESTROY {
1184	my ($pid, $cb) = @{$_[0]};	1327	my ($pid, $cb) = @{$_[0]};
1185		1328
1186	delete $PID_CB{$pid}{$cb};	1329	delete $PID_CB{$pid}{$cb};
1187	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1330	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1188		1331
1189	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]};
1190	}	1369	}
1191		1370
1192	package AnyEvent::CondVar;	1371	package AnyEvent::CondVar;
1193		1372
1194	our @ISA = AnyEvent::CondVar::Base::;	1373	our @ISA = AnyEvent::CondVar::Base::;
…		…
1268	so on.	1447	so on.
1269		1448
1270	=head1 ENVIRONMENT VARIABLES	1449	=head1 ENVIRONMENT VARIABLES
1271		1450
1272	The following environment variables are used by this module or its	1451	The following environment variables are used by this module or its
1273	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.
1274		1457
1275	=over 4	1458	=over 4
1276		1459
1277	=item C<PERL_ANYEVENT_VERBOSE>	1460	=item C<PERL_ANYEVENT_VERBOSE>
1278		1461
…		…
1290	=item C<PERL_ANYEVENT_STRICT>	1473	=item C<PERL_ANYEVENT_STRICT>
1291		1474
1292	AnyEvent does not do much argument checking by default, as thorough	1475	AnyEvent does not do much argument checking by default, as thorough
1293	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
1294	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
1295	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,
1296	it will croak.	1479	it will croak.
1297		1480
1298	In other words, enables "strict" mode.	1481	In other words, enables "strict" mode.
1299		1482
1300	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
1301	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1484	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
1302	developing programs can be very useful, however.	1485	developing programs can be very useful, however.
1303		1486
1304	=item C<PERL_ANYEVENT_MODEL>	1487	=item C<PERL_ANYEVENT_MODEL>
1305		1488
…		…
1350		1533
1351	=item C<PERL_ANYEVENT_MAX_FORKS>	1534	=item C<PERL_ANYEVENT_MAX_FORKS>
1352		1535
1353	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>
1354	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.
1355		1557
1356	=back	1558	=back
1357		1559
1358	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1560	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1359		1561
…		…
1604	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	1806	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1605	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	1807	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1606	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	1808	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1607	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	1809	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1608	Event/Any 16000 590 35.85 31.55 1.06 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
1609	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	1813	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1610	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	1814	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1611	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	1815	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1612	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	1816	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1613		1817
…		…
1642	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
1643	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.
1644		1848
1645	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
1646	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.
1647		1854
1648	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
1649	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
1650	C<Event>. However, Glib scales extremely badly, doubling the number of	1857	C<Event>. However, Glib scales extremely badly, doubling the number of
1651	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,
…		…
1729	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
1730	a new one that moves the timeout into the future.	1937	a new one that moves the timeout into the future.
1731		1938
1732	=head3 Results	1939	=head3 Results
1733		1940
1734	name sockets create request	1941	name sockets create request
1735	EV 20000 69.01 11.16	1942	EV 20000 69.01 11.16
1736	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
1737	Event 20000 212.62 257.32	1946	Event 20000 212.62 257.32
1738	Glib 20000 651.16 1896.30	1947	Glib 20000 651.16 1896.30
1739	POE 20000 349.67 12317.24 uses POE::Loop::Event	1948	POE 20000 349.67 12317.24 uses POE::Loop::Event
1740		1949
1741	=head3 Discussion	1950	=head3 Discussion
1742		1951
1743	This benchmark I<does> measure scalability and overall performance of the	1952	This benchmark I<does> measure scalability and overall performance of the
1744	particular event loop.	1953	particular event loop.
…		…
1746	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
1747	is relatively high, though.	1956	is relatively high, though.
1748		1957
1749	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
1750	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.
1751		1963
1752	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
1753	understand why). Callback invocation also has a high overhead compared to	1965	understand why). Callback invocation also has a high overhead compared to
1754	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
1755	uses select or poll in basically all documented configurations.	1967	uses select or poll in basically all documented configurations.
…		…
1818	=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
1819	watchers, as the management overhead dominates.	2031	watchers, as the management overhead dominates.
1820		2032
1821	=back	2033	=back
1822		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
1823		2092
1824	=head1 SIGNALS	2093	=head1 SIGNALS
1825		2094
1826	AnyEvent currently installs handlers for these signals:	2095	AnyEvent currently installs handlers for these signals:
1827		2096
…		…
1830	=item SIGCHLD	2099	=item SIGCHLD
1831		2100
1832	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher	2101	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1833	emulation for event loops that do not support them natively. Also, some	2102	emulation for event loops that do not support them natively. Also, some
1834	event loops install a similar handler.	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.
1835		2107
1836	=item SIGPIPE	2108	=item SIGPIPE
1837		2109
1838	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>	2110	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1839	when AnyEvent gets loaded.	2111	when AnyEvent gets loaded.
…		…
1851		2123
1852	=back	2124	=back
1853		2125
1854	=cut	2126	=cut
1855		2127
		2128	undef $SIG{CHLD}
		2129	if $SIG{CHLD} eq 'IGNORE';
		2130
1856	$SIG{PIPE} = sub { }	2131	$SIG{PIPE} = sub { }
1857	unless defined $SIG{PIPE};	2132	unless defined $SIG{PIPE};
1858
1859		2133
1860	=head1 FORK	2134	=head1 FORK
1861		2135
1862	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
1863	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>
…		…
1884	use AnyEvent;	2158	use AnyEvent;
1885		2159
1886	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2160	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1887	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
1888	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
1889	$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.
1890		2168
1891		2169
1892	=head1 BUGS	2170	=head1 BUGS
1893		2171
1894	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
…		…
1906	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2184	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1907		2185
1908	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2186	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1909	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>,
1910	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2188	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1911	L<AnyEvent::Impl::POE>.	2189	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
1912		2190
1913	Non-blocking file handles, sockets, TCP clients and	2191	Non-blocking file handles, sockets, TCP clients and
1914	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2192	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1915		2193
1916	Asynchronous DNS: L<AnyEvent::DNS>.	2194	Asynchronous DNS: L<AnyEvent::DNS>.
1917		2195
1918	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>,
1919		2198
1920	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>.
1921		2201
1922		2202
1923	=head1 AUTHOR	2203	=head1 AUTHOR
1924		2204
1925	Marc Lehmann <schmorp@schmorp.de>	2205	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.206 by root, Mon Apr 20 14:34:18 2009 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 1.206 by root, Mon Apr 20 14:34:18 2009 UTC vs.
Revision 1.238 by root, Thu Jul 16 03:48:33 2009 UTC