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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.208 by root, Sun Apr 26 18:12:53 2009 UTC vs.
Revision 1.233 by root, Thu Jul 9 01:22:50 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
175	=head2 I/O WATCHERS	176	=head2 I/O WATCHERS
176		177
177	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
178	with the following mandatory key-value pairs as arguments:	179	with the following mandatory key-value pairs as arguments:
179		180
180	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
181	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
182	handle). Note that only file handles pointing to things for which	183	handle). Note that only file handles pointing to things for which
183	non-blocking operation makes sense are allowed. This includes sockets,	184	non-blocking operation makes sense are allowed. This includes sockets,
184	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
185	or block devices.	186	or block devices.
…		…
391		392
392	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
393	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
394	have exited already (and no SIGCHLD will be sent anymore).	395	have exited already (and no SIGCHLD will be sent anymore).
395		396
396	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
397	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
398	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.
399		403
400	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
401	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
402	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>).
403		408
404	Example: fork a process and wait for it	409	Example: fork a process and wait for it
405		410
406	my $done = AnyEvent->condvar;	411	my $done = AnyEvent->condvar;
407		412
…		…
594		599
595	=item $cv->begin ([group callback])	600	=item $cv->begin ([group callback])
596		601
597	=item $cv->end	602	=item $cv->end
598		603
599	These two methods are EXPERIMENTAL and MIGHT CHANGE.
600
601	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
602	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
603	to use a condition variable for the whole process.	606	to use a condition variable for the whole process.
604		607
605	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
606	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
607	>>, 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
608	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
609	callback was set, C<send> will be called without any arguments.	612	callback was set, C<send> will be called without any arguments.
610		613
611	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:
612		645
613	my $cv = AnyEvent->condvar;	646	my $cv = AnyEvent->condvar;
614		647
615	my %result;	648	my %result;
616	$cv->begin (sub { $cv->send (\%result) });	649	$cv->begin (sub { $cv->send (\%result) });
…		…
636	loop, which serves two important purposes: first, it sets the callback	669	loop, which serves two important purposes: first, it sets the callback
637	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
638	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
639	doesn't execute once).	672	doesn't execute once).
640		673
641	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
642	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
643	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
644	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>.
645		679
646	=back	680	=back
647		681
648	=head3 METHODS FOR CONSUMERS	682	=head3 METHODS FOR CONSUMERS
649		683
…		…
706	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
707	is guaranteed not to block.	741	is guaranteed not to block.
708		742
709	=back	743	=back
710		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
711	=head1 GLOBAL VARIABLES AND FUNCTIONS	812	=head1 GLOBAL VARIABLES AND FUNCTIONS
712		813
		814	These are not normally required to use AnyEvent, but can be useful to
		815	write AnyEvent extension modules.
		816
713	=over 4	817	=over 4
714		818
715	=item $AnyEvent::MODEL	819	=item $AnyEvent::MODEL
716		820
717	Contains C<undef> until the first watcher is being created. Then it	821	Contains C<undef> until the first watcher is being created, before the
		822	backend has been autodetected.
		823
718	contains the event model that is being used, which is the name of the	824	Afterwards it contains the event model that is being used, which is the
719	Perl class implementing the model. This class is usually one of the	825	name of the Perl class implementing the model. This class is usually one
720	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	826	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
721	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	827	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
722		828	will be C<urxvt::anyevent>).
723	The known classes so far are:
724
725	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
726	AnyEvent::Impl::Event based on Event, second best choice.
727	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
728	AnyEvent::Impl::Glib based on Glib, third-best choice.
729	AnyEvent::Impl::Tk based on Tk, very bad choice.
730	AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
731	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
732	AnyEvent::Impl::POE based on POE, not generic enough for full support.
733
734	There is no support for WxWidgets, as WxWidgets has no support for
735	watching file handles. However, you can use WxWidgets through the
736	POE Adaptor, as POE has a Wx backend that simply polls 20 times per
737	second, which was considered to be too horrible to even consider for
738	AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
739	it's adaptor.
740
741	AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
742	autodetecting them.
743		829
744	=item AnyEvent::detect	830	=item AnyEvent::detect
745		831
746	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	832	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
747	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
748	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
749	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>.
750		839
751	=item $guard = AnyEvent::post_detect { BLOCK }	840	=item $guard = AnyEvent::post_detect { BLOCK }
752		841
753	Arranges for the code block to be executed as soon as the event model is	842	Arranges for the code block to be executed as soon as the event model is
754	autodetected (or immediately if this has already happened).	843	autodetected (or immediately if this has already happened).
		844
		845	The block will be executed I<after> the actual backend has been detected
		846	(C<$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.
755		855
756	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
757	that automatically removes the callback again when it is destroyed. See	857	that automatically removes the callback again when it is destroyed. See
758	L<Coro::BDB> for a case where this is useful.	858	L<Coro::BDB> for a case where this is useful.
759		859
…		…
762	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
763	before or after loading AnyEvent), then they will called directly after	863	before or after loading AnyEvent), then they will called directly after
764	the event loop has been chosen.	864	the event loop has been chosen.
765		865
766	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:
767	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
768	and the array will be ignored.	868	array will be ignored.
769		869
770	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.
771		877
772	=back	878	=back
773		879
774	=head1 WHAT TO DO IN A MODULE	880	=head1 WHAT TO DO IN A MODULE
775		881
…		…
830		936
831		937
832	=head1 OTHER MODULES	938	=head1 OTHER MODULES
833		939
834	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
835	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
836	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
837	available via CPAN.	943	come with AnyEvent, most are available via CPAN.
838		944
839	=over 4	945	=over 4
840		946
841	=item L<AnyEvent::Util>	947	=item L<AnyEvent::Util>
842		948
…		…
851		957
852	=item L<AnyEvent::Handle>	958	=item L<AnyEvent::Handle>
853		959
854	Provide read and write buffers, manages watchers for reads and writes,	960	Provide read and write buffers, manages watchers for reads and writes,
855	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
856	non-blocking SSL/TLS.	962	non-blocking SSL/TLS (via L<AnyEvent::TLS>.
857		963
858	=item L<AnyEvent::DNS>	964	=item L<AnyEvent::DNS>
859		965
860	Provides rich asynchronous DNS resolver capabilities.	966	Provides rich asynchronous DNS resolver capabilities.
861		967
…		…
889		995
890	=item L<AnyEvent::GPSD>	996	=item L<AnyEvent::GPSD>
891		997
892	A non-blocking interface to gpsd, a daemon delivering GPS information.	998	A non-blocking interface to gpsd, a daemon delivering GPS information.
893		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
894	=item L<AnyEvent::IGS>	1009	=item L<AnyEvent::IGS>
895		1010
896	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
897	L<App::IGS>).	1012	L<App::IGS>).
898		1013
899	=item L<AnyEvent::IRC>
900
901	AnyEvent based IRC client module family (replacing the older Net::IRC3).
902
903	=item L<Net::XMPP2>
904
905	AnyEvent based XMPP (Jabber protocol) module family.
906
907	=item L<Net::FCP>	1014	=item L<Net::FCP>
908		1015
909	AnyEvent-based implementation of the Freenet Client Protocol, birthplace	1016	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
910	of AnyEvent.	1017	of AnyEvent.
911		1018
…		…
915		1022
916	=item L<Coro>	1023	=item L<Coro>
917		1024
918	Has special support for AnyEvent via L<Coro::AnyEvent>.	1025	Has special support for AnyEvent via L<Coro::AnyEvent>.
919		1026
920	=item L<IO::Lambda>
921
922	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
923
924	=back	1027	=back
925		1028
926	=cut	1029	=cut
927		1030
928	package AnyEvent;	1031	package AnyEvent;
…		…
930	no warnings;	1033	no warnings;
931	use strict qw(vars subs);	1034	use strict qw(vars subs);
932		1035
933	use Carp;	1036	use Carp;
934		1037
935	our $VERSION = 4.4;	1038	our $VERSION = 4.801;
936	our $MODEL;	1039	our $MODEL;
937		1040
938	our $AUTOLOAD;	1041	our $AUTOLOAD;
939	our @ISA;	1042	our @ISA;
940		1043
941	our @REGISTRY;	1044	our @REGISTRY;
942		1045
943	our $WIN32;	1046	our $WIN32;
944		1047
945	BEGIN {	1048	BEGIN {
946	my $win32 = ! ! ($^O =~ /mswin32/i);	1049	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
947	eval "sub WIN32(){ $win32 }";	1050	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
		1051
		1052	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		1053	if ${^TAINT};
948	}	1054	}
949		1055
950	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1056	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
951		1057
952	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	1058	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
…		…
963	[Event:: => AnyEvent::Impl::Event::],	1069	[Event:: => AnyEvent::Impl::Event::],
964	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	1070	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
965	# everything below here will not be autoprobed	1071	# everything below here will not be autoprobed
966	# as the pureperl backend should work everywhere	1072	# as the pureperl backend should work everywhere
967	# and is usually faster	1073	# and is usually faster
968	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
969	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers	1074	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
970	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1075	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
		1076	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		1077	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
971	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1078	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
972	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
973	[Wx:: => AnyEvent::Impl::POE::],	1079	[Wx:: => AnyEvent::Impl::POE::],
974	[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
975	);	1088	);
976		1089
977	our %method = map +($_ => 1),	1090	our %method = map +($_ => 1),
978	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1091	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
979		1092
…		…
1071	}	1184	}
1072		1185
1073	# 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
1074	# to support binding more than one watcher per filehandle (they usually	1187	# to support binding more than one watcher per filehandle (they usually
1075	# 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).
1076	sub _dupfh($$$$) {	1189	sub _dupfh($$;$$) {
1077	my ($poll, $fh, $r, $w) = @_;	1190	my ($poll, $fh, $r, $w) = @_;
1078		1191
1079	# cygwin requires the fh mode to be matching, unix doesn't	1192	# cygwin requires the fh mode to be matching, unix doesn't
1080	my ($rw, $mode) = $poll eq "r" ? ($r, "<")	1193	my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");
1081	: $poll eq "w" ? ($w, ">")
1082	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1083		1194
1084	open my $fh2, "$mode&" . fileno $fh	1195	open my $fh2, "$mode&", $fh
1085	or die "cannot dup() filehandle: $!,";	1196	or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1086		1197
1087	# we assume CLOEXEC is already set by perl in all important cases	1198	# we assume CLOEXEC is already set by perl in all important cases
1088		1199
1089	($fh2, $rw)	1200	($fh2, $rw)
1090	}	1201	}
…		…
1141	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case	1252	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1142	} else {	1253	} else {
1143	pipe $SIGPIPE_R, $SIGPIPE_W;	1254	pipe $SIGPIPE_R, $SIGPIPE_W;
1144	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;
1145	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;
1146	}	1261	}
1147		1262
1148	$SIGPIPE_R	1263	$SIGPIPE_R
1149	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";
1150
1151	# not strictly required, as $^F is normally 2, but let's make sure...
1152	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1153	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1154		1265
1155	$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);
1156	}	1267	}
1157		1268
1158	my $signal = uc $arg{signal}	1269	my $signal = uc $arg{signal}
…		…
1171	sub AnyEvent::Base::signal::DESTROY {	1282	sub AnyEvent::Base::signal::DESTROY {
1172	my ($signal, $cb) = @{$_[0]};	1283	my ($signal, $cb) = @{$_[0]};
1173		1284
1174	delete $SIG_CB{$signal}{$cb};	1285	delete $SIG_CB{$signal}{$cb};
1175		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.
1176	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };	1290	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1177	}	1291	}
1178		1292
1179	# default implementation for ->child	1293	# default implementation for ->child
1180		1294
1181	our %PID_CB;	1295	our %PID_CB;
1182	our $CHLD_W;	1296	our $CHLD_W;
1183	our $CHLD_DELAY_W;	1297	our $CHLD_DELAY_W;
1184	our $PID_IDLE;
1185	our $WNOHANG;	1298	our $WNOHANG;
1186		1299
1187	sub _child_wait {	1300	sub _sigchld {
1188	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1301	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1189	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1302	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),
1190	(values %{ $PID_CB{0} \|\| {} });	1303	(values %{ $PID_CB{0} \|\| {} });
1191	}	1304	}
1192
1193	undef $PID_IDLE;
1194	}
1195
1196	sub _sigchld {
1197	# make sure we deliver these changes "synchronous" with the event loop.
1198	$CHLD_DELAY_W \|\|= AnyEvent->timer (after => 0, cb => sub {
1199	undef $CHLD_DELAY_W;
1200	&_child_wait;
1201	});
1202	}	1305	}
1203		1306
1204	sub child {	1307	sub child {
1205	my (undef, %arg) = @_;	1308	my (undef, %arg) = @_;
1206		1309
1207	defined (my $pid = $arg{pid} + 0)	1310	defined (my $pid = $arg{pid} + 0)
1208	or Carp::croak "required option 'pid' is missing";	1311	or Carp::croak "required option 'pid' is missing";
1209		1312
1210	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1313	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1211		1314
1212	unless ($WNOHANG) {
1213	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1315	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1214	}
1215		1316
1216	unless ($CHLD_W) {	1317	unless ($CHLD_W) {
1217	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1318	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1218	# 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
1219	&_sigchld;	1320	&_sigchld;
…		…
1230		1331
1231	undef $CHLD_W unless keys %PID_CB;	1332	undef $CHLD_W unless keys %PID_CB;
1232	}	1333	}
1233		1334
1234	# idle emulation is done by simply using a timer, regardless	1335	# idle emulation is done by simply using a timer, regardless
1235	# of whether the proces sis idle or not, and not letting	1336	# of whether the process is idle or not, and not letting
1236	# the callback use more than 50% of the time.	1337	# the callback use more than 50% of the time.
1237	sub idle {	1338	sub idle {
1238	my (undef, %arg) = @_;	1339	my (undef, %arg) = @_;
1239		1340
1240	my ($cb, $w, $rcb) = $arg{cb};	1341	my ($cb, $w, $rcb) = $arg{cb};
…		…
1346	so on.	1447	so on.
1347		1448
1348	=head1 ENVIRONMENT VARIABLES	1449	=head1 ENVIRONMENT VARIABLES
1349		1450
1350	The following environment variables are used by this module or its	1451	The following environment variables are used by this module or its
1351	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.
1352		1457
1353	=over 4	1458	=over 4
1354		1459
1355	=item C<PERL_ANYEVENT_VERBOSE>	1460	=item C<PERL_ANYEVENT_VERBOSE>
1356		1461
…		…
1368	=item C<PERL_ANYEVENT_STRICT>	1473	=item C<PERL_ANYEVENT_STRICT>
1369		1474
1370	AnyEvent does not do much argument checking by default, as thorough	1475	AnyEvent does not do much argument checking by default, as thorough
1371	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
1372	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
1373	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,
1374	it will croak.	1479	it will croak.
1375		1480
1376	In other words, enables "strict" mode.	1481	In other words, enables "strict" mode.
1377		1482
1378	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
1379	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while	1484	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
1380	developing programs can be very useful, however.	1485	developing programs can be very useful, however.
1381		1486
1382	=item C<PERL_ANYEVENT_MODEL>	1487	=item C<PERL_ANYEVENT_MODEL>
1383		1488
…		…
1428		1533
1429	=item C<PERL_ANYEVENT_MAX_FORKS>	1534	=item C<PERL_ANYEVENT_MAX_FORKS>
1430		1535
1431	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>
1432	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.
1433		1557
1434	=back	1558	=back
1435		1559
1436	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1560	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1437		1561
…		…
1682	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
1683	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
1684	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
1685	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
1686	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
1687	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
1688	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
1689	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
1690	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
1691		1817
…		…
1720	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
1721	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.
1722		1848
1723	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
1724	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.
1725		1854
1726	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
1727	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
1728	C<Event>. However, Glib scales extremely badly, doubling the number of	1857	C<Event>. However, Glib scales extremely badly, doubling the number of
1729	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,
…		…
1807	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
1808	a new one that moves the timeout into the future.	1937	a new one that moves the timeout into the future.
1809		1938
1810	=head3 Results	1939	=head3 Results
1811		1940
1812	name sockets create request	1941	name sockets create request
1813	EV 20000 69.01 11.16	1942	EV 20000 69.01 11.16
1814	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
1815	Event 20000 212.62 257.32	1946	Event 20000 212.62 257.32
1816	Glib 20000 651.16 1896.30	1947	Glib 20000 651.16 1896.30
1817	POE 20000 349.67 12317.24 uses POE::Loop::Event	1948	POE 20000 349.67 12317.24 uses POE::Loop::Event
1818		1949
1819	=head3 Discussion	1950	=head3 Discussion
1820		1951
1821	This benchmark I<does> measure scalability and overall performance of the	1952	This benchmark I<does> measure scalability and overall performance of the
1822	particular event loop.	1953	particular event loop.
…		…
1824	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
1825	is relatively high, though.	1956	is relatively high, though.
1826		1957
1827	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
1828	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.
1829		1963
1830	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
1831	understand why). Callback invocation also has a high overhead compared to	1965	understand why). Callback invocation also has a high overhead compared to
1832	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
1833	uses select or poll in basically all documented configurations.	1967	uses select or poll in basically all documented configurations.
…		…
1896	=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
1897	watchers, as the management overhead dominates.	2031	watchers, as the management overhead dominates.
1898		2032
1899	=back	2033	=back
1900		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
1901		2092
1902	=head1 SIGNALS	2093	=head1 SIGNALS
1903		2094
1904	AnyEvent currently installs handlers for these signals:	2095	AnyEvent currently installs handlers for these signals:
1905		2096
…		…
1908	=item SIGCHLD	2099	=item SIGCHLD
1909		2100
1910	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
1911	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
1912	event loops install a similar handler.	2103	event loops install a similar handler.
		2104
		2105	If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will
		2106	reset it to default, to avoid losing child exit statuses.
1913		2107
1914	=item SIGPIPE	2108	=item SIGPIPE
1915		2109
1916	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>
1917	when AnyEvent gets loaded.	2111	when AnyEvent gets loaded.
…		…
1929		2123
1930	=back	2124	=back
1931		2125
1932	=cut	2126	=cut
1933		2127
		2128	undef $SIG{CHLD}
		2129	if $SIG{CHLD} eq 'IGNORE';
		2130
1934	$SIG{PIPE} = sub { }	2131	$SIG{PIPE} = sub { }
1935	unless defined $SIG{PIPE};	2132	unless defined $SIG{PIPE};
1936
1937		2133
1938	=head1 FORK	2134	=head1 FORK
1939		2135
1940	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
1941	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>
…		…
1962	use AnyEvent;	2158	use AnyEvent;
1963		2159
1964	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	2160	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1965	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
1966	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
1967	$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.
1968		2168
1969		2169
1970	=head1 BUGS	2170	=head1 BUGS
1971		2171
1972	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
…		…
1984	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2184	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1985		2185
1986	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2186	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1987	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>,
1988	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2188	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1989	L<AnyEvent::Impl::POE>.	2189	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
1990		2190
1991	Non-blocking file handles, sockets, TCP clients and	2191	Non-blocking file handles, sockets, TCP clients and
1992	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.	2192	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1993		2193
1994	Asynchronous DNS: L<AnyEvent::DNS>.	2194	Asynchronous DNS: L<AnyEvent::DNS>.
1995		2195
1996	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>,
1997		2198
1998	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>.
1999		2201
2000		2202
2001	=head1 AUTHOR	2203	=head1 AUTHOR
2002		2204
2003	Marc Lehmann <schmorp@schmorp.de>	2205	Marc Lehmann <schmorp@schmorp.de>

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.208 by root, Sun Apr 26 18:12:53 2009 UTC vs. Revision 1.233 by root, Thu Jul 9 01:22:50 2009 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.208 by root, Sun Apr 26 18:12:53 2009 UTC vs.
Revision 1.233 by root, Thu Jul 9 01:22:50 2009 UTC