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Revision 1.223 by root, Mon Jun 29 21:00:32 2009 UTC vs.
Revision 1.242 by root, Fri Jul 17 22:05:12 2009 UTC

176=head2 I/O WATCHERS 176=head2 I/O WATCHERS
177 177
178You can create an I/O watcher by calling the C<< AnyEvent->io >> method 178You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179with the following mandatory key-value pairs as arguments: 179with the following mandatory key-value pairs as arguments:
180 180
181C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch 181C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182for events (AnyEvent might or might not keep a reference to this file 182for events (AnyEvent might or might not keep a reference to this file
183handle). Note that only file handles pointing to things for which 183handle). Note that only file handles pointing to things for which
184non-blocking operation makes sense are allowed. This includes sockets, 184non-blocking operation makes sense are allowed. This includes sockets,
185most character devices, pipes, fifos and so on, but not for example files 185most character devices, pipes, fifos and so on, but not for example files
186or block devices. 186or block devices.
361invocation, and callback invocation will be synchronous. Synchronous means 361invocation, and callback invocation will be synchronous. Synchronous means
362that it might take a while until the signal gets handled by the process, 362that it might take a while until the signal gets handled by the process,
363but it is guaranteed not to interrupt any other callbacks. 363but it is guaranteed not to interrupt any other callbacks.
364 364
365The main advantage of using these watchers is that you can share a signal 365The main advantage of using these watchers is that you can share a signal
366between multiple watchers. 366between multiple watchers, and AnyEvent will ensure that signals will not
367interrupt your program at bad times.
367 368
368This watcher might use C<%SIG>, so programs overwriting those signals 369This watcher might use C<%SIG> (depending on the event loop used),
369directly will likely not work correctly. 370so programs overwriting those signals directly will likely not work
371correctly.
372
373Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not
374support attaching callbacks to signals, which is a pity, as you cannot do
375race-free signal handling in perl. AnyEvent will try to do it's best, but
376in some cases, signals will be delayed. The maximum time a signal might
377be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
378seconds). This variable can be changed only before the first signal
379watcher is created, and should be left alone otherwise. Higher values
380will cause fewer spurious wake-ups, which is better for power and CPU
381saving. All these problems can be avoided by installing the optional
382L<Async::Interrupt> module.
370 383
371Example: exit on SIGINT 384Example: exit on SIGINT
372 385
373 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 386 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374 387
403 416
404This means you cannot create a child watcher as the very first 417This means you cannot create a child watcher as the very first
405thing in an AnyEvent program, you I<have> to create at least one 418thing in an AnyEvent program, you I<have> to create at least one
406watcher before you C<fork> the child (alternatively, you can call 419watcher before you C<fork> the child (alternatively, you can call
407C<AnyEvent::detect>). 420C<AnyEvent::detect>).
421
422As most event loops do not support waiting for child events, they will be
423emulated by AnyEvent in most cases, in which the latency and race problems
424mentioned in the description of signal watchers apply.
408 425
409Example: fork a process and wait for it 426Example: fork a process and wait for it
410 427
411 my $done = AnyEvent->condvar; 428 my $done = AnyEvent->condvar;
412 429
463 480
464If you are familiar with some event loops you will know that all of them 481If you are familiar with some event loops you will know that all of them
465require you to run some blocking "loop", "run" or similar function that 482require you to run some blocking "loop", "run" or similar function that
466will actively watch for new events and call your callbacks. 483will actively watch for new events and call your callbacks.
467 484
468AnyEvent is different, it expects somebody else to run the event loop and 485AnyEvent is slightly different: it expects somebody else to run the event
469will only block when necessary (usually when told by the user). 486loop and will only block when necessary (usually when told by the user).
470 487
471The instrument to do that is called a "condition variable", so called 488The instrument to do that is called a "condition variable", so called
472because they represent a condition that must become true. 489because they represent a condition that must become true.
473 490
491Now is probably a good time to look at the examples further below.
492
474Condition variables can be created by calling the C<< AnyEvent->condvar 493Condition variables can be created by calling the C<< AnyEvent->condvar
475>> method, usually without arguments. The only argument pair allowed is 494>> method, usually without arguments. The only argument pair allowed is
476
477C<cb>, which specifies a callback to be called when the condition variable 495C<cb>, which specifies a callback to be called when the condition variable
478becomes true, with the condition variable as the first argument (but not 496becomes true, with the condition variable as the first argument (but not
479the results). 497the results).
480 498
481After creation, the condition variable is "false" until it becomes "true" 499After creation, the condition variable is "false" until it becomes "true"
530 after => 1, 548 after => 1,
531 cb => sub { $result_ready->send }, 549 cb => sub { $result_ready->send },
532 ); 550 );
533 551
534 # this "blocks" (while handling events) till the callback 552 # this "blocks" (while handling events) till the callback
535 # calls send 553 # calls -<send
536 $result_ready->recv; 554 $result_ready->recv;
537 555
538Example: wait for a timer, but take advantage of the fact that 556Example: wait for a timer, but take advantage of the fact that condition
539condition variables are also code references. 557variables are also callable directly.
540 558
541 my $done = AnyEvent->condvar; 559 my $done = AnyEvent->condvar;
542 my $delay = AnyEvent->timer (after => 5, cb => $done); 560 my $delay = AnyEvent->timer (after => 5, cb => $done);
543 $done->recv; 561 $done->recv;
544 562
550 568
551 ... 569 ...
552 570
553 my @info = $couchdb->info->recv; 571 my @info = $couchdb->info->recv;
554 572
555And this is how you would just ste a callback to be called whenever the 573And this is how you would just set a callback to be called whenever the
556results are available: 574results are available:
557 575
558 $couchdb->info->cb (sub { 576 $couchdb->info->cb (sub {
559 my @info = $_[0]->recv; 577 my @info = $_[0]->recv;
560 }); 578 });
578immediately from within send. 596immediately from within send.
579 597
580Any arguments passed to the C<send> call will be returned by all 598Any arguments passed to the C<send> call will be returned by all
581future C<< ->recv >> calls. 599future C<< ->recv >> calls.
582 600
583Condition variables are overloaded so one can call them directly 601Condition variables are overloaded so one can call them directly (as if
584(as a code reference). Calling them directly is the same as calling 602they were a code reference). Calling them directly is the same as calling
585C<send>. Note, however, that many C-based event loops do not handle 603C<send>.
586overloading, so as tempting as it may be, passing a condition variable
587instead of a callback does not work. Both the pure perl and EV loops
588support overloading, however, as well as all functions that use perl to
589invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
590example).
591 604
592=item $cv->croak ($error) 605=item $cv->croak ($error)
593 606
594Similar to send, but causes all call's to C<< ->recv >> to invoke 607Similar to send, but causes all call's to C<< ->recv >> to invoke
595C<Carp::croak> with the given error message/object/scalar. 608C<Carp::croak> with the given error message/object/scalar.
596 609
597This can be used to signal any errors to the condition variable 610This can be used to signal any errors to the condition variable
598user/consumer. 611user/consumer. Doing it this way instead of calling C<croak> directly
612delays the error detetcion, but has the overwhelmign advantage that it
613diagnoses the error at the place where the result is expected, and not
614deep in some event clalback without connection to the actual code causing
615the problem.
599 616
600=item $cv->begin ([group callback]) 617=item $cv->begin ([group callback])
601 618
602=item $cv->end 619=item $cv->end
603 620
699function will call C<croak>. 716function will call C<croak>.
700 717
701In list context, all parameters passed to C<send> will be returned, 718In list context, all parameters passed to C<send> will be returned,
702in scalar context only the first one will be returned. 719in scalar context only the first one will be returned.
703 720
721Note that doing a blocking wait in a callback is not supported by any
722event loop, that is, recursive invocation of a blocking C<< ->recv
723>> is not allowed, and the C<recv> call will C<croak> if such a
724condition is detected. This condition can be slightly loosened by using
725L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
726any thread that doesn't run the event loop itself.
727
704Not all event models support a blocking wait - some die in that case 728Not all event models support a blocking wait - some die in that case
705(programs might want to do that to stay interactive), so I<if you are 729(programs might want to do that to stay interactive), so I<if you are
706using this from a module, never require a blocking wait>, but let the 730using this from a module, never require a blocking wait>. Instead, let the
707caller decide whether the call will block or not (for example, by coupling 731caller decide whether the call will block or not (for example, by coupling
708condition variables with some kind of request results and supporting 732condition variables with some kind of request results and supporting
709callbacks so the caller knows that getting the result will not block, 733callbacks so the caller knows that getting the result will not block,
710while still supporting blocking waits if the caller so desires). 734while still supporting blocking waits if the caller so desires).
711 735
712Another reason I<never> to C<< ->recv >> in a module is that you cannot
713sensibly have two C<< ->recv >>'s in parallel, as that would require
714multiple interpreters or coroutines/threads, none of which C<AnyEvent>
715can supply.
716
717The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
718fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
719versions and also integrates coroutines into AnyEvent, making blocking
720C<< ->recv >> calls perfectly safe as long as they are done from another
721coroutine (one that doesn't run the event loop).
722
723You can ensure that C<< -recv >> never blocks by setting a callback and 736You can ensure that C<< -recv >> never blocks by setting a callback and
724only calling C<< ->recv >> from within that callback (or at a later 737only calling C<< ->recv >> from within that callback (or at a later
725time). This will work even when the event loop does not support blocking 738time). This will work even when the event loop does not support blocking
726waits otherwise. 739waits otherwise.
727 740
740variable itself. Calling C<recv> inside the callback or at any later time 753variable itself. Calling C<recv> inside the callback or at any later time
741is guaranteed not to block. 754is guaranteed not to block.
742 755
743=back 756=back
744 757
758=head1 SUPPORTED EVENT LOOPS/BACKENDS
759
760The available backend classes are (every class has its own manpage):
761
762=over 4
763
764=item Backends that are autoprobed when no other event loop can be found.
765
766EV is the preferred backend when no other event loop seems to be in
767use. If EV is not installed, then AnyEvent will try Event, and, failing
768that, will fall back to its own pure-perl implementation, which is
769available everywhere as it comes with AnyEvent itself.
770
771 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
772 AnyEvent::Impl::Event based on Event, very stable, few glitches.
773 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
774
775=item Backends that are transparently being picked up when they are used.
776
777These will be used when they are currently loaded when the first watcher
778is created, in which case it is assumed that the application is using
779them. This means that AnyEvent will automatically pick the right backend
780when the main program loads an event module before anything starts to
781create watchers. Nothing special needs to be done by the main program.
782
783 AnyEvent::Impl::Glib based on Glib, slow but very stable.
784 AnyEvent::Impl::Tk based on Tk, very broken.
785 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
786 AnyEvent::Impl::POE based on POE, very slow, some limitations.
787
788=item Backends with special needs.
789
790Qt requires the Qt::Application to be instantiated first, but will
791otherwise be picked up automatically. As long as the main program
792instantiates the application before any AnyEvent watchers are created,
793everything should just work.
794
795 AnyEvent::Impl::Qt based on Qt.
796
797Support for IO::Async can only be partial, as it is too broken and
798architecturally limited to even support the AnyEvent API. It also
799is the only event loop that needs the loop to be set explicitly, so
800it can only be used by a main program knowing about AnyEvent. See
801L<AnyEvent::Impl::Async> for the gory details.
802
803 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
804
805=item Event loops that are indirectly supported via other backends.
806
807Some event loops can be supported via other modules:
808
809There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
810
811B<WxWidgets> has no support for watching file handles. However, you can
812use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
813polls 20 times per second, which was considered to be too horrible to even
814consider for AnyEvent.
815
816B<Prima> is not supported as nobody seems to be using it, but it has a POE
817backend, so it can be supported through POE.
818
819AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
820load L<POE> when detecting them, in the hope that POE will pick them up,
821in which case everything will be automatic.
822
823=back
824
745=head1 GLOBAL VARIABLES AND FUNCTIONS 825=head1 GLOBAL VARIABLES AND FUNCTIONS
746 826
827These are not normally required to use AnyEvent, but can be useful to
828write AnyEvent extension modules.
829
747=over 4 830=over 4
748 831
749=item $AnyEvent::MODEL 832=item $AnyEvent::MODEL
750 833
751Contains C<undef> until the first watcher is being created. Then it 834Contains C<undef> until the first watcher is being created, before the
835backend has been autodetected.
836
752contains the event model that is being used, which is the name of the 837Afterwards it contains the event model that is being used, which is the
753Perl class implementing the model. This class is usually one of the 838name of the Perl class implementing the model. This class is usually one
754C<AnyEvent::Impl:xxx> modules, but can be any other class in the case 839of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
755AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). 840case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
756 841will be C<urxvt::anyevent>).
757The known classes so far are:
758
759 AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
760 AnyEvent::Impl::Event based on Event, second best choice.
761 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
762 AnyEvent::Impl::Glib based on Glib, third-best choice.
763 AnyEvent::Impl::Tk based on Tk, very bad choice.
764 AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
765 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
766 AnyEvent::Impl::POE based on POE, not generic enough for full support.
767
768 # warning, support for IO::Async is only partial, as it is too broken
769 # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
770 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
771
772There is no support for WxWidgets, as WxWidgets has no support for
773watching file handles. However, you can use WxWidgets through the
774POE Adaptor, as POE has a Wx backend that simply polls 20 times per
775second, which was considered to be too horrible to even consider for
776AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
777it's adaptor.
778
779AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
780autodetecting them.
781 842
782=item AnyEvent::detect 843=item AnyEvent::detect
783 844
784Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 845Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
785if necessary. You should only call this function right before you would 846if necessary. You should only call this function right before you would
786have created an AnyEvent watcher anyway, that is, as late as possible at 847have created an AnyEvent watcher anyway, that is, as late as possible at
787runtime. 848runtime, and not e.g. while initialising of your module.
849
850If you need to do some initialisation before AnyEvent watchers are
851created, use C<post_detect>.
788 852
789=item $guard = AnyEvent::post_detect { BLOCK } 853=item $guard = AnyEvent::post_detect { BLOCK }
790 854
791Arranges for the code block to be executed as soon as the event model is 855Arranges for the code block to be executed as soon as the event model is
792autodetected (or immediately if this has already happened). 856autodetected (or immediately if this has already happened).
857
858The block will be executed I<after> the actual backend has been detected
859(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
860created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
861other initialisations - see the sources of L<AnyEvent::Strict> or
862L<AnyEvent::AIO> to see how this is used.
863
864The most common usage is to create some global watchers, without forcing
865event module detection too early, for example, L<AnyEvent::AIO> creates
866and installs the global L<IO::AIO> watcher in a C<post_detect> block to
867avoid autodetecting the event module at load time.
793 868
794If called in scalar or list context, then it creates and returns an object 869If called in scalar or list context, then it creates and returns an object
795that automatically removes the callback again when it is destroyed. See 870that automatically removes the callback again when it is destroyed. See
796L<Coro::BDB> for a case where this is useful. 871L<Coro::BDB> for a case where this is useful.
797 872
800If there are any code references in this array (you can C<push> to it 875If there are any code references in this array (you can C<push> to it
801before or after loading AnyEvent), then they will called directly after 876before or after loading AnyEvent), then they will called directly after
802the event loop has been chosen. 877the event loop has been chosen.
803 878
804You should check C<$AnyEvent::MODEL> before adding to this array, though: 879You should check C<$AnyEvent::MODEL> before adding to this array, though:
805if it contains a true value then the event loop has already been detected, 880if it is defined then the event loop has already been detected, and the
806and the array will be ignored. 881array will be ignored.
807 882
808Best use C<AnyEvent::post_detect { BLOCK }> instead. 883Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
884it,as it takes care of these details.
885
886This variable is mainly useful for modules that can do something useful
887when AnyEvent is used and thus want to know when it is initialised, but do
888not need to even load it by default. This array provides the means to hook
889into AnyEvent passively, without loading it.
809 890
810=back 891=back
811 892
812=head1 WHAT TO DO IN A MODULE 893=head1 WHAT TO DO IN A MODULE
813 894
868 949
869 950
870=head1 OTHER MODULES 951=head1 OTHER MODULES
871 952
872The following is a non-exhaustive list of additional modules that use 953The following is a non-exhaustive list of additional modules that use
873AnyEvent and can therefore be mixed easily with other AnyEvent modules 954AnyEvent as a client and can therefore be mixed easily with other AnyEvent
874in the same program. Some of the modules come with AnyEvent, some are 955modules and other event loops in the same program. Some of the modules
875available via CPAN. 956come with AnyEvent, most are available via CPAN.
876 957
877=over 4 958=over 4
878 959
879=item L<AnyEvent::Util> 960=item L<AnyEvent::Util>
880 961
889 970
890=item L<AnyEvent::Handle> 971=item L<AnyEvent::Handle>
891 972
892Provide read and write buffers, manages watchers for reads and writes, 973Provide read and write buffers, manages watchers for reads and writes,
893supports raw and formatted I/O, I/O queued and fully transparent and 974supports raw and formatted I/O, I/O queued and fully transparent and
894non-blocking SSL/TLS. 975non-blocking SSL/TLS (via L<AnyEvent::TLS>.
895 976
896=item L<AnyEvent::DNS> 977=item L<AnyEvent::DNS>
897 978
898Provides rich asynchronous DNS resolver capabilities. 979Provides rich asynchronous DNS resolver capabilities.
899 980
927 1008
928=item L<AnyEvent::GPSD> 1009=item L<AnyEvent::GPSD>
929 1010
930A non-blocking interface to gpsd, a daemon delivering GPS information. 1011A non-blocking interface to gpsd, a daemon delivering GPS information.
931 1012
1013=item L<AnyEvent::IRC>
1014
1015AnyEvent based IRC client module family (replacing the older Net::IRC3).
1016
1017=item L<AnyEvent::XMPP>
1018
1019AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1020Net::XMPP2>.
1021
932=item L<AnyEvent::IGS> 1022=item L<AnyEvent::IGS>
933 1023
934A non-blocking interface to the Internet Go Server protocol (used by 1024A non-blocking interface to the Internet Go Server protocol (used by
935L<App::IGS>). 1025L<App::IGS>).
936 1026
937=item L<AnyEvent::IRC>
938
939AnyEvent based IRC client module family (replacing the older Net::IRC3).
940
941=item L<Net::XMPP2>
942
943AnyEvent based XMPP (Jabber protocol) module family.
944
945=item L<Net::FCP> 1027=item L<Net::FCP>
946 1028
947AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1029AnyEvent-based implementation of the Freenet Client Protocol, birthplace
948of AnyEvent. 1030of AnyEvent.
949 1031
953 1035
954=item L<Coro> 1036=item L<Coro>
955 1037
956Has special support for AnyEvent via L<Coro::AnyEvent>. 1038Has special support for AnyEvent via L<Coro::AnyEvent>.
957 1039
958=item L<IO::Lambda>
959
960The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
961
962=back 1040=back
963 1041
964=cut 1042=cut
965 1043
966package AnyEvent; 1044package AnyEvent;
967 1045
968no warnings; 1046no warnings;
969use strict qw(vars subs); 1047use strict qw(vars subs);
970 1048
971use Carp; 1049use Carp ();
972 1050
973our $VERSION = 4.45; 1051our $VERSION = 4.83;
974our $MODEL; 1052our $MODEL;
975 1053
976our $AUTOLOAD; 1054our $AUTOLOAD;
977our @ISA; 1055our @ISA;
978 1056
979our @REGISTRY; 1057our @REGISTRY;
980 1058
981our $WIN32; 1059our $WIN32;
1060
1061our $VERBOSE;
982 1062
983BEGIN { 1063BEGIN {
984 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1064 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
985 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1065 eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
986 1066
987 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1067 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
988 if ${^TAINT}; 1068 if ${^TAINT};
989}
990 1069
991our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1070 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1071
1072}
1073
1074our $MAX_SIGNAL_LATENCY = 10;
992 1075
993our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1076our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
994 1077
995{ 1078{
996 my $idx; 1079 my $idx;
1004 [Event:: => AnyEvent::Impl::Event::], 1087 [Event:: => AnyEvent::Impl::Event::],
1005 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1088 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
1006 # everything below here will not be autoprobed 1089 # everything below here will not be autoprobed
1007 # as the pureperl backend should work everywhere 1090 # as the pureperl backend should work everywhere
1008 # and is usually faster 1091 # and is usually faster
1009 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1010 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers 1092 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1011 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1093 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1094 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1012 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1095 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1013 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1096 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1014 [Wx:: => AnyEvent::Impl::POE::], 1097 [Wx:: => AnyEvent::Impl::POE::],
1015 [Prima:: => AnyEvent::Impl::POE::], 1098 [Prima:: => AnyEvent::Impl::POE::],
1016 # IO::Async is just too broken - we would need workaorunds for its 1099 # IO::Async is just too broken - we would need workarounds for its
1017 # byzantine signal and broken child handling, among others. 1100 # byzantine signal and broken child handling, among others.
1018 # IO::Async is rather hard to detect, as it doesn't have any 1101 # IO::Async is rather hard to detect, as it doesn't have any
1019 # obvious default class. 1102 # obvious default class.
1020# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1103# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1021# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1104# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1054 1137
1055 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1138 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1056 my $model = "AnyEvent::Impl::$1"; 1139 my $model = "AnyEvent::Impl::$1";
1057 if (eval "require $model") { 1140 if (eval "require $model") {
1058 $MODEL = $model; 1141 $MODEL = $model;
1059 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1142 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1060 } else { 1143 } else {
1061 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1144 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1062 } 1145 }
1063 } 1146 }
1064 1147
1065 # check for already loaded models 1148 # check for already loaded models
1066 unless ($MODEL) { 1149 unless ($MODEL) {
1067 for (@REGISTRY, @models) { 1150 for (@REGISTRY, @models) {
1068 my ($package, $model) = @$_; 1151 my ($package, $model) = @$_;
1069 if (${"$package\::VERSION"} > 0) { 1152 if (${"$package\::VERSION"} > 0) {
1070 if (eval "require $model") { 1153 if (eval "require $model") {
1071 $MODEL = $model; 1154 $MODEL = $model;
1072 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1155 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1073 last; 1156 last;
1074 } 1157 }
1075 } 1158 }
1076 } 1159 }
1077 1160
1082 my ($package, $model) = @$_; 1165 my ($package, $model) = @$_;
1083 if (eval "require $package" 1166 if (eval "require $package"
1084 and ${"$package\::VERSION"} > 0 1167 and ${"$package\::VERSION"} > 0
1085 and eval "require $model") { 1168 and eval "require $model") {
1086 $MODEL = $model; 1169 $MODEL = $model;
1087 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; 1170 warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1088 last; 1171 last;
1089 } 1172 }
1090 } 1173 }
1091 1174
1092 $MODEL 1175 $MODEL
1108 1191
1109sub AUTOLOAD { 1192sub AUTOLOAD {
1110 (my $func = $AUTOLOAD) =~ s/.*://; 1193 (my $func = $AUTOLOAD) =~ s/.*://;
1111 1194
1112 $method{$func} 1195 $method{$func}
1113 or croak "$func: not a valid method for AnyEvent objects"; 1196 or Carp::croak "$func: not a valid method for AnyEvent objects";
1114 1197
1115 detect unless $MODEL; 1198 detect unless $MODEL;
1116 1199
1117 my $class = shift; 1200 my $class = shift;
1118 $class->$func (@_); 1201 $class->$func (@_);
1123# allow only one watcher per fd, so we dup it to get a different one). 1206# allow only one watcher per fd, so we dup it to get a different one).
1124sub _dupfh($$;$$) { 1207sub _dupfh($$;$$) {
1125 my ($poll, $fh, $r, $w) = @_; 1208 my ($poll, $fh, $r, $w) = @_;
1126 1209
1127 # cygwin requires the fh mode to be matching, unix doesn't 1210 # cygwin requires the fh mode to be matching, unix doesn't
1128 my ($rw, $mode) = $poll eq "r" ? ($r, "<") 1211 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1129 : $poll eq "w" ? ($w, ">")
1130 : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1131 1212
1132 open my $fh2, "$mode&" . fileno $fh 1213 open my $fh2, $mode, $fh
1133 or die "cannot dup() filehandle: $!,"; 1214 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1134 1215
1135 # we assume CLOEXEC is already set by perl in all important cases 1216 # we assume CLOEXEC is already set by perl in all important cases
1136 1217
1137 ($fh2, $rw) 1218 ($fh2, $rw)
1138} 1219}
1139 1220
1140package AnyEvent::Base; 1221package AnyEvent::Base;
1141 1222
1142# default implementations for many methods 1223# default implementations for many methods
1143 1224
1144BEGIN { 1225sub _time {
1226 # probe for availability of Time::HiRes
1145 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1227 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1228 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1146 *_time = \&Time::HiRes::time; 1229 *_time = \&Time::HiRes::time;
1147 # if (eval "use POSIX (); (POSIX::times())... 1230 # if (eval "use POSIX (); (POSIX::times())...
1148 } else { 1231 } else {
1232 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1149 *_time = sub { time }; # epic fail 1233 *_time = sub { time }; # epic fail
1150 } 1234 }
1235
1236 &_time
1151} 1237}
1152 1238
1153sub time { _time } 1239sub time { _time }
1154sub now { _time } 1240sub now { _time }
1155sub now_update { } 1241sub now_update { }
1160 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1246 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1161} 1247}
1162 1248
1163# default implementation for ->signal 1249# default implementation for ->signal
1164 1250
1251our $HAVE_ASYNC_INTERRUPT;
1165our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1252our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1253our (%SIG_ASY, %SIG_ASY_W);
1254our ($SIG_COUNT, $SIG_TW);
1166 1255
1167sub _signal_exec { 1256sub _signal_exec {
1257 $HAVE_ASYNC_INTERRUPT
1258 ? $SIGPIPE_R->drain
1168 sysread $SIGPIPE_R, my $dummy, 4; 1259 : sysread $SIGPIPE_R, my $dummy, 9;
1169 1260
1170 while (%SIG_EV) { 1261 while (%SIG_EV) {
1171 for (keys %SIG_EV) { 1262 for (keys %SIG_EV) {
1172 delete $SIG_EV{$_}; 1263 delete $SIG_EV{$_};
1173 $_->() for values %{ $SIG_CB{$_} || {} }; 1264 $_->() for values %{ $SIG_CB{$_} || {} };
1174 } 1265 }
1175 } 1266 }
1176} 1267}
1177 1268
1269sub _signal {
1270 my (undef, %arg) = @_;
1271
1272 my $signal = uc $arg{signal}
1273 or Carp::croak "required option 'signal' is missing";
1274
1275 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1276
1277 if ($HAVE_ASYNC_INTERRUPT) {
1278 # async::interrupt
1279
1280 $SIG_ASY{$signal} ||= do {
1281 my $asy = new Async::Interrupt
1282 cb => sub { undef $SIG_EV{$signal} },
1283 signal => $signal,
1284 pipe => [$SIGPIPE_R->filenos],
1285 ;
1286 $asy->pipe_autodrain (0);
1287
1288 $asy
1289 };
1290
1291 } else {
1292 # pure perl
1293
1294 $SIG{$signal} ||= sub {
1295 local $!;
1296 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1297 undef $SIG_EV{$signal};
1298 };
1299
1300 # can't do signal processing without introducing races in pure perl,
1301 # so limit the signal latency.
1302 ++$SIG_COUNT;
1303 $SIG_TW ||= AnyEvent->timer (
1304 after => $MAX_SIGNAL_LATENCY,
1305 interval => $MAX_SIGNAL_LATENCY,
1306 cb => sub { }, # just for the PERL_ASYNC_CHECK
1307 );
1308 }
1309
1310 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1311}
1312
1178sub signal { 1313sub signal {
1179 my (undef, %arg) = @_; 1314 # probe for availability of Async::Interrupt
1315 if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1316 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1180 1317
1181 unless ($SIGPIPE_R) { 1318 $HAVE_ASYNC_INTERRUPT = 1;
1319 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1320 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1321
1322 } else {
1323 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1324
1182 require Fcntl; 1325 require Fcntl;
1183 1326
1184 if (AnyEvent::WIN32) { 1327 if (AnyEvent::WIN32) {
1185 require AnyEvent::Util; 1328 require AnyEvent::Util;
1186 1329
1201 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1344 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1202 1345
1203 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); 1346 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1204 } 1347 }
1205 1348
1206 my $signal = uc $arg{signal} 1349 *signal = \&_signal;
1207 or Carp::croak "required option 'signal' is missing"; 1350 &signal
1208
1209 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1210 $SIG{$signal} ||= sub {
1211 local $!;
1212 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1213 undef $SIG_EV{$signal};
1214 };
1215
1216 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1217} 1351}
1218 1352
1219sub AnyEvent::Base::signal::DESTROY { 1353sub AnyEvent::Base::signal::DESTROY {
1220 my ($signal, $cb) = @{$_[0]}; 1354 my ($signal, $cb) = @{$_[0]};
1355
1356 undef $SIG_TW
1357 unless --$SIG_COUNT;
1221 1358
1222 delete $SIG_CB{$signal}{$cb}; 1359 delete $SIG_CB{$signal}{$cb};
1223 1360
1224 # delete doesn't work with older perls - they then 1361 # delete doesn't work with older perls - they then
1225 # print weird messages, or just unconditionally exit 1362 # print weird messages, or just unconditionally exit
1226 # instead of getting the default action. 1363 # instead of getting the default action.
1364 undef $SIG{$signal}
1227 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; 1365 unless keys %{ $SIG_CB{$signal} };
1228} 1366}
1229 1367
1230# default implementation for ->child 1368# default implementation for ->child
1231 1369
1232our %PID_CB; 1370our %PID_CB;
1234our $CHLD_DELAY_W; 1372our $CHLD_DELAY_W;
1235our $WNOHANG; 1373our $WNOHANG;
1236 1374
1237sub _sigchld { 1375sub _sigchld {
1238 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1376 while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1377 $_->($pid, $?)
1239 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1378 for values %{ $PID_CB{$pid} || {} },
1240 (values %{ $PID_CB{0} || {} }); 1379 values %{ $PID_CB{0} || {} };
1241 } 1380 }
1242} 1381}
1243 1382
1244sub child { 1383sub child {
1245 my (undef, %arg) = @_; 1384 my (undef, %arg) = @_;
1313 1452
1314use overload 1453use overload
1315 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1454 '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1316 fallback => 1; 1455 fallback => 1;
1317 1456
1457our $WAITING;
1458
1318sub _send { 1459sub _send {
1319 # nop 1460 # nop
1320} 1461}
1321 1462
1322sub send { 1463sub send {
1334sub ready { 1475sub ready {
1335 $_[0]{_ae_sent} 1476 $_[0]{_ae_sent}
1336} 1477}
1337 1478
1338sub _wait { 1479sub _wait {
1480 $WAITING
1481 and !$_[0]{_ae_sent}
1482 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1483
1484 local $WAITING = 1;
1339 AnyEvent->one_event while !$_[0]{_ae_sent}; 1485 AnyEvent->one_event while !$_[0]{_ae_sent};
1340} 1486}
1341 1487
1342sub recv { 1488sub recv {
1343 $_[0]->_wait; 1489 $_[0]->_wait;
1470 1616
1471=item C<PERL_ANYEVENT_MAX_FORKS> 1617=item C<PERL_ANYEVENT_MAX_FORKS>
1472 1618
1473The maximum number of child processes that C<AnyEvent::Util::fork_call> 1619The maximum number of child processes that C<AnyEvent::Util::fork_call>
1474will create in parallel. 1620will create in parallel.
1621
1622=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
1623
1624The default value for the C<max_outstanding> parameter for the default DNS
1625resolver - this is the maximum number of parallel DNS requests that are
1626sent to the DNS server.
1627
1628=item C<PERL_ANYEVENT_RESOLV_CONF>
1629
1630The file to use instead of F</etc/resolv.conf> (or OS-specific
1631configuration) in the default resolver. When set to the empty string, no
1632default config will be used.
1633
1634=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1635
1636When neither C<ca_file> nor C<ca_path> was specified during
1637L<AnyEvent::TLS> context creation, and either of these environment
1638variables exist, they will be used to specify CA certificate locations
1639instead of a system-dependent default.
1475 1640
1476=back 1641=back
1477 1642
1478=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1643=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1479 1644
2018 2183
2019A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2184A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2020emulation for event loops that do not support them natively. Also, some 2185emulation for event loops that do not support them natively. Also, some
2021event loops install a similar handler. 2186event loops install a similar handler.
2022 2187
2023If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2188Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2024reset it to default, to avoid losing child exit statuses. 2189AnyEvent will reset it to default, to avoid losing child exit statuses.
2025 2190
2026=item SIGPIPE 2191=item SIGPIPE
2027 2192
2028A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2193A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2029when AnyEvent gets loaded. 2194when AnyEvent gets loaded.
2047 if $SIG{CHLD} eq 'IGNORE'; 2212 if $SIG{CHLD} eq 'IGNORE';
2048 2213
2049$SIG{PIPE} = sub { } 2214$SIG{PIPE} = sub { }
2050 unless defined $SIG{PIPE}; 2215 unless defined $SIG{PIPE};
2051 2216
2217=head1 RECOMMENDED/OPTIONAL MODULES
2218
2219One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2220it's built-in modules) are required to use it.
2221
2222That does not mean that AnyEvent won't take advantage of some additional
2223modules if they are installed.
2224
2225This section epxlains which additional modules will be used, and how they
2226affect AnyEvent's operetion.
2227
2228=over 4
2229
2230=item L<Async::Interrupt>
2231
2232This slightly arcane module is used to implement fast signal handling: To
2233my knowledge, there is no way to do completely race-free and quick
2234signal handling in pure perl. To ensure that signals still get
2235delivered, AnyEvent will start an interval timer to wake up perl (and
2236catch the signals) with soemd elay (default is 10 seconds, look for
2237C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2238
2239If this module is available, then it will be used to implement signal
2240catching, which means that signals will not be delayed, and the event loop
2241will not be interrupted regularly, which is more efficient (And good for
2242battery life on laptops).
2243
2244This affects not just the pure-perl event loop, but also other event loops
2245that have no signal handling on their own (e.g. Glib, Tk, Qt).
2246
2247=item L<EV>
2248
2249This module isn't really "optional", as it is simply one of the backend
2250event loops that AnyEvent can use. However, it is simply the best event
2251loop available in terms of features, speed and stability: It supports
2252the AnyEvent API optimally, implements all the watcher types in XS, does
2253automatic timer adjustments even when no monotonic clock is available,
2254can take avdantage of advanced kernel interfaces such as C<epoll> and
2255C<kqueue>, and is the fastest backend I<by far>. You can even embed
2256L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2257
2258=item L<Guard>
2259
2260The guard module, when used, will be used to implement
2261C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2262lot less memory), but otherwise doesn't affect guard operation much. It is
2263purely used for performance.
2264
2265=item L<JSON> and L<JSON::XS>
2266
2267This module is required when you want to read or write JSON data via
2268L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2269advantage of the ulta-high-speed L<JSON::XS> module when it is installed.
2270
2271In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2272installed.
2273
2274=item L<Net::SSLeay>
2275
2276Implementing TLS/SSL in Perl is certainly interesting, but not very
2277worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2278the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2279
2280=item L<Time::HiRes>
2281
2282This module is part of perl since release 5.008. It will be used when the
2283chosen event library does not come with a timing source on it's own. The
2284pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2285try to use a monotonic clock for timing stability.
2286
2287=back
2288
2289
2052=head1 FORK 2290=head1 FORK
2053 2291
2054Most event libraries are not fork-safe. The ones who are usually are 2292Most event libraries are not fork-safe. The ones who are usually are
2055because they rely on inefficient but fork-safe C<select> or C<poll> 2293because they rely on inefficient but fork-safe C<select> or C<poll>
2056calls. Only L<EV> is fully fork-aware. 2294calls. Only L<EV> is fully fork-aware.
2057 2295
2058If you have to fork, you must either do so I<before> creating your first 2296If you have to fork, you must either do so I<before> creating your first
2059watcher OR you must not use AnyEvent at all in the child. 2297watcher OR you must not use AnyEvent at all in the child OR you must do
2298something completely out of the scope of AnyEvent.
2060 2299
2061 2300
2062=head1 SECURITY CONSIDERATIONS 2301=head1 SECURITY CONSIDERATIONS
2063 2302
2064AnyEvent can be forced to load any event model via 2303AnyEvent can be forced to load any event model via
2102L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2341L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2103 2342
2104Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2343Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2105L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2344L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2106L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2345L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2107L<AnyEvent::Impl::POE>. 2346L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
2108 2347
2109Non-blocking file handles, sockets, TCP clients and 2348Non-blocking file handles, sockets, TCP clients and
2110servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2349servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2111 2350
2112Asynchronous DNS: L<AnyEvent::DNS>. 2351Asynchronous DNS: L<AnyEvent::DNS>.
2113 2352
2114Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2353Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2354L<Coro::Event>,
2115 2355
2116Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2356Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2357L<AnyEvent::HTTP>.
2117 2358
2118 2359
2119=head1 AUTHOR 2360=head1 AUTHOR
2120 2361
2121 Marc Lehmann <schmorp@schmorp.de> 2362 Marc Lehmann <schmorp@schmorp.de>

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