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1=head1 NAME 1=head1 NAME
2 2
3AnyEvent - provide framework for multiple event loops 3AnyEvent - the DBI of event loop programming
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported 5EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6event loops. 6and POE are various supported event loops/environments.
7 7
8=head1 SYNOPSIS 8=head1 SYNOPSIS
9 9
10 use AnyEvent; 10 use AnyEvent;
11 11
40=head1 INTRODUCTION/TUTORIAL 40=head1 INTRODUCTION/TUTORIAL
41 41
42This manpage is mainly a reference manual. If you are interested 42This manpage is mainly a reference manual. If you are interested
43in a tutorial or some gentle introduction, have a look at the 43in a tutorial or some gentle introduction, have a look at the
44L<AnyEvent::Intro> manpage. 44L<AnyEvent::Intro> manpage.
45
46=head1 SUPPORT
47
48There is a mailinglist for discussing all things AnyEvent, and an IRC
49channel, too.
50
51See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52Repository>, at L<http://anyevent.schmorp.de>, for more info.
45 53
46=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 54=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47 55
48Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 56Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49nowadays. So what is different about AnyEvent? 57nowadays. So what is different about AnyEvent?
361invocation, and callback invocation will be synchronous. Synchronous means 369invocation, and callback invocation will be synchronous. Synchronous means
362that it might take a while until the signal gets handled by the process, 370that it might take a while until the signal gets handled by the process,
363but it is guaranteed not to interrupt any other callbacks. 371but it is guaranteed not to interrupt any other callbacks.
364 372
365The main advantage of using these watchers is that you can share a signal 373The main advantage of using these watchers is that you can share a signal
366between multiple watchers. 374between multiple watchers, and AnyEvent will ensure that signals will not
375interrupt your program at bad times.
367 376
368This watcher might use C<%SIG>, so programs overwriting those signals 377This watcher might use C<%SIG> (depending on the event loop used),
369directly will likely not work correctly. 378so programs overwriting those signals directly will likely not work
379correctly.
370 380
371Example: exit on SIGINT 381Example: exit on SIGINT
372 382
373 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 383 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374 384
385=head3 Signal Races, Delays and Workarounds
386
387Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
388callbacks to signals in a generic way, which is a pity, as you cannot do
389race-free signal handling in perl. AnyEvent will try to do it's best, but
390in some cases, signals will be delayed. The maximum time a signal might
391be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
392seconds). This variable can be changed only before the first signal
393watcher is created, and should be left alone otherwise. Higher values
394will cause fewer spurious wake-ups, which is better for power and CPU
395saving. All these problems can be avoided by installing the optional
396L<Async::Interrupt> module. This will not work with inherently broken
397event loops such as L<Event> or L<Event::Lib> (and not with L<POE>
398currently, as POE does it's own workaround with one-second latency). With
399those, you just have to suffer the delays.
400
375=head2 CHILD PROCESS WATCHERS 401=head2 CHILD PROCESS WATCHERS
376 402
377You can also watch on a child process exit and catch its exit status. 403You can also watch on a child process exit and catch its exit status.
378 404
379The child process is specified by the C<pid> argument (if set to C<0>, it 405The child process is specified by the C<pid> argument (one some backends,
380watches for any child process exit). The watcher will triggered only when 406using C<0> watches for any child process exit, on others this will
381the child process has finished and an exit status is available, not on 407croak). The watcher will be triggered only when the child process has
382any trace events (stopped/continued). 408finished and an exit status is available, not on any trace events
409(stopped/continued).
383 410
384The callback will be called with the pid and exit status (as returned by 411The callback will be called with the pid and exit status (as returned by
385waitpid), so unlike other watcher types, you I<can> rely on child watcher 412waitpid), so unlike other watcher types, you I<can> rely on child watcher
386callback arguments. 413callback arguments.
387 414
403 430
404This means you cannot create a child watcher as the very first 431This means you cannot create a child watcher as the very first
405thing in an AnyEvent program, you I<have> to create at least one 432thing in an AnyEvent program, you I<have> to create at least one
406watcher before you C<fork> the child (alternatively, you can call 433watcher before you C<fork> the child (alternatively, you can call
407C<AnyEvent::detect>). 434C<AnyEvent::detect>).
435
436As most event loops do not support waiting for child events, they will be
437emulated by AnyEvent in most cases, in which the latency and race problems
438mentioned in the description of signal watchers apply.
408 439
409Example: fork a process and wait for it 440Example: fork a process and wait for it
410 441
411 my $done = AnyEvent->condvar; 442 my $done = AnyEvent->condvar;
412 443
463 494
464If you are familiar with some event loops you will know that all of them 495If 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 496require you to run some blocking "loop", "run" or similar function that
466will actively watch for new events and call your callbacks. 497will actively watch for new events and call your callbacks.
467 498
468AnyEvent is different, it expects somebody else to run the event loop and 499AnyEvent is slightly different: it expects somebody else to run the event
469will only block when necessary (usually when told by the user). 500loop and will only block when necessary (usually when told by the user).
470 501
471The instrument to do that is called a "condition variable", so called 502The instrument to do that is called a "condition variable", so called
472because they represent a condition that must become true. 503because they represent a condition that must become true.
473 504
505Now is probably a good time to look at the examples further below.
506
474Condition variables can be created by calling the C<< AnyEvent->condvar 507Condition variables can be created by calling the C<< AnyEvent->condvar
475>> method, usually without arguments. The only argument pair allowed is 508>> method, usually without arguments. The only argument pair allowed is
476
477C<cb>, which specifies a callback to be called when the condition variable 509C<cb>, which specifies a callback to be called when the condition variable
478becomes true, with the condition variable as the first argument (but not 510becomes true, with the condition variable as the first argument (but not
479the results). 511the results).
480 512
481After creation, the condition variable is "false" until it becomes "true" 513After creation, the condition variable is "false" until it becomes "true"
486Condition variables are similar to callbacks, except that you can 518Condition variables are similar to callbacks, except that you can
487optionally wait for them. They can also be called merge points - points 519optionally wait for them. They can also be called merge points - points
488in time where multiple outstanding events have been processed. And yet 520in time where multiple outstanding events have been processed. And yet
489another way to call them is transactions - each condition variable can be 521another way to call them is transactions - each condition variable can be
490used to represent a transaction, which finishes at some point and delivers 522used to represent a transaction, which finishes at some point and delivers
491a result. 523a result. And yet some people know them as "futures" - a promise to
524compute/deliver something that you can wait for.
492 525
493Condition variables are very useful to signal that something has finished, 526Condition variables are very useful to signal that something has finished,
494for example, if you write a module that does asynchronous http requests, 527for example, if you write a module that does asynchronous http requests,
495then a condition variable would be the ideal candidate to signal the 528then a condition variable would be the ideal candidate to signal the
496availability of results. The user can either act when the callback is 529availability of results. The user can either act when the callback is
530 after => 1, 563 after => 1,
531 cb => sub { $result_ready->send }, 564 cb => sub { $result_ready->send },
532 ); 565 );
533 566
534 # this "blocks" (while handling events) till the callback 567 # this "blocks" (while handling events) till the callback
535 # calls send 568 # calls -<send
536 $result_ready->recv; 569 $result_ready->recv;
537 570
538Example: wait for a timer, but take advantage of the fact that 571Example: wait for a timer, but take advantage of the fact that condition
539condition variables are also code references. 572variables are also callable directly.
540 573
541 my $done = AnyEvent->condvar; 574 my $done = AnyEvent->condvar;
542 my $delay = AnyEvent->timer (after => 5, cb => $done); 575 my $delay = AnyEvent->timer (after => 5, cb => $done);
543 $done->recv; 576 $done->recv;
544 577
550 583
551 ... 584 ...
552 585
553 my @info = $couchdb->info->recv; 586 my @info = $couchdb->info->recv;
554 587
555And this is how you would just ste a callback to be called whenever the 588And this is how you would just set a callback to be called whenever the
556results are available: 589results are available:
557 590
558 $couchdb->info->cb (sub { 591 $couchdb->info->cb (sub {
559 my @info = $_[0]->recv; 592 my @info = $_[0]->recv;
560 }); 593 });
578immediately from within send. 611immediately from within send.
579 612
580Any arguments passed to the C<send> call will be returned by all 613Any arguments passed to the C<send> call will be returned by all
581future C<< ->recv >> calls. 614future C<< ->recv >> calls.
582 615
583Condition variables are overloaded so one can call them directly 616Condition variables are overloaded so one can call them directly (as if
584(as a code reference). Calling them directly is the same as calling 617they 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 618C<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).
591 619
592=item $cv->croak ($error) 620=item $cv->croak ($error)
593 621
594Similar to send, but causes all call's to C<< ->recv >> to invoke 622Similar to send, but causes all call's to C<< ->recv >> to invoke
595C<Carp::croak> with the given error message/object/scalar. 623C<Carp::croak> with the given error message/object/scalar.
596 624
597This can be used to signal any errors to the condition variable 625This can be used to signal any errors to the condition variable
598user/consumer. 626user/consumer. Doing it this way instead of calling C<croak> directly
627delays the error detetcion, but has the overwhelmign advantage that it
628diagnoses the error at the place where the result is expected, and not
629deep in some event clalback without connection to the actual code causing
630the problem.
599 631
600=item $cv->begin ([group callback]) 632=item $cv->begin ([group callback])
601 633
602=item $cv->end 634=item $cv->end
603 635
699function will call C<croak>. 731function will call C<croak>.
700 732
701In list context, all parameters passed to C<send> will be returned, 733In list context, all parameters passed to C<send> will be returned,
702in scalar context only the first one will be returned. 734in scalar context only the first one will be returned.
703 735
736Note that doing a blocking wait in a callback is not supported by any
737event loop, that is, recursive invocation of a blocking C<< ->recv
738>> is not allowed, and the C<recv> call will C<croak> if such a
739condition is detected. This condition can be slightly loosened by using
740L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
741any thread that doesn't run the event loop itself.
742
704Not all event models support a blocking wait - some die in that case 743Not 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 744(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 745using 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 746caller decide whether the call will block or not (for example, by coupling
708condition variables with some kind of request results and supporting 747condition variables with some kind of request results and supporting
709callbacks so the caller knows that getting the result will not block, 748callbacks so the caller knows that getting the result will not block,
710while still supporting blocking waits if the caller so desires). 749while still supporting blocking waits if the caller so desires).
711 750
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 751You can ensure that C<< -recv >> never blocks by setting a callback and
724only calling C<< ->recv >> from within that callback (or at a later 752only calling C<< ->recv >> from within that callback (or at a later
725time). This will work even when the event loop does not support blocking 753time). This will work even when the event loop does not support blocking
726waits otherwise. 754waits otherwise.
727 755
740variable itself. Calling C<recv> inside the callback or at any later time 768variable itself. Calling C<recv> inside the callback or at any later time
741is guaranteed not to block. 769is guaranteed not to block.
742 770
743=back 771=back
744 772
773=head1 SUPPORTED EVENT LOOPS/BACKENDS
774
775The available backend classes are (every class has its own manpage):
776
777=over 4
778
779=item Backends that are autoprobed when no other event loop can be found.
780
781EV is the preferred backend when no other event loop seems to be in
782use. If EV is not installed, then AnyEvent will try Event, and, failing
783that, will fall back to its own pure-perl implementation, which is
784available everywhere as it comes with AnyEvent itself.
785
786 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
787 AnyEvent::Impl::Event based on Event, very stable, few glitches.
788 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
789
790=item Backends that are transparently being picked up when they are used.
791
792These will be used when they are currently loaded when the first watcher
793is created, in which case it is assumed that the application is using
794them. This means that AnyEvent will automatically pick the right backend
795when the main program loads an event module before anything starts to
796create watchers. Nothing special needs to be done by the main program.
797
798 AnyEvent::Impl::Glib based on Glib, slow but very stable.
799 AnyEvent::Impl::Tk based on Tk, very broken.
800 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
801 AnyEvent::Impl::POE based on POE, very slow, some limitations.
802 AnyEvent::Impl::Irssi used when running within irssi.
803
804=item Backends with special needs.
805
806Qt requires the Qt::Application to be instantiated first, but will
807otherwise be picked up automatically. As long as the main program
808instantiates the application before any AnyEvent watchers are created,
809everything should just work.
810
811 AnyEvent::Impl::Qt based on Qt.
812
813Support for IO::Async can only be partial, as it is too broken and
814architecturally limited to even support the AnyEvent API. It also
815is the only event loop that needs the loop to be set explicitly, so
816it can only be used by a main program knowing about AnyEvent. See
817L<AnyEvent::Impl::Async> for the gory details.
818
819 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
820
821=item Event loops that are indirectly supported via other backends.
822
823Some event loops can be supported via other modules:
824
825There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
826
827B<WxWidgets> has no support for watching file handles. However, you can
828use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
829polls 20 times per second, which was considered to be too horrible to even
830consider for AnyEvent.
831
832B<Prima> is not supported as nobody seems to be using it, but it has a POE
833backend, so it can be supported through POE.
834
835AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
836load L<POE> when detecting them, in the hope that POE will pick them up,
837in which case everything will be automatic.
838
839=back
840
745=head1 GLOBAL VARIABLES AND FUNCTIONS 841=head1 GLOBAL VARIABLES AND FUNCTIONS
746 842
843These are not normally required to use AnyEvent, but can be useful to
844write AnyEvent extension modules.
845
747=over 4 846=over 4
748 847
749=item $AnyEvent::MODEL 848=item $AnyEvent::MODEL
750 849
751Contains C<undef> until the first watcher is being created. Then it 850Contains C<undef> until the first watcher is being created, before the
851backend has been autodetected.
852
752contains the event model that is being used, which is the name of the 853Afterwards it contains the event model that is being used, which is the
753Perl class implementing the model. This class is usually one of the 854name 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 855of 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>). 856case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
756 857will 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.
781 858
782=item AnyEvent::detect 859=item AnyEvent::detect
783 860
784Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 861Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
785if necessary. You should only call this function right before you would 862if necessary. You should only call this function right before you would
786have created an AnyEvent watcher anyway, that is, as late as possible at 863have created an AnyEvent watcher anyway, that is, as late as possible at
787runtime. 864runtime, and not e.g. while initialising of your module.
865
866If you need to do some initialisation before AnyEvent watchers are
867created, use C<post_detect>.
788 868
789=item $guard = AnyEvent::post_detect { BLOCK } 869=item $guard = AnyEvent::post_detect { BLOCK }
790 870
791Arranges for the code block to be executed as soon as the event model is 871Arranges for the code block to be executed as soon as the event model is
792autodetected (or immediately if this has already happened). 872autodetected (or immediately if this has already happened).
793 873
874The block will be executed I<after> the actual backend has been detected
875(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
876created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
877other initialisations - see the sources of L<AnyEvent::Strict> or
878L<AnyEvent::AIO> to see how this is used.
879
880The most common usage is to create some global watchers, without forcing
881event module detection too early, for example, L<AnyEvent::AIO> creates
882and installs the global L<IO::AIO> watcher in a C<post_detect> block to
883avoid autodetecting the event module at load time.
884
794If called in scalar or list context, then it creates and returns an object 885If called in scalar or list context, then it creates and returns an object
795that automatically removes the callback again when it is destroyed. See 886that automatically removes the callback again when it is destroyed (or
887C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
796L<Coro::BDB> for a case where this is useful. 888a case where this is useful.
889
890Example: Create a watcher for the IO::AIO module and store it in
891C<$WATCHER>. Only do so after the event loop is initialised, though.
892
893 our WATCHER;
894
895 my $guard = AnyEvent::post_detect {
896 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
897 };
898
899 # the ||= is important in case post_detect immediately runs the block,
900 # as to not clobber the newly-created watcher. assigning both watcher and
901 # post_detect guard to the same variable has the advantage of users being
902 # able to just C<undef $WATCHER> if the watcher causes them grief.
903
904 $WATCHER ||= $guard;
797 905
798=item @AnyEvent::post_detect 906=item @AnyEvent::post_detect
799 907
800If there are any code references in this array (you can C<push> to it 908If there are any code references in this array (you can C<push> to it
801before or after loading AnyEvent), then they will called directly after 909before or after loading AnyEvent), then they will called directly after
802the event loop has been chosen. 910the event loop has been chosen.
803 911
804You should check C<$AnyEvent::MODEL> before adding to this array, though: 912You 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, 913if it is defined then the event loop has already been detected, and the
806and the array will be ignored. 914array will be ignored.
807 915
808Best use C<AnyEvent::post_detect { BLOCK }> instead. 916Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
917it,as it takes care of these details.
918
919This variable is mainly useful for modules that can do something useful
920when AnyEvent is used and thus want to know when it is initialised, but do
921not need to even load it by default. This array provides the means to hook
922into AnyEvent passively, without loading it.
809 923
810=back 924=back
811 925
812=head1 WHAT TO DO IN A MODULE 926=head1 WHAT TO DO IN A MODULE
813 927
868 982
869 983
870=head1 OTHER MODULES 984=head1 OTHER MODULES
871 985
872The following is a non-exhaustive list of additional modules that use 986The following is a non-exhaustive list of additional modules that use
873AnyEvent and can therefore be mixed easily with other AnyEvent modules 987AnyEvent 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 988modules and other event loops in the same program. Some of the modules
875available via CPAN. 989come with AnyEvent, most are available via CPAN.
876 990
877=over 4 991=over 4
878 992
879=item L<AnyEvent::Util> 993=item L<AnyEvent::Util>
880 994
889 1003
890=item L<AnyEvent::Handle> 1004=item L<AnyEvent::Handle>
891 1005
892Provide read and write buffers, manages watchers for reads and writes, 1006Provide read and write buffers, manages watchers for reads and writes,
893supports raw and formatted I/O, I/O queued and fully transparent and 1007supports raw and formatted I/O, I/O queued and fully transparent and
894non-blocking SSL/TLS. 1008non-blocking SSL/TLS (via L<AnyEvent::TLS>.
895 1009
896=item L<AnyEvent::DNS> 1010=item L<AnyEvent::DNS>
897 1011
898Provides rich asynchronous DNS resolver capabilities. 1012Provides rich asynchronous DNS resolver capabilities.
899 1013
927 1041
928=item L<AnyEvent::GPSD> 1042=item L<AnyEvent::GPSD>
929 1043
930A non-blocking interface to gpsd, a daemon delivering GPS information. 1044A non-blocking interface to gpsd, a daemon delivering GPS information.
931 1045
1046=item L<AnyEvent::IRC>
1047
1048AnyEvent based IRC client module family (replacing the older Net::IRC3).
1049
1050=item L<AnyEvent::XMPP>
1051
1052AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1053Net::XMPP2>.
1054
932=item L<AnyEvent::IGS> 1055=item L<AnyEvent::IGS>
933 1056
934A non-blocking interface to the Internet Go Server protocol (used by 1057A non-blocking interface to the Internet Go Server protocol (used by
935L<App::IGS>). 1058L<App::IGS>).
936 1059
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> 1060=item L<Net::FCP>
946 1061
947AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1062AnyEvent-based implementation of the Freenet Client Protocol, birthplace
948of AnyEvent. 1063of AnyEvent.
949 1064
953 1068
954=item L<Coro> 1069=item L<Coro>
955 1070
956Has special support for AnyEvent via L<Coro::AnyEvent>. 1071Has special support for AnyEvent via L<Coro::AnyEvent>.
957 1072
958=item L<IO::Lambda>
959
960The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
961
962=back 1073=back
963 1074
964=cut 1075=cut
965 1076
966package AnyEvent; 1077package AnyEvent;
967 1078
1079# basically a tuned-down version of common::sense
1080sub common_sense {
968no warnings; 1081 # no warnings
1082 ${^WARNING_BITS} ^= ${^WARNING_BITS};
969use strict qw(vars subs); 1083 # use strict vars subs
1084 $^H |= 0x00000600;
1085}
970 1086
1087BEGIN { AnyEvent::common_sense }
1088
971use Carp; 1089use Carp ();
972 1090
973our $VERSION = 4.8; 1091our $VERSION = 4.881;
974our $MODEL; 1092our $MODEL;
975 1093
976our $AUTOLOAD; 1094our $AUTOLOAD;
977our @ISA; 1095our @ISA;
978 1096
979our @REGISTRY; 1097our @REGISTRY;
980 1098
981our $WIN32; 1099our $WIN32;
1100
1101our $VERBOSE;
982 1102
983BEGIN { 1103BEGIN {
984 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1104 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
985 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1105 eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
986 1106
987 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1107 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
988 if ${^TAINT}; 1108 if ${^TAINT};
989}
990 1109
991our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1110 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1111
1112}
1113
1114our $MAX_SIGNAL_LATENCY = 10;
992 1115
993our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1116our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
994 1117
995{ 1118{
996 my $idx; 1119 my $idx;
998 for reverse split /\s*,\s*/, 1121 for reverse split /\s*,\s*/,
999 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1122 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1000} 1123}
1001 1124
1002my @models = ( 1125my @models = (
1003 [EV:: => AnyEvent::Impl::EV::], 1126 [EV:: => AnyEvent::Impl::EV:: , 1],
1004 [Event:: => AnyEvent::Impl::Event::], 1127 [Event:: => AnyEvent::Impl::Event::, 1],
1005 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1128 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1006 # everything below here will not be autoprobed 1129 # everything below here will not (normally) be autoprobed
1007 # as the pureperl backend should work everywhere 1130 # as the pureperl backend should work everywhere
1008 # and is usually faster 1131 # and is usually faster
1132 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1133 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1134 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1009 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1135 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1010 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1011 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1012 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1136 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1013 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1137 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1014 [Wx:: => AnyEvent::Impl::POE::], 1138 [Wx:: => AnyEvent::Impl::POE::],
1015 [Prima:: => AnyEvent::Impl::POE::], 1139 [Prima:: => AnyEvent::Impl::POE::],
1016 # IO::Async is just too broken - we would need workaorunds for its 1140 # IO::Async is just too broken - we would need workarounds for its
1017 # byzantine signal and broken child handling, among others. 1141 # byzantine signal and broken child handling, among others.
1018 # IO::Async is rather hard to detect, as it doesn't have any 1142 # IO::Async is rather hard to detect, as it doesn't have any
1019 # obvious default class. 1143 # obvious default class.
1020# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1144# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1021# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1145# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1022# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1146# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1023); 1147);
1024 1148
1025our %method = map +($_ => 1), 1149our %method = map +($_ => 1),
1026 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1150 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1027 1151
1031 my ($cb) = @_; 1155 my ($cb) = @_;
1032 1156
1033 if ($MODEL) { 1157 if ($MODEL) {
1034 $cb->(); 1158 $cb->();
1035 1159
1036 1 1160 undef
1037 } else { 1161 } else {
1038 push @post_detect, $cb; 1162 push @post_detect, $cb;
1039 1163
1040 defined wantarray 1164 defined wantarray
1041 ? bless \$cb, "AnyEvent::Util::postdetect" 1165 ? bless \$cb, "AnyEvent::Util::postdetect"
1047 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1171 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1048} 1172}
1049 1173
1050sub detect() { 1174sub detect() {
1051 unless ($MODEL) { 1175 unless ($MODEL) {
1052 no strict 'refs';
1053 local $SIG{__DIE__}; 1176 local $SIG{__DIE__};
1054 1177
1055 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1178 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1056 my $model = "AnyEvent::Impl::$1"; 1179 my $model = "AnyEvent::Impl::$1";
1057 if (eval "require $model") { 1180 if (eval "require $model") {
1058 $MODEL = $model; 1181 $MODEL = $model;
1059 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1182 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1060 } else { 1183 } else {
1061 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1184 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1062 } 1185 }
1063 } 1186 }
1064 1187
1065 # check for already loaded models 1188 # check for already loaded models
1066 unless ($MODEL) { 1189 unless ($MODEL) {
1067 for (@REGISTRY, @models) { 1190 for (@REGISTRY, @models) {
1068 my ($package, $model) = @$_; 1191 my ($package, $model) = @$_;
1069 if (${"$package\::VERSION"} > 0) { 1192 if (${"$package\::VERSION"} > 0) {
1070 if (eval "require $model") { 1193 if (eval "require $model") {
1071 $MODEL = $model; 1194 $MODEL = $model;
1072 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1195 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1073 last; 1196 last;
1074 } 1197 }
1075 } 1198 }
1076 } 1199 }
1077 1200
1078 unless ($MODEL) { 1201 unless ($MODEL) {
1079 # try to load a model 1202 # try to autoload a model
1080
1081 for (@REGISTRY, @models) { 1203 for (@REGISTRY, @models) {
1082 my ($package, $model) = @$_; 1204 my ($package, $model, $autoload) = @$_;
1205 if (
1206 $autoload
1083 if (eval "require $package" 1207 and eval "require $package"
1084 and ${"$package\::VERSION"} > 0 1208 and ${"$package\::VERSION"} > 0
1085 and eval "require $model") { 1209 and eval "require $model"
1210 ) {
1086 $MODEL = $model; 1211 $MODEL = $model;
1087 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; 1212 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1088 last; 1213 last;
1089 } 1214 }
1090 } 1215 }
1091 1216
1092 $MODEL 1217 $MODEL
1108 1233
1109sub AUTOLOAD { 1234sub AUTOLOAD {
1110 (my $func = $AUTOLOAD) =~ s/.*://; 1235 (my $func = $AUTOLOAD) =~ s/.*://;
1111 1236
1112 $method{$func} 1237 $method{$func}
1113 or croak "$func: not a valid method for AnyEvent objects"; 1238 or Carp::croak "$func: not a valid method for AnyEvent objects";
1114 1239
1115 detect unless $MODEL; 1240 detect unless $MODEL;
1116 1241
1117 my $class = shift; 1242 my $class = shift;
1118 $class->$func (@_); 1243 $class->$func (@_);
1123# allow only one watcher per fd, so we dup it to get a different one). 1248# allow only one watcher per fd, so we dup it to get a different one).
1124sub _dupfh($$;$$) { 1249sub _dupfh($$;$$) {
1125 my ($poll, $fh, $r, $w) = @_; 1250 my ($poll, $fh, $r, $w) = @_;
1126 1251
1127 # cygwin requires the fh mode to be matching, unix doesn't 1252 # cygwin requires the fh mode to be matching, unix doesn't
1128 my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">"); 1253 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1129 1254
1130 open my $fh2, "$mode&", $fh 1255 open my $fh2, $mode, $fh
1131 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; 1256 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1132 1257
1133 # we assume CLOEXEC is already set by perl in all important cases 1258 # we assume CLOEXEC is already set by perl in all important cases
1134 1259
1135 ($fh2, $rw) 1260 ($fh2, $rw)
1137 1262
1138package AnyEvent::Base; 1263package AnyEvent::Base;
1139 1264
1140# default implementations for many methods 1265# default implementations for many methods
1141 1266
1142BEGIN { 1267sub _time {
1268 # probe for availability of Time::HiRes
1143 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1269 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1270 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1144 *_time = \&Time::HiRes::time; 1271 *_time = \&Time::HiRes::time;
1145 # if (eval "use POSIX (); (POSIX::times())... 1272 # if (eval "use POSIX (); (POSIX::times())...
1146 } else { 1273 } else {
1274 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1147 *_time = sub { time }; # epic fail 1275 *_time = sub { time }; # epic fail
1148 } 1276 }
1277
1278 &_time
1149} 1279}
1150 1280
1151sub time { _time } 1281sub time { _time }
1152sub now { _time } 1282sub now { _time }
1153sub now_update { } 1283sub now_update { }
1158 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1288 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1159} 1289}
1160 1290
1161# default implementation for ->signal 1291# default implementation for ->signal
1162 1292
1293our $HAVE_ASYNC_INTERRUPT;
1294
1295sub _have_async_interrupt() {
1296 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1297 && eval "use Async::Interrupt 1.0 (); 1")
1298 unless defined $HAVE_ASYNC_INTERRUPT;
1299
1300 $HAVE_ASYNC_INTERRUPT
1301}
1302
1163our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1303our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1304our (%SIG_ASY, %SIG_ASY_W);
1305our ($SIG_COUNT, $SIG_TW);
1164 1306
1165sub _signal_exec { 1307sub _signal_exec {
1308 $HAVE_ASYNC_INTERRUPT
1309 ? $SIGPIPE_R->drain
1166 sysread $SIGPIPE_R, my $dummy, 4; 1310 : sysread $SIGPIPE_R, my $dummy, 9;
1167 1311
1168 while (%SIG_EV) { 1312 while (%SIG_EV) {
1169 for (keys %SIG_EV) { 1313 for (keys %SIG_EV) {
1170 delete $SIG_EV{$_}; 1314 delete $SIG_EV{$_};
1171 $_->() for values %{ $SIG_CB{$_} || {} }; 1315 $_->() for values %{ $SIG_CB{$_} || {} };
1172 } 1316 }
1173 } 1317 }
1174} 1318}
1175 1319
1320# install a dummy wakeup watcher to reduce signal catching latency
1321sub _sig_add() {
1322 unless ($SIG_COUNT++) {
1323 # try to align timer on a full-second boundary, if possible
1324 my $NOW = AnyEvent->now;
1325
1326 $SIG_TW = AnyEvent->timer (
1327 after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1328 interval => $MAX_SIGNAL_LATENCY,
1329 cb => sub { }, # just for the PERL_ASYNC_CHECK
1330 );
1331 }
1332}
1333
1334sub _sig_del {
1335 undef $SIG_TW
1336 unless --$SIG_COUNT;
1337}
1338
1339our $_sig_name_init; $_sig_name_init = sub {
1340 eval q{ # poor man's autoloading
1341 undef $_sig_name_init;
1342
1343 if (_have_async_interrupt) {
1344 *sig2num = \&Async::Interrupt::sig2num;
1345 *sig2name = \&Async::Interrupt::sig2name;
1346 } else {
1347 require Config;
1348
1349 my %signame2num;
1350 @signame2num{ split ' ', $Config::Config{sig_name} }
1351 = split ' ', $Config::Config{sig_num};
1352
1353 my @signum2name;
1354 @signum2name[values %signame2num] = keys %signame2num;
1355
1356 *sig2num = sub($) {
1357 $_[0] > 0 ? shift : $signame2num{+shift}
1358 };
1359 *sig2name = sub ($) {
1360 $_[0] > 0 ? $signum2name[+shift] : shift
1361 };
1362 }
1363 };
1364 die if $@;
1365};
1366
1367sub sig2num ($) { &$_sig_name_init; &sig2num }
1368sub sig2name($) { &$_sig_name_init; &sig2name }
1369
1176sub signal { 1370sub signal {
1177 my (undef, %arg) = @_; 1371 eval q{ # poor man's autoloading {}
1372 # probe for availability of Async::Interrupt
1373 if (_have_async_interrupt) {
1374 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1178 1375
1179 unless ($SIGPIPE_R) { 1376 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1180 require Fcntl; 1377 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1181 1378
1182 if (AnyEvent::WIN32) {
1183 require AnyEvent::Util;
1184
1185 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1186 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1187 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1188 } else { 1379 } else {
1380 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1381
1382 require Fcntl;
1383
1384 if (AnyEvent::WIN32) {
1385 require AnyEvent::Util;
1386
1387 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1388 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1389 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1390 } else {
1189 pipe $SIGPIPE_R, $SIGPIPE_W; 1391 pipe $SIGPIPE_R, $SIGPIPE_W;
1190 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1392 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1191 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1393 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1192 1394
1193 # not strictly required, as $^F is normally 2, but let's make sure... 1395 # not strictly required, as $^F is normally 2, but let's make sure...
1194 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1396 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1195 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1397 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1398 }
1399
1400 $SIGPIPE_R
1401 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1402
1403 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1196 } 1404 }
1197 1405
1198 $SIGPIPE_R 1406 *signal = sub {
1199 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1407 my (undef, %arg) = @_;
1200 1408
1201 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1202 }
1203
1204 my $signal = uc $arg{signal} 1409 my $signal = uc $arg{signal}
1205 or Carp::croak "required option 'signal' is missing"; 1410 or Carp::croak "required option 'signal' is missing";
1206 1411
1412 if ($HAVE_ASYNC_INTERRUPT) {
1413 # async::interrupt
1414
1415 $signal = sig2num $signal;
1207 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1416 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1417
1418 $SIG_ASY{$signal} ||= new Async::Interrupt
1419 cb => sub { undef $SIG_EV{$signal} },
1420 signal => $signal,
1421 pipe => [$SIGPIPE_R->filenos],
1422 pipe_autodrain => 0,
1423 ;
1424
1425 } else {
1426 # pure perl
1427
1428 # AE::Util has been loaded in signal
1429 $signal = sig2name $signal;
1430 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1431
1208 $SIG{$signal} ||= sub { 1432 $SIG{$signal} ||= sub {
1209 local $!; 1433 local $!;
1210 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1434 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1211 undef $SIG_EV{$signal}; 1435 undef $SIG_EV{$signal};
1436 };
1437
1438 # can't do signal processing without introducing races in pure perl,
1439 # so limit the signal latency.
1440 _sig_add;
1441 }
1442
1443 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1444 };
1445
1446 *AnyEvent::Base::signal::DESTROY = sub {
1447 my ($signal, $cb) = @{$_[0]};
1448
1449 _sig_del;
1450
1451 delete $SIG_CB{$signal}{$cb};
1452
1453 $HAVE_ASYNC_INTERRUPT
1454 ? delete $SIG_ASY{$signal}
1455 : # delete doesn't work with older perls - they then
1456 # print weird messages, or just unconditionally exit
1457 # instead of getting the default action.
1458 undef $SIG{$signal}
1459 unless keys %{ $SIG_CB{$signal} };
1460 };
1212 }; 1461 };
1213 1462 die if $@;
1214 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1463 &signal
1215}
1216
1217sub AnyEvent::Base::signal::DESTROY {
1218 my ($signal, $cb) = @{$_[0]};
1219
1220 delete $SIG_CB{$signal}{$cb};
1221
1222 # delete doesn't work with older perls - they then
1223 # print weird messages, or just unconditionally exit
1224 # instead of getting the default action.
1225 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1226} 1464}
1227 1465
1228# default implementation for ->child 1466# default implementation for ->child
1229 1467
1230our %PID_CB; 1468our %PID_CB;
1231our $CHLD_W; 1469our $CHLD_W;
1232our $CHLD_DELAY_W; 1470our $CHLD_DELAY_W;
1233our $WNOHANG; 1471our $WNOHANG;
1234 1472
1473sub _emit_childstatus($$) {
1474 my (undef, $rpid, $rstatus) = @_;
1475
1476 $_->($rpid, $rstatus)
1477 for values %{ $PID_CB{$rpid} || {} },
1478 values %{ $PID_CB{0} || {} };
1479}
1480
1235sub _sigchld { 1481sub _sigchld {
1482 my $pid;
1483
1484 AnyEvent->_emit_childstatus ($pid, $?)
1236 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1485 while ($pid = waitpid -1, $WNOHANG) > 0;
1237 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1238 (values %{ $PID_CB{0} || {} });
1239 }
1240} 1486}
1241 1487
1242sub child { 1488sub child {
1243 my (undef, %arg) = @_; 1489 my (undef, %arg) = @_;
1244 1490
1245 defined (my $pid = $arg{pid} + 0) 1491 defined (my $pid = $arg{pid} + 0)
1246 or Carp::croak "required option 'pid' is missing"; 1492 or Carp::croak "required option 'pid' is missing";
1247 1493
1248 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1494 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1249 1495
1496 # WNOHANG is almost cetrainly 1 everywhere
1497 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1498 ? 1
1250 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1499 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1251 1500
1252 unless ($CHLD_W) { 1501 unless ($CHLD_W) {
1253 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1502 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1254 # child could be a zombie already, so make at least one round 1503 # child could be a zombie already, so make at least one round
1255 &_sigchld; 1504 &_sigchld;
1307 1556
1308our @ISA = AnyEvent::CondVar::Base::; 1557our @ISA = AnyEvent::CondVar::Base::;
1309 1558
1310package AnyEvent::CondVar::Base; 1559package AnyEvent::CondVar::Base;
1311 1560
1312use overload 1561#use overload
1313 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1562# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1314 fallback => 1; 1563# fallback => 1;
1564
1565# save 300+ kilobytes by dirtily hardcoding overloading
1566${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1567*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1568*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1569${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1570
1571our $WAITING;
1315 1572
1316sub _send { 1573sub _send {
1317 # nop 1574 # nop
1318} 1575}
1319 1576
1332sub ready { 1589sub ready {
1333 $_[0]{_ae_sent} 1590 $_[0]{_ae_sent}
1334} 1591}
1335 1592
1336sub _wait { 1593sub _wait {
1594 $WAITING
1595 and !$_[0]{_ae_sent}
1596 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1597
1598 local $WAITING = 1;
1337 AnyEvent->one_event while !$_[0]{_ae_sent}; 1599 AnyEvent->one_event while !$_[0]{_ae_sent};
1338} 1600}
1339 1601
1340sub recv { 1602sub recv {
1341 $_[0]->_wait; 1603 $_[0]->_wait;
1403C<PERL_ANYEVENT_MODEL>. 1665C<PERL_ANYEVENT_MODEL>.
1404 1666
1405When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1667When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1406model it chooses. 1668model it chooses.
1407 1669
1670When set to C<8> or higher, then AnyEvent will report extra information on
1671which optional modules it loads and how it implements certain features.
1672
1408=item C<PERL_ANYEVENT_STRICT> 1673=item C<PERL_ANYEVENT_STRICT>
1409 1674
1410AnyEvent does not do much argument checking by default, as thorough 1675AnyEvent does not do much argument checking by default, as thorough
1411argument checking is very costly. Setting this variable to a true value 1676argument checking is very costly. Setting this variable to a true value
1412will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1677will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1413check the arguments passed to most method calls. If it finds any problems, 1678check the arguments passed to most method calls. If it finds any problems,
1414it will croak. 1679it will croak.
1415 1680
1416In other words, enables "strict" mode. 1681In other words, enables "strict" mode.
1417 1682
1418Unlike C<use strict>, it is definitely recommended to keep it off in 1683Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1419production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1684>>, it is definitely recommended to keep it off in production. Keeping
1420developing programs can be very useful, however. 1685C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1686can be very useful, however.
1421 1687
1422=item C<PERL_ANYEVENT_MODEL> 1688=item C<PERL_ANYEVENT_MODEL>
1423 1689
1424This can be used to specify the event model to be used by AnyEvent, before 1690This can be used to specify the event model to be used by AnyEvent, before
1425auto detection and -probing kicks in. It must be a string consisting 1691auto detection and -probing kicks in. It must be a string consisting
1487 1753
1488When neither C<ca_file> nor C<ca_path> was specified during 1754When neither C<ca_file> nor C<ca_path> was specified during
1489L<AnyEvent::TLS> context creation, and either of these environment 1755L<AnyEvent::TLS> context creation, and either of these environment
1490variables exist, they will be used to specify CA certificate locations 1756variables exist, they will be used to specify CA certificate locations
1491instead of a system-dependent default. 1757instead of a system-dependent default.
1758
1759=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1760
1761When these are set to C<1>, then the respective modules are not
1762loaded. Mostly good for testing AnyEvent itself.
1492 1763
1493=back 1764=back
1494 1765
1495=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1766=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1496 1767
2035 2306
2036A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2307A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2037emulation for event loops that do not support them natively. Also, some 2308emulation for event loops that do not support them natively. Also, some
2038event loops install a similar handler. 2309event loops install a similar handler.
2039 2310
2040If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2311Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2041reset it to default, to avoid losing child exit statuses. 2312AnyEvent will reset it to default, to avoid losing child exit statuses.
2042 2313
2043=item SIGPIPE 2314=item SIGPIPE
2044 2315
2045A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2316A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2046when AnyEvent gets loaded. 2317when AnyEvent gets loaded.
2064 if $SIG{CHLD} eq 'IGNORE'; 2335 if $SIG{CHLD} eq 'IGNORE';
2065 2336
2066$SIG{PIPE} = sub { } 2337$SIG{PIPE} = sub { }
2067 unless defined $SIG{PIPE}; 2338 unless defined $SIG{PIPE};
2068 2339
2340=head1 RECOMMENDED/OPTIONAL MODULES
2341
2342One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2343it's built-in modules) are required to use it.
2344
2345That does not mean that AnyEvent won't take advantage of some additional
2346modules if they are installed.
2347
2348This section epxlains which additional modules will be used, and how they
2349affect AnyEvent's operetion.
2350
2351=over 4
2352
2353=item L<Async::Interrupt>
2354
2355This slightly arcane module is used to implement fast signal handling: To
2356my knowledge, there is no way to do completely race-free and quick
2357signal handling in pure perl. To ensure that signals still get
2358delivered, AnyEvent will start an interval timer to wake up perl (and
2359catch the signals) with some delay (default is 10 seconds, look for
2360C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2361
2362If this module is available, then it will be used to implement signal
2363catching, which means that signals will not be delayed, and the event loop
2364will not be interrupted regularly, which is more efficient (And good for
2365battery life on laptops).
2366
2367This affects not just the pure-perl event loop, but also other event loops
2368that have no signal handling on their own (e.g. Glib, Tk, Qt).
2369
2370Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2371and either employ their own workarounds (POE) or use AnyEvent's workaround
2372(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2373does nothing for those backends.
2374
2375=item L<EV>
2376
2377This module isn't really "optional", as it is simply one of the backend
2378event loops that AnyEvent can use. However, it is simply the best event
2379loop available in terms of features, speed and stability: It supports
2380the AnyEvent API optimally, implements all the watcher types in XS, does
2381automatic timer adjustments even when no monotonic clock is available,
2382can take avdantage of advanced kernel interfaces such as C<epoll> and
2383C<kqueue>, and is the fastest backend I<by far>. You can even embed
2384L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2385
2386=item L<Guard>
2387
2388The guard module, when used, will be used to implement
2389C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2390lot less memory), but otherwise doesn't affect guard operation much. It is
2391purely used for performance.
2392
2393=item L<JSON> and L<JSON::XS>
2394
2395This module is required when you want to read or write JSON data via
2396L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2397advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2398
2399In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2400installed.
2401
2402=item L<Net::SSLeay>
2403
2404Implementing TLS/SSL in Perl is certainly interesting, but not very
2405worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2406the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2407
2408=item L<Time::HiRes>
2409
2410This module is part of perl since release 5.008. It will be used when the
2411chosen event library does not come with a timing source on it's own. The
2412pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2413try to use a monotonic clock for timing stability.
2414
2415=back
2416
2417
2069=head1 FORK 2418=head1 FORK
2070 2419
2071Most event libraries are not fork-safe. The ones who are usually are 2420Most event libraries are not fork-safe. The ones who are usually are
2072because they rely on inefficient but fork-safe C<select> or C<poll> 2421because they rely on inefficient but fork-safe C<select> or C<poll>
2073calls. Only L<EV> is fully fork-aware. 2422calls. Only L<EV> is fully fork-aware.
2074 2423
2075If you have to fork, you must either do so I<before> creating your first 2424If you have to fork, you must either do so I<before> creating your first
2076watcher OR you must not use AnyEvent at all in the child. 2425watcher OR you must not use AnyEvent at all in the child OR you must do
2426something completely out of the scope of AnyEvent.
2077 2427
2078 2428
2079=head1 SECURITY CONSIDERATIONS 2429=head1 SECURITY CONSIDERATIONS
2080 2430
2081AnyEvent can be forced to load any event model via 2431AnyEvent can be forced to load any event model via
2119L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2469L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2120 2470
2121Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2471Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2122L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2472L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2123L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2473L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2124L<AnyEvent::Impl::POE>. 2474L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2125 2475
2126Non-blocking file handles, sockets, TCP clients and 2476Non-blocking file handles, sockets, TCP clients and
2127servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2477servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2128 2478
2129Asynchronous DNS: L<AnyEvent::DNS>. 2479Asynchronous DNS: L<AnyEvent::DNS>.
2130 2480
2131Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2481Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2482L<Coro::Event>,
2132 2483
2133Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2484Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2485L<AnyEvent::HTTP>.
2134 2486
2135 2487
2136=head1 AUTHOR 2488=head1 AUTHOR
2137 2489
2138 Marc Lehmann <schmorp@schmorp.de> 2490 Marc Lehmann <schmorp@schmorp.de>

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