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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?
173my variables are only visible after the statement in which they are 181my variables are only visible after the statement in which they are
174declared. 182declared.
175 183
176=head2 I/O WATCHERS 184=head2 I/O WATCHERS
177 185
186 $w = AnyEvent->io (
187 fh => <filehandle_or_fileno>,
188 poll => <"r" or "w">,
189 cb => <callback>,
190 );
191
178You can create an I/O watcher by calling the C<< AnyEvent->io >> method 192You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179with the following mandatory key-value pairs as arguments: 193with the following mandatory key-value pairs as arguments:
180 194
181C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch 195C<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 196for events (AnyEvent might or might not keep a reference to this file
211 undef $w; 225 undef $w;
212 }); 226 });
213 227
214=head2 TIME WATCHERS 228=head2 TIME WATCHERS
215 229
230 $w = AnyEvent->timer (after => <seconds>, cb => <callback>);
231
232 $w = AnyEvent->timer (
233 after => <fractional_seconds>,
234 interval => <fractional_seconds>,
235 cb => <callback>,
236 );
237
216You can create a time watcher by calling the C<< AnyEvent->timer >> 238You can create a time watcher by calling the C<< AnyEvent->timer >>
217method with the following mandatory arguments: 239method with the following mandatory arguments:
218 240
219C<after> specifies after how many seconds (fractional values are 241C<after> specifies after how many seconds (fractional values are
220supported) the callback should be invoked. C<cb> is the callback to invoke 242supported) the callback should be invoked. C<cb> is the callback to invoke
347 369
348=back 370=back
349 371
350=head2 SIGNAL WATCHERS 372=head2 SIGNAL WATCHERS
351 373
374 $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
375
352You can watch for signals using a signal watcher, C<signal> is the signal 376You can watch for signals using a signal watcher, C<signal> is the signal
353I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl 377I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354callback to be invoked whenever a signal occurs. 378callback to be invoked whenever a signal occurs.
355 379
356Although the callback might get passed parameters, their value and 380Although the callback might get passed parameters, their value and
361invocation, and callback invocation will be synchronous. Synchronous means 385invocation, and callback invocation will be synchronous. Synchronous means
362that it might take a while until the signal gets handled by the process, 386that it might take a while until the signal gets handled by the process,
363but it is guaranteed not to interrupt any other callbacks. 387but it is guaranteed not to interrupt any other callbacks.
364 388
365The main advantage of using these watchers is that you can share a signal 389The main advantage of using these watchers is that you can share a signal
366between multiple watchers. 390between multiple watchers, and AnyEvent will ensure that signals will not
391interrupt your program at bad times.
367 392
368This watcher might use C<%SIG>, so programs overwriting those signals 393This watcher might use C<%SIG> (depending on the event loop used),
369directly will likely not work correctly. 394so programs overwriting those signals directly will likely not work
395correctly.
370 396
371Example: exit on SIGINT 397Example: exit on SIGINT
372 398
373 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 399 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374 400
401=head3 Signal Races, Delays and Workarounds
402
403Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
404callbacks to signals in a generic way, which is a pity, as you cannot do
405race-free signal handling in perl. AnyEvent will try to do it's best, but
406in some cases, signals will be delayed. The maximum time a signal might
407be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
408seconds). This variable can be changed only before the first signal
409watcher is created, and should be left alone otherwise. Higher values
410will cause fewer spurious wake-ups, which is better for power and CPU
411saving. All these problems can be avoided by installing the optional
412L<Async::Interrupt> module. This will not work with inherently broken
413event loops such as L<Event> or L<Event::Lib> (and not with L<POE>
414currently, as POE does it's own workaround with one-second latency). With
415those, you just have to suffer the delays.
416
375=head2 CHILD PROCESS WATCHERS 417=head2 CHILD PROCESS WATCHERS
376 418
419 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
420
377You can also watch on a child process exit and catch its exit status. 421You can also watch on a child process exit and catch its exit status.
378 422
379The child process is specified by the C<pid> argument (if set to C<0>, it 423The child process is specified by the C<pid> argument (one some backends,
380watches for any child process exit). The watcher will triggered only when 424using 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 425croak). The watcher will be triggered only when the child process has
382any trace events (stopped/continued). 426finished and an exit status is available, not on any trace events
427(stopped/continued).
383 428
384The callback will be called with the pid and exit status (as returned by 429The 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 430waitpid), so unlike other watcher types, you I<can> rely on child watcher
386callback arguments. 431callback arguments.
387 432
403 448
404This means you cannot create a child watcher as the very first 449This means you cannot create a child watcher as the very first
405thing in an AnyEvent program, you I<have> to create at least one 450thing in an AnyEvent program, you I<have> to create at least one
406watcher before you C<fork> the child (alternatively, you can call 451watcher before you C<fork> the child (alternatively, you can call
407C<AnyEvent::detect>). 452C<AnyEvent::detect>).
453
454As most event loops do not support waiting for child events, they will be
455emulated by AnyEvent in most cases, in which the latency and race problems
456mentioned in the description of signal watchers apply.
408 457
409Example: fork a process and wait for it 458Example: fork a process and wait for it
410 459
411 my $done = AnyEvent->condvar; 460 my $done = AnyEvent->condvar;
412 461
424 # do something else, then wait for process exit 473 # do something else, then wait for process exit
425 $done->recv; 474 $done->recv;
426 475
427=head2 IDLE WATCHERS 476=head2 IDLE WATCHERS
428 477
478 $w = AnyEvent->idle (cb => <callback>);
479
429Sometimes there is a need to do something, but it is not so important 480Sometimes there is a need to do something, but it is not so important
430to do it instantly, but only when there is nothing better to do. This 481to do it instantly, but only when there is nothing better to do. This
431"nothing better to do" is usually defined to be "no other events need 482"nothing better to do" is usually defined to be "no other events need
432attention by the event loop". 483attention by the event loop".
433 484
459 }); 510 });
460 }); 511 });
461 512
462=head2 CONDITION VARIABLES 513=head2 CONDITION VARIABLES
463 514
515 $cv = AnyEvent->condvar;
516
517 $cv->send (<list>);
518 my @res = $cv->recv;
519
464If you are familiar with some event loops you will know that all of them 520If 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 521require you to run some blocking "loop", "run" or similar function that
466will actively watch for new events and call your callbacks. 522will actively watch for new events and call your callbacks.
467 523
468AnyEvent is different, it expects somebody else to run the event loop and 524AnyEvent is slightly different: it expects somebody else to run the event
469will only block when necessary (usually when told by the user). 525loop and will only block when necessary (usually when told by the user).
470 526
471The instrument to do that is called a "condition variable", so called 527The instrument to do that is called a "condition variable", so called
472because they represent a condition that must become true. 528because they represent a condition that must become true.
473 529
530Now is probably a good time to look at the examples further below.
531
474Condition variables can be created by calling the C<< AnyEvent->condvar 532Condition variables can be created by calling the C<< AnyEvent->condvar
475>> method, usually without arguments. The only argument pair allowed is 533>> method, usually without arguments. The only argument pair allowed is
476
477C<cb>, which specifies a callback to be called when the condition variable 534C<cb>, which specifies a callback to be called when the condition variable
478becomes true, with the condition variable as the first argument (but not 535becomes true, with the condition variable as the first argument (but not
479the results). 536the results).
480 537
481After creation, the condition variable is "false" until it becomes "true" 538After creation, the condition variable is "false" until it becomes "true"
486Condition variables are similar to callbacks, except that you can 543Condition variables are similar to callbacks, except that you can
487optionally wait for them. They can also be called merge points - points 544optionally wait for them. They can also be called merge points - points
488in time where multiple outstanding events have been processed. And yet 545in time where multiple outstanding events have been processed. And yet
489another way to call them is transactions - each condition variable can be 546another way to call them is transactions - each condition variable can be
490used to represent a transaction, which finishes at some point and delivers 547used to represent a transaction, which finishes at some point and delivers
491a result. 548a result. And yet some people know them as "futures" - a promise to
549compute/deliver something that you can wait for.
492 550
493Condition variables are very useful to signal that something has finished, 551Condition variables are very useful to signal that something has finished,
494for example, if you write a module that does asynchronous http requests, 552for example, if you write a module that does asynchronous http requests,
495then a condition variable would be the ideal candidate to signal the 553then a condition variable would be the ideal candidate to signal the
496availability of results. The user can either act when the callback is 554availability of results. The user can either act when the callback is
530 after => 1, 588 after => 1,
531 cb => sub { $result_ready->send }, 589 cb => sub { $result_ready->send },
532 ); 590 );
533 591
534 # this "blocks" (while handling events) till the callback 592 # this "blocks" (while handling events) till the callback
535 # calls send 593 # calls -<send
536 $result_ready->recv; 594 $result_ready->recv;
537 595
538Example: wait for a timer, but take advantage of the fact that 596Example: wait for a timer, but take advantage of the fact that condition
539condition variables are also code references. 597variables are also callable directly.
540 598
541 my $done = AnyEvent->condvar; 599 my $done = AnyEvent->condvar;
542 my $delay = AnyEvent->timer (after => 5, cb => $done); 600 my $delay = AnyEvent->timer (after => 5, cb => $done);
543 $done->recv; 601 $done->recv;
544 602
550 608
551 ... 609 ...
552 610
553 my @info = $couchdb->info->recv; 611 my @info = $couchdb->info->recv;
554 612
555And this is how you would just ste a callback to be called whenever the 613And this is how you would just set a callback to be called whenever the
556results are available: 614results are available:
557 615
558 $couchdb->info->cb (sub { 616 $couchdb->info->cb (sub {
559 my @info = $_[0]->recv; 617 my @info = $_[0]->recv;
560 }); 618 });
578immediately from within send. 636immediately from within send.
579 637
580Any arguments passed to the C<send> call will be returned by all 638Any arguments passed to the C<send> call will be returned by all
581future C<< ->recv >> calls. 639future C<< ->recv >> calls.
582 640
583Condition variables are overloaded so one can call them directly 641Condition variables are overloaded so one can call them directly (as if
584(as a code reference). Calling them directly is the same as calling 642they 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 643C<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).
591 644
592=item $cv->croak ($error) 645=item $cv->croak ($error)
593 646
594Similar to send, but causes all call's to C<< ->recv >> to invoke 647Similar to send, but causes all call's to C<< ->recv >> to invoke
595C<Carp::croak> with the given error message/object/scalar. 648C<Carp::croak> with the given error message/object/scalar.
596 649
597This can be used to signal any errors to the condition variable 650This can be used to signal any errors to the condition variable
598user/consumer. 651user/consumer. Doing it this way instead of calling C<croak> directly
652delays the error detetcion, but has the overwhelmign advantage that it
653diagnoses the error at the place where the result is expected, and not
654deep in some event clalback without connection to the actual code causing
655the problem.
599 656
600=item $cv->begin ([group callback]) 657=item $cv->begin ([group callback])
601 658
602=item $cv->end 659=item $cv->end
603 660
699function will call C<croak>. 756function will call C<croak>.
700 757
701In list context, all parameters passed to C<send> will be returned, 758In list context, all parameters passed to C<send> will be returned,
702in scalar context only the first one will be returned. 759in scalar context only the first one will be returned.
703 760
761Note that doing a blocking wait in a callback is not supported by any
762event loop, that is, recursive invocation of a blocking C<< ->recv
763>> is not allowed, and the C<recv> call will C<croak> if such a
764condition is detected. This condition can be slightly loosened by using
765L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
766any thread that doesn't run the event loop itself.
767
704Not all event models support a blocking wait - some die in that case 768Not 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 769(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 770using 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 771caller decide whether the call will block or not (for example, by coupling
708condition variables with some kind of request results and supporting 772condition variables with some kind of request results and supporting
709callbacks so the caller knows that getting the result will not block, 773callbacks so the caller knows that getting the result will not block,
710while still supporting blocking waits if the caller so desires). 774while still supporting blocking waits if the caller so desires).
711 775
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 776You can ensure that C<< -recv >> never blocks by setting a callback and
724only calling C<< ->recv >> from within that callback (or at a later 777only calling C<< ->recv >> from within that callback (or at a later
725time). This will work even when the event loop does not support blocking 778time). This will work even when the event loop does not support blocking
726waits otherwise. 779waits otherwise.
727 780
740variable itself. Calling C<recv> inside the callback or at any later time 793variable itself. Calling C<recv> inside the callback or at any later time
741is guaranteed not to block. 794is guaranteed not to block.
742 795
743=back 796=back
744 797
798=head1 SUPPORTED EVENT LOOPS/BACKENDS
799
800The available backend classes are (every class has its own manpage):
801
802=over 4
803
804=item Backends that are autoprobed when no other event loop can be found.
805
806EV is the preferred backend when no other event loop seems to be in
807use. If EV is not installed, then AnyEvent will try Event, and, failing
808that, will fall back to its own pure-perl implementation, which is
809available everywhere as it comes with AnyEvent itself.
810
811 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
812 AnyEvent::Impl::Event based on Event, very stable, few glitches.
813 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
814
815=item Backends that are transparently being picked up when they are used.
816
817These will be used when they are currently loaded when the first watcher
818is created, in which case it is assumed that the application is using
819them. This means that AnyEvent will automatically pick the right backend
820when the main program loads an event module before anything starts to
821create watchers. Nothing special needs to be done by the main program.
822
823 AnyEvent::Impl::Glib based on Glib, slow but very stable.
824 AnyEvent::Impl::Tk based on Tk, very broken.
825 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
826 AnyEvent::Impl::POE based on POE, very slow, some limitations.
827 AnyEvent::Impl::Irssi used when running within irssi.
828
829=item Backends with special needs.
830
831Qt requires the Qt::Application to be instantiated first, but will
832otherwise be picked up automatically. As long as the main program
833instantiates the application before any AnyEvent watchers are created,
834everything should just work.
835
836 AnyEvent::Impl::Qt based on Qt.
837
838Support for IO::Async can only be partial, as it is too broken and
839architecturally limited to even support the AnyEvent API. It also
840is the only event loop that needs the loop to be set explicitly, so
841it can only be used by a main program knowing about AnyEvent. See
842L<AnyEvent::Impl::Async> for the gory details.
843
844 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
845
846=item Event loops that are indirectly supported via other backends.
847
848Some event loops can be supported via other modules:
849
850There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
851
852B<WxWidgets> has no support for watching file handles. However, you can
853use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
854polls 20 times per second, which was considered to be too horrible to even
855consider for AnyEvent.
856
857B<Prima> is not supported as nobody seems to be using it, but it has a POE
858backend, so it can be supported through POE.
859
860AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
861load L<POE> when detecting them, in the hope that POE will pick them up,
862in which case everything will be automatic.
863
864=back
865
745=head1 GLOBAL VARIABLES AND FUNCTIONS 866=head1 GLOBAL VARIABLES AND FUNCTIONS
746 867
868These are not normally required to use AnyEvent, but can be useful to
869write AnyEvent extension modules.
870
747=over 4 871=over 4
748 872
749=item $AnyEvent::MODEL 873=item $AnyEvent::MODEL
750 874
751Contains C<undef> until the first watcher is being created. Then it 875Contains C<undef> until the first watcher is being created, before the
876backend has been autodetected.
877
752contains the event model that is being used, which is the name of the 878Afterwards it contains the event model that is being used, which is the
753Perl class implementing the model. This class is usually one of the 879name 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 880of 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>). 881case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
756 882will 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.
781 883
782=item AnyEvent::detect 884=item AnyEvent::detect
783 885
784Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 886Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
785if necessary. You should only call this function right before you would 887if necessary. You should only call this function right before you would
786have created an AnyEvent watcher anyway, that is, as late as possible at 888have created an AnyEvent watcher anyway, that is, as late as possible at
787runtime. 889runtime, and not e.g. while initialising of your module.
890
891If you need to do some initialisation before AnyEvent watchers are
892created, use C<post_detect>.
788 893
789=item $guard = AnyEvent::post_detect { BLOCK } 894=item $guard = AnyEvent::post_detect { BLOCK }
790 895
791Arranges for the code block to be executed as soon as the event model is 896Arranges for the code block to be executed as soon as the event model is
792autodetected (or immediately if this has already happened). 897autodetected (or immediately if this has already happened).
793 898
899The block will be executed I<after> the actual backend has been detected
900(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
901created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
902other initialisations - see the sources of L<AnyEvent::Strict> or
903L<AnyEvent::AIO> to see how this is used.
904
905The most common usage is to create some global watchers, without forcing
906event module detection too early, for example, L<AnyEvent::AIO> creates
907and installs the global L<IO::AIO> watcher in a C<post_detect> block to
908avoid autodetecting the event module at load time.
909
794If called in scalar or list context, then it creates and returns an object 910If called in scalar or list context, then it creates and returns an object
795that automatically removes the callback again when it is destroyed. See 911that automatically removes the callback again when it is destroyed (or
912C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
796L<Coro::BDB> for a case where this is useful. 913a case where this is useful.
914
915Example: Create a watcher for the IO::AIO module and store it in
916C<$WATCHER>. Only do so after the event loop is initialised, though.
917
918 our WATCHER;
919
920 my $guard = AnyEvent::post_detect {
921 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
922 };
923
924 # the ||= is important in case post_detect immediately runs the block,
925 # as to not clobber the newly-created watcher. assigning both watcher and
926 # post_detect guard to the same variable has the advantage of users being
927 # able to just C<undef $WATCHER> if the watcher causes them grief.
928
929 $WATCHER ||= $guard;
797 930
798=item @AnyEvent::post_detect 931=item @AnyEvent::post_detect
799 932
800If there are any code references in this array (you can C<push> to it 933If there are any code references in this array (you can C<push> to it
801before or after loading AnyEvent), then they will called directly after 934before or after loading AnyEvent), then they will called directly after
802the event loop has been chosen. 935the event loop has been chosen.
803 936
804You should check C<$AnyEvent::MODEL> before adding to this array, though: 937You 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, 938if it is defined then the event loop has already been detected, and the
806and the array will be ignored. 939array will be ignored.
807 940
808Best use C<AnyEvent::post_detect { BLOCK }> instead. 941Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
942it,as it takes care of these details.
943
944This variable is mainly useful for modules that can do something useful
945when AnyEvent is used and thus want to know when it is initialised, but do
946not need to even load it by default. This array provides the means to hook
947into AnyEvent passively, without loading it.
809 948
810=back 949=back
811 950
812=head1 WHAT TO DO IN A MODULE 951=head1 WHAT TO DO IN A MODULE
813 952
960 1099
961=cut 1100=cut
962 1101
963package AnyEvent; 1102package AnyEvent;
964 1103
1104# basically a tuned-down version of common::sense
1105sub common_sense {
965no warnings; 1106 # no warnings
1107 ${^WARNING_BITS} ^= ${^WARNING_BITS};
966use strict qw(vars subs); 1108 # use strict vars subs
1109 $^H |= 0x00000600;
1110}
967 1111
1112BEGIN { AnyEvent::common_sense }
1113
968use Carp; 1114use Carp ();
969 1115
970our $VERSION = 4.8; 1116our $VERSION = 4.881;
971our $MODEL; 1117our $MODEL;
972 1118
973our $AUTOLOAD; 1119our $AUTOLOAD;
974our @ISA; 1120our @ISA;
975 1121
976our @REGISTRY; 1122our @REGISTRY;
977 1123
978our $WIN32; 1124our $WIN32;
1125
1126our $VERBOSE;
979 1127
980BEGIN { 1128BEGIN {
981 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1129 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
982 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1130 eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
983 1131
984 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1132 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
985 if ${^TAINT}; 1133 if ${^TAINT};
986}
987 1134
988our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1135 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1136
1137}
1138
1139our $MAX_SIGNAL_LATENCY = 10;
989 1140
990our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1141our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
991 1142
992{ 1143{
993 my $idx; 1144 my $idx;
995 for reverse split /\s*,\s*/, 1146 for reverse split /\s*,\s*/,
996 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1147 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
997} 1148}
998 1149
999my @models = ( 1150my @models = (
1000 [EV:: => AnyEvent::Impl::EV::], 1151 [EV:: => AnyEvent::Impl::EV:: , 1],
1001 [Event:: => AnyEvent::Impl::Event::], 1152 [Event:: => AnyEvent::Impl::Event::, 1],
1002 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1153 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1003 # everything below here will not be autoprobed 1154 # everything below here will not (normally) be autoprobed
1004 # as the pureperl backend should work everywhere 1155 # as the pureperl backend should work everywhere
1005 # and is usually faster 1156 # and is usually faster
1157 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1158 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1159 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1006 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1160 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1007 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1008 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1009 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1161 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1010 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1162 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1011 [Wx:: => AnyEvent::Impl::POE::], 1163 [Wx:: => AnyEvent::Impl::POE::],
1012 [Prima:: => AnyEvent::Impl::POE::], 1164 [Prima:: => AnyEvent::Impl::POE::],
1013 # IO::Async is just too broken - we would need workaorunds for its 1165 # IO::Async is just too broken - we would need workarounds for its
1014 # byzantine signal and broken child handling, among others. 1166 # byzantine signal and broken child handling, among others.
1015 # IO::Async is rather hard to detect, as it doesn't have any 1167 # IO::Async is rather hard to detect, as it doesn't have any
1016 # obvious default class. 1168 # obvious default class.
1017# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1169# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1018# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1170# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1019# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1171# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1020); 1172);
1021 1173
1022our %method = map +($_ => 1), 1174our %method = map +($_ => 1),
1023 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1175 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1024 1176
1028 my ($cb) = @_; 1180 my ($cb) = @_;
1029 1181
1030 if ($MODEL) { 1182 if ($MODEL) {
1031 $cb->(); 1183 $cb->();
1032 1184
1033 1 1185 undef
1034 } else { 1186 } else {
1035 push @post_detect, $cb; 1187 push @post_detect, $cb;
1036 1188
1037 defined wantarray 1189 defined wantarray
1038 ? bless \$cb, "AnyEvent::Util::postdetect" 1190 ? bless \$cb, "AnyEvent::Util::postdetect"
1044 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1196 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1045} 1197}
1046 1198
1047sub detect() { 1199sub detect() {
1048 unless ($MODEL) { 1200 unless ($MODEL) {
1049 no strict 'refs';
1050 local $SIG{__DIE__}; 1201 local $SIG{__DIE__};
1051 1202
1052 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1203 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1053 my $model = "AnyEvent::Impl::$1"; 1204 my $model = "AnyEvent::Impl::$1";
1054 if (eval "require $model") { 1205 if (eval "require $model") {
1055 $MODEL = $model; 1206 $MODEL = $model;
1056 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1207 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1057 } else { 1208 } else {
1058 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1209 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1059 } 1210 }
1060 } 1211 }
1061 1212
1062 # check for already loaded models 1213 # check for already loaded models
1063 unless ($MODEL) { 1214 unless ($MODEL) {
1064 for (@REGISTRY, @models) { 1215 for (@REGISTRY, @models) {
1065 my ($package, $model) = @$_; 1216 my ($package, $model) = @$_;
1066 if (${"$package\::VERSION"} > 0) { 1217 if (${"$package\::VERSION"} > 0) {
1067 if (eval "require $model") { 1218 if (eval "require $model") {
1068 $MODEL = $model; 1219 $MODEL = $model;
1069 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1220 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1070 last; 1221 last;
1071 } 1222 }
1072 } 1223 }
1073 } 1224 }
1074 1225
1075 unless ($MODEL) { 1226 unless ($MODEL) {
1076 # try to load a model 1227 # try to autoload a model
1077
1078 for (@REGISTRY, @models) { 1228 for (@REGISTRY, @models) {
1079 my ($package, $model) = @$_; 1229 my ($package, $model, $autoload) = @$_;
1230 if (
1231 $autoload
1080 if (eval "require $package" 1232 and eval "require $package"
1081 and ${"$package\::VERSION"} > 0 1233 and ${"$package\::VERSION"} > 0
1082 and eval "require $model") { 1234 and eval "require $model"
1235 ) {
1083 $MODEL = $model; 1236 $MODEL = $model;
1084 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; 1237 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1085 last; 1238 last;
1086 } 1239 }
1087 } 1240 }
1088 1241
1089 $MODEL 1242 $MODEL
1105 1258
1106sub AUTOLOAD { 1259sub AUTOLOAD {
1107 (my $func = $AUTOLOAD) =~ s/.*://; 1260 (my $func = $AUTOLOAD) =~ s/.*://;
1108 1261
1109 $method{$func} 1262 $method{$func}
1110 or croak "$func: not a valid method for AnyEvent objects"; 1263 or Carp::croak "$func: not a valid method for AnyEvent objects";
1111 1264
1112 detect unless $MODEL; 1265 detect unless $MODEL;
1113 1266
1114 my $class = shift; 1267 my $class = shift;
1115 $class->$func (@_); 1268 $class->$func (@_);
1120# allow only one watcher per fd, so we dup it to get a different one). 1273# allow only one watcher per fd, so we dup it to get a different one).
1121sub _dupfh($$;$$) { 1274sub _dupfh($$;$$) {
1122 my ($poll, $fh, $r, $w) = @_; 1275 my ($poll, $fh, $r, $w) = @_;
1123 1276
1124 # cygwin requires the fh mode to be matching, unix doesn't 1277 # cygwin requires the fh mode to be matching, unix doesn't
1125 my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">"); 1278 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1126 1279
1127 open my $fh2, "$mode&", $fh 1280 open my $fh2, $mode, $fh
1128 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; 1281 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1129 1282
1130 # we assume CLOEXEC is already set by perl in all important cases 1283 # we assume CLOEXEC is already set by perl in all important cases
1131 1284
1132 ($fh2, $rw) 1285 ($fh2, $rw)
1134 1287
1135package AnyEvent::Base; 1288package AnyEvent::Base;
1136 1289
1137# default implementations for many methods 1290# default implementations for many methods
1138 1291
1139BEGIN { 1292sub _time {
1293 # probe for availability of Time::HiRes
1140 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1294 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1295 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1141 *_time = \&Time::HiRes::time; 1296 *_time = \&Time::HiRes::time;
1142 # if (eval "use POSIX (); (POSIX::times())... 1297 # if (eval "use POSIX (); (POSIX::times())...
1143 } else { 1298 } else {
1299 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1144 *_time = sub { time }; # epic fail 1300 *_time = sub { time }; # epic fail
1145 } 1301 }
1302
1303 &_time
1146} 1304}
1147 1305
1148sub time { _time } 1306sub time { _time }
1149sub now { _time } 1307sub now { _time }
1150sub now_update { } 1308sub now_update { }
1155 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1313 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1156} 1314}
1157 1315
1158# default implementation for ->signal 1316# default implementation for ->signal
1159 1317
1318our $HAVE_ASYNC_INTERRUPT;
1319
1320sub _have_async_interrupt() {
1321 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1322 && eval "use Async::Interrupt 1.0 (); 1")
1323 unless defined $HAVE_ASYNC_INTERRUPT;
1324
1325 $HAVE_ASYNC_INTERRUPT
1326}
1327
1160our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1328our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1329our (%SIG_ASY, %SIG_ASY_W);
1330our ($SIG_COUNT, $SIG_TW);
1161 1331
1162sub _signal_exec { 1332sub _signal_exec {
1333 $HAVE_ASYNC_INTERRUPT
1334 ? $SIGPIPE_R->drain
1163 sysread $SIGPIPE_R, my $dummy, 4; 1335 : sysread $SIGPIPE_R, my $dummy, 9;
1164 1336
1165 while (%SIG_EV) { 1337 while (%SIG_EV) {
1166 for (keys %SIG_EV) { 1338 for (keys %SIG_EV) {
1167 delete $SIG_EV{$_}; 1339 delete $SIG_EV{$_};
1168 $_->() for values %{ $SIG_CB{$_} || {} }; 1340 $_->() for values %{ $SIG_CB{$_} || {} };
1169 } 1341 }
1170 } 1342 }
1171} 1343}
1172 1344
1345# install a dummy wakeup watcher to reduce signal catching latency
1346sub _sig_add() {
1347 unless ($SIG_COUNT++) {
1348 # try to align timer on a full-second boundary, if possible
1349 my $NOW = AnyEvent->now;
1350
1351 $SIG_TW = AnyEvent->timer (
1352 after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1353 interval => $MAX_SIGNAL_LATENCY,
1354 cb => sub { }, # just for the PERL_ASYNC_CHECK
1355 );
1356 }
1357}
1358
1359sub _sig_del {
1360 undef $SIG_TW
1361 unless --$SIG_COUNT;
1362}
1363
1364our $_sig_name_init; $_sig_name_init = sub {
1365 eval q{ # poor man's autoloading
1366 undef $_sig_name_init;
1367
1368 if (_have_async_interrupt) {
1369 *sig2num = \&Async::Interrupt::sig2num;
1370 *sig2name = \&Async::Interrupt::sig2name;
1371 } else {
1372 require Config;
1373
1374 my %signame2num;
1375 @signame2num{ split ' ', $Config::Config{sig_name} }
1376 = split ' ', $Config::Config{sig_num};
1377
1378 my @signum2name;
1379 @signum2name[values %signame2num] = keys %signame2num;
1380
1381 *sig2num = sub($) {
1382 $_[0] > 0 ? shift : $signame2num{+shift}
1383 };
1384 *sig2name = sub ($) {
1385 $_[0] > 0 ? $signum2name[+shift] : shift
1386 };
1387 }
1388 };
1389 die if $@;
1390};
1391
1392sub sig2num ($) { &$_sig_name_init; &sig2num }
1393sub sig2name($) { &$_sig_name_init; &sig2name }
1394
1173sub signal { 1395sub signal {
1174 my (undef, %arg) = @_; 1396 eval q{ # poor man's autoloading {}
1397 # probe for availability of Async::Interrupt
1398 if (_have_async_interrupt) {
1399 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1175 1400
1176 unless ($SIGPIPE_R) { 1401 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1177 require Fcntl; 1402 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1178 1403
1179 if (AnyEvent::WIN32) {
1180 require AnyEvent::Util;
1181
1182 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1183 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1184 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1185 } else { 1404 } else {
1405 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1406
1407 require Fcntl;
1408
1409 if (AnyEvent::WIN32) {
1410 require AnyEvent::Util;
1411
1412 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1413 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1414 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1415 } else {
1186 pipe $SIGPIPE_R, $SIGPIPE_W; 1416 pipe $SIGPIPE_R, $SIGPIPE_W;
1187 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1417 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1188 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1418 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1189 1419
1190 # not strictly required, as $^F is normally 2, but let's make sure... 1420 # not strictly required, as $^F is normally 2, but let's make sure...
1191 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1421 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1192 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1422 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1423 }
1424
1425 $SIGPIPE_R
1426 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1427
1428 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1193 } 1429 }
1194 1430
1195 $SIGPIPE_R 1431 *signal = sub {
1196 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1432 my (undef, %arg) = @_;
1197 1433
1198 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1199 }
1200
1201 my $signal = uc $arg{signal} 1434 my $signal = uc $arg{signal}
1202 or Carp::croak "required option 'signal' is missing"; 1435 or Carp::croak "required option 'signal' is missing";
1203 1436
1437 if ($HAVE_ASYNC_INTERRUPT) {
1438 # async::interrupt
1439
1440 $signal = sig2num $signal;
1204 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1441 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1442
1443 $SIG_ASY{$signal} ||= new Async::Interrupt
1444 cb => sub { undef $SIG_EV{$signal} },
1445 signal => $signal,
1446 pipe => [$SIGPIPE_R->filenos],
1447 pipe_autodrain => 0,
1448 ;
1449
1450 } else {
1451 # pure perl
1452
1453 # AE::Util has been loaded in signal
1454 $signal = sig2name $signal;
1455 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1456
1205 $SIG{$signal} ||= sub { 1457 $SIG{$signal} ||= sub {
1206 local $!; 1458 local $!;
1207 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1459 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1208 undef $SIG_EV{$signal}; 1460 undef $SIG_EV{$signal};
1461 };
1462
1463 # can't do signal processing without introducing races in pure perl,
1464 # so limit the signal latency.
1465 _sig_add;
1466 }
1467
1468 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1469 };
1470
1471 *AnyEvent::Base::signal::DESTROY = sub {
1472 my ($signal, $cb) = @{$_[0]};
1473
1474 _sig_del;
1475
1476 delete $SIG_CB{$signal}{$cb};
1477
1478 $HAVE_ASYNC_INTERRUPT
1479 ? delete $SIG_ASY{$signal}
1480 : # delete doesn't work with older perls - they then
1481 # print weird messages, or just unconditionally exit
1482 # instead of getting the default action.
1483 undef $SIG{$signal}
1484 unless keys %{ $SIG_CB{$signal} };
1485 };
1209 }; 1486 };
1210 1487 die if $@;
1211 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1488 &signal
1212}
1213
1214sub AnyEvent::Base::signal::DESTROY {
1215 my ($signal, $cb) = @{$_[0]};
1216
1217 delete $SIG_CB{$signal}{$cb};
1218
1219 # delete doesn't work with older perls - they then
1220 # print weird messages, or just unconditionally exit
1221 # instead of getting the default action.
1222 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1223} 1489}
1224 1490
1225# default implementation for ->child 1491# default implementation for ->child
1226 1492
1227our %PID_CB; 1493our %PID_CB;
1228our $CHLD_W; 1494our $CHLD_W;
1229our $CHLD_DELAY_W; 1495our $CHLD_DELAY_W;
1230our $WNOHANG; 1496our $WNOHANG;
1231 1497
1498sub _emit_childstatus($$) {
1499 my (undef, $rpid, $rstatus) = @_;
1500
1501 $_->($rpid, $rstatus)
1502 for values %{ $PID_CB{$rpid} || {} },
1503 values %{ $PID_CB{0} || {} };
1504}
1505
1232sub _sigchld { 1506sub _sigchld {
1507 my $pid;
1508
1509 AnyEvent->_emit_childstatus ($pid, $?)
1233 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1510 while ($pid = waitpid -1, $WNOHANG) > 0;
1234 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1235 (values %{ $PID_CB{0} || {} });
1236 }
1237} 1511}
1238 1512
1239sub child { 1513sub child {
1240 my (undef, %arg) = @_; 1514 my (undef, %arg) = @_;
1241 1515
1242 defined (my $pid = $arg{pid} + 0) 1516 defined (my $pid = $arg{pid} + 0)
1243 or Carp::croak "required option 'pid' is missing"; 1517 or Carp::croak "required option 'pid' is missing";
1244 1518
1245 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1519 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1246 1520
1521 # WNOHANG is almost cetrainly 1 everywhere
1522 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1523 ? 1
1247 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1524 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1248 1525
1249 unless ($CHLD_W) { 1526 unless ($CHLD_W) {
1250 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1527 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1251 # child could be a zombie already, so make at least one round 1528 # child could be a zombie already, so make at least one round
1252 &_sigchld; 1529 &_sigchld;
1304 1581
1305our @ISA = AnyEvent::CondVar::Base::; 1582our @ISA = AnyEvent::CondVar::Base::;
1306 1583
1307package AnyEvent::CondVar::Base; 1584package AnyEvent::CondVar::Base;
1308 1585
1309use overload 1586#use overload
1310 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1587# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1311 fallback => 1; 1588# fallback => 1;
1589
1590# save 300+ kilobytes by dirtily hardcoding overloading
1591${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1592*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1593*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1594${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1595
1596our $WAITING;
1312 1597
1313sub _send { 1598sub _send {
1314 # nop 1599 # nop
1315} 1600}
1316 1601
1329sub ready { 1614sub ready {
1330 $_[0]{_ae_sent} 1615 $_[0]{_ae_sent}
1331} 1616}
1332 1617
1333sub _wait { 1618sub _wait {
1619 $WAITING
1620 and !$_[0]{_ae_sent}
1621 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1622
1623 local $WAITING = 1;
1334 AnyEvent->one_event while !$_[0]{_ae_sent}; 1624 AnyEvent->one_event while !$_[0]{_ae_sent};
1335} 1625}
1336 1626
1337sub recv { 1627sub recv {
1338 $_[0]->_wait; 1628 $_[0]->_wait;
1357} 1647}
1358 1648
1359# undocumented/compatibility with pre-3.4 1649# undocumented/compatibility with pre-3.4
1360*broadcast = \&send; 1650*broadcast = \&send;
1361*wait = \&_wait; 1651*wait = \&_wait;
1652
1653#############################################################################
1654# "new" API, currently only emulation of it
1655#############################################################################
1656
1657package AE;
1658
1659sub io($$$) {
1660 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1661}
1662
1663sub timer($$$) {
1664 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]);
1665}
1666
1667sub signal($$) {
1668 AnyEvent->signal (signal => $_[0], cb => $_[1]);
1669}
1670
1671sub child($$) {
1672 AnyEvent->child (pid => $_[0], cb => $_[1]);
1673}
1674
1675sub idle($) {
1676 AnyEvent->idle (cb => $_[0]);
1677}
1678
1679sub cv() {
1680 AnyEvent->condvar
1681}
1682
1683sub now() {
1684 AnyEvent->now
1685}
1686
1687sub now_update() {
1688 AnyEvent->now_update
1689}
1690
1691sub time() {
1692 AnyEvent->time
1693}
1362 1694
1363=head1 ERROR AND EXCEPTION HANDLING 1695=head1 ERROR AND EXCEPTION HANDLING
1364 1696
1365In general, AnyEvent does not do any error handling - it relies on the 1697In general, AnyEvent does not do any error handling - it relies on the
1366caller to do that if required. The L<AnyEvent::Strict> module (see also 1698caller to do that if required. The L<AnyEvent::Strict> module (see also
1400C<PERL_ANYEVENT_MODEL>. 1732C<PERL_ANYEVENT_MODEL>.
1401 1733
1402When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1734When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1403model it chooses. 1735model it chooses.
1404 1736
1737When set to C<8> or higher, then AnyEvent will report extra information on
1738which optional modules it loads and how it implements certain features.
1739
1405=item C<PERL_ANYEVENT_STRICT> 1740=item C<PERL_ANYEVENT_STRICT>
1406 1741
1407AnyEvent does not do much argument checking by default, as thorough 1742AnyEvent does not do much argument checking by default, as thorough
1408argument checking is very costly. Setting this variable to a true value 1743argument checking is very costly. Setting this variable to a true value
1409will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1744will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1410check the arguments passed to most method calls. If it finds any problems, 1745check the arguments passed to most method calls. If it finds any problems,
1411it will croak. 1746it will croak.
1412 1747
1413In other words, enables "strict" mode. 1748In other words, enables "strict" mode.
1414 1749
1415Unlike C<use strict>, it is definitely recommended to keep it off in 1750Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1416production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1751>>, it is definitely recommended to keep it off in production. Keeping
1417developing programs can be very useful, however. 1752C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1753can be very useful, however.
1418 1754
1419=item C<PERL_ANYEVENT_MODEL> 1755=item C<PERL_ANYEVENT_MODEL>
1420 1756
1421This can be used to specify the event model to be used by AnyEvent, before 1757This can be used to specify the event model to be used by AnyEvent, before
1422auto detection and -probing kicks in. It must be a string consisting 1758auto detection and -probing kicks in. It must be a string consisting
1484 1820
1485When neither C<ca_file> nor C<ca_path> was specified during 1821When neither C<ca_file> nor C<ca_path> was specified during
1486L<AnyEvent::TLS> context creation, and either of these environment 1822L<AnyEvent::TLS> context creation, and either of these environment
1487variables exist, they will be used to specify CA certificate locations 1823variables exist, they will be used to specify CA certificate locations
1488instead of a system-dependent default. 1824instead of a system-dependent default.
1825
1826=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1827
1828When these are set to C<1>, then the respective modules are not
1829loaded. Mostly good for testing AnyEvent itself.
1489 1830
1490=back 1831=back
1491 1832
1492=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1833=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1493 1834
2032 2373
2033A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2374A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2034emulation for event loops that do not support them natively. Also, some 2375emulation for event loops that do not support them natively. Also, some
2035event loops install a similar handler. 2376event loops install a similar handler.
2036 2377
2037If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2378Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2038reset it to default, to avoid losing child exit statuses. 2379AnyEvent will reset it to default, to avoid losing child exit statuses.
2039 2380
2040=item SIGPIPE 2381=item SIGPIPE
2041 2382
2042A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2383A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2043when AnyEvent gets loaded. 2384when AnyEvent gets loaded.
2061 if $SIG{CHLD} eq 'IGNORE'; 2402 if $SIG{CHLD} eq 'IGNORE';
2062 2403
2063$SIG{PIPE} = sub { } 2404$SIG{PIPE} = sub { }
2064 unless defined $SIG{PIPE}; 2405 unless defined $SIG{PIPE};
2065 2406
2407=head1 RECOMMENDED/OPTIONAL MODULES
2408
2409One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2410it's built-in modules) are required to use it.
2411
2412That does not mean that AnyEvent won't take advantage of some additional
2413modules if they are installed.
2414
2415This section epxlains which additional modules will be used, and how they
2416affect AnyEvent's operetion.
2417
2418=over 4
2419
2420=item L<Async::Interrupt>
2421
2422This slightly arcane module is used to implement fast signal handling: To
2423my knowledge, there is no way to do completely race-free and quick
2424signal handling in pure perl. To ensure that signals still get
2425delivered, AnyEvent will start an interval timer to wake up perl (and
2426catch the signals) with some delay (default is 10 seconds, look for
2427C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2428
2429If this module is available, then it will be used to implement signal
2430catching, which means that signals will not be delayed, and the event loop
2431will not be interrupted regularly, which is more efficient (And good for
2432battery life on laptops).
2433
2434This affects not just the pure-perl event loop, but also other event loops
2435that have no signal handling on their own (e.g. Glib, Tk, Qt).
2436
2437Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2438and either employ their own workarounds (POE) or use AnyEvent's workaround
2439(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2440does nothing for those backends.
2441
2442=item L<EV>
2443
2444This module isn't really "optional", as it is simply one of the backend
2445event loops that AnyEvent can use. However, it is simply the best event
2446loop available in terms of features, speed and stability: It supports
2447the AnyEvent API optimally, implements all the watcher types in XS, does
2448automatic timer adjustments even when no monotonic clock is available,
2449can take avdantage of advanced kernel interfaces such as C<epoll> and
2450C<kqueue>, and is the fastest backend I<by far>. You can even embed
2451L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2452
2453=item L<Guard>
2454
2455The guard module, when used, will be used to implement
2456C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2457lot less memory), but otherwise doesn't affect guard operation much. It is
2458purely used for performance.
2459
2460=item L<JSON> and L<JSON::XS>
2461
2462This module is required when you want to read or write JSON data via
2463L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2464advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2465
2466In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2467installed.
2468
2469=item L<Net::SSLeay>
2470
2471Implementing TLS/SSL in Perl is certainly interesting, but not very
2472worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2473the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2474
2475=item L<Time::HiRes>
2476
2477This module is part of perl since release 5.008. It will be used when the
2478chosen event library does not come with a timing source on it's own. The
2479pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2480try to use a monotonic clock for timing stability.
2481
2482=back
2483
2484
2066=head1 FORK 2485=head1 FORK
2067 2486
2068Most event libraries are not fork-safe. The ones who are usually are 2487Most event libraries are not fork-safe. The ones who are usually are
2069because they rely on inefficient but fork-safe C<select> or C<poll> 2488because they rely on inefficient but fork-safe C<select> or C<poll>
2070calls. Only L<EV> is fully fork-aware. 2489calls. Only L<EV> is fully fork-aware.
2071 2490
2072If you have to fork, you must either do so I<before> creating your first 2491If you have to fork, you must either do so I<before> creating your first
2073watcher OR you must not use AnyEvent at all in the child. 2492watcher OR you must not use AnyEvent at all in the child OR you must do
2493something completely out of the scope of AnyEvent.
2074 2494
2075 2495
2076=head1 SECURITY CONSIDERATIONS 2496=head1 SECURITY CONSIDERATIONS
2077 2497
2078AnyEvent can be forced to load any event model via 2498AnyEvent can be forced to load any event model via
2116L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2536L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2117 2537
2118Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2538Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2119L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2539L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2120L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2540L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2121L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>. 2541L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2122 2542
2123Non-blocking file handles, sockets, TCP clients and 2543Non-blocking file handles, sockets, TCP clients and
2124servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. 2544servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2125 2545
2126Asynchronous DNS: L<AnyEvent::DNS>. 2546Asynchronous DNS: L<AnyEvent::DNS>.

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