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1=head1 NAME 1=head1 NAME
2 2
3AnyEvent - provide framework for multiple event loops 3AnyEvent - events independent of event loop implementation
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported 5EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported
6event loops. 6event loops.
7 7
8=head1 SYNOPSIS 8=head1 SYNOPSIS
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
52Respository>, 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?
176=head2 I/O WATCHERS 184=head2 I/O WATCHERS
177 185
178You can create an I/O watcher by calling the C<< AnyEvent->io >> method 186You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179with the following mandatory key-value pairs as arguments: 187with the following mandatory key-value pairs as arguments:
180 188
181C<fh> is the Perl I<file handle> (I<not> file descriptor, see below) to 189C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182watch for events (AnyEvent might or might not keep a reference to this 190for events (AnyEvent might or might not keep a reference to this file
183file handle). Note that only file handles pointing to things for which 191handle). Note that only file handles pointing to things for which
184non-blocking operation makes sense are allowed. This includes sockets, 192non-blocking operation makes sense are allowed. This includes sockets,
185most character devices, pipes, fifos and so on, but not for example files 193most character devices, pipes, fifos and so on, but not for example files
186or block devices. 194or block devices.
187 195
188C<poll> must be a string that is either C<r> or C<w>, which creates a 196C<poll> must be a string that is either C<r> or C<w>, which creates a
209 chomp (my $input = <STDIN>); 217 chomp (my $input = <STDIN>);
210 warn "read: $input\n"; 218 warn "read: $input\n";
211 undef $w; 219 undef $w;
212 }); 220 });
213 221
214=head3 GETTING A FILE HANDLE FROM A FILE DESCRIPTOR
215
216It is not uncommon to only have a file descriptor, while AnyEvent requires
217a Perl file handle.
218
219There are basically two methods to convert a file descriptor into a file handle. If you own
220the file descriptor, you can open it with C<&=>, as in:
221
222 open my $fh, "<&=$fileno" or die "xxx: ยง!";
223
224This will "own" the file descriptor, meaning that when C<$fh> is
225destroyed, it will automatically close the C<$fileno>. Also, note that
226the open mode (read, write, read/write) must correspond with how the
227underlying file descriptor was opened.
228
229In many cases, taking over the file descriptor is now what you want, in
230which case the only alternative is to dup the file descriptor:
231
232 open my $fh, "<&$fileno" or die "xxx: $!";
233
234This has the advantage of not closing the file descriptor and the
235disadvantage of making a slow copy.
236
237=head2 TIME WATCHERS 222=head2 TIME WATCHERS
238 223
239You can create a time watcher by calling the C<< AnyEvent->timer >> 224You can create a time watcher by calling the C<< AnyEvent->timer >>
240method with the following mandatory arguments: 225method with the following mandatory arguments:
241 226
384invocation, and callback invocation will be synchronous. Synchronous means 369invocation, and callback invocation will be synchronous. Synchronous means
385that 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,
386but it is guaranteed not to interrupt any other callbacks. 371but it is guaranteed not to interrupt any other callbacks.
387 372
388The 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
389between multiple watchers. 374between multiple watchers, and AnyEvent will ensure that signals will not
375interrupt your program at bad times.
390 376
391This watcher might use C<%SIG>, so programs overwriting those signals 377This watcher might use C<%SIG> (depending on the event loop used),
392directly will likely not work correctly. 378so programs overwriting those signals directly will likely not work
379correctly.
393 380
394Example: exit on SIGINT 381Example: exit on SIGINT
395 382
396 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 383 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
384
385=head3 Signal Races, Delays and Workarounds
386
387Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
388callbacks to signals in a generic way, which is a pity, as you cannot do
389race-free signal handling in perl. AnyEvent will try to do it's best, but
390in some cases, signals will be delayed. The maximum time a signal might
391be delayed is specified in C<$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.
397 400
398=head2 CHILD PROCESS WATCHERS 401=head2 CHILD PROCESS WATCHERS
399 402
400You 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.
401 404
426 429
427This means you cannot create a child watcher as the very first 430This means you cannot create a child watcher as the very first
428thing in an AnyEvent program, you I<have> to create at least one 431thing in an AnyEvent program, you I<have> to create at least one
429watcher before you C<fork> the child (alternatively, you can call 432watcher before you C<fork> the child (alternatively, you can call
430C<AnyEvent::detect>). 433C<AnyEvent::detect>).
434
435As most event loops do not support waiting for child events, they will be
436emulated by AnyEvent in most cases, in which the latency and race problems
437mentioned in the description of signal watchers apply.
431 438
432Example: fork a process and wait for it 439Example: fork a process and wait for it
433 440
434 my $done = AnyEvent->condvar; 441 my $done = AnyEvent->condvar;
435 442
486 493
487If you are familiar with some event loops you will know that all of them 494If you are familiar with some event loops you will know that all of them
488require you to run some blocking "loop", "run" or similar function that 495require you to run some blocking "loop", "run" or similar function that
489will actively watch for new events and call your callbacks. 496will actively watch for new events and call your callbacks.
490 497
491AnyEvent is different, it expects somebody else to run the event loop and 498AnyEvent is slightly different: it expects somebody else to run the event
492will only block when necessary (usually when told by the user). 499loop and will only block when necessary (usually when told by the user).
493 500
494The instrument to do that is called a "condition variable", so called 501The instrument to do that is called a "condition variable", so called
495because they represent a condition that must become true. 502because they represent a condition that must become true.
496 503
504Now is probably a good time to look at the examples further below.
505
497Condition variables can be created by calling the C<< AnyEvent->condvar 506Condition variables can be created by calling the C<< AnyEvent->condvar
498>> method, usually without arguments. The only argument pair allowed is 507>> method, usually without arguments. The only argument pair allowed is
499
500C<cb>, which specifies a callback to be called when the condition variable 508C<cb>, which specifies a callback to be called when the condition variable
501becomes true, with the condition variable as the first argument (but not 509becomes true, with the condition variable as the first argument (but not
502the results). 510the results).
503 511
504After creation, the condition variable is "false" until it becomes "true" 512After creation, the condition variable is "false" until it becomes "true"
509Condition variables are similar to callbacks, except that you can 517Condition variables are similar to callbacks, except that you can
510optionally wait for them. They can also be called merge points - points 518optionally wait for them. They can also be called merge points - points
511in time where multiple outstanding events have been processed. And yet 519in time where multiple outstanding events have been processed. And yet
512another way to call them is transactions - each condition variable can be 520another way to call them is transactions - each condition variable can be
513used to represent a transaction, which finishes at some point and delivers 521used to represent a transaction, which finishes at some point and delivers
514a result. 522a result. And yet some people know them as "futures" - a promise to
523compute/deliver something that you can wait for.
515 524
516Condition variables are very useful to signal that something has finished, 525Condition variables are very useful to signal that something has finished,
517for example, if you write a module that does asynchronous http requests, 526for example, if you write a module that does asynchronous http requests,
518then a condition variable would be the ideal candidate to signal the 527then a condition variable would be the ideal candidate to signal the
519availability of results. The user can either act when the callback is 528availability of results. The user can either act when the callback is
553 after => 1, 562 after => 1,
554 cb => sub { $result_ready->send }, 563 cb => sub { $result_ready->send },
555 ); 564 );
556 565
557 # this "blocks" (while handling events) till the callback 566 # this "blocks" (while handling events) till the callback
558 # calls send 567 # calls -<send
559 $result_ready->recv; 568 $result_ready->recv;
560 569
561Example: wait for a timer, but take advantage of the fact that 570Example: wait for a timer, but take advantage of the fact that condition
562condition variables are also code references. 571variables are also callable directly.
563 572
564 my $done = AnyEvent->condvar; 573 my $done = AnyEvent->condvar;
565 my $delay = AnyEvent->timer (after => 5, cb => $done); 574 my $delay = AnyEvent->timer (after => 5, cb => $done);
566 $done->recv; 575 $done->recv;
567 576
573 582
574 ... 583 ...
575 584
576 my @info = $couchdb->info->recv; 585 my @info = $couchdb->info->recv;
577 586
578And this is how you would just ste a callback to be called whenever the 587And this is how you would just set a callback to be called whenever the
579results are available: 588results are available:
580 589
581 $couchdb->info->cb (sub { 590 $couchdb->info->cb (sub {
582 my @info = $_[0]->recv; 591 my @info = $_[0]->recv;
583 }); 592 });
601immediately from within send. 610immediately from within send.
602 611
603Any arguments passed to the C<send> call will be returned by all 612Any arguments passed to the C<send> call will be returned by all
604future C<< ->recv >> calls. 613future C<< ->recv >> calls.
605 614
606Condition variables are overloaded so one can call them directly 615Condition variables are overloaded so one can call them directly (as if
607(as a code reference). Calling them directly is the same as calling 616they were a code reference). Calling them directly is the same as calling
608C<send>. Note, however, that many C-based event loops do not handle 617C<send>.
609overloading, so as tempting as it may be, passing a condition variable
610instead of a callback does not work. Both the pure perl and EV loops
611support overloading, however, as well as all functions that use perl to
612invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
613example).
614 618
615=item $cv->croak ($error) 619=item $cv->croak ($error)
616 620
617Similar to send, but causes all call's to C<< ->recv >> to invoke 621Similar to send, but causes all call's to C<< ->recv >> to invoke
618C<Carp::croak> with the given error message/object/scalar. 622C<Carp::croak> with the given error message/object/scalar.
619 623
620This can be used to signal any errors to the condition variable 624This can be used to signal any errors to the condition variable
621user/consumer. 625user/consumer. Doing it this way instead of calling C<croak> directly
626delays the error detetcion, but has the overwhelmign advantage that it
627diagnoses the error at the place where the result is expected, and not
628deep in some event clalback without connection to the actual code causing
629the problem.
622 630
623=item $cv->begin ([group callback]) 631=item $cv->begin ([group callback])
624 632
625=item $cv->end 633=item $cv->end
626 634
722function will call C<croak>. 730function will call C<croak>.
723 731
724In list context, all parameters passed to C<send> will be returned, 732In list context, all parameters passed to C<send> will be returned,
725in scalar context only the first one will be returned. 733in scalar context only the first one will be returned.
726 734
735Note that doing a blocking wait in a callback is not supported by any
736event loop, that is, recursive invocation of a blocking C<< ->recv
737>> is not allowed, and the C<recv> call will C<croak> if such a
738condition is detected. This condition can be slightly loosened by using
739L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
740any thread that doesn't run the event loop itself.
741
727Not all event models support a blocking wait - some die in that case 742Not all event models support a blocking wait - some die in that case
728(programs might want to do that to stay interactive), so I<if you are 743(programs might want to do that to stay interactive), so I<if you are
729using this from a module, never require a blocking wait>, but let the 744using this from a module, never require a blocking wait>. Instead, let the
730caller decide whether the call will block or not (for example, by coupling 745caller decide whether the call will block or not (for example, by coupling
731condition variables with some kind of request results and supporting 746condition variables with some kind of request results and supporting
732callbacks so the caller knows that getting the result will not block, 747callbacks so the caller knows that getting the result will not block,
733while still supporting blocking waits if the caller so desires). 748while still supporting blocking waits if the caller so desires).
734 749
735Another reason I<never> to C<< ->recv >> in a module is that you cannot
736sensibly have two C<< ->recv >>'s in parallel, as that would require
737multiple interpreters or coroutines/threads, none of which C<AnyEvent>
738can supply.
739
740The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
741fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
742versions and also integrates coroutines into AnyEvent, making blocking
743C<< ->recv >> calls perfectly safe as long as they are done from another
744coroutine (one that doesn't run the event loop).
745
746You can ensure that C<< -recv >> never blocks by setting a callback and 750You can ensure that C<< -recv >> never blocks by setting a callback and
747only calling C<< ->recv >> from within that callback (or at a later 751only calling C<< ->recv >> from within that callback (or at a later
748time). This will work even when the event loop does not support blocking 752time). This will work even when the event loop does not support blocking
749waits otherwise. 753waits otherwise.
750 754
763variable itself. Calling C<recv> inside the callback or at any later time 767variable itself. Calling C<recv> inside the callback or at any later time
764is guaranteed not to block. 768is guaranteed not to block.
765 769
766=back 770=back
767 771
772=head1 SUPPORTED EVENT LOOPS/BACKENDS
773
774The available backend classes are (every class has its own manpage):
775
776=over 4
777
778=item Backends that are autoprobed when no other event loop can be found.
779
780EV is the preferred backend when no other event loop seems to be in
781use. If EV is not installed, then AnyEvent will try Event, and, failing
782that, will fall back to its own pure-perl implementation, which is
783available everywhere as it comes with AnyEvent itself.
784
785 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
786 AnyEvent::Impl::Event based on Event, very stable, few glitches.
787 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
788
789=item Backends that are transparently being picked up when they are used.
790
791These will be used when they are currently loaded when the first watcher
792is created, in which case it is assumed that the application is using
793them. This means that AnyEvent will automatically pick the right backend
794when the main program loads an event module before anything starts to
795create watchers. Nothing special needs to be done by the main program.
796
797 AnyEvent::Impl::Glib based on Glib, slow but very stable.
798 AnyEvent::Impl::Tk based on Tk, very broken.
799 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
800 AnyEvent::Impl::POE based on POE, very slow, some limitations.
801
802=item Backends with special needs.
803
804Qt requires the Qt::Application to be instantiated first, but will
805otherwise be picked up automatically. As long as the main program
806instantiates the application before any AnyEvent watchers are created,
807everything should just work.
808
809 AnyEvent::Impl::Qt based on Qt.
810
811Support for IO::Async can only be partial, as it is too broken and
812architecturally limited to even support the AnyEvent API. It also
813is the only event loop that needs the loop to be set explicitly, so
814it can only be used by a main program knowing about AnyEvent. See
815L<AnyEvent::Impl::Async> for the gory details.
816
817 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
818
819=item Event loops that are indirectly supported via other backends.
820
821Some event loops can be supported via other modules:
822
823There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
824
825B<WxWidgets> has no support for watching file handles. However, you can
826use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
827polls 20 times per second, which was considered to be too horrible to even
828consider for AnyEvent.
829
830B<Prima> is not supported as nobody seems to be using it, but it has a POE
831backend, so it can be supported through POE.
832
833AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
834load L<POE> when detecting them, in the hope that POE will pick them up,
835in which case everything will be automatic.
836
837=back
838
768=head1 GLOBAL VARIABLES AND FUNCTIONS 839=head1 GLOBAL VARIABLES AND FUNCTIONS
769 840
841These are not normally required to use AnyEvent, but can be useful to
842write AnyEvent extension modules.
843
770=over 4 844=over 4
771 845
772=item $AnyEvent::MODEL 846=item $AnyEvent::MODEL
773 847
774Contains C<undef> until the first watcher is being created. Then it 848Contains C<undef> until the first watcher is being created, before the
849backend has been autodetected.
850
775contains the event model that is being used, which is the name of the 851Afterwards it contains the event model that is being used, which is the
776Perl class implementing the model. This class is usually one of the 852name of the Perl class implementing the model. This class is usually one
777C<AnyEvent::Impl:xxx> modules, but can be any other class in the case 853of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
778AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). 854case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
779 855will be C<urxvt::anyevent>).
780The known classes so far are:
781
782 AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
783 AnyEvent::Impl::Event based on Event, second best choice.
784 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
785 AnyEvent::Impl::Glib based on Glib, third-best choice.
786 AnyEvent::Impl::Tk based on Tk, very bad choice.
787 AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
788 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
789 AnyEvent::Impl::POE based on POE, not generic enough for full support.
790
791 # warning, support for IO::Async is only partial, as it is too broken
792 # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
793 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
794
795There is no support for WxWidgets, as WxWidgets has no support for
796watching file handles. However, you can use WxWidgets through the
797POE Adaptor, as POE has a Wx backend that simply polls 20 times per
798second, which was considered to be too horrible to even consider for
799AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
800it's adaptor.
801
802AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
803autodetecting them.
804 856
805=item AnyEvent::detect 857=item AnyEvent::detect
806 858
807Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 859Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
808if necessary. You should only call this function right before you would 860if necessary. You should only call this function right before you would
809have created an AnyEvent watcher anyway, that is, as late as possible at 861have created an AnyEvent watcher anyway, that is, as late as possible at
810runtime. 862runtime, and not e.g. while initialising of your module.
863
864If you need to do some initialisation before AnyEvent watchers are
865created, use C<post_detect>.
811 866
812=item $guard = AnyEvent::post_detect { BLOCK } 867=item $guard = AnyEvent::post_detect { BLOCK }
813 868
814Arranges for the code block to be executed as soon as the event model is 869Arranges for the code block to be executed as soon as the event model is
815autodetected (or immediately if this has already happened). 870autodetected (or immediately if this has already happened).
871
872The block will be executed I<after> the actual backend has been detected
873(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
874created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
875other initialisations - see the sources of L<AnyEvent::Strict> or
876L<AnyEvent::AIO> to see how this is used.
877
878The most common usage is to create some global watchers, without forcing
879event module detection too early, for example, L<AnyEvent::AIO> creates
880and installs the global L<IO::AIO> watcher in a C<post_detect> block to
881avoid autodetecting the event module at load time.
816 882
817If called in scalar or list context, then it creates and returns an object 883If called in scalar or list context, then it creates and returns an object
818that automatically removes the callback again when it is destroyed. See 884that automatically removes the callback again when it is destroyed. See
819L<Coro::BDB> for a case where this is useful. 885L<Coro::BDB> for a case where this is useful.
820 886
823If there are any code references in this array (you can C<push> to it 889If there are any code references in this array (you can C<push> to it
824before or after loading AnyEvent), then they will called directly after 890before or after loading AnyEvent), then they will called directly after
825the event loop has been chosen. 891the event loop has been chosen.
826 892
827You should check C<$AnyEvent::MODEL> before adding to this array, though: 893You should check C<$AnyEvent::MODEL> before adding to this array, though:
828if it contains a true value then the event loop has already been detected, 894if it is defined then the event loop has already been detected, and the
829and the array will be ignored. 895array will be ignored.
830 896
831Best use C<AnyEvent::post_detect { BLOCK }> instead. 897Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
898it,as it takes care of these details.
899
900This variable is mainly useful for modules that can do something useful
901when AnyEvent is used and thus want to know when it is initialised, but do
902not need to even load it by default. This array provides the means to hook
903into AnyEvent passively, without loading it.
832 904
833=back 905=back
834 906
835=head1 WHAT TO DO IN A MODULE 907=head1 WHAT TO DO IN A MODULE
836 908
891 963
892 964
893=head1 OTHER MODULES 965=head1 OTHER MODULES
894 966
895The following is a non-exhaustive list of additional modules that use 967The following is a non-exhaustive list of additional modules that use
896AnyEvent and can therefore be mixed easily with other AnyEvent modules 968AnyEvent as a client and can therefore be mixed easily with other AnyEvent
897in the same program. Some of the modules come with AnyEvent, some are 969modules and other event loops in the same program. Some of the modules
898available via CPAN. 970come with AnyEvent, most are available via CPAN.
899 971
900=over 4 972=over 4
901 973
902=item L<AnyEvent::Util> 974=item L<AnyEvent::Util>
903 975
912 984
913=item L<AnyEvent::Handle> 985=item L<AnyEvent::Handle>
914 986
915Provide read and write buffers, manages watchers for reads and writes, 987Provide read and write buffers, manages watchers for reads and writes,
916supports raw and formatted I/O, I/O queued and fully transparent and 988supports raw and formatted I/O, I/O queued and fully transparent and
917non-blocking SSL/TLS. 989non-blocking SSL/TLS (via L<AnyEvent::TLS>.
918 990
919=item L<AnyEvent::DNS> 991=item L<AnyEvent::DNS>
920 992
921Provides rich asynchronous DNS resolver capabilities. 993Provides rich asynchronous DNS resolver capabilities.
922 994
950 1022
951=item L<AnyEvent::GPSD> 1023=item L<AnyEvent::GPSD>
952 1024
953A non-blocking interface to gpsd, a daemon delivering GPS information. 1025A non-blocking interface to gpsd, a daemon delivering GPS information.
954 1026
1027=item L<AnyEvent::IRC>
1028
1029AnyEvent based IRC client module family (replacing the older Net::IRC3).
1030
1031=item L<AnyEvent::XMPP>
1032
1033AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1034Net::XMPP2>.
1035
955=item L<AnyEvent::IGS> 1036=item L<AnyEvent::IGS>
956 1037
957A non-blocking interface to the Internet Go Server protocol (used by 1038A non-blocking interface to the Internet Go Server protocol (used by
958L<App::IGS>). 1039L<App::IGS>).
959 1040
960=item L<AnyEvent::IRC>
961
962AnyEvent based IRC client module family (replacing the older Net::IRC3).
963
964=item L<Net::XMPP2>
965
966AnyEvent based XMPP (Jabber protocol) module family.
967
968=item L<Net::FCP> 1041=item L<Net::FCP>
969 1042
970AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1043AnyEvent-based implementation of the Freenet Client Protocol, birthplace
971of AnyEvent. 1044of AnyEvent.
972 1045
976 1049
977=item L<Coro> 1050=item L<Coro>
978 1051
979Has special support for AnyEvent via L<Coro::AnyEvent>. 1052Has special support for AnyEvent via L<Coro::AnyEvent>.
980 1053
981=item L<IO::Lambda>
982
983The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
984
985=back 1054=back
986 1055
987=cut 1056=cut
988 1057
989package AnyEvent; 1058package AnyEvent;
990 1059
1060# basically a tuned-down version of common::sense
1061sub common_sense {
991no warnings; 1062 # no warnings
1063 ${^WARNING_BITS} ^= ${^WARNING_BITS};
992use strict qw(vars subs); 1064 # use strict vars subs
1065 $^H |= 0x00000600;
1066}
993 1067
1068BEGIN { AnyEvent::common_sense }
1069
994use Carp; 1070use Carp ();
995 1071
996our $VERSION = 4.8; 1072our $VERSION = 4.86;
997our $MODEL; 1073our $MODEL;
998 1074
999our $AUTOLOAD; 1075our $AUTOLOAD;
1000our @ISA; 1076our @ISA;
1001 1077
1002our @REGISTRY; 1078our @REGISTRY;
1003 1079
1004our $WIN32; 1080our $WIN32;
1081
1082our $VERBOSE;
1005 1083
1006BEGIN { 1084BEGIN {
1007 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1085 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
1008 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1086 eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
1009 1087
1010 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1088 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1011 if ${^TAINT}; 1089 if ${^TAINT};
1012}
1013 1090
1014our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1091 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1092
1093}
1094
1095our $MAX_SIGNAL_LATENCY = 10;
1015 1096
1016our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1097our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1017 1098
1018{ 1099{
1019 my $idx; 1100 my $idx;
1027 [Event:: => AnyEvent::Impl::Event::], 1108 [Event:: => AnyEvent::Impl::Event::],
1028 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1109 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
1029 # everything below here will not be autoprobed 1110 # everything below here will not be autoprobed
1030 # as the pureperl backend should work everywhere 1111 # as the pureperl backend should work everywhere
1031 # and is usually faster 1112 # and is usually faster
1032 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1033 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers 1113 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1034 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1114 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1115 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1035 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1116 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1036 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1117 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1037 [Wx:: => AnyEvent::Impl::POE::], 1118 [Wx:: => AnyEvent::Impl::POE::],
1038 [Prima:: => AnyEvent::Impl::POE::], 1119 [Prima:: => AnyEvent::Impl::POE::],
1039 # IO::Async is just too broken - we would need workaorunds for its 1120 # IO::Async is just too broken - we would need workarounds for its
1040 # byzantine signal and broken child handling, among others. 1121 # byzantine signal and broken child handling, among others.
1041 # IO::Async is rather hard to detect, as it doesn't have any 1122 # IO::Async is rather hard to detect, as it doesn't have any
1042 # obvious default class. 1123 # obvious default class.
1043# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1124# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1044# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1125# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1070 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1151 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1071} 1152}
1072 1153
1073sub detect() { 1154sub detect() {
1074 unless ($MODEL) { 1155 unless ($MODEL) {
1075 no strict 'refs';
1076 local $SIG{__DIE__}; 1156 local $SIG{__DIE__};
1077 1157
1078 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1158 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1079 my $model = "AnyEvent::Impl::$1"; 1159 my $model = "AnyEvent::Impl::$1";
1080 if (eval "require $model") { 1160 if (eval "require $model") {
1081 $MODEL = $model; 1161 $MODEL = $model;
1082 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1162 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1083 } else { 1163 } else {
1084 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1164 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1085 } 1165 }
1086 } 1166 }
1087 1167
1088 # check for already loaded models 1168 # check for already loaded models
1089 unless ($MODEL) { 1169 unless ($MODEL) {
1090 for (@REGISTRY, @models) { 1170 for (@REGISTRY, @models) {
1091 my ($package, $model) = @$_; 1171 my ($package, $model) = @$_;
1092 if (${"$package\::VERSION"} > 0) { 1172 if (${"$package\::VERSION"} > 0) {
1093 if (eval "require $model") { 1173 if (eval "require $model") {
1094 $MODEL = $model; 1174 $MODEL = $model;
1095 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1175 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1096 last; 1176 last;
1097 } 1177 }
1098 } 1178 }
1099 } 1179 }
1100 1180
1105 my ($package, $model) = @$_; 1185 my ($package, $model) = @$_;
1106 if (eval "require $package" 1186 if (eval "require $package"
1107 and ${"$package\::VERSION"} > 0 1187 and ${"$package\::VERSION"} > 0
1108 and eval "require $model") { 1188 and eval "require $model") {
1109 $MODEL = $model; 1189 $MODEL = $model;
1110 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; 1190 warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1111 last; 1191 last;
1112 } 1192 }
1113 } 1193 }
1114 1194
1115 $MODEL 1195 $MODEL
1131 1211
1132sub AUTOLOAD { 1212sub AUTOLOAD {
1133 (my $func = $AUTOLOAD) =~ s/.*://; 1213 (my $func = $AUTOLOAD) =~ s/.*://;
1134 1214
1135 $method{$func} 1215 $method{$func}
1136 or croak "$func: not a valid method for AnyEvent objects"; 1216 or Carp::croak "$func: not a valid method for AnyEvent objects";
1137 1217
1138 detect unless $MODEL; 1218 detect unless $MODEL;
1139 1219
1140 my $class = shift; 1220 my $class = shift;
1141 $class->$func (@_); 1221 $class->$func (@_);
1146# allow only one watcher per fd, so we dup it to get a different one). 1226# allow only one watcher per fd, so we dup it to get a different one).
1147sub _dupfh($$;$$) { 1227sub _dupfh($$;$$) {
1148 my ($poll, $fh, $r, $w) = @_; 1228 my ($poll, $fh, $r, $w) = @_;
1149 1229
1150 # cygwin requires the fh mode to be matching, unix doesn't 1230 # cygwin requires the fh mode to be matching, unix doesn't
1151 my ($rw, $mode) = $poll eq "r" ? ($r, "<") 1231 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1152 : $poll eq "w" ? ($w, ">")
1153 : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1154 1232
1155 open my $fh2, "$mode&" . fileno $fh 1233 open my $fh2, $mode, $fh
1156 or die "cannot dup() filehandle: $!,"; 1234 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1157 1235
1158 # we assume CLOEXEC is already set by perl in all important cases 1236 # we assume CLOEXEC is already set by perl in all important cases
1159 1237
1160 ($fh2, $rw) 1238 ($fh2, $rw)
1161} 1239}
1162 1240
1163package AnyEvent::Base; 1241package AnyEvent::Base;
1164 1242
1165# default implementations for many methods 1243# default implementations for many methods
1166 1244
1167BEGIN { 1245sub _time {
1246 # probe for availability of Time::HiRes
1168 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1247 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1248 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1169 *_time = \&Time::HiRes::time; 1249 *_time = \&Time::HiRes::time;
1170 # if (eval "use POSIX (); (POSIX::times())... 1250 # if (eval "use POSIX (); (POSIX::times())...
1171 } else { 1251 } else {
1252 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1172 *_time = sub { time }; # epic fail 1253 *_time = sub { time }; # epic fail
1173 } 1254 }
1255
1256 &_time
1174} 1257}
1175 1258
1176sub time { _time } 1259sub time { _time }
1177sub now { _time } 1260sub now { _time }
1178sub now_update { } 1261sub now_update { }
1183 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1266 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1184} 1267}
1185 1268
1186# default implementation for ->signal 1269# default implementation for ->signal
1187 1270
1271our $HAVE_ASYNC_INTERRUPT;
1188our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1272our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1273our (%SIG_ASY, %SIG_ASY_W);
1274our ($SIG_COUNT, $SIG_TW);
1189 1275
1190sub _signal_exec { 1276sub _signal_exec {
1277 $HAVE_ASYNC_INTERRUPT
1278 ? $SIGPIPE_R->drain
1191 sysread $SIGPIPE_R, my $dummy, 4; 1279 : sysread $SIGPIPE_R, my $dummy, 9;
1192 1280
1193 while (%SIG_EV) { 1281 while (%SIG_EV) {
1194 for (keys %SIG_EV) { 1282 for (keys %SIG_EV) {
1195 delete $SIG_EV{$_}; 1283 delete $SIG_EV{$_};
1196 $_->() for values %{ $SIG_CB{$_} || {} }; 1284 $_->() for values %{ $SIG_CB{$_} || {} };
1197 } 1285 }
1198 } 1286 }
1199} 1287}
1200 1288
1289# install a dumym wakeupw atcher to reduce signal catching latency
1290sub _sig_add() {
1291 unless ($SIG_COUNT++) {
1292 # try to align timer on a full-second boundary, if possible
1293 my $NOW = AnyEvent->now;
1294
1295 $SIG_TW = AnyEvent->timer (
1296 after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1297 interval => $MAX_SIGNAL_LATENCY,
1298 cb => sub { }, # just for the PERL_ASYNC_CHECK
1299 );
1300 }
1301}
1302
1303sub _sig_del {
1304 undef $SIG_TW
1305 unless --$SIG_COUNT;
1306}
1307
1308sub _signal {
1309 my (undef, %arg) = @_;
1310
1311 my $signal = uc $arg{signal}
1312 or Carp::croak "required option 'signal' is missing";
1313
1314 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1315
1316 if ($HAVE_ASYNC_INTERRUPT) {
1317 # async::interrupt
1318
1319 $SIG_ASY{$signal} ||= do {
1320 my $asy = new Async::Interrupt
1321 cb => sub { undef $SIG_EV{$signal} },
1322 signal => $signal,
1323 pipe => [$SIGPIPE_R->filenos],
1324 ;
1325 $asy->pipe_autodrain (0);
1326
1327 $asy
1328 };
1329
1330 } else {
1331 # pure perl
1332
1333 $SIG{$signal} ||= sub {
1334 local $!;
1335 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1336 undef $SIG_EV{$signal};
1337 };
1338
1339 # can't do signal processing without introducing races in pure perl,
1340 # so limit the signal latency.
1341 _sig_add;
1342 }
1343
1344 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1345}
1346
1201sub signal { 1347sub signal {
1202 my (undef, %arg) = @_; 1348 # probe for availability of Async::Interrupt
1349 if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1350 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1203 1351
1204 unless ($SIGPIPE_R) { 1352 $HAVE_ASYNC_INTERRUPT = 1;
1353 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1354 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1355
1356 } else {
1357 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1358
1205 require Fcntl; 1359 require Fcntl;
1206 1360
1207 if (AnyEvent::WIN32) { 1361 if (AnyEvent::WIN32) {
1208 require AnyEvent::Util; 1362 require AnyEvent::Util;
1209 1363
1224 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1378 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1225 1379
1226 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); 1380 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1227 } 1381 }
1228 1382
1229 my $signal = uc $arg{signal} 1383 *signal = \&_signal;
1230 or Carp::croak "required option 'signal' is missing"; 1384 &signal
1231
1232 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1233 $SIG{$signal} ||= sub {
1234 local $!;
1235 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1236 undef $SIG_EV{$signal};
1237 };
1238
1239 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1240} 1385}
1241 1386
1242sub AnyEvent::Base::signal::DESTROY { 1387sub AnyEvent::Base::signal::DESTROY {
1243 my ($signal, $cb) = @{$_[0]}; 1388 my ($signal, $cb) = @{$_[0]};
1244 1389
1390 _sig_del;
1391
1245 delete $SIG_CB{$signal}{$cb}; 1392 delete $SIG_CB{$signal}{$cb};
1246 1393
1394 $HAVE_ASYNC_INTERRUPT
1395 ? delete $SIG_ASY{$signal}
1247 # delete doesn't work with older perls - they then 1396 : # delete doesn't work with older perls - they then
1248 # print weird messages, or just unconditionally exit 1397 # print weird messages, or just unconditionally exit
1249 # instead of getting the default action. 1398 # instead of getting the default action.
1399 undef $SIG{$signal}
1250 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; 1400 unless keys %{ $SIG_CB{$signal} };
1251} 1401}
1252 1402
1253# default implementation for ->child 1403# default implementation for ->child
1254 1404
1255our %PID_CB; 1405our %PID_CB;
1257our $CHLD_DELAY_W; 1407our $CHLD_DELAY_W;
1258our $WNOHANG; 1408our $WNOHANG;
1259 1409
1260sub _sigchld { 1410sub _sigchld {
1261 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1411 while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1412 $_->($pid, $?)
1262 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1413 for values %{ $PID_CB{$pid} || {} },
1263 (values %{ $PID_CB{0} || {} }); 1414 values %{ $PID_CB{0} || {} };
1264 } 1415 }
1265} 1416}
1266 1417
1267sub child { 1418sub child {
1268 my (undef, %arg) = @_; 1419 my (undef, %arg) = @_;
1270 defined (my $pid = $arg{pid} + 0) 1421 defined (my $pid = $arg{pid} + 0)
1271 or Carp::croak "required option 'pid' is missing"; 1422 or Carp::croak "required option 'pid' is missing";
1272 1423
1273 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1424 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1274 1425
1426 # WNOHANG is almost cetrainly 1 everywhere
1427 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1428 ? 1
1275 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1429 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1276 1430
1277 unless ($CHLD_W) { 1431 unless ($CHLD_W) {
1278 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1432 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1279 # child could be a zombie already, so make at least one round 1433 # child could be a zombie already, so make at least one round
1280 &_sigchld; 1434 &_sigchld;
1332 1486
1333our @ISA = AnyEvent::CondVar::Base::; 1487our @ISA = AnyEvent::CondVar::Base::;
1334 1488
1335package AnyEvent::CondVar::Base; 1489package AnyEvent::CondVar::Base;
1336 1490
1337use overload 1491#use overload
1338 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1492# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1339 fallback => 1; 1493# fallback => 1;
1494
1495# save 300+ kilobytes by dirtily hardcoding overloading
1496${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1497*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1498*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1499${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1500
1501our $WAITING;
1340 1502
1341sub _send { 1503sub _send {
1342 # nop 1504 # nop
1343} 1505}
1344 1506
1357sub ready { 1519sub ready {
1358 $_[0]{_ae_sent} 1520 $_[0]{_ae_sent}
1359} 1521}
1360 1522
1361sub _wait { 1523sub _wait {
1524 $WAITING
1525 and !$_[0]{_ae_sent}
1526 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1527
1528 local $WAITING = 1;
1362 AnyEvent->one_event while !$_[0]{_ae_sent}; 1529 AnyEvent->one_event while !$_[0]{_ae_sent};
1363} 1530}
1364 1531
1365sub recv { 1532sub recv {
1366 $_[0]->_wait; 1533 $_[0]->_wait;
1428C<PERL_ANYEVENT_MODEL>. 1595C<PERL_ANYEVENT_MODEL>.
1429 1596
1430When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1597When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1431model it chooses. 1598model it chooses.
1432 1599
1600When set to C<8> or higher, then AnyEvent will report extra information on
1601which optional modules it loads and how it implements certain features.
1602
1433=item C<PERL_ANYEVENT_STRICT> 1603=item C<PERL_ANYEVENT_STRICT>
1434 1604
1435AnyEvent does not do much argument checking by default, as thorough 1605AnyEvent does not do much argument checking by default, as thorough
1436argument checking is very costly. Setting this variable to a true value 1606argument checking is very costly. Setting this variable to a true value
1437will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1607will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1438check the arguments passed to most method calls. If it finds any problems, 1608check the arguments passed to most method calls. If it finds any problems,
1439it will croak. 1609it will croak.
1440 1610
1441In other words, enables "strict" mode. 1611In other words, enables "strict" mode.
1442 1612
1443Unlike C<use strict>, it is definitely recommended to keep it off in 1613Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1444production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1614>>, it is definitely recommended to keep it off in production. Keeping
1445developing programs can be very useful, however. 1615C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1616can be very useful, however.
1446 1617
1447=item C<PERL_ANYEVENT_MODEL> 1618=item C<PERL_ANYEVENT_MODEL>
1448 1619
1449This can be used to specify the event model to be used by AnyEvent, before 1620This can be used to specify the event model to be used by AnyEvent, before
1450auto detection and -probing kicks in. It must be a string consisting 1621auto detection and -probing kicks in. It must be a string consisting
1512 1683
1513When neither C<ca_file> nor C<ca_path> was specified during 1684When neither C<ca_file> nor C<ca_path> was specified during
1514L<AnyEvent::TLS> context creation, and either of these environment 1685L<AnyEvent::TLS> context creation, and either of these environment
1515variables exist, they will be used to specify CA certificate locations 1686variables exist, they will be used to specify CA certificate locations
1516instead of a system-dependent default. 1687instead of a system-dependent default.
1688
1689=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1690
1691When these are set to C<1>, then the respective modules are not
1692loaded. Mostly good for testing AnyEvent itself.
1517 1693
1518=back 1694=back
1519 1695
1520=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1696=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1521 1697
2060 2236
2061A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2237A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2062emulation for event loops that do not support them natively. Also, some 2238emulation for event loops that do not support them natively. Also, some
2063event loops install a similar handler. 2239event loops install a similar handler.
2064 2240
2065If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2241Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2066reset it to default, to avoid losing child exit statuses. 2242AnyEvent will reset it to default, to avoid losing child exit statuses.
2067 2243
2068=item SIGPIPE 2244=item SIGPIPE
2069 2245
2070A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2246A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2071when AnyEvent gets loaded. 2247when AnyEvent gets loaded.
2089 if $SIG{CHLD} eq 'IGNORE'; 2265 if $SIG{CHLD} eq 'IGNORE';
2090 2266
2091$SIG{PIPE} = sub { } 2267$SIG{PIPE} = sub { }
2092 unless defined $SIG{PIPE}; 2268 unless defined $SIG{PIPE};
2093 2269
2270=head1 RECOMMENDED/OPTIONAL MODULES
2271
2272One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2273it's built-in modules) are required to use it.
2274
2275That does not mean that AnyEvent won't take advantage of some additional
2276modules if they are installed.
2277
2278This section epxlains which additional modules will be used, and how they
2279affect AnyEvent's operetion.
2280
2281=over 4
2282
2283=item L<Async::Interrupt>
2284
2285This slightly arcane module is used to implement fast signal handling: To
2286my knowledge, there is no way to do completely race-free and quick
2287signal handling in pure perl. To ensure that signals still get
2288delivered, AnyEvent will start an interval timer to wake up perl (and
2289catch the signals) with some delay (default is 10 seconds, look for
2290C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2291
2292If this module is available, then it will be used to implement signal
2293catching, which means that signals will not be delayed, and the event loop
2294will not be interrupted regularly, which is more efficient (And good for
2295battery life on laptops).
2296
2297This affects not just the pure-perl event loop, but also other event loops
2298that have no signal handling on their own (e.g. Glib, Tk, Qt).
2299
2300Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2301and either employ their own workarounds (POE) or use AnyEvent's workaround
2302(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2303does nothing for those backends.
2304
2305=item L<EV>
2306
2307This module isn't really "optional", as it is simply one of the backend
2308event loops that AnyEvent can use. However, it is simply the best event
2309loop available in terms of features, speed and stability: It supports
2310the AnyEvent API optimally, implements all the watcher types in XS, does
2311automatic timer adjustments even when no monotonic clock is available,
2312can take avdantage of advanced kernel interfaces such as C<epoll> and
2313C<kqueue>, and is the fastest backend I<by far>. You can even embed
2314L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2315
2316=item L<Guard>
2317
2318The guard module, when used, will be used to implement
2319C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2320lot less memory), but otherwise doesn't affect guard operation much. It is
2321purely used for performance.
2322
2323=item L<JSON> and L<JSON::XS>
2324
2325This module is required when you want to read or write JSON data via
2326L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2327advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2328
2329In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2330installed.
2331
2332=item L<Net::SSLeay>
2333
2334Implementing TLS/SSL in Perl is certainly interesting, but not very
2335worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2336the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2337
2338=item L<Time::HiRes>
2339
2340This module is part of perl since release 5.008. It will be used when the
2341chosen event library does not come with a timing source on it's own. The
2342pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2343try to use a monotonic clock for timing stability.
2344
2345=back
2346
2347
2094=head1 FORK 2348=head1 FORK
2095 2349
2096Most event libraries are not fork-safe. The ones who are usually are 2350Most event libraries are not fork-safe. The ones who are usually are
2097because they rely on inefficient but fork-safe C<select> or C<poll> 2351because they rely on inefficient but fork-safe C<select> or C<poll>
2098calls. Only L<EV> is fully fork-aware. 2352calls. Only L<EV> is fully fork-aware.
2099 2353
2100If you have to fork, you must either do so I<before> creating your first 2354If you have to fork, you must either do so I<before> creating your first
2101watcher OR you must not use AnyEvent at all in the child. 2355watcher OR you must not use AnyEvent at all in the child OR you must do
2356something completely out of the scope of AnyEvent.
2102 2357
2103 2358
2104=head1 SECURITY CONSIDERATIONS 2359=head1 SECURITY CONSIDERATIONS
2105 2360
2106AnyEvent can be forced to load any event model via 2361AnyEvent can be forced to load any event model via
2144L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2399L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2145 2400
2146Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2401Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2147L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2402L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2148L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2403L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2149L<AnyEvent::Impl::POE>. 2404L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
2150 2405
2151Non-blocking file handles, sockets, TCP clients and 2406Non-blocking file handles, sockets, TCP clients and
2152servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2407servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2153 2408
2154Asynchronous DNS: L<AnyEvent::DNS>. 2409Asynchronous DNS: L<AnyEvent::DNS>.
2155 2410
2156Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2411Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2412L<Coro::Event>,
2157 2413
2158Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2414Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2415L<AnyEvent::HTTP>.
2159 2416
2160 2417
2161=head1 AUTHOR 2418=head1 AUTHOR
2162 2419
2163 Marc Lehmann <schmorp@schmorp.de> 2420 Marc Lehmann <schmorp@schmorp.de>

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