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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 $guard = AnyEvent::post_detect { BLOCK }
813 868
814Arranges for the code block to be executed as soon as the event model is 869Arranges for the code block to be executed as soon as the event model is
815autodetected (or immediately if this has already happened). 870autodetected (or immediately if this has already happened).
816 871
872The block will be executed I<after> the actual backend has been detected
873(C<$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.
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 (or
885C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
819L<Coro::BDB> for a case where this is useful. 886a case where this is useful.
887
888Example: Create a watcher for the IO::AIO module and store it in
889C<$WATCHER>. Only do so after the event loop is initialised, though.
890
891 our WATCHER;
892
893 my $guard = AnyEvent::post_detect {
894 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
895 };
896
897 # the ||= is important in case post_detect immediately runs the block,
898 # as to not clobber the newly-created watcher. assigning both watcher and
899 # post_detect guard to the same variable has the advantage of users being
900 # able to just C<undef $WATCHER> if the watcher causes them grief.
901
902 $WATCHER ||= $guard;
820 903
821=item @AnyEvent::post_detect 904=item @AnyEvent::post_detect
822 905
823If there are any code references in this array (you can C<push> to it 906If there are any code references in this array (you can C<push> to it
824before or after loading AnyEvent), then they will called directly after 907before or after loading AnyEvent), then they will called directly after
825the event loop has been chosen. 908the event loop has been chosen.
826 909
827You should check C<$AnyEvent::MODEL> before adding to this array, though: 910You 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, 911if it is defined then the event loop has already been detected, and the
829and the array will be ignored. 912array will be ignored.
830 913
831Best use C<AnyEvent::post_detect { BLOCK }> instead. 914Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
915it,as it takes care of these details.
916
917This variable is mainly useful for modules that can do something useful
918when AnyEvent is used and thus want to know when it is initialised, but do
919not need to even load it by default. This array provides the means to hook
920into AnyEvent passively, without loading it.
832 921
833=back 922=back
834 923
835=head1 WHAT TO DO IN A MODULE 924=head1 WHAT TO DO IN A MODULE
836 925
891 980
892 981
893=head1 OTHER MODULES 982=head1 OTHER MODULES
894 983
895The following is a non-exhaustive list of additional modules that use 984The following is a non-exhaustive list of additional modules that use
896AnyEvent and can therefore be mixed easily with other AnyEvent modules 985AnyEvent 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 986modules and other event loops in the same program. Some of the modules
898available via CPAN. 987come with AnyEvent, most are available via CPAN.
899 988
900=over 4 989=over 4
901 990
902=item L<AnyEvent::Util> 991=item L<AnyEvent::Util>
903 992
912 1001
913=item L<AnyEvent::Handle> 1002=item L<AnyEvent::Handle>
914 1003
915Provide read and write buffers, manages watchers for reads and writes, 1004Provide read and write buffers, manages watchers for reads and writes,
916supports raw and formatted I/O, I/O queued and fully transparent and 1005supports raw and formatted I/O, I/O queued and fully transparent and
917non-blocking SSL/TLS. 1006non-blocking SSL/TLS (via L<AnyEvent::TLS>.
918 1007
919=item L<AnyEvent::DNS> 1008=item L<AnyEvent::DNS>
920 1009
921Provides rich asynchronous DNS resolver capabilities. 1010Provides rich asynchronous DNS resolver capabilities.
922 1011
950 1039
951=item L<AnyEvent::GPSD> 1040=item L<AnyEvent::GPSD>
952 1041
953A non-blocking interface to gpsd, a daemon delivering GPS information. 1042A non-blocking interface to gpsd, a daemon delivering GPS information.
954 1043
1044=item L<AnyEvent::IRC>
1045
1046AnyEvent based IRC client module family (replacing the older Net::IRC3).
1047
1048=item L<AnyEvent::XMPP>
1049
1050AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1051Net::XMPP2>.
1052
955=item L<AnyEvent::IGS> 1053=item L<AnyEvent::IGS>
956 1054
957A non-blocking interface to the Internet Go Server protocol (used by 1055A non-blocking interface to the Internet Go Server protocol (used by
958L<App::IGS>). 1056L<App::IGS>).
959 1057
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> 1058=item L<Net::FCP>
969 1059
970AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1060AnyEvent-based implementation of the Freenet Client Protocol, birthplace
971of AnyEvent. 1061of AnyEvent.
972 1062
976 1066
977=item L<Coro> 1067=item L<Coro>
978 1068
979Has special support for AnyEvent via L<Coro::AnyEvent>. 1069Has special support for AnyEvent via L<Coro::AnyEvent>.
980 1070
981=item L<IO::Lambda>
982
983The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
984
985=back 1071=back
986 1072
987=cut 1073=cut
988 1074
989package AnyEvent; 1075package AnyEvent;
990 1076
1077# basically a tuned-down version of common::sense
1078sub common_sense {
991no warnings; 1079 # no warnings
1080 ${^WARNING_BITS} ^= ${^WARNING_BITS};
992use strict qw(vars subs); 1081 # use strict vars subs
1082 $^H |= 0x00000600;
1083}
993 1084
1085BEGIN { AnyEvent::common_sense }
1086
994use Carp; 1087use Carp ();
995 1088
996our $VERSION = 4.8; 1089our $VERSION = 4.86;
997our $MODEL; 1090our $MODEL;
998 1091
999our $AUTOLOAD; 1092our $AUTOLOAD;
1000our @ISA; 1093our @ISA;
1001 1094
1002our @REGISTRY; 1095our @REGISTRY;
1003 1096
1004our $WIN32; 1097our $WIN32;
1098
1099our $VERBOSE;
1005 1100
1006BEGIN { 1101BEGIN {
1007 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1102 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
1008 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1103 eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
1009 1104
1010 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1105 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1011 if ${^TAINT}; 1106 if ${^TAINT};
1012}
1013 1107
1014our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1108 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1109
1110}
1111
1112our $MAX_SIGNAL_LATENCY = 10;
1015 1113
1016our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1114our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1017 1115
1018{ 1116{
1019 my $idx; 1117 my $idx;
1027 [Event:: => AnyEvent::Impl::Event::], 1125 [Event:: => AnyEvent::Impl::Event::],
1028 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1126 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
1029 # everything below here will not be autoprobed 1127 # everything below here will not be autoprobed
1030 # as the pureperl backend should work everywhere 1128 # as the pureperl backend should work everywhere
1031 # and is usually faster 1129 # and is usually faster
1032 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1033 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers 1130 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1034 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1131 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1132 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1035 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1133 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1036 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1134 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1037 [Wx:: => AnyEvent::Impl::POE::], 1135 [Wx:: => AnyEvent::Impl::POE::],
1038 [Prima:: => AnyEvent::Impl::POE::], 1136 [Prima:: => AnyEvent::Impl::POE::],
1039 # IO::Async is just too broken - we would need workaorunds for its 1137 # IO::Async is just too broken - we would need workarounds for its
1040 # byzantine signal and broken child handling, among others. 1138 # byzantine signal and broken child handling, among others.
1041 # IO::Async is rather hard to detect, as it doesn't have any 1139 # IO::Async is rather hard to detect, as it doesn't have any
1042 # obvious default class. 1140 # obvious default class.
1043# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1141# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1044# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1142# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1054 my ($cb) = @_; 1152 my ($cb) = @_;
1055 1153
1056 if ($MODEL) { 1154 if ($MODEL) {
1057 $cb->(); 1155 $cb->();
1058 1156
1059 1 1157 undef
1060 } else { 1158 } else {
1061 push @post_detect, $cb; 1159 push @post_detect, $cb;
1062 1160
1063 defined wantarray 1161 defined wantarray
1064 ? bless \$cb, "AnyEvent::Util::postdetect" 1162 ? bless \$cb, "AnyEvent::Util::postdetect"
1070 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1168 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1071} 1169}
1072 1170
1073sub detect() { 1171sub detect() {
1074 unless ($MODEL) { 1172 unless ($MODEL) {
1075 no strict 'refs';
1076 local $SIG{__DIE__}; 1173 local $SIG{__DIE__};
1077 1174
1078 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1175 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1079 my $model = "AnyEvent::Impl::$1"; 1176 my $model = "AnyEvent::Impl::$1";
1080 if (eval "require $model") { 1177 if (eval "require $model") {
1081 $MODEL = $model; 1178 $MODEL = $model;
1082 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1179 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1083 } else { 1180 } else {
1084 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1181 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1085 } 1182 }
1086 } 1183 }
1087 1184
1088 # check for already loaded models 1185 # check for already loaded models
1089 unless ($MODEL) { 1186 unless ($MODEL) {
1090 for (@REGISTRY, @models) { 1187 for (@REGISTRY, @models) {
1091 my ($package, $model) = @$_; 1188 my ($package, $model) = @$_;
1092 if (${"$package\::VERSION"} > 0) { 1189 if (${"$package\::VERSION"} > 0) {
1093 if (eval "require $model") { 1190 if (eval "require $model") {
1094 $MODEL = $model; 1191 $MODEL = $model;
1095 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1192 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1096 last; 1193 last;
1097 } 1194 }
1098 } 1195 }
1099 } 1196 }
1100 1197
1105 my ($package, $model) = @$_; 1202 my ($package, $model) = @$_;
1106 if (eval "require $package" 1203 if (eval "require $package"
1107 and ${"$package\::VERSION"} > 0 1204 and ${"$package\::VERSION"} > 0
1108 and eval "require $model") { 1205 and eval "require $model") {
1109 $MODEL = $model; 1206 $MODEL = $model;
1110 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; 1207 warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2;
1111 last; 1208 last;
1112 } 1209 }
1113 } 1210 }
1114 1211
1115 $MODEL 1212 $MODEL
1131 1228
1132sub AUTOLOAD { 1229sub AUTOLOAD {
1133 (my $func = $AUTOLOAD) =~ s/.*://; 1230 (my $func = $AUTOLOAD) =~ s/.*://;
1134 1231
1135 $method{$func} 1232 $method{$func}
1136 or croak "$func: not a valid method for AnyEvent objects"; 1233 or Carp::croak "$func: not a valid method for AnyEvent objects";
1137 1234
1138 detect unless $MODEL; 1235 detect unless $MODEL;
1139 1236
1140 my $class = shift; 1237 my $class = shift;
1141 $class->$func (@_); 1238 $class->$func (@_);
1146# allow only one watcher per fd, so we dup it to get a different one). 1243# allow only one watcher per fd, so we dup it to get a different one).
1147sub _dupfh($$;$$) { 1244sub _dupfh($$;$$) {
1148 my ($poll, $fh, $r, $w) = @_; 1245 my ($poll, $fh, $r, $w) = @_;
1149 1246
1150 # cygwin requires the fh mode to be matching, unix doesn't 1247 # cygwin requires the fh mode to be matching, unix doesn't
1151 my ($rw, $mode) = $poll eq "r" ? ($r, "<") 1248 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 1249
1155 open my $fh2, "$mode&" . fileno $fh 1250 open my $fh2, $mode, $fh
1156 or die "cannot dup() filehandle: $!,"; 1251 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1157 1252
1158 # we assume CLOEXEC is already set by perl in all important cases 1253 # we assume CLOEXEC is already set by perl in all important cases
1159 1254
1160 ($fh2, $rw) 1255 ($fh2, $rw)
1161} 1256}
1162 1257
1163package AnyEvent::Base; 1258package AnyEvent::Base;
1164 1259
1165# default implementations for many methods 1260# default implementations for many methods
1166 1261
1167BEGIN { 1262sub _time {
1263 # probe for availability of Time::HiRes
1168 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1264 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1265 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1169 *_time = \&Time::HiRes::time; 1266 *_time = \&Time::HiRes::time;
1170 # if (eval "use POSIX (); (POSIX::times())... 1267 # if (eval "use POSIX (); (POSIX::times())...
1171 } else { 1268 } else {
1269 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1172 *_time = sub { time }; # epic fail 1270 *_time = sub { time }; # epic fail
1173 } 1271 }
1272
1273 &_time
1174} 1274}
1175 1275
1176sub time { _time } 1276sub time { _time }
1177sub now { _time } 1277sub now { _time }
1178sub now_update { } 1278sub now_update { }
1183 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1283 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1184} 1284}
1185 1285
1186# default implementation for ->signal 1286# default implementation for ->signal
1187 1287
1288our $HAVE_ASYNC_INTERRUPT;
1188our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1289our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1290our (%SIG_ASY, %SIG_ASY_W);
1291our ($SIG_COUNT, $SIG_TW);
1189 1292
1190sub _signal_exec { 1293sub _signal_exec {
1294 $HAVE_ASYNC_INTERRUPT
1295 ? $SIGPIPE_R->drain
1191 sysread $SIGPIPE_R, my $dummy, 4; 1296 : sysread $SIGPIPE_R, my $dummy, 9;
1192 1297
1193 while (%SIG_EV) { 1298 while (%SIG_EV) {
1194 for (keys %SIG_EV) { 1299 for (keys %SIG_EV) {
1195 delete $SIG_EV{$_}; 1300 delete $SIG_EV{$_};
1196 $_->() for values %{ $SIG_CB{$_} || {} }; 1301 $_->() for values %{ $SIG_CB{$_} || {} };
1197 } 1302 }
1198 } 1303 }
1199} 1304}
1200 1305
1306# install a dumym wakeupw atcher to reduce signal catching latency
1307sub _sig_add() {
1308 unless ($SIG_COUNT++) {
1309 # try to align timer on a full-second boundary, if possible
1310 my $NOW = AnyEvent->now;
1311
1312 $SIG_TW = AnyEvent->timer (
1313 after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1314 interval => $MAX_SIGNAL_LATENCY,
1315 cb => sub { }, # just for the PERL_ASYNC_CHECK
1316 );
1317 }
1318}
1319
1320sub _sig_del {
1321 undef $SIG_TW
1322 unless --$SIG_COUNT;
1323}
1324
1325sub _signal {
1326 my (undef, %arg) = @_;
1327
1328 my $signal = uc $arg{signal}
1329 or Carp::croak "required option 'signal' is missing";
1330
1331 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1332
1333 if ($HAVE_ASYNC_INTERRUPT) {
1334 # async::interrupt
1335
1336 $SIG_ASY{$signal} ||= do {
1337 my $asy = new Async::Interrupt
1338 cb => sub { undef $SIG_EV{$signal} },
1339 signal => $signal,
1340 pipe => [$SIGPIPE_R->filenos],
1341 ;
1342 $asy->pipe_autodrain (0);
1343
1344 $asy
1345 };
1346
1347 } else {
1348 # pure perl
1349
1350 $SIG{$signal} ||= sub {
1351 local $!;
1352 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1353 undef $SIG_EV{$signal};
1354 };
1355
1356 # can't do signal processing without introducing races in pure perl,
1357 # so limit the signal latency.
1358 _sig_add;
1359 }
1360
1361 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1362}
1363
1201sub signal { 1364sub signal {
1202 my (undef, %arg) = @_; 1365 # probe for availability of Async::Interrupt
1366 if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1367 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1203 1368
1204 unless ($SIGPIPE_R) { 1369 $HAVE_ASYNC_INTERRUPT = 1;
1370 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1371 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1372
1373 } else {
1374 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1375
1205 require Fcntl; 1376 require Fcntl;
1206 1377
1207 if (AnyEvent::WIN32) { 1378 if (AnyEvent::WIN32) {
1208 require AnyEvent::Util; 1379 require AnyEvent::Util;
1209 1380
1224 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1395 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1225 1396
1226 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); 1397 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1227 } 1398 }
1228 1399
1229 my $signal = uc $arg{signal} 1400 *signal = \&_signal;
1230 or Carp::croak "required option 'signal' is missing"; 1401 &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, $arg{cb}], "AnyEvent::Base::signal"
1240} 1402}
1241 1403
1242sub AnyEvent::Base::signal::DESTROY { 1404sub AnyEvent::Base::signal::DESTROY {
1243 my ($signal, $cb) = @{$_[0]}; 1405 my ($signal, $cb) = @{$_[0]};
1244 1406
1407 _sig_del;
1408
1245 delete $SIG_CB{$signal}{$cb}; 1409 delete $SIG_CB{$signal}{$cb};
1246 1410
1411 $HAVE_ASYNC_INTERRUPT
1412 ? delete $SIG_ASY{$signal}
1247 # delete doesn't work with older perls - they then 1413 : # delete doesn't work with older perls - they then
1248 # print weird messages, or just unconditionally exit 1414 # print weird messages, or just unconditionally exit
1249 # instead of getting the default action. 1415 # instead of getting the default action.
1416 undef $SIG{$signal}
1250 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; 1417 unless keys %{ $SIG_CB{$signal} };
1251} 1418}
1252 1419
1253# default implementation for ->child 1420# default implementation for ->child
1254 1421
1255our %PID_CB; 1422our %PID_CB;
1257our $CHLD_DELAY_W; 1424our $CHLD_DELAY_W;
1258our $WNOHANG; 1425our $WNOHANG;
1259 1426
1260sub _sigchld { 1427sub _sigchld {
1261 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1428 while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1429 $_->($pid, $?)
1262 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1430 for values %{ $PID_CB{$pid} || {} },
1263 (values %{ $PID_CB{0} || {} }); 1431 values %{ $PID_CB{0} || {} };
1264 } 1432 }
1265} 1433}
1266 1434
1267sub child { 1435sub child {
1268 my (undef, %arg) = @_; 1436 my (undef, %arg) = @_;
1270 defined (my $pid = $arg{pid} + 0) 1438 defined (my $pid = $arg{pid} + 0)
1271 or Carp::croak "required option 'pid' is missing"; 1439 or Carp::croak "required option 'pid' is missing";
1272 1440
1273 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1441 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1274 1442
1443 # WNOHANG is almost cetrainly 1 everywhere
1444 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1445 ? 1
1275 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1446 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1276 1447
1277 unless ($CHLD_W) { 1448 unless ($CHLD_W) {
1278 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1449 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1279 # child could be a zombie already, so make at least one round 1450 # child could be a zombie already, so make at least one round
1280 &_sigchld; 1451 &_sigchld;
1332 1503
1333our @ISA = AnyEvent::CondVar::Base::; 1504our @ISA = AnyEvent::CondVar::Base::;
1334 1505
1335package AnyEvent::CondVar::Base; 1506package AnyEvent::CondVar::Base;
1336 1507
1337use overload 1508#use overload
1338 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1509# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1339 fallback => 1; 1510# fallback => 1;
1511
1512# save 300+ kilobytes by dirtily hardcoding overloading
1513${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1514*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1515*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1516${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1517
1518our $WAITING;
1340 1519
1341sub _send { 1520sub _send {
1342 # nop 1521 # nop
1343} 1522}
1344 1523
1357sub ready { 1536sub ready {
1358 $_[0]{_ae_sent} 1537 $_[0]{_ae_sent}
1359} 1538}
1360 1539
1361sub _wait { 1540sub _wait {
1541 $WAITING
1542 and !$_[0]{_ae_sent}
1543 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1544
1545 local $WAITING = 1;
1362 AnyEvent->one_event while !$_[0]{_ae_sent}; 1546 AnyEvent->one_event while !$_[0]{_ae_sent};
1363} 1547}
1364 1548
1365sub recv { 1549sub recv {
1366 $_[0]->_wait; 1550 $_[0]->_wait;
1428C<PERL_ANYEVENT_MODEL>. 1612C<PERL_ANYEVENT_MODEL>.
1429 1613
1430When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1614When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1431model it chooses. 1615model it chooses.
1432 1616
1617When set to C<8> or higher, then AnyEvent will report extra information on
1618which optional modules it loads and how it implements certain features.
1619
1433=item C<PERL_ANYEVENT_STRICT> 1620=item C<PERL_ANYEVENT_STRICT>
1434 1621
1435AnyEvent does not do much argument checking by default, as thorough 1622AnyEvent does not do much argument checking by default, as thorough
1436argument checking is very costly. Setting this variable to a true value 1623argument checking is very costly. Setting this variable to a true value
1437will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1624will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1438check the arguments passed to most method calls. If it finds any problems, 1625check the arguments passed to most method calls. If it finds any problems,
1439it will croak. 1626it will croak.
1440 1627
1441In other words, enables "strict" mode. 1628In other words, enables "strict" mode.
1442 1629
1443Unlike C<use strict>, it is definitely recommended to keep it off in 1630Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1444production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1631>>, it is definitely recommended to keep it off in production. Keeping
1445developing programs can be very useful, however. 1632C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1633can be very useful, however.
1446 1634
1447=item C<PERL_ANYEVENT_MODEL> 1635=item C<PERL_ANYEVENT_MODEL>
1448 1636
1449This can be used to specify the event model to be used by AnyEvent, before 1637This 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 1638auto detection and -probing kicks in. It must be a string consisting
1512 1700
1513When neither C<ca_file> nor C<ca_path> was specified during 1701When neither C<ca_file> nor C<ca_path> was specified during
1514L<AnyEvent::TLS> context creation, and either of these environment 1702L<AnyEvent::TLS> context creation, and either of these environment
1515variables exist, they will be used to specify CA certificate locations 1703variables exist, they will be used to specify CA certificate locations
1516instead of a system-dependent default. 1704instead of a system-dependent default.
1705
1706=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1707
1708When these are set to C<1>, then the respective modules are not
1709loaded. Mostly good for testing AnyEvent itself.
1517 1710
1518=back 1711=back
1519 1712
1520=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1713=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1521 1714
2060 2253
2061A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2254A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2062emulation for event loops that do not support them natively. Also, some 2255emulation for event loops that do not support them natively. Also, some
2063event loops install a similar handler. 2256event loops install a similar handler.
2064 2257
2065If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2258Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2066reset it to default, to avoid losing child exit statuses. 2259AnyEvent will reset it to default, to avoid losing child exit statuses.
2067 2260
2068=item SIGPIPE 2261=item SIGPIPE
2069 2262
2070A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2263A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2071when AnyEvent gets loaded. 2264when AnyEvent gets loaded.
2089 if $SIG{CHLD} eq 'IGNORE'; 2282 if $SIG{CHLD} eq 'IGNORE';
2090 2283
2091$SIG{PIPE} = sub { } 2284$SIG{PIPE} = sub { }
2092 unless defined $SIG{PIPE}; 2285 unless defined $SIG{PIPE};
2093 2286
2287=head1 RECOMMENDED/OPTIONAL MODULES
2288
2289One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2290it's built-in modules) are required to use it.
2291
2292That does not mean that AnyEvent won't take advantage of some additional
2293modules if they are installed.
2294
2295This section epxlains which additional modules will be used, and how they
2296affect AnyEvent's operetion.
2297
2298=over 4
2299
2300=item L<Async::Interrupt>
2301
2302This slightly arcane module is used to implement fast signal handling: To
2303my knowledge, there is no way to do completely race-free and quick
2304signal handling in pure perl. To ensure that signals still get
2305delivered, AnyEvent will start an interval timer to wake up perl (and
2306catch the signals) with some delay (default is 10 seconds, look for
2307C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2308
2309If this module is available, then it will be used to implement signal
2310catching, which means that signals will not be delayed, and the event loop
2311will not be interrupted regularly, which is more efficient (And good for
2312battery life on laptops).
2313
2314This affects not just the pure-perl event loop, but also other event loops
2315that have no signal handling on their own (e.g. Glib, Tk, Qt).
2316
2317Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2318and either employ their own workarounds (POE) or use AnyEvent's workaround
2319(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2320does nothing for those backends.
2321
2322=item L<EV>
2323
2324This module isn't really "optional", as it is simply one of the backend
2325event loops that AnyEvent can use. However, it is simply the best event
2326loop available in terms of features, speed and stability: It supports
2327the AnyEvent API optimally, implements all the watcher types in XS, does
2328automatic timer adjustments even when no monotonic clock is available,
2329can take avdantage of advanced kernel interfaces such as C<epoll> and
2330C<kqueue>, and is the fastest backend I<by far>. You can even embed
2331L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2332
2333=item L<Guard>
2334
2335The guard module, when used, will be used to implement
2336C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2337lot less memory), but otherwise doesn't affect guard operation much. It is
2338purely used for performance.
2339
2340=item L<JSON> and L<JSON::XS>
2341
2342This module is required when you want to read or write JSON data via
2343L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2344advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2345
2346In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2347installed.
2348
2349=item L<Net::SSLeay>
2350
2351Implementing TLS/SSL in Perl is certainly interesting, but not very
2352worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2353the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2354
2355=item L<Time::HiRes>
2356
2357This module is part of perl since release 5.008. It will be used when the
2358chosen event library does not come with a timing source on it's own. The
2359pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2360try to use a monotonic clock for timing stability.
2361
2362=back
2363
2364
2094=head1 FORK 2365=head1 FORK
2095 2366
2096Most event libraries are not fork-safe. The ones who are usually are 2367Most 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> 2368because they rely on inefficient but fork-safe C<select> or C<poll>
2098calls. Only L<EV> is fully fork-aware. 2369calls. Only L<EV> is fully fork-aware.
2099 2370
2100If you have to fork, you must either do so I<before> creating your first 2371If 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. 2372watcher OR you must not use AnyEvent at all in the child OR you must do
2373something completely out of the scope of AnyEvent.
2102 2374
2103 2375
2104=head1 SECURITY CONSIDERATIONS 2376=head1 SECURITY CONSIDERATIONS
2105 2377
2106AnyEvent can be forced to load any event model via 2378AnyEvent can be forced to load any event model via
2144L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2416L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2145 2417
2146Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2418Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2147L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2419L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2148L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2420L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2149L<AnyEvent::Impl::POE>. 2421L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
2150 2422
2151Non-blocking file handles, sockets, TCP clients and 2423Non-blocking file handles, sockets, TCP clients and
2152servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2424servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2153 2425
2154Asynchronous DNS: L<AnyEvent::DNS>. 2426Asynchronous DNS: L<AnyEvent::DNS>.
2155 2427
2156Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2428Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2429L<Coro::Event>,
2157 2430
2158Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2431Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2432L<AnyEvent::HTTP>.
2159 2433
2160 2434
2161=head1 AUTHOR 2435=head1 AUTHOR
2162 2436
2163 Marc Lehmann <schmorp@schmorp.de> 2437 Marc Lehmann <schmorp@schmorp.de>

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