ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/AnyEvent/lib/AnyEvent.pm
(Generate patch)

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.228 by root, Wed Jul 8 01:11:12 2009 UTC vs.
Revision 1.262 by root, Tue Jul 28 13:08:17 2009 UTC

1=head1 NAME 1=head1 NAME
2 2
3AnyEvent - provide framework for multiple event loops 3AnyEvent - the DBI of event loop programming
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported 5EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6event loops. 6and POE are various supported event loops/environments.
7 7
8=head1 SYNOPSIS 8=head1 SYNOPSIS
9 9
10 use AnyEvent; 10 use AnyEvent;
11 11
40=head1 INTRODUCTION/TUTORIAL 40=head1 INTRODUCTION/TUTORIAL
41 41
42This manpage is mainly a reference manual. If you are interested 42This manpage is mainly a reference manual. If you are interested
43in a tutorial or some gentle introduction, have a look at the 43in a tutorial or some gentle introduction, have a look at the
44L<AnyEvent::Intro> manpage. 44L<AnyEvent::Intro> manpage.
45
46=head1 SUPPORT
47
48There is a mailinglist for discussing all things AnyEvent, and an IRC
49channel, too.
50
51See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52Repository>, at L<http://anyevent.schmorp.de>, for more info.
45 53
46=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 54=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47 55
48Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 56Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49nowadays. So what is different about AnyEvent? 57nowadays. So what is different about AnyEvent?
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 $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
397 384
385=head3 Signal Races, Delays and Workarounds
386
387Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
388callbacks to signals in a generic way, which is a pity, as you cannot do
389race-free signal handling in perl. AnyEvent will try to do it's best, but
390in some cases, signals will be delayed. The maximum time a signal might
391be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10
392seconds). This variable can be changed only before the first signal
393watcher is created, and should be left alone otherwise. Higher values
394will cause fewer spurious wake-ups, which is better for power and CPU
395saving. All these problems can be avoided by installing the optional
396L<Async::Interrupt> module. This will not work with inherently broken
397event loops such as L<Event> or L<Event::Lib> (and not with L<POE>
398currently, as POE does it's own workaround with one-second latency). With
399those, you just have to suffer the delays.
400
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
402The child process is specified by the C<pid> argument (if set to C<0>, it 405The child process is specified by the C<pid> argument (one some backends,
403watches for any child process exit). The watcher will triggered only when 406using C<0> watches for any child process exit, on others this will
404the child process has finished and an exit status is available, not on 407croak). The watcher will be triggered only when the child process has
405any trace events (stopped/continued). 408finished and an exit status is available, not on any trace events
409(stopped/continued).
406 410
407The callback will be called with the pid and exit status (as returned by 411The callback will be called with the pid and exit status (as returned by
408waitpid), so unlike other watcher types, you I<can> rely on child watcher 412waitpid), so unlike other watcher types, you I<can> rely on child watcher
409callback arguments. 413callback arguments.
410 414
426 430
427This means you cannot create a child watcher as the very first 431This means you cannot create a child watcher as the very first
428thing in an AnyEvent program, you I<have> to create at least one 432thing in an AnyEvent program, you I<have> to create at least one
429watcher before you C<fork> the child (alternatively, you can call 433watcher before you C<fork> the child (alternatively, you can call
430C<AnyEvent::detect>). 434C<AnyEvent::detect>).
435
436As most event loops do not support waiting for child events, they will be
437emulated by AnyEvent in most cases, in which the latency and race problems
438mentioned in the description of signal watchers apply.
431 439
432Example: fork a process and wait for it 440Example: fork a process and wait for it
433 441
434 my $done = AnyEvent->condvar; 442 my $done = AnyEvent->condvar;
435 443
486 494
487If you are familiar with some event loops you will know that all of them 495If you are familiar with some event loops you will know that all of them
488require you to run some blocking "loop", "run" or similar function that 496require you to run some blocking "loop", "run" or similar function that
489will actively watch for new events and call your callbacks. 497will actively watch for new events and call your callbacks.
490 498
491AnyEvent is different, it expects somebody else to run the event loop and 499AnyEvent is slightly different: it expects somebody else to run the event
492will only block when necessary (usually when told by the user). 500loop and will only block when necessary (usually when told by the user).
493 501
494The instrument to do that is called a "condition variable", so called 502The instrument to do that is called a "condition variable", so called
495because they represent a condition that must become true. 503because they represent a condition that must become true.
496 504
505Now is probably a good time to look at the examples further below.
506
497Condition variables can be created by calling the C<< AnyEvent->condvar 507Condition variables can be created by calling the C<< AnyEvent->condvar
498>> method, usually without arguments. The only argument pair allowed is 508>> method, usually without arguments. The only argument pair allowed is
499
500C<cb>, which specifies a callback to be called when the condition variable 509C<cb>, which specifies a callback to be called when the condition variable
501becomes true, with the condition variable as the first argument (but not 510becomes true, with the condition variable as the first argument (but not
502the results). 511the results).
503 512
504After creation, the condition variable is "false" until it becomes "true" 513After creation, the condition variable is "false" until it becomes "true"
509Condition variables are similar to callbacks, except that you can 518Condition variables are similar to callbacks, except that you can
510optionally wait for them. They can also be called merge points - points 519optionally wait for them. They can also be called merge points - points
511in time where multiple outstanding events have been processed. And yet 520in time where multiple outstanding events have been processed. And yet
512another way to call them is transactions - each condition variable can be 521another way to call them is transactions - each condition variable can be
513used to represent a transaction, which finishes at some point and delivers 522used to represent a transaction, which finishes at some point and delivers
514a result. 523a result. And yet some people know them as "futures" - a promise to
524compute/deliver something that you can wait for.
515 525
516Condition variables are very useful to signal that something has finished, 526Condition variables are very useful to signal that something has finished,
517for example, if you write a module that does asynchronous http requests, 527for example, if you write a module that does asynchronous http requests,
518then a condition variable would be the ideal candidate to signal the 528then a condition variable would be the ideal candidate to signal the
519availability of results. The user can either act when the callback is 529availability of results. The user can either act when the callback is
553 after => 1, 563 after => 1,
554 cb => sub { $result_ready->send }, 564 cb => sub { $result_ready->send },
555 ); 565 );
556 566
557 # this "blocks" (while handling events) till the callback 567 # this "blocks" (while handling events) till the callback
558 # calls send 568 # calls -<send
559 $result_ready->recv; 569 $result_ready->recv;
560 570
561Example: wait for a timer, but take advantage of the fact that 571Example: wait for a timer, but take advantage of the fact that condition
562condition variables are also code references. 572variables are also callable directly.
563 573
564 my $done = AnyEvent->condvar; 574 my $done = AnyEvent->condvar;
565 my $delay = AnyEvent->timer (after => 5, cb => $done); 575 my $delay = AnyEvent->timer (after => 5, cb => $done);
566 $done->recv; 576 $done->recv;
567 577
573 583
574 ... 584 ...
575 585
576 my @info = $couchdb->info->recv; 586 my @info = $couchdb->info->recv;
577 587
578And this is how you would just ste a callback to be called whenever the 588And this is how you would just set a callback to be called whenever the
579results are available: 589results are available:
580 590
581 $couchdb->info->cb (sub { 591 $couchdb->info->cb (sub {
582 my @info = $_[0]->recv; 592 my @info = $_[0]->recv;
583 }); 593 });
601immediately from within send. 611immediately from within send.
602 612
603Any arguments passed to the C<send> call will be returned by all 613Any arguments passed to the C<send> call will be returned by all
604future C<< ->recv >> calls. 614future C<< ->recv >> calls.
605 615
606Condition variables are overloaded so one can call them directly 616Condition variables are overloaded so one can call them directly (as if
607(as a code reference). Calling them directly is the same as calling 617they were a code reference). Calling them directly is the same as calling
608C<send>. Note, however, that many C-based event loops do not handle 618C<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).
614 619
615=item $cv->croak ($error) 620=item $cv->croak ($error)
616 621
617Similar to send, but causes all call's to C<< ->recv >> to invoke 622Similar to send, but causes all call's to C<< ->recv >> to invoke
618C<Carp::croak> with the given error message/object/scalar. 623C<Carp::croak> with the given error message/object/scalar.
619 624
620This can be used to signal any errors to the condition variable 625This can be used to signal any errors to the condition variable
621user/consumer. 626user/consumer. Doing it this way instead of calling C<croak> directly
627delays the error detetcion, but has the overwhelmign advantage that it
628diagnoses the error at the place where the result is expected, and not
629deep in some event clalback without connection to the actual code causing
630the problem.
622 631
623=item $cv->begin ([group callback]) 632=item $cv->begin ([group callback])
624 633
625=item $cv->end 634=item $cv->end
626 635
722function will call C<croak>. 731function will call C<croak>.
723 732
724In list context, all parameters passed to C<send> will be returned, 733In list context, all parameters passed to C<send> will be returned,
725in scalar context only the first one will be returned. 734in scalar context only the first one will be returned.
726 735
736Note that doing a blocking wait in a callback is not supported by any
737event loop, that is, recursive invocation of a blocking C<< ->recv
738>> is not allowed, and the C<recv> call will C<croak> if such a
739condition is detected. This condition can be slightly loosened by using
740L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
741any thread that doesn't run the event loop itself.
742
727Not all event models support a blocking wait - some die in that case 743Not all event models support a blocking wait - some die in that case
728(programs might want to do that to stay interactive), so I<if you are 744(programs might want to do that to stay interactive), so I<if you are
729using this from a module, never require a blocking wait>, but let the 745using this from a module, never require a blocking wait>. Instead, let the
730caller decide whether the call will block or not (for example, by coupling 746caller decide whether the call will block or not (for example, by coupling
731condition variables with some kind of request results and supporting 747condition variables with some kind of request results and supporting
732callbacks so the caller knows that getting the result will not block, 748callbacks so the caller knows that getting the result will not block,
733while still supporting blocking waits if the caller so desires). 749while still supporting blocking waits if the caller so desires).
734 750
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 751You can ensure that C<< -recv >> never blocks by setting a callback and
747only calling C<< ->recv >> from within that callback (or at a later 752only calling C<< ->recv >> from within that callback (or at a later
748time). This will work even when the event loop does not support blocking 753time). This will work even when the event loop does not support blocking
749waits otherwise. 754waits otherwise.
750 755
763variable itself. Calling C<recv> inside the callback or at any later time 768variable itself. Calling C<recv> inside the callback or at any later time
764is guaranteed not to block. 769is guaranteed not to block.
765 770
766=back 771=back
767 772
773=head1 SUPPORTED EVENT LOOPS/BACKENDS
774
775The available backend classes are (every class has its own manpage):
776
777=over 4
778
779=item Backends that are autoprobed when no other event loop can be found.
780
781EV is the preferred backend when no other event loop seems to be in
782use. If EV is not installed, then AnyEvent will try Event, and, failing
783that, will fall back to its own pure-perl implementation, which is
784available everywhere as it comes with AnyEvent itself.
785
786 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
787 AnyEvent::Impl::Event based on Event, very stable, few glitches.
788 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
789
790=item Backends that are transparently being picked up when they are used.
791
792These will be used when they are currently loaded when the first watcher
793is created, in which case it is assumed that the application is using
794them. This means that AnyEvent will automatically pick the right backend
795when the main program loads an event module before anything starts to
796create watchers. Nothing special needs to be done by the main program.
797
798 AnyEvent::Impl::Glib based on Glib, slow but very stable.
799 AnyEvent::Impl::Tk based on Tk, very broken.
800 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
801 AnyEvent::Impl::POE based on POE, very slow, some limitations.
802 AnyEvent::Impl::Irssi used when running within irssi.
803
804=item Backends with special needs.
805
806Qt requires the Qt::Application to be instantiated first, but will
807otherwise be picked up automatically. As long as the main program
808instantiates the application before any AnyEvent watchers are created,
809everything should just work.
810
811 AnyEvent::Impl::Qt based on Qt.
812
813Support for IO::Async can only be partial, as it is too broken and
814architecturally limited to even support the AnyEvent API. It also
815is the only event loop that needs the loop to be set explicitly, so
816it can only be used by a main program knowing about AnyEvent. See
817L<AnyEvent::Impl::Async> for the gory details.
818
819 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
820
821=item Event loops that are indirectly supported via other backends.
822
823Some event loops can be supported via other modules:
824
825There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
826
827B<WxWidgets> has no support for watching file handles. However, you can
828use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
829polls 20 times per second, which was considered to be too horrible to even
830consider for AnyEvent.
831
832B<Prima> is not supported as nobody seems to be using it, but it has a POE
833backend, so it can be supported through POE.
834
835AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
836load L<POE> when detecting them, in the hope that POE will pick them up,
837in which case everything will be automatic.
838
839=back
840
768=head1 GLOBAL VARIABLES AND FUNCTIONS 841=head1 GLOBAL VARIABLES AND FUNCTIONS
769 842
843These are not normally required to use AnyEvent, but can be useful to
844write AnyEvent extension modules.
845
770=over 4 846=over 4
771 847
772=item $AnyEvent::MODEL 848=item $AnyEvent::MODEL
773 849
774Contains C<undef> until the first watcher is being created. Then it 850Contains C<undef> until the first watcher is being created, before the
851backend has been autodetected.
852
775contains the event model that is being used, which is the name of the 853Afterwards it contains the event model that is being used, which is the
776Perl class implementing the model. This class is usually one of the 854name 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 855of 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>). 856case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
779 857will 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.
804 858
805=item AnyEvent::detect 859=item AnyEvent::detect
806 860
807Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 861Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
808if necessary. You should only call this function right before you would 862if necessary. You should only call this function right before you would
809have created an AnyEvent watcher anyway, that is, as late as possible at 863have created an AnyEvent watcher anyway, that is, as late as possible at
810runtime. 864runtime, and not e.g. while initialising of your module.
865
866If you need to do some initialisation before AnyEvent watchers are
867created, use C<post_detect>.
811 868
812=item $guard = AnyEvent::post_detect { BLOCK } 869=item $guard = AnyEvent::post_detect { BLOCK }
813 870
814Arranges for the code block to be executed as soon as the event model is 871Arranges for the code block to be executed as soon as the event model is
815autodetected (or immediately if this has already happened). 872autodetected (or immediately if this has already happened).
816 873
874The block will be executed I<after> the actual backend has been detected
875(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
876created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
877other initialisations - see the sources of L<AnyEvent::Strict> or
878L<AnyEvent::AIO> to see how this is used.
879
880The most common usage is to create some global watchers, without forcing
881event module detection too early, for example, L<AnyEvent::AIO> creates
882and installs the global L<IO::AIO> watcher in a C<post_detect> block to
883avoid autodetecting the event module at load time.
884
817If called in scalar or list context, then it creates and returns an object 885If called in scalar or list context, then it creates and returns an object
818that automatically removes the callback again when it is destroyed. See 886that automatically removes the callback again when it is destroyed (or
887C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
819L<Coro::BDB> for a case where this is useful. 888a case where this is useful.
889
890Example: Create a watcher for the IO::AIO module and store it in
891C<$WATCHER>. Only do so after the event loop is initialised, though.
892
893 our WATCHER;
894
895 my $guard = AnyEvent::post_detect {
896 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
897 };
898
899 # the ||= is important in case post_detect immediately runs the block,
900 # as to not clobber the newly-created watcher. assigning both watcher and
901 # post_detect guard to the same variable has the advantage of users being
902 # able to just C<undef $WATCHER> if the watcher causes them grief.
903
904 $WATCHER ||= $guard;
820 905
821=item @AnyEvent::post_detect 906=item @AnyEvent::post_detect
822 907
823If there are any code references in this array (you can C<push> to it 908If there are any code references in this array (you can C<push> to it
824before or after loading AnyEvent), then they will called directly after 909before or after loading AnyEvent), then they will called directly after
825the event loop has been chosen. 910the event loop has been chosen.
826 911
827You should check C<$AnyEvent::MODEL> before adding to this array, though: 912You 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, 913if it is defined then the event loop has already been detected, and the
829and the array will be ignored. 914array will be ignored.
830 915
831Best use C<AnyEvent::post_detect { BLOCK }> instead. 916Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
917it,as it takes care of these details.
918
919This variable is mainly useful for modules that can do something useful
920when AnyEvent is used and thus want to know when it is initialised, but do
921not need to even load it by default. This array provides the means to hook
922into AnyEvent passively, without loading it.
832 923
833=back 924=back
834 925
835=head1 WHAT TO DO IN A MODULE 926=head1 WHAT TO DO IN A MODULE
836 927
891 982
892 983
893=head1 OTHER MODULES 984=head1 OTHER MODULES
894 985
895The following is a non-exhaustive list of additional modules that use 986The following is a non-exhaustive list of additional modules that use
896AnyEvent and can therefore be mixed easily with other AnyEvent modules 987AnyEvent 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 988modules and other event loops in the same program. Some of the modules
898available via CPAN. 989come with AnyEvent, most are available via CPAN.
899 990
900=over 4 991=over 4
901 992
902=item L<AnyEvent::Util> 993=item L<AnyEvent::Util>
903 994
912 1003
913=item L<AnyEvent::Handle> 1004=item L<AnyEvent::Handle>
914 1005
915Provide read and write buffers, manages watchers for reads and writes, 1006Provide read and write buffers, manages watchers for reads and writes,
916supports raw and formatted I/O, I/O queued and fully transparent and 1007supports raw and formatted I/O, I/O queued and fully transparent and
917non-blocking SSL/TLS. 1008non-blocking SSL/TLS (via L<AnyEvent::TLS>.
918 1009
919=item L<AnyEvent::DNS> 1010=item L<AnyEvent::DNS>
920 1011
921Provides rich asynchronous DNS resolver capabilities. 1012Provides rich asynchronous DNS resolver capabilities.
922 1013
950 1041
951=item L<AnyEvent::GPSD> 1042=item L<AnyEvent::GPSD>
952 1043
953A non-blocking interface to gpsd, a daemon delivering GPS information. 1044A non-blocking interface to gpsd, a daemon delivering GPS information.
954 1045
1046=item L<AnyEvent::IRC>
1047
1048AnyEvent based IRC client module family (replacing the older Net::IRC3).
1049
1050=item L<AnyEvent::XMPP>
1051
1052AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1053Net::XMPP2>.
1054
955=item L<AnyEvent::IGS> 1055=item L<AnyEvent::IGS>
956 1056
957A non-blocking interface to the Internet Go Server protocol (used by 1057A non-blocking interface to the Internet Go Server protocol (used by
958L<App::IGS>). 1058L<App::IGS>).
959 1059
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> 1060=item L<Net::FCP>
969 1061
970AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1062AnyEvent-based implementation of the Freenet Client Protocol, birthplace
971of AnyEvent. 1063of AnyEvent.
972 1064
976 1068
977=item L<Coro> 1069=item L<Coro>
978 1070
979Has special support for AnyEvent via L<Coro::AnyEvent>. 1071Has special support for AnyEvent via L<Coro::AnyEvent>.
980 1072
981=item L<IO::Lambda>
982
983The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
984
985=back 1073=back
986 1074
987=cut 1075=cut
988 1076
989package AnyEvent; 1077package AnyEvent;
990 1078
1079# basically a tuned-down version of common::sense
1080sub common_sense {
991no warnings; 1081 # no warnings
1082 ${^WARNING_BITS} ^= ${^WARNING_BITS};
992use strict qw(vars subs); 1083 # use strict vars subs
1084 $^H |= 0x00000600;
1085}
993 1086
1087BEGIN { AnyEvent::common_sense }
1088
994use Carp; 1089use Carp ();
995 1090
996our $VERSION = 4.8; 1091our $VERSION = 4.881;
997our $MODEL; 1092our $MODEL;
998 1093
999our $AUTOLOAD; 1094our $AUTOLOAD;
1000our @ISA; 1095our @ISA;
1001 1096
1002our @REGISTRY; 1097our @REGISTRY;
1003 1098
1004our $WIN32; 1099our $WIN32;
1100
1101our $VERBOSE;
1005 1102
1006BEGIN { 1103BEGIN {
1007 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1104 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
1008 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1105 eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
1009 1106
1010 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1107 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1011 if ${^TAINT}; 1108 if ${^TAINT};
1012}
1013 1109
1014our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1110 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1111
1112}
1113
1114our $MAX_SIGNAL_LATENCY = 10;
1015 1115
1016our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1116our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1017 1117
1018{ 1118{
1019 my $idx; 1119 my $idx;
1021 for reverse split /\s*,\s*/, 1121 for reverse split /\s*,\s*/,
1022 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1122 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1023} 1123}
1024 1124
1025my @models = ( 1125my @models = (
1026 [EV:: => AnyEvent::Impl::EV::], 1126 [EV:: => AnyEvent::Impl::EV:: , 1],
1027 [Event:: => AnyEvent::Impl::Event::], 1127 [Event:: => AnyEvent::Impl::Event::, 1],
1028 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1128 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1029 # everything below here will not be autoprobed 1129 # everything below here will not (normally) be autoprobed
1030 # as the pureperl backend should work everywhere 1130 # as the pureperl backend should work everywhere
1031 # and is usually faster 1131 # and is usually faster
1132 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1133 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1134 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1032 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1135 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1033 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1034 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1035 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1136 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1036 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1137 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1037 [Wx:: => AnyEvent::Impl::POE::], 1138 [Wx:: => AnyEvent::Impl::POE::],
1038 [Prima:: => AnyEvent::Impl::POE::], 1139 [Prima:: => AnyEvent::Impl::POE::],
1039 # IO::Async is just too broken - we would need workaorunds for its 1140 # IO::Async is just too broken - we would need workarounds for its
1040 # byzantine signal and broken child handling, among others. 1141 # byzantine signal and broken child handling, among others.
1041 # IO::Async is rather hard to detect, as it doesn't have any 1142 # IO::Async is rather hard to detect, as it doesn't have any
1042 # obvious default class. 1143 # obvious default class.
1043# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1144# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1044# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1145# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1045# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1146# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1046); 1147);
1047 1148
1048our %method = map +($_ => 1), 1149our %method = map +($_ => 1),
1049 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1150 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1050 1151
1054 my ($cb) = @_; 1155 my ($cb) = @_;
1055 1156
1056 if ($MODEL) { 1157 if ($MODEL) {
1057 $cb->(); 1158 $cb->();
1058 1159
1059 1 1160 undef
1060 } else { 1161 } else {
1061 push @post_detect, $cb; 1162 push @post_detect, $cb;
1062 1163
1063 defined wantarray 1164 defined wantarray
1064 ? bless \$cb, "AnyEvent::Util::postdetect" 1165 ? bless \$cb, "AnyEvent::Util::postdetect"
1070 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1171 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1071} 1172}
1072 1173
1073sub detect() { 1174sub detect() {
1074 unless ($MODEL) { 1175 unless ($MODEL) {
1075 no strict 'refs';
1076 local $SIG{__DIE__}; 1176 local $SIG{__DIE__};
1077 1177
1078 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1178 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1079 my $model = "AnyEvent::Impl::$1"; 1179 my $model = "AnyEvent::Impl::$1";
1080 if (eval "require $model") { 1180 if (eval "require $model") {
1081 $MODEL = $model; 1181 $MODEL = $model;
1082 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1182 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1083 } else { 1183 } else {
1084 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1184 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1085 } 1185 }
1086 } 1186 }
1087 1187
1088 # check for already loaded models 1188 # check for already loaded models
1089 unless ($MODEL) { 1189 unless ($MODEL) {
1090 for (@REGISTRY, @models) { 1190 for (@REGISTRY, @models) {
1091 my ($package, $model) = @$_; 1191 my ($package, $model) = @$_;
1092 if (${"$package\::VERSION"} > 0) { 1192 if (${"$package\::VERSION"} > 0) {
1093 if (eval "require $model") { 1193 if (eval "require $model") {
1094 $MODEL = $model; 1194 $MODEL = $model;
1095 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1195 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1096 last; 1196 last;
1097 } 1197 }
1098 } 1198 }
1099 } 1199 }
1100 1200
1101 unless ($MODEL) { 1201 unless ($MODEL) {
1102 # try to load a model 1202 # try to autoload a model
1103
1104 for (@REGISTRY, @models) { 1203 for (@REGISTRY, @models) {
1105 my ($package, $model) = @$_; 1204 my ($package, $model, $autoload) = @$_;
1205 if (
1206 $autoload
1106 if (eval "require $package" 1207 and eval "require $package"
1107 and ${"$package\::VERSION"} > 0 1208 and ${"$package\::VERSION"} > 0
1108 and eval "require $model") { 1209 and eval "require $model"
1210 ) {
1109 $MODEL = $model; 1211 $MODEL = $model;
1110 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; 1212 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1111 last; 1213 last;
1112 } 1214 }
1113 } 1215 }
1114 1216
1115 $MODEL 1217 $MODEL
1131 1233
1132sub AUTOLOAD { 1234sub AUTOLOAD {
1133 (my $func = $AUTOLOAD) =~ s/.*://; 1235 (my $func = $AUTOLOAD) =~ s/.*://;
1134 1236
1135 $method{$func} 1237 $method{$func}
1136 or croak "$func: not a valid method for AnyEvent objects"; 1238 or Carp::croak "$func: not a valid method for AnyEvent objects";
1137 1239
1138 detect unless $MODEL; 1240 detect unless $MODEL;
1139 1241
1140 my $class = shift; 1242 my $class = shift;
1141 $class->$func (@_); 1243 $class->$func (@_);
1146# allow only one watcher per fd, so we dup it to get a different one). 1248# allow only one watcher per fd, so we dup it to get a different one).
1147sub _dupfh($$;$$) { 1249sub _dupfh($$;$$) {
1148 my ($poll, $fh, $r, $w) = @_; 1250 my ($poll, $fh, $r, $w) = @_;
1149 1251
1150 # cygwin requires the fh mode to be matching, unix doesn't 1252 # cygwin requires the fh mode to be matching, unix doesn't
1151 my ($rw, $mode) = $poll eq "r" ? ($r, "<") 1253 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 1254
1155 open my $fh2, "$mode&" . fileno $fh 1255 open my $fh2, $mode, $fh
1156 or die "cannot dup() filehandle: $!,"; 1256 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1157 1257
1158 # we assume CLOEXEC is already set by perl in all important cases 1258 # we assume CLOEXEC is already set by perl in all important cases
1159 1259
1160 ($fh2, $rw) 1260 ($fh2, $rw)
1161} 1261}
1162 1262
1163package AnyEvent::Base; 1263package AnyEvent::Base;
1164 1264
1165# default implementations for many methods 1265# default implementations for many methods
1166 1266
1167BEGIN { 1267sub _time {
1268 # probe for availability of Time::HiRes
1168 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1269 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1270 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1169 *_time = \&Time::HiRes::time; 1271 *_time = \&Time::HiRes::time;
1170 # if (eval "use POSIX (); (POSIX::times())... 1272 # if (eval "use POSIX (); (POSIX::times())...
1171 } else { 1273 } else {
1274 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1172 *_time = sub { time }; # epic fail 1275 *_time = sub { time }; # epic fail
1173 } 1276 }
1277
1278 &_time
1174} 1279}
1175 1280
1176sub time { _time } 1281sub time { _time }
1177sub now { _time } 1282sub now { _time }
1178sub now_update { } 1283sub now_update { }
1183 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1288 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1184} 1289}
1185 1290
1186# default implementation for ->signal 1291# default implementation for ->signal
1187 1292
1293our $HAVE_ASYNC_INTERRUPT;
1188our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1294our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1295our (%SIG_ASY, %SIG_ASY_W);
1296our ($SIG_COUNT, $SIG_TW);
1189 1297
1190sub _signal_exec { 1298sub _signal_exec {
1299 $HAVE_ASYNC_INTERRUPT
1300 ? $SIGPIPE_R->drain
1191 sysread $SIGPIPE_R, my $dummy, 4; 1301 : sysread $SIGPIPE_R, my $dummy, 9;
1192 1302
1193 while (%SIG_EV) { 1303 while (%SIG_EV) {
1194 for (keys %SIG_EV) { 1304 for (keys %SIG_EV) {
1195 delete $SIG_EV{$_}; 1305 delete $SIG_EV{$_};
1196 $_->() for values %{ $SIG_CB{$_} || {} }; 1306 $_->() for values %{ $SIG_CB{$_} || {} };
1197 } 1307 }
1198 } 1308 }
1199} 1309}
1200 1310
1311# install a dummy wakeup watcher to reduce signal catching latency
1312sub _sig_add() {
1313 unless ($SIG_COUNT++) {
1314 # try to align timer on a full-second boundary, if possible
1315 my $NOW = AnyEvent->now;
1316
1317 $SIG_TW = AnyEvent->timer (
1318 after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1319 interval => $MAX_SIGNAL_LATENCY,
1320 cb => sub { }, # just for the PERL_ASYNC_CHECK
1321 );
1322 }
1323}
1324
1325sub _sig_del {
1326 undef $SIG_TW
1327 unless --$SIG_COUNT;
1328}
1329
1330sub _signal {
1331 my (undef, %arg) = @_;
1332
1333 my $signal = uc $arg{signal}
1334 or Carp::croak "required option 'signal' is missing";
1335
1336 if ($HAVE_ASYNC_INTERRUPT) {
1337 # async::interrupt
1338
1339 $signal = Async::Interrupt::sig2num ($signal);
1340 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1341
1342 $SIG_ASY{$signal} ||= new Async::Interrupt
1343 cb => sub { undef $SIG_EV{$signal} },
1344 signal => $signal,
1345 pipe => [$SIGPIPE_R->filenos],
1346 pipe_autodrain => 0,
1347 ;
1348
1349 } else {
1350 # pure perl
1351
1352 # AE::Util has been loaded in signal
1353 $signal = AnyEvent::Util::sig2name ($signal);
1354 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1355
1356 $SIG{$signal} ||= sub {
1357 local $!;
1358 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1359 undef $SIG_EV{$signal};
1360 };
1361
1362 # can't do signal processing without introducing races in pure perl,
1363 # so limit the signal latency.
1364 _sig_add;
1365 }
1366
1367 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1368}
1369
1201sub signal { 1370sub signal {
1202 my (undef, %arg) = @_; 1371 # probe for availability of Async::Interrupt
1372 if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 1.0 (); 1") {
1373 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1203 1374
1204 unless ($SIGPIPE_R) { 1375 $HAVE_ASYNC_INTERRUPT = 1;
1376 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1377 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1378
1379 } else {
1380 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1381
1205 require Fcntl; 1382 require Fcntl;
1206 1383
1207 if (AnyEvent::WIN32) { 1384 if (AnyEvent::WIN32) {
1208 require AnyEvent::Util; 1385 require AnyEvent::Util;
1209 1386
1224 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1401 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1225 1402
1226 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); 1403 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1227 } 1404 }
1228 1405
1229 my $signal = uc $arg{signal} 1406 *signal = \&_signal;
1230 or Carp::croak "required option 'signal' is missing"; 1407 &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, $arg{cb}], "AnyEvent::Base::signal"
1240} 1408}
1241 1409
1242sub AnyEvent::Base::signal::DESTROY { 1410sub AnyEvent::Base::signal::DESTROY {
1243 my ($signal, $cb) = @{$_[0]}; 1411 my ($signal, $cb) = @{$_[0]};
1244 1412
1413 _sig_del;
1414
1245 delete $SIG_CB{$signal}{$cb}; 1415 delete $SIG_CB{$signal}{$cb};
1246 1416
1417 $HAVE_ASYNC_INTERRUPT
1418 ? delete $SIG_ASY{$signal}
1247 # delete doesn't work with older perls - they then 1419 : # delete doesn't work with older perls - they then
1248 # print weird messages, or just unconditionally exit 1420 # print weird messages, or just unconditionally exit
1249 # instead of getting the default action. 1421 # instead of getting the default action.
1422 undef $SIG{$signal}
1250 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; 1423 unless keys %{ $SIG_CB{$signal} };
1251} 1424}
1252 1425
1253# default implementation for ->child 1426# default implementation for ->child
1254 1427
1255our %PID_CB; 1428our %PID_CB;
1256our $CHLD_W; 1429our $CHLD_W;
1257our $CHLD_DELAY_W; 1430our $CHLD_DELAY_W;
1258our $WNOHANG; 1431our $WNOHANG;
1259 1432
1433sub _emit_childstatus($$) {
1434 my (undef, $rpid, $rstatus) = @_;
1435
1436 $_->($rpid, $rstatus)
1437 for values %{ $PID_CB{$rpid} || {} },
1438 values %{ $PID_CB{0} || {} };
1439}
1440
1260sub _sigchld { 1441sub _sigchld {
1442 my $pid;
1443
1444 AnyEvent->_emit_childstatus ($pid, $?)
1261 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1445 while ($pid = waitpid -1, $WNOHANG) > 0;
1262 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1263 (values %{ $PID_CB{0} || {} });
1264 }
1265} 1446}
1266 1447
1267sub child { 1448sub child {
1268 my (undef, %arg) = @_; 1449 my (undef, %arg) = @_;
1269 1450
1270 defined (my $pid = $arg{pid} + 0) 1451 defined (my $pid = $arg{pid} + 0)
1271 or Carp::croak "required option 'pid' is missing"; 1452 or Carp::croak "required option 'pid' is missing";
1272 1453
1273 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1454 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1274 1455
1456 # WNOHANG is almost cetrainly 1 everywhere
1457 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1458 ? 1
1275 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1459 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1276 1460
1277 unless ($CHLD_W) { 1461 unless ($CHLD_W) {
1278 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1462 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1279 # child could be a zombie already, so make at least one round 1463 # child could be a zombie already, so make at least one round
1280 &_sigchld; 1464 &_sigchld;
1332 1516
1333our @ISA = AnyEvent::CondVar::Base::; 1517our @ISA = AnyEvent::CondVar::Base::;
1334 1518
1335package AnyEvent::CondVar::Base; 1519package AnyEvent::CondVar::Base;
1336 1520
1337use overload 1521#use overload
1338 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1522# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1339 fallback => 1; 1523# fallback => 1;
1524
1525# save 300+ kilobytes by dirtily hardcoding overloading
1526${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1527*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1528*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1529${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1530
1531our $WAITING;
1340 1532
1341sub _send { 1533sub _send {
1342 # nop 1534 # nop
1343} 1535}
1344 1536
1357sub ready { 1549sub ready {
1358 $_[0]{_ae_sent} 1550 $_[0]{_ae_sent}
1359} 1551}
1360 1552
1361sub _wait { 1553sub _wait {
1554 $WAITING
1555 and !$_[0]{_ae_sent}
1556 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1557
1558 local $WAITING = 1;
1362 AnyEvent->one_event while !$_[0]{_ae_sent}; 1559 AnyEvent->one_event while !$_[0]{_ae_sent};
1363} 1560}
1364 1561
1365sub recv { 1562sub recv {
1366 $_[0]->_wait; 1563 $_[0]->_wait;
1428C<PERL_ANYEVENT_MODEL>. 1625C<PERL_ANYEVENT_MODEL>.
1429 1626
1430When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1627When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1431model it chooses. 1628model it chooses.
1432 1629
1630When set to C<8> or higher, then AnyEvent will report extra information on
1631which optional modules it loads and how it implements certain features.
1632
1433=item C<PERL_ANYEVENT_STRICT> 1633=item C<PERL_ANYEVENT_STRICT>
1434 1634
1435AnyEvent does not do much argument checking by default, as thorough 1635AnyEvent does not do much argument checking by default, as thorough
1436argument checking is very costly. Setting this variable to a true value 1636argument checking is very costly. Setting this variable to a true value
1437will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1637will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1438check the arguments passed to most method calls. If it finds any problems, 1638check the arguments passed to most method calls. If it finds any problems,
1439it will croak. 1639it will croak.
1440 1640
1441In other words, enables "strict" mode. 1641In other words, enables "strict" mode.
1442 1642
1443Unlike C<use strict>, it is definitely recommended to keep it off in 1643Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1444production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1644>>, it is definitely recommended to keep it off in production. Keeping
1445developing programs can be very useful, however. 1645C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1646can be very useful, however.
1446 1647
1447=item C<PERL_ANYEVENT_MODEL> 1648=item C<PERL_ANYEVENT_MODEL>
1448 1649
1449This can be used to specify the event model to be used by AnyEvent, before 1650This 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 1651auto detection and -probing kicks in. It must be a string consisting
1512 1713
1513When neither C<ca_file> nor C<ca_path> was specified during 1714When neither C<ca_file> nor C<ca_path> was specified during
1514L<AnyEvent::TLS> context creation, and either of these environment 1715L<AnyEvent::TLS> context creation, and either of these environment
1515variables exist, they will be used to specify CA certificate locations 1716variables exist, they will be used to specify CA certificate locations
1516instead of a system-dependent default. 1717instead of a system-dependent default.
1718
1719=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1720
1721When these are set to C<1>, then the respective modules are not
1722loaded. Mostly good for testing AnyEvent itself.
1517 1723
1518=back 1724=back
1519 1725
1520=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1726=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1521 1727
2060 2266
2061A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2267A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2062emulation for event loops that do not support them natively. Also, some 2268emulation for event loops that do not support them natively. Also, some
2063event loops install a similar handler. 2269event loops install a similar handler.
2064 2270
2065If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2271Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2066reset it to default, to avoid losing child exit statuses. 2272AnyEvent will reset it to default, to avoid losing child exit statuses.
2067 2273
2068=item SIGPIPE 2274=item SIGPIPE
2069 2275
2070A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2276A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2071when AnyEvent gets loaded. 2277when AnyEvent gets loaded.
2089 if $SIG{CHLD} eq 'IGNORE'; 2295 if $SIG{CHLD} eq 'IGNORE';
2090 2296
2091$SIG{PIPE} = sub { } 2297$SIG{PIPE} = sub { }
2092 unless defined $SIG{PIPE}; 2298 unless defined $SIG{PIPE};
2093 2299
2300=head1 RECOMMENDED/OPTIONAL MODULES
2301
2302One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2303it's built-in modules) are required to use it.
2304
2305That does not mean that AnyEvent won't take advantage of some additional
2306modules if they are installed.
2307
2308This section epxlains which additional modules will be used, and how they
2309affect AnyEvent's operetion.
2310
2311=over 4
2312
2313=item L<Async::Interrupt>
2314
2315This slightly arcane module is used to implement fast signal handling: To
2316my knowledge, there is no way to do completely race-free and quick
2317signal handling in pure perl. To ensure that signals still get
2318delivered, AnyEvent will start an interval timer to wake up perl (and
2319catch the signals) with some delay (default is 10 seconds, look for
2320C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2321
2322If this module is available, then it will be used to implement signal
2323catching, which means that signals will not be delayed, and the event loop
2324will not be interrupted regularly, which is more efficient (And good for
2325battery life on laptops).
2326
2327This affects not just the pure-perl event loop, but also other event loops
2328that have no signal handling on their own (e.g. Glib, Tk, Qt).
2329
2330Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2331and either employ their own workarounds (POE) or use AnyEvent's workaround
2332(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2333does nothing for those backends.
2334
2335=item L<EV>
2336
2337This module isn't really "optional", as it is simply one of the backend
2338event loops that AnyEvent can use. However, it is simply the best event
2339loop available in terms of features, speed and stability: It supports
2340the AnyEvent API optimally, implements all the watcher types in XS, does
2341automatic timer adjustments even when no monotonic clock is available,
2342can take avdantage of advanced kernel interfaces such as C<epoll> and
2343C<kqueue>, and is the fastest backend I<by far>. You can even embed
2344L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2345
2346=item L<Guard>
2347
2348The guard module, when used, will be used to implement
2349C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2350lot less memory), but otherwise doesn't affect guard operation much. It is
2351purely used for performance.
2352
2353=item L<JSON> and L<JSON::XS>
2354
2355This module is required when you want to read or write JSON data via
2356L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2357advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2358
2359In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2360installed.
2361
2362=item L<Net::SSLeay>
2363
2364Implementing TLS/SSL in Perl is certainly interesting, but not very
2365worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2366the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2367
2368=item L<Time::HiRes>
2369
2370This module is part of perl since release 5.008. It will be used when the
2371chosen event library does not come with a timing source on it's own. The
2372pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2373try to use a monotonic clock for timing stability.
2374
2375=back
2376
2377
2094=head1 FORK 2378=head1 FORK
2095 2379
2096Most event libraries are not fork-safe. The ones who are usually are 2380Most 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> 2381because they rely on inefficient but fork-safe C<select> or C<poll>
2098calls. Only L<EV> is fully fork-aware. 2382calls. Only L<EV> is fully fork-aware.
2099 2383
2100If you have to fork, you must either do so I<before> creating your first 2384If 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. 2385watcher OR you must not use AnyEvent at all in the child OR you must do
2386something completely out of the scope of AnyEvent.
2102 2387
2103 2388
2104=head1 SECURITY CONSIDERATIONS 2389=head1 SECURITY CONSIDERATIONS
2105 2390
2106AnyEvent can be forced to load any event model via 2391AnyEvent can be forced to load any event model via
2144L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2429L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2145 2430
2146Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2431Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2147L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2432L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2148L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2433L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2149L<AnyEvent::Impl::POE>. 2434L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2150 2435
2151Non-blocking file handles, sockets, TCP clients and 2436Non-blocking file handles, sockets, TCP clients and
2152servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2437servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2153 2438
2154Asynchronous DNS: L<AnyEvent::DNS>. 2439Asynchronous DNS: L<AnyEvent::DNS>.
2155 2440
2156Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2441Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2442L<Coro::Event>,
2157 2443
2158Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2444Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2445L<AnyEvent::HTTP>.
2159 2446
2160 2447
2161=head1 AUTHOR 2448=head1 AUTHOR
2162 2449
2163 Marc Lehmann <schmorp@schmorp.de> 2450 Marc Lehmann <schmorp@schmorp.de>

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines