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 1.195 by root, Wed Mar 25 17:33:11 2009 UTC vs.
Revision 1.238 by root, Thu Jul 16 03:48:33 2009 UTC

1=head1 NAME 1=head1 NAME
2 2
3AnyEvent - provide framework for multiple event loops 3AnyEvent - provide framework for multiple event loops
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops 5EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported
6event loops.
6 7
7=head1 SYNOPSIS 8=head1 SYNOPSIS
8 9
9 use AnyEvent; 10 use AnyEvent;
10 11
12 # file descriptor readable
11 my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { ... }); 13 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
12 14
15 # one-shot or repeating timers
13 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); 16 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
14 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... 17 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
15 18
16 print AnyEvent->now; # prints current event loop time 19 print AnyEvent->now; # prints current event loop time
17 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. 20 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
18 21
22 # POSIX signal
19 my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); 23 my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
20 24
25 # child process exit
21 my $w = AnyEvent->child (pid => $pid, cb => sub { 26 my $w = AnyEvent->child (pid => $pid, cb => sub {
22 my ($pid, $status) = @_; 27 my ($pid, $status) = @_;
23 ... 28 ...
24 }); 29 });
30
31 # called when event loop idle (if applicable)
32 my $w = AnyEvent->idle (cb => sub { ... });
25 33
26 my $w = AnyEvent->condvar; # stores whether a condition was flagged 34 my $w = AnyEvent->condvar; # stores whether a condition was flagged
27 $w->send; # wake up current and all future recv's 35 $w->send; # wake up current and all future recv's
28 $w->recv; # enters "main loop" till $condvar gets ->send 36 $w->recv; # enters "main loop" till $condvar gets ->send
29 # use a condvar in callback mode: 37 # use a condvar in callback mode:
137These watchers are normal Perl objects with normal Perl lifetime. After 145These watchers are normal Perl objects with normal Perl lifetime. After
138creating a watcher it will immediately "watch" for events and invoke the 146creating a watcher it will immediately "watch" for events and invoke the
139callback when the event occurs (of course, only when the event model 147callback when the event occurs (of course, only when the event model
140is in control). 148is in control).
141 149
150Note that B<callbacks must not permanently change global variables>
151potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
152callbacks must not C<die> >>. The former is good programming practise in
153Perl and the latter stems from the fact that exception handling differs
154widely between event loops.
155
142To disable the watcher you have to destroy it (e.g. by setting the 156To disable the watcher you have to destroy it (e.g. by setting the
143variable you store it in to C<undef> or otherwise deleting all references 157variable you store it in to C<undef> or otherwise deleting all references
144to it). 158to it).
145 159
146All watchers are created by calling a method on the C<AnyEvent> class. 160All watchers are created by calling a method on the C<AnyEvent> class.
162=head2 I/O WATCHERS 176=head2 I/O WATCHERS
163 177
164You can create an I/O watcher by calling the C<< AnyEvent->io >> method 178You can create an I/O watcher by calling the C<< AnyEvent->io >> method
165with the following mandatory key-value pairs as arguments: 179with the following mandatory key-value pairs as arguments:
166 180
167C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events 181C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
168(AnyEvent might or might not keep a reference to this file handle). C<poll> 182for events (AnyEvent might or might not keep a reference to this file
183handle). Note that only file handles pointing to things for which
184non-blocking operation makes sense are allowed. This includes sockets,
185most character devices, pipes, fifos and so on, but not for example files
186or block devices.
187
169must be a string that is either C<r> or C<w>, which creates a watcher 188C<poll> must be a string that is either C<r> or C<w>, which creates a
170waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the 189watcher waiting for "r"eadable or "w"ritable events, respectively.
190
171callback to invoke each time the file handle becomes ready. 191C<cb> is the callback to invoke each time the file handle becomes ready.
172 192
173Although the callback might get passed parameters, their value and 193Although the callback might get passed parameters, their value and
174presence is undefined and you cannot rely on them. Portable AnyEvent 194presence is undefined and you cannot rely on them. Portable AnyEvent
175callbacks cannot use arguments passed to I/O watcher callbacks. 195callbacks cannot use arguments passed to I/O watcher callbacks.
176 196
308In either case, if you care (and in most cases, you don't), then you 328In either case, if you care (and in most cases, you don't), then you
309can get whatever behaviour you want with any event loop, by taking the 329can get whatever behaviour you want with any event loop, by taking the
310difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into 330difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
311account. 331account.
312 332
333=item AnyEvent->now_update
334
335Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache
336the current time for each loop iteration (see the discussion of L<<
337AnyEvent->now >>, above).
338
339When a callback runs for a long time (or when the process sleeps), then
340this "current" time will differ substantially from the real time, which
341might affect timers and time-outs.
342
343When this is the case, you can call this method, which will update the
344event loop's idea of "current time".
345
346Note that updating the time I<might> cause some events to be handled.
347
313=back 348=back
314 349
315=head2 SIGNAL WATCHERS 350=head2 SIGNAL WATCHERS
316 351
317You can watch for signals using a signal watcher, C<signal> is the signal 352You can watch for signals using a signal watcher, C<signal> is the signal
357 392
358There is a slight catch to child watchers, however: you usually start them 393There is a slight catch to child watchers, however: you usually start them
359I<after> the child process was created, and this means the process could 394I<after> the child process was created, and this means the process could
360have exited already (and no SIGCHLD will be sent anymore). 395have exited already (and no SIGCHLD will be sent anymore).
361 396
362Not all event models handle this correctly (POE doesn't), but even for 397Not all event models handle this correctly (neither POE nor IO::Async do,
398see their AnyEvent::Impl manpages for details), but even for event models
363event models that I<do> handle this correctly, they usually need to be 399that I<do> handle this correctly, they usually need to be loaded before
364loaded before the process exits (i.e. before you fork in the first place). 400the process exits (i.e. before you fork in the first place). AnyEvent's
401pure perl event loop handles all cases correctly regardless of when you
402start the watcher.
365 403
366This means you cannot create a child watcher as the very first thing in an 404This means you cannot create a child watcher as the very first
367AnyEvent program, you I<have> to create at least one watcher before you 405thing in an AnyEvent program, you I<have> to create at least one
368C<fork> the child (alternatively, you can call C<AnyEvent::detect>). 406watcher before you C<fork> the child (alternatively, you can call
407C<AnyEvent::detect>).
369 408
370Example: fork a process and wait for it 409Example: fork a process and wait for it
371 410
372 my $done = AnyEvent->condvar; 411 my $done = AnyEvent->condvar;
373 412
383 ); 422 );
384 423
385 # do something else, then wait for process exit 424 # do something else, then wait for process exit
386 $done->recv; 425 $done->recv;
387 426
427=head2 IDLE WATCHERS
428
429Sometimes there is a need to do something, but it is not so important
430to do it instantly, but only when there is nothing better to do. This
431"nothing better to do" is usually defined to be "no other events need
432attention by the event loop".
433
434Idle watchers ideally get invoked when the event loop has nothing
435better to do, just before it would block the process to wait for new
436events. Instead of blocking, the idle watcher is invoked.
437
438Most event loops unfortunately do not really support idle watchers (only
439EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
440will simply call the callback "from time to time".
441
442Example: read lines from STDIN, but only process them when the
443program is otherwise idle:
444
445 my @lines; # read data
446 my $idle_w;
447 my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
448 push @lines, scalar <STDIN>;
449
450 # start an idle watcher, if not already done
451 $idle_w ||= AnyEvent->idle (cb => sub {
452 # handle only one line, when there are lines left
453 if (my $line = shift @lines) {
454 print "handled when idle: $line";
455 } else {
456 # otherwise disable the idle watcher again
457 undef $idle_w;
458 }
459 });
460 });
461
388=head2 CONDITION VARIABLES 462=head2 CONDITION VARIABLES
389 463
390If you are familiar with some event loops you will know that all of them 464If you are familiar with some event loops you will know that all of them
391require you to run some blocking "loop", "run" or similar function that 465require you to run some blocking "loop", "run" or similar function that
392will actively watch for new events and call your callbacks. 466will actively watch for new events and call your callbacks.
525 599
526=item $cv->begin ([group callback]) 600=item $cv->begin ([group callback])
527 601
528=item $cv->end 602=item $cv->end
529 603
530These two methods are EXPERIMENTAL and MIGHT CHANGE.
531
532These two methods can be used to combine many transactions/events into 604These two methods can be used to combine many transactions/events into
533one. For example, a function that pings many hosts in parallel might want 605one. For example, a function that pings many hosts in parallel might want
534to use a condition variable for the whole process. 606to use a condition variable for the whole process.
535 607
536Every call to C<< ->begin >> will increment a counter, and every call to 608Every call to C<< ->begin >> will increment a counter, and every call to
537C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end 609C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
538>>, the (last) callback passed to C<begin> will be executed. That callback 610>>, the (last) callback passed to C<begin> will be executed. That callback
539is I<supposed> to call C<< ->send >>, but that is not required. If no 611is I<supposed> to call C<< ->send >>, but that is not required. If no
540callback was set, C<send> will be called without any arguments. 612callback was set, C<send> will be called without any arguments.
541 613
542Let's clarify this with the ping example: 614You can think of C<< $cv->send >> giving you an OR condition (one call
615sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
616condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617
618Let's start with a simple example: you have two I/O watchers (for example,
619STDOUT and STDERR for a program), and you want to wait for both streams to
620close before activating a condvar:
621
622 my $cv = AnyEvent->condvar;
623
624 $cv->begin; # first watcher
625 my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
626 defined sysread $fh1, my $buf, 4096
627 or $cv->end;
628 });
629
630 $cv->begin; # second watcher
631 my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
632 defined sysread $fh2, my $buf, 4096
633 or $cv->end;
634 });
635
636 $cv->recv;
637
638This works because for every event source (EOF on file handle), there is
639one call to C<begin>, so the condvar waits for all calls to C<end> before
640sending.
641
642The ping example mentioned above is slightly more complicated, as the
643there are results to be passwd back, and the number of tasks that are
644begung can potentially be zero:
543 645
544 my $cv = AnyEvent->condvar; 646 my $cv = AnyEvent->condvar;
545 647
546 my %result; 648 my %result;
547 $cv->begin (sub { $cv->send (\%result) }); 649 $cv->begin (sub { $cv->send (\%result) });
567loop, which serves two important purposes: first, it sets the callback 669loop, which serves two important purposes: first, it sets the callback
568to be called once the counter reaches C<0>, and second, it ensures that 670to be called once the counter reaches C<0>, and second, it ensures that
569C<send> is called even when C<no> hosts are being pinged (the loop 671C<send> is called even when C<no> hosts are being pinged (the loop
570doesn't execute once). 672doesn't execute once).
571 673
572This is the general pattern when you "fan out" into multiple subrequests: 674This is the general pattern when you "fan out" into multiple (but
573use an outer C<begin>/C<end> pair to set the callback and ensure C<end> 675potentially none) subrequests: use an outer C<begin>/C<end> pair to set
574is called at least once, and then, for each subrequest you start, call 676the callback and ensure C<end> is called at least once, and then, for each
575C<begin> and for each subrequest you finish, call C<end>. 677subrequest you start, call C<begin> and for each subrequest you finish,
678call C<end>.
576 679
577=back 680=back
578 681
579=head3 METHODS FOR CONSUMERS 682=head3 METHODS FOR CONSUMERS
580 683
637variable itself. Calling C<recv> inside the callback or at any later time 740variable itself. Calling C<recv> inside the callback or at any later time
638is guaranteed not to block. 741is guaranteed not to block.
639 742
640=back 743=back
641 744
745=head1 SUPPORTED EVENT LOOPS/BACKENDS
746
747The available backend classes are (every class has its own manpage):
748
749=over 4
750
751=item Backends that are autoprobed when no other event loop can be found.
752
753EV is the preferred backend when no other event loop seems to be in
754use. If EV is not installed, then AnyEvent will try Event, and, failing
755that, will fall back to its own pure-perl implementation, which is
756available everywhere as it comes with AnyEvent itself.
757
758 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
759 AnyEvent::Impl::Event based on Event, very stable, few glitches.
760 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
761
762=item Backends that are transparently being picked up when they are used.
763
764These will be used when they are currently loaded when the first watcher
765is created, in which case it is assumed that the application is using
766them. This means that AnyEvent will automatically pick the right backend
767when the main program loads an event module before anything starts to
768create watchers. Nothing special needs to be done by the main program.
769
770 AnyEvent::Impl::Glib based on Glib, slow but very stable.
771 AnyEvent::Impl::Tk based on Tk, very broken.
772 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
773 AnyEvent::Impl::POE based on POE, very slow, some limitations.
774
775=item Backends with special needs.
776
777Qt requires the Qt::Application to be instantiated first, but will
778otherwise be picked up automatically. As long as the main program
779instantiates the application before any AnyEvent watchers are created,
780everything should just work.
781
782 AnyEvent::Impl::Qt based on Qt.
783
784Support for IO::Async can only be partial, as it is too broken and
785architecturally limited to even support the AnyEvent API. It also
786is the only event loop that needs the loop to be set explicitly, so
787it can only be used by a main program knowing about AnyEvent. See
788L<AnyEvent::Impl::Async> for the gory details.
789
790 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
791
792=item Event loops that are indirectly supported via other backends.
793
794Some event loops can be supported via other modules:
795
796There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
797
798B<WxWidgets> has no support for watching file handles. However, you can
799use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
800polls 20 times per second, which was considered to be too horrible to even
801consider for AnyEvent.
802
803B<Prima> is not supported as nobody seems to be using it, but it has a POE
804backend, so it can be supported through POE.
805
806AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
807load L<POE> when detecting them, in the hope that POE will pick them up,
808in which case everything will be automatic.
809
810=back
811
642=head1 GLOBAL VARIABLES AND FUNCTIONS 812=head1 GLOBAL VARIABLES AND FUNCTIONS
643 813
814These are not normally required to use AnyEvent, but can be useful to
815write AnyEvent extension modules.
816
644=over 4 817=over 4
645 818
646=item $AnyEvent::MODEL 819=item $AnyEvent::MODEL
647 820
648Contains C<undef> until the first watcher is being created. Then it 821Contains C<undef> until the first watcher is being created, before the
822backend has been autodetected.
823
649contains the event model that is being used, which is the name of the 824Afterwards it contains the event model that is being used, which is the
650Perl class implementing the model. This class is usually one of the 825name of the Perl class implementing the model. This class is usually one
651C<AnyEvent::Impl:xxx> modules, but can be any other class in the case 826of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
652AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). 827case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
653 828will be C<urxvt::anyevent>).
654The known classes so far are:
655
656 AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
657 AnyEvent::Impl::Event based on Event, second best choice.
658 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
659 AnyEvent::Impl::Glib based on Glib, third-best choice.
660 AnyEvent::Impl::Tk based on Tk, very bad choice.
661 AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
662 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
663 AnyEvent::Impl::POE based on POE, not generic enough for full support.
664
665There is no support for WxWidgets, as WxWidgets has no support for
666watching file handles. However, you can use WxWidgets through the
667POE Adaptor, as POE has a Wx backend that simply polls 20 times per
668second, which was considered to be too horrible to even consider for
669AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
670it's adaptor.
671
672AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
673autodetecting them.
674 829
675=item AnyEvent::detect 830=item AnyEvent::detect
676 831
677Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 832Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
678if necessary. You should only call this function right before you would 833if necessary. You should only call this function right before you would
679have created an AnyEvent watcher anyway, that is, as late as possible at 834have created an AnyEvent watcher anyway, that is, as late as possible at
680runtime. 835runtime, and not e.g. while initialising of your module.
836
837If you need to do some initialisation before AnyEvent watchers are
838created, use C<post_detect>.
681 839
682=item $guard = AnyEvent::post_detect { BLOCK } 840=item $guard = AnyEvent::post_detect { BLOCK }
683 841
684Arranges for the code block to be executed as soon as the event model is 842Arranges for the code block to be executed as soon as the event model is
685autodetected (or immediately if this has already happened). 843autodetected (or immediately if this has already happened).
844
845The block will be executed I<after> the actual backend has been detected
846(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
847created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
848other initialisations - see the sources of L<AnyEvent::Strict> or
849L<AnyEvent::AIO> to see how this is used.
850
851The most common usage is to create some global watchers, without forcing
852event module detection too early, for example, L<AnyEvent::AIO> creates
853and installs the global L<IO::AIO> watcher in a C<post_detect> block to
854avoid autodetecting the event module at load time.
686 855
687If called in scalar or list context, then it creates and returns an object 856If called in scalar or list context, then it creates and returns an object
688that automatically removes the callback again when it is destroyed. See 857that automatically removes the callback again when it is destroyed. See
689L<Coro::BDB> for a case where this is useful. 858L<Coro::BDB> for a case where this is useful.
690 859
693If there are any code references in this array (you can C<push> to it 862If there are any code references in this array (you can C<push> to it
694before or after loading AnyEvent), then they will called directly after 863before or after loading AnyEvent), then they will called directly after
695the event loop has been chosen. 864the event loop has been chosen.
696 865
697You should check C<$AnyEvent::MODEL> before adding to this array, though: 866You should check C<$AnyEvent::MODEL> before adding to this array, though:
698if it contains a true value then the event loop has already been detected, 867if it is defined then the event loop has already been detected, and the
699and the array will be ignored. 868array will be ignored.
700 869
701Best use C<AnyEvent::post_detect { BLOCK }> instead. 870Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
871it,as it takes care of these details.
872
873This variable is mainly useful for modules that can do something useful
874when AnyEvent is used and thus want to know when it is initialised, but do
875not need to even load it by default. This array provides the means to hook
876into AnyEvent passively, without loading it.
702 877
703=back 878=back
704 879
705=head1 WHAT TO DO IN A MODULE 880=head1 WHAT TO DO IN A MODULE
706 881
761 936
762 937
763=head1 OTHER MODULES 938=head1 OTHER MODULES
764 939
765The following is a non-exhaustive list of additional modules that use 940The following is a non-exhaustive list of additional modules that use
766AnyEvent and can therefore be mixed easily with other AnyEvent modules 941AnyEvent as a client and can therefore be mixed easily with other AnyEvent
767in the same program. Some of the modules come with AnyEvent, some are 942modules and other event loops in the same program. Some of the modules
768available via CPAN. 943come with AnyEvent, most are available via CPAN.
769 944
770=over 4 945=over 4
771 946
772=item L<AnyEvent::Util> 947=item L<AnyEvent::Util>
773 948
782 957
783=item L<AnyEvent::Handle> 958=item L<AnyEvent::Handle>
784 959
785Provide read and write buffers, manages watchers for reads and writes, 960Provide read and write buffers, manages watchers for reads and writes,
786supports raw and formatted I/O, I/O queued and fully transparent and 961supports raw and formatted I/O, I/O queued and fully transparent and
787non-blocking SSL/TLS. 962non-blocking SSL/TLS (via L<AnyEvent::TLS>.
788 963
789=item L<AnyEvent::DNS> 964=item L<AnyEvent::DNS>
790 965
791Provides rich asynchronous DNS resolver capabilities. 966Provides rich asynchronous DNS resolver capabilities.
792 967
820 995
821=item L<AnyEvent::GPSD> 996=item L<AnyEvent::GPSD>
822 997
823A non-blocking interface to gpsd, a daemon delivering GPS information. 998A non-blocking interface to gpsd, a daemon delivering GPS information.
824 999
1000=item L<AnyEvent::IRC>
1001
1002AnyEvent based IRC client module family (replacing the older Net::IRC3).
1003
1004=item L<AnyEvent::XMPP>
1005
1006AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1007Net::XMPP2>.
1008
825=item L<AnyEvent::IGS> 1009=item L<AnyEvent::IGS>
826 1010
827A non-blocking interface to the Internet Go Server protocol (used by 1011A non-blocking interface to the Internet Go Server protocol (used by
828L<App::IGS>). 1012L<App::IGS>).
829 1013
830=item L<AnyEvent::IRC>
831
832AnyEvent based IRC client module family (replacing the older Net::IRC3).
833
834=item L<Net::XMPP2>
835
836AnyEvent based XMPP (Jabber protocol) module family.
837
838=item L<Net::FCP> 1014=item L<Net::FCP>
839 1015
840AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1016AnyEvent-based implementation of the Freenet Client Protocol, birthplace
841of AnyEvent. 1017of AnyEvent.
842 1018
846 1022
847=item L<Coro> 1023=item L<Coro>
848 1024
849Has special support for AnyEvent via L<Coro::AnyEvent>. 1025Has special support for AnyEvent via L<Coro::AnyEvent>.
850 1026
851=item L<IO::Lambda>
852
853The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
854
855=back 1027=back
856 1028
857=cut 1029=cut
858 1030
859package AnyEvent; 1031package AnyEvent;
861no warnings; 1033no warnings;
862use strict qw(vars subs); 1034use strict qw(vars subs);
863 1035
864use Carp; 1036use Carp;
865 1037
866our $VERSION = 4.341; 1038our $VERSION = 4.82;
867our $MODEL; 1039our $MODEL;
868 1040
869our $AUTOLOAD; 1041our $AUTOLOAD;
870our @ISA; 1042our @ISA;
871 1043
872our @REGISTRY; 1044our @REGISTRY;
873 1045
874our $WIN32; 1046our $WIN32;
875 1047
876BEGIN { 1048BEGIN {
877 my $win32 = ! ! ($^O =~ /mswin32/i); 1049 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
878 eval "sub WIN32(){ $win32 }"; 1050 eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
1051
1052 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1053 if ${^TAINT};
879} 1054}
880 1055
881our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1056our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
882 1057
883our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1058our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
894 [Event:: => AnyEvent::Impl::Event::], 1069 [Event:: => AnyEvent::Impl::Event::],
895 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1070 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
896 # everything below here will not be autoprobed 1071 # everything below here will not be autoprobed
897 # as the pureperl backend should work everywhere 1072 # as the pureperl backend should work everywhere
898 # and is usually faster 1073 # and is usually faster
899 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
900 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers 1074 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
901 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1075 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1076 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
902 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1077 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
903 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1078 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
904 [Wx:: => AnyEvent::Impl::POE::], 1079 [Wx:: => AnyEvent::Impl::POE::],
905 [Prima:: => AnyEvent::Impl::POE::], 1080 [Prima:: => AnyEvent::Impl::POE::],
1081 # IO::Async is just too broken - we would need workarounds for its
1082 # byzantine signal and broken child handling, among others.
1083 # IO::Async is rather hard to detect, as it doesn't have any
1084 # obvious default class.
1085# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1086# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1087# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
906); 1088);
907 1089
908our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); 1090our %method = map +($_ => 1),
1091 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
909 1092
910our @post_detect; 1093our @post_detect;
911 1094
912sub post_detect(&) { 1095sub post_detect(&) {
913 my ($cb) = @_; 1096 my ($cb) = @_;
918 1 1101 1
919 } else { 1102 } else {
920 push @post_detect, $cb; 1103 push @post_detect, $cb;
921 1104
922 defined wantarray 1105 defined wantarray
923 ? bless \$cb, "AnyEvent::Util::PostDetect" 1106 ? bless \$cb, "AnyEvent::Util::postdetect"
924 : () 1107 : ()
925 } 1108 }
926} 1109}
927 1110
928sub AnyEvent::Util::PostDetect::DESTROY { 1111sub AnyEvent::Util::postdetect::DESTROY {
929 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1112 @post_detect = grep $_ != ${$_[0]}, @post_detect;
930} 1113}
931 1114
932sub detect() { 1115sub detect() {
933 unless ($MODEL) { 1116 unless ($MODEL) {
936 1119
937 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1120 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
938 my $model = "AnyEvent::Impl::$1"; 1121 my $model = "AnyEvent::Impl::$1";
939 if (eval "require $model") { 1122 if (eval "require $model") {
940 $MODEL = $model; 1123 $MODEL = $model;
941 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1124 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $verbose > 1;
942 } else { 1125 } else {
943 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1126 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $verbose;
944 } 1127 }
945 } 1128 }
946 1129
947 # check for already loaded models 1130 # check for already loaded models
948 unless ($MODEL) { 1131 unless ($MODEL) {
970 last; 1153 last;
971 } 1154 }
972 } 1155 }
973 1156
974 $MODEL 1157 $MODEL
975 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; 1158 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
976 } 1159 }
977 } 1160 }
978 1161
979 push @{"$MODEL\::ISA"}, "AnyEvent::Base"; 1162 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
980 1163
1001} 1184}
1002 1185
1003# utility function to dup a filehandle. this is used by many backends 1186# utility function to dup a filehandle. this is used by many backends
1004# to support binding more than one watcher per filehandle (they usually 1187# to support binding more than one watcher per filehandle (they usually
1005# allow only one watcher per fd, so we dup it to get a different one). 1188# allow only one watcher per fd, so we dup it to get a different one).
1006sub _dupfh($$$$) { 1189sub _dupfh($$;$$) {
1007 my ($poll, $fh, $r, $w) = @_; 1190 my ($poll, $fh, $r, $w) = @_;
1008 1191
1009 # cygwin requires the fh mode to be matching, unix doesn't 1192 # cygwin requires the fh mode to be matching, unix doesn't
1010 my ($rw, $mode) = $poll eq "r" ? ($r, "<") 1193 my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">");
1011 : $poll eq "w" ? ($w, ">")
1012 : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1013 1194
1014 open my $fh2, "$mode&" . fileno $fh 1195 open my $fh2, "$mode&", $fh
1015 or die "cannot dup() filehandle: $!"; 1196 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1016 1197
1017 # we assume CLOEXEC is already set by perl in all important cases 1198 # we assume CLOEXEC is already set by perl in all important cases
1018 1199
1019 ($fh2, $rw) 1200 ($fh2, $rw)
1020} 1201}
1021 1202
1022package AnyEvent::Base; 1203package AnyEvent::Base;
1023 1204
1024# default implementation for now and time 1205# default implementations for many methods
1025 1206
1026BEGIN { 1207BEGIN {
1027 if (eval "use Time::HiRes (); time (); 1") { 1208 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1028 *_time = \&Time::HiRes::time; 1209 *_time = \&Time::HiRes::time;
1029 # if (eval "use POSIX (); (POSIX::times())... 1210 # if (eval "use POSIX (); (POSIX::times())...
1030 } else { 1211 } else {
1031 *_time = sub { time }; # epic fail 1212 *_time = sub { time }; # epic fail
1032 } 1213 }
1033} 1214}
1034 1215
1035sub time { _time } 1216sub time { _time }
1036sub now { _time } 1217sub now { _time }
1218sub now_update { }
1037 1219
1038# default implementation for ->condvar 1220# default implementation for ->condvar
1039 1221
1040sub condvar { 1222sub condvar {
1041 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: 1223 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1042} 1224}
1043 1225
1044# default implementation for ->signal 1226# default implementation for ->signal
1045 1227
1046our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1228our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1047 1229
1048sub _signal_exec { 1230sub _signal_exec {
1231 sysread $SIGPIPE_R, my $dummy, 4;
1232
1049 while (%SIG_EV) { 1233 while (%SIG_EV) {
1050 sysread $SIGPIPE_R, my $dummy, 4;
1051 for (keys %SIG_EV) { 1234 for (keys %SIG_EV) {
1052 delete $SIG_EV{$_}; 1235 delete $SIG_EV{$_};
1053 $_->() for values %{ $SIG_CB{$_} || {} }; 1236 $_->() for values %{ $SIG_CB{$_} || {} };
1054 } 1237 }
1055 } 1238 }
1057 1240
1058sub signal { 1241sub signal {
1059 my (undef, %arg) = @_; 1242 my (undef, %arg) = @_;
1060 1243
1061 unless ($SIGPIPE_R) { 1244 unless ($SIGPIPE_R) {
1245 require Fcntl;
1246
1062 if (AnyEvent::WIN32) { 1247 if (AnyEvent::WIN32) {
1248 require AnyEvent::Util;
1249
1063 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); 1250 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1064 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; 1251 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1065 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case 1252 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1066 } else { 1253 } else {
1067 pipe $SIGPIPE_R, $SIGPIPE_W; 1254 pipe $SIGPIPE_R, $SIGPIPE_W;
1068 require Fcntl;
1069 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1255 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1070 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1256 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1257
1258 # not strictly required, as $^F is normally 2, but let's make sure...
1259 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1260 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1071 } 1261 }
1072 1262
1073 $SIGPIPE_R 1263 $SIGPIPE_R
1074 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1264 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1075 1265
1079 my $signal = uc $arg{signal} 1269 my $signal = uc $arg{signal}
1080 or Carp::croak "required option 'signal' is missing"; 1270 or Carp::croak "required option 'signal' is missing";
1081 1271
1082 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1272 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1083 $SIG{$signal} ||= sub { 1273 $SIG{$signal} ||= sub {
1274 local $!;
1084 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1275 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1085 undef $SIG_EV{$signal}; 1276 undef $SIG_EV{$signal};
1086 }; 1277 };
1087 1278
1088 bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" 1279 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1089} 1280}
1090 1281
1091sub AnyEvent::Base::Signal::DESTROY { 1282sub AnyEvent::Base::signal::DESTROY {
1092 my ($signal, $cb) = @{$_[0]}; 1283 my ($signal, $cb) = @{$_[0]};
1093 1284
1094 delete $SIG_CB{$signal}{$cb}; 1285 delete $SIG_CB{$signal}{$cb};
1095 1286
1287 # delete doesn't work with older perls - they then
1288 # print weird messages, or just unconditionally exit
1289 # instead of getting the default action.
1096 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; 1290 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1097} 1291}
1098 1292
1099# default implementation for ->child 1293# default implementation for ->child
1100 1294
1101our %PID_CB; 1295our %PID_CB;
1102our $CHLD_W; 1296our $CHLD_W;
1103our $CHLD_DELAY_W; 1297our $CHLD_DELAY_W;
1104our $PID_IDLE;
1105our $WNOHANG; 1298our $WNOHANG;
1106 1299
1107sub _child_wait { 1300sub _sigchld {
1108 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1301 while (0 < (my $pid = waitpid -1, $WNOHANG)) {
1109 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1302 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }),
1110 (values %{ $PID_CB{0} || {} }); 1303 (values %{ $PID_CB{0} || {} });
1111 } 1304 }
1112
1113 undef $PID_IDLE;
1114}
1115
1116sub _sigchld {
1117 # make sure we deliver these changes "synchronous" with the event loop.
1118 $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub {
1119 undef $CHLD_DELAY_W;
1120 &_child_wait;
1121 });
1122} 1305}
1123 1306
1124sub child { 1307sub child {
1125 my (undef, %arg) = @_; 1308 my (undef, %arg) = @_;
1126 1309
1127 defined (my $pid = $arg{pid} + 0) 1310 defined (my $pid = $arg{pid} + 0)
1128 or Carp::croak "required option 'pid' is missing"; 1311 or Carp::croak "required option 'pid' is missing";
1129 1312
1130 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1313 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1131 1314
1132 unless ($WNOHANG) {
1133 $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1315 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1134 }
1135 1316
1136 unless ($CHLD_W) { 1317 unless ($CHLD_W) {
1137 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1318 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1138 # child could be a zombie already, so make at least one round 1319 # child could be a zombie already, so make at least one round
1139 &_sigchld; 1320 &_sigchld;
1140 } 1321 }
1141 1322
1142 bless [$pid, $arg{cb}], "AnyEvent::Base::Child" 1323 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1143} 1324}
1144 1325
1145sub AnyEvent::Base::Child::DESTROY { 1326sub AnyEvent::Base::child::DESTROY {
1146 my ($pid, $cb) = @{$_[0]}; 1327 my ($pid, $cb) = @{$_[0]};
1147 1328
1148 delete $PID_CB{$pid}{$cb}; 1329 delete $PID_CB{$pid}{$cb};
1149 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1330 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1150 1331
1151 undef $CHLD_W unless keys %PID_CB; 1332 undef $CHLD_W unless keys %PID_CB;
1333}
1334
1335# idle emulation is done by simply using a timer, regardless
1336# of whether the process is idle or not, and not letting
1337# the callback use more than 50% of the time.
1338sub idle {
1339 my (undef, %arg) = @_;
1340
1341 my ($cb, $w, $rcb) = $arg{cb};
1342
1343 $rcb = sub {
1344 if ($cb) {
1345 $w = _time;
1346 &$cb;
1347 $w = _time - $w;
1348
1349 # never use more then 50% of the time for the idle watcher,
1350 # within some limits
1351 $w = 0.0001 if $w < 0.0001;
1352 $w = 5 if $w > 5;
1353
1354 $w = AnyEvent->timer (after => $w, cb => $rcb);
1355 } else {
1356 # clean up...
1357 undef $w;
1358 undef $rcb;
1359 }
1360 };
1361
1362 $w = AnyEvent->timer (after => 0.05, cb => $rcb);
1363
1364 bless \\$cb, "AnyEvent::Base::idle"
1365}
1366
1367sub AnyEvent::Base::idle::DESTROY {
1368 undef $${$_[0]};
1152} 1369}
1153 1370
1154package AnyEvent::CondVar; 1371package AnyEvent::CondVar;
1155 1372
1156our @ISA = AnyEvent::CondVar::Base::; 1373our @ISA = AnyEvent::CondVar::Base::;
1230so on. 1447so on.
1231 1448
1232=head1 ENVIRONMENT VARIABLES 1449=head1 ENVIRONMENT VARIABLES
1233 1450
1234The following environment variables are used by this module or its 1451The following environment variables are used by this module or its
1235submodules: 1452submodules.
1453
1454Note that AnyEvent will remove I<all> environment variables starting with
1455C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
1456enabled.
1236 1457
1237=over 4 1458=over 4
1238 1459
1239=item C<PERL_ANYEVENT_VERBOSE> 1460=item C<PERL_ANYEVENT_VERBOSE>
1240 1461
1252=item C<PERL_ANYEVENT_STRICT> 1473=item C<PERL_ANYEVENT_STRICT>
1253 1474
1254AnyEvent does not do much argument checking by default, as thorough 1475AnyEvent does not do much argument checking by default, as thorough
1255argument checking is very costly. Setting this variable to a true value 1476argument checking is very costly. Setting this variable to a true value
1256will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1477will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1257check the arguments passed to most method calls. If it finds any problems 1478check the arguments passed to most method calls. If it finds any problems,
1258it will croak. 1479it will croak.
1259 1480
1260In other words, enables "strict" mode. 1481In other words, enables "strict" mode.
1261 1482
1262Unlike C<use strict>, it is definitely recommended ot keep it off in 1483Unlike C<use strict>, it is definitely recommended to keep it off in
1263production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1484production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
1264developing programs can be very useful, however. 1485developing programs can be very useful, however.
1265 1486
1266=item C<PERL_ANYEVENT_MODEL> 1487=item C<PERL_ANYEVENT_MODEL>
1267 1488
1312 1533
1313=item C<PERL_ANYEVENT_MAX_FORKS> 1534=item C<PERL_ANYEVENT_MAX_FORKS>
1314 1535
1315The maximum number of child processes that C<AnyEvent::Util::fork_call> 1536The maximum number of child processes that C<AnyEvent::Util::fork_call>
1316will create in parallel. 1537will create in parallel.
1538
1539=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
1540
1541The default value for the C<max_outstanding> parameter for the default DNS
1542resolver - this is the maximum number of parallel DNS requests that are
1543sent to the DNS server.
1544
1545=item C<PERL_ANYEVENT_RESOLV_CONF>
1546
1547The file to use instead of F</etc/resolv.conf> (or OS-specific
1548configuration) in the default resolver. When set to the empty string, no
1549default config will be used.
1550
1551=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1552
1553When neither C<ca_file> nor C<ca_path> was specified during
1554L<AnyEvent::TLS> context creation, and either of these environment
1555variables exist, they will be used to specify CA certificate locations
1556instead of a system-dependent default.
1317 1557
1318=back 1558=back
1319 1559
1320=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1560=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1321 1561
1566 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers 1806 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1567 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal 1807 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1568 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation 1808 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1569 Event/Event 16000 517 32.20 31.80 0.81 Event native interface 1809 Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1570 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers 1810 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1811 IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll
1812 IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll
1571 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour 1813 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1572 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers 1814 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1573 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event 1815 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1574 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select 1816 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1575 1817
1604performance becomes really bad with lots of file descriptors (and few of 1846performance becomes really bad with lots of file descriptors (and few of
1605them active), of course, but this was not subject of this benchmark. 1847them active), of course, but this was not subject of this benchmark.
1606 1848
1607The C<Event> module has a relatively high setup and callback invocation 1849The C<Event> module has a relatively high setup and callback invocation
1608cost, but overall scores in on the third place. 1850cost, but overall scores in on the third place.
1851
1852C<IO::Async> performs admirably well, about on par with C<Event>, even
1853when using its pure perl backend.
1609 1854
1610C<Glib>'s memory usage is quite a bit higher, but it features a 1855C<Glib>'s memory usage is quite a bit higher, but it features a
1611faster callback invocation and overall ends up in the same class as 1856faster callback invocation and overall ends up in the same class as
1612C<Event>. However, Glib scales extremely badly, doubling the number of 1857C<Event>. However, Glib scales extremely badly, doubling the number of
1613watchers increases the processing time by more than a factor of four, 1858watchers increases the processing time by more than a factor of four,
1691it to another server. This includes deleting the old timeout and creating 1936it to another server. This includes deleting the old timeout and creating
1692a new one that moves the timeout into the future. 1937a new one that moves the timeout into the future.
1693 1938
1694=head3 Results 1939=head3 Results
1695 1940
1696 name sockets create request 1941 name sockets create request
1697 EV 20000 69.01 11.16 1942 EV 20000 69.01 11.16
1698 Perl 20000 73.32 35.87 1943 Perl 20000 73.32 35.87
1944 IOAsync 20000 157.00 98.14 epoll
1945 IOAsync 20000 159.31 616.06 poll
1699 Event 20000 212.62 257.32 1946 Event 20000 212.62 257.32
1700 Glib 20000 651.16 1896.30 1947 Glib 20000 651.16 1896.30
1701 POE 20000 349.67 12317.24 uses POE::Loop::Event 1948 POE 20000 349.67 12317.24 uses POE::Loop::Event
1702 1949
1703=head3 Discussion 1950=head3 Discussion
1704 1951
1705This benchmark I<does> measure scalability and overall performance of the 1952This benchmark I<does> measure scalability and overall performance of the
1706particular event loop. 1953particular event loop.
1708EV is again fastest. Since it is using epoll on my system, the setup time 1955EV is again fastest. Since it is using epoll on my system, the setup time
1709is relatively high, though. 1956is relatively high, though.
1710 1957
1711Perl surprisingly comes second. It is much faster than the C-based event 1958Perl surprisingly comes second. It is much faster than the C-based event
1712loops Event and Glib. 1959loops Event and Glib.
1960
1961IO::Async performs very well when using its epoll backend, and still quite
1962good compared to Glib when using its pure perl backend.
1713 1963
1714Event suffers from high setup time as well (look at its code and you will 1964Event suffers from high setup time as well (look at its code and you will
1715understand why). Callback invocation also has a high overhead compared to 1965understand why). Callback invocation also has a high overhead compared to
1716the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event 1966the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1717uses select or poll in basically all documented configurations. 1967uses select or poll in basically all documented configurations.
1780=item * C-based event loops perform very well with small number of 2030=item * C-based event loops perform very well with small number of
1781watchers, as the management overhead dominates. 2031watchers, as the management overhead dominates.
1782 2032
1783=back 2033=back
1784 2034
2035=head2 THE IO::Lambda BENCHMARK
2036
2037Recently I was told about the benchmark in the IO::Lambda manpage, which
2038could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
2039simply compares IO::Lambda with POE, and IO::Lambda looks better (which
2040shouldn't come as a surprise to anybody). As such, the benchmark is
2041fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
2042very optimal. But how would AnyEvent compare when used without the extra
2043baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
2044
2045The benchmark itself creates an echo-server, and then, for 500 times,
2046connects to the echo server, sends a line, waits for the reply, and then
2047creates the next connection. This is a rather bad benchmark, as it doesn't
2048test the efficiency of the framework or much non-blocking I/O, but it is a
2049benchmark nevertheless.
2050
2051 name runtime
2052 Lambda/select 0.330 sec
2053 + optimized 0.122 sec
2054 Lambda/AnyEvent 0.327 sec
2055 + optimized 0.138 sec
2056 Raw sockets/select 0.077 sec
2057 POE/select, components 0.662 sec
2058 POE/select, raw sockets 0.226 sec
2059 POE/select, optimized 0.404 sec
2060
2061 AnyEvent/select/nb 0.085 sec
2062 AnyEvent/EV/nb 0.068 sec
2063 +state machine 0.134 sec
2064
2065The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
2066benchmarks actually make blocking connects and use 100% blocking I/O,
2067defeating the purpose of an event-based solution. All of the newly
2068written AnyEvent benchmarks use 100% non-blocking connects (using
2069AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
2070resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
2071generally require a lot more bookkeeping and event handling than blocking
2072connects (which involve a single syscall only).
2073
2074The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
2075offers similar expressive power as POE and IO::Lambda, using conventional
2076Perl syntax. This means that both the echo server and the client are 100%
2077non-blocking, further placing it at a disadvantage.
2078
2079As you can see, the AnyEvent + EV combination even beats the
2080hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2081backend easily beats IO::Lambda and POE.
2082
2083And even the 100% non-blocking version written using the high-level (and
2084slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a
2085large margin, even though it does all of DNS, tcp-connect and socket I/O
2086in a non-blocking way.
2087
2088The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2089F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2090part of the IO::lambda distribution and were used without any changes.
2091
1785 2092
1786=head1 SIGNALS 2093=head1 SIGNALS
1787 2094
1788AnyEvent currently installs handlers for these signals: 2095AnyEvent currently installs handlers for these signals:
1789 2096
1792=item SIGCHLD 2099=item SIGCHLD
1793 2100
1794A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2101A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1795emulation for event loops that do not support them natively. Also, some 2102emulation for event loops that do not support them natively. Also, some
1796event loops install a similar handler. 2103event loops install a similar handler.
2104
2105Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2106AnyEvent will reset it to default, to avoid losing child exit statuses.
1797 2107
1798=item SIGPIPE 2108=item SIGPIPE
1799 2109
1800A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2110A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1801when AnyEvent gets loaded. 2111when AnyEvent gets loaded.
1813 2123
1814=back 2124=back
1815 2125
1816=cut 2126=cut
1817 2127
2128undef $SIG{CHLD}
2129 if $SIG{CHLD} eq 'IGNORE';
2130
1818$SIG{PIPE} = sub { } 2131$SIG{PIPE} = sub { }
1819 unless defined $SIG{PIPE}; 2132 unless defined $SIG{PIPE};
1820
1821 2133
1822=head1 FORK 2134=head1 FORK
1823 2135
1824Most event libraries are not fork-safe. The ones who are usually are 2136Most event libraries are not fork-safe. The ones who are usually are
1825because they rely on inefficient but fork-safe C<select> or C<poll> 2137because they rely on inefficient but fork-safe C<select> or C<poll>
1846 use AnyEvent; 2158 use AnyEvent;
1847 2159
1848Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 2160Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1849be used to probe what backend is used and gain other information (which is 2161be used to probe what backend is used and gain other information (which is
1850probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and 2162probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1851$ENV{PERL_ANYEGENT_STRICT}. 2163$ENV{PERL_ANYEVENT_STRICT}.
2164
2165Note that AnyEvent will remove I<all> environment variables starting with
2166C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
2167enabled.
1852 2168
1853 2169
1854=head1 BUGS 2170=head1 BUGS
1855 2171
1856Perl 5.8 has numerous memleaks that sometimes hit this module and are hard 2172Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1857to work around. If you suffer from memleaks, first upgrade to Perl 5.10 2173to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1858and check wether the leaks still show up. (Perl 5.10.0 has other annoying 2174and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1859mamleaks, such as leaking on C<map> and C<grep> but it is usually not as 2175memleaks, such as leaking on C<map> and C<grep> but it is usually not as
1860pronounced). 2176pronounced).
1861 2177
1862 2178
1863=head1 SEE ALSO 2179=head1 SEE ALSO
1864 2180
1868L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2184L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1869 2185
1870Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2186Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1871L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2187L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1872L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2188L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1873L<AnyEvent::Impl::POE>. 2189L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>.
1874 2190
1875Non-blocking file handles, sockets, TCP clients and 2191Non-blocking file handles, sockets, TCP clients and
1876servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2192servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1877 2193
1878Asynchronous DNS: L<AnyEvent::DNS>. 2194Asynchronous DNS: L<AnyEvent::DNS>.
1879 2195
1880Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2196Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2197L<Coro::Event>,
1881 2198
1882Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2199Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2200L<AnyEvent::HTTP>.
1883 2201
1884 2202
1885=head1 AUTHOR 2203=head1 AUTHOR
1886 2204
1887 Marc Lehmann <schmorp@schmorp.de> 2205 Marc Lehmann <schmorp@schmorp.de>

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines