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 1.130 by root, Sat May 24 17:21:50 2008 UTC vs.
Revision 1.143 by root, Wed May 28 23:57:38 2008 UTC

… …
48isn't itself. What's worse, all the potential users of your module are 48isn't itself. What's worse, all the potential users of your module are
49I<also> forced to use the same event loop you use. 49I<also> forced to use the same event loop you use.
50 50
51AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 51AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52fine. AnyEvent + Tk works fine etc. etc. but none of these work together 52fine. AnyEvent + Tk works fine etc. etc. but none of these work together
53with the rest: POE + IO::Async? no go. Tk + Event? no go. Again: if 53with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
54your module uses one of those, every user of your module has to use it, 54your module uses one of those, every user of your module has to use it,
55too. But if your module uses AnyEvent, it works transparently with all 55too. But if your module uses AnyEvent, it works transparently with all
56event models it supports (including stuff like POE and IO::Async, as long 56event models it supports (including stuff like POE and IO::Async, as long
57as those use one of the supported event loops. It is trivial to add new 57as those use one of the supported event loops. It is trivial to add new
58event loops to AnyEvent, too, so it is future-proof). 58event loops to AnyEvent, too, so it is future-proof).
… …
62modules, you get an enormous amount of code and strict rules you have to 62modules, you get an enormous amount of code and strict rules you have to
63follow. AnyEvent, on the other hand, is lean and up to the point, by only 63follow. AnyEvent, on the other hand, is lean and up to the point, by only
64offering the functionality that is necessary, in as thin as a wrapper as 64offering the functionality that is necessary, in as thin as a wrapper as
65technically possible. 65technically possible.
66 66
67Of course, AnyEvent comes with a big (and fully optional!) toolbox
68of useful functionality, such as an asynchronous DNS resolver, 100%
69non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
70such as Windows) and lots of real-world knowledge and workarounds for
71platform bugs and differences.
72
67Of course, if you want lots of policy (this can arguably be somewhat 73Now, if you I<do want> lots of policy (this can arguably be somewhat
68useful) and you want to force your users to use the one and only event 74useful) and you want to force your users to use the one and only event
69model, you should I<not> use this module. 75model, you should I<not> use this module.
70 76
71=head1 DESCRIPTION 77=head1 DESCRIPTION
72 78
… …
102starts using it, all bets are off. Maybe you should tell their authors to 108starts using it, all bets are off. Maybe you should tell their authors to
103use AnyEvent so their modules work together with others seamlessly... 109use AnyEvent so their modules work together with others seamlessly...
104 110
105The pure-perl implementation of AnyEvent is called 111The pure-perl implementation of AnyEvent is called
106C<AnyEvent::Impl::Perl>. Like other event modules you can load it 112C<AnyEvent::Impl::Perl>. Like other event modules you can load it
107explicitly. 113explicitly and enjoy the high availability of that event loop :)
108 114
109=head1 WATCHERS 115=head1 WATCHERS
110 116
111AnyEvent has the central concept of a I<watcher>, which is an object that 117AnyEvent has the central concept of a I<watcher>, which is an object that
112stores relevant data for each kind of event you are waiting for, such as 118stores relevant data for each kind of event you are waiting for, such as
… …
226on true relative time) and absolute (ev_periodic, based on wallclock time) 232on true relative time) and absolute (ev_periodic, based on wallclock time)
227timers. 233timers.
228 234
229AnyEvent always prefers relative timers, if available, matching the 235AnyEvent always prefers relative timers, if available, matching the
230AnyEvent API. 236AnyEvent API.
237
238AnyEvent has two additional methods that return the "current time":
239
240=over 4
241
242=item AnyEvent->time
243
244This returns the "current wallclock time" as a fractional number of
245seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
246return, and the result is guaranteed to be compatible with those).
247
248It progresses independently of any event loop processing.
249
250In almost all cases (in all cases if you don't care), this is the function
251to call when you want to know the current time.
252
253=item AnyEvent->now
254
255This also returns the "current wallclock time", but unlike C<time>, above,
256this value might change only once per event loop iteration, depending on
257the event loop (most return the same time as C<time>, above). This is the
258time that AnyEvent timers get scheduled against.
259
260For a practical example of when these times differ, consider L<Event::Lib>
261and L<EV> and the following set-up:
262
263The event loop is running and has just invoked one of your callback at
264time=500 (assume no other callbacks delay processing). In your callback,
265you wait a second by executing C<sleep 1> (blocking the process for a
266second) and then (at time=501) you create a relative timer that fires
267after three seconds.
268
269With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
270both return C<501>, because that is the current time, and the timer will
271be scheduled to fire at time=504 (C<501> + C<3>).
272
273With L<EV>m C<< AnyEvent->time >> returns C<501> (as that is the current
274time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
275last event processing phase started. With L<EV>, your timer gets scheduled
276to run at time=503 (C<500> + C<3>).
277
278In one sense, L<Event::Lib> is more exact, as it uses the current time
279regardless of any delays introduced by event processing. However, most
280callbacks do not expect large delays in processing, so this causes a
281higher drift (and a lot more syscalls to get the current time).
282
283In another sense, L<EV> is more exact, as your timer will be scheduled at
284the same time, regardless of how long event processing actually took.
285
286In either case, if you care (and in most cases, you don't), then you
287can get whatever behaviour you want with any event loop, by taking the
288difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
289account.
290
291=back
231 292
232=head2 SIGNAL WATCHERS 293=head2 SIGNAL WATCHERS
233 294
234You can watch for signals using a signal watcher, C<signal> is the signal 295You can watch for signals using a signal watcher, C<signal> is the signal
235I<name> without any C<SIG> prefix, C<cb> is the Perl callback to 296I<name> without any C<SIG> prefix, C<cb> is the Perl callback to
… …
311>> method, usually without arguments. The only argument pair allowed is 372>> method, usually without arguments. The only argument pair allowed is
312C<cb>, which specifies a callback to be called when the condition variable 373C<cb>, which specifies a callback to be called when the condition variable
313becomes true. 374becomes true.
314 375
315After creation, the condition variable is "false" until it becomes "true" 376After creation, the condition variable is "false" until it becomes "true"
316by calling the C<send> method. 377by calling the C<send> method (or calling the condition variable as if it
378were a callback, read about the caveats in the description for the C<<
379->send >> method).
317 380
318Condition variables are similar to callbacks, except that you can 381Condition variables are similar to callbacks, except that you can
319optionally wait for them. They can also be called merge points - points 382optionally wait for them. They can also be called merge points - points
320in time where multiple outstanding events have been processed. And yet 383in time where multiple outstanding events have been processed. And yet
321another way to call them is transactions - each condition variable can be 384another way to call them is transactions - each condition variable can be
… …
347 410
348There are two "sides" to a condition variable - the "producer side" which 411There are two "sides" to a condition variable - the "producer side" which
349eventually calls C<< -> send >>, and the "consumer side", which waits 412eventually calls C<< -> send >>, and the "consumer side", which waits
350for the send to occur. 413for the send to occur.
351 414
352Example: 415Example: wait for a timer.
353 416
354 # wait till the result is ready 417 # wait till the result is ready
355 my $result_ready = AnyEvent->condvar; 418 my $result_ready = AnyEvent->condvar;
356 419
357 # do something such as adding a timer 420 # do something such as adding a timer
… …
365 428
366 # this "blocks" (while handling events) till the callback 429 # this "blocks" (while handling events) till the callback
367 # calls send 430 # calls send
368 $result_ready->recv; 431 $result_ready->recv;
369 432
433Example: wait for a timer, but take advantage of the fact that
434condition variables are also code references.
435
436 my $done = AnyEvent->condvar;
437 my $delay = AnyEvent->timer (after => 5, cb => $done);
438 $done->recv;
439
370=head3 METHODS FOR PRODUCERS 440=head3 METHODS FOR PRODUCERS
371 441
372These methods should only be used by the producing side, i.e. the 442These methods should only be used by the producing side, i.e. the
373code/module that eventually sends the signal. Note that it is also 443code/module that eventually sends the signal. Note that it is also
374the producer side which creates the condvar in most cases, but it isn't 444the producer side which creates the condvar in most cases, but it isn't
… …
385If a callback has been set on the condition variable, it is called 455If a callback has been set on the condition variable, it is called
386immediately from within send. 456immediately from within send.
387 457
388Any arguments passed to the C<send> call will be returned by all 458Any arguments passed to the C<send> call will be returned by all
389future C<< ->recv >> calls. 459future C<< ->recv >> calls.
460
461Condition variables are overloaded so one can call them directly
462(as a code reference). Calling them directly is the same as calling
463C<send>. Note, however, that many C-based event loops do not handle
464overloading, so as tempting as it may be, passing a condition variable
465instead of a callback does not work. Both the pure perl and EV loops
466support overloading, however, as well as all functions that use perl to
467invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
468example).
390 469
391=item $cv->croak ($error) 470=item $cv->croak ($error)
392 471
393Similar to send, but causes all call's to C<< ->recv >> to invoke 472Similar to send, but causes all call's to C<< ->recv >> to invoke
394C<Carp::croak> with the given error message/object/scalar. 473C<Carp::croak> with the given error message/object/scalar.
… …
601 680
602If it doesn't care, it can just "use AnyEvent" and use it itself, or not 681If it doesn't care, it can just "use AnyEvent" and use it itself, or not
603do anything special (it does not need to be event-based) and let AnyEvent 682do anything special (it does not need to be event-based) and let AnyEvent
604decide which implementation to chose if some module relies on it. 683decide which implementation to chose if some module relies on it.
605 684
606If the main program relies on a specific event model. For example, in 685If the main program relies on a specific event model - for example, in
607Gtk2 programs you have to rely on the Glib module. You should load the 686Gtk2 programs you have to rely on the Glib module - you should load the
608event module before loading AnyEvent or any module that uses it: generally 687event module before loading AnyEvent or any module that uses it: generally
609speaking, you should load it as early as possible. The reason is that 688speaking, you should load it as early as possible. The reason is that
610modules might create watchers when they are loaded, and AnyEvent will 689modules might create watchers when they are loaded, and AnyEvent will
611decide on the event model to use as soon as it creates watchers, and it 690decide on the event model to use as soon as it creates watchers, and it
612might chose the wrong one unless you load the correct one yourself. 691might chose the wrong one unless you load the correct one yourself.
613 692
614You can chose to use a rather inefficient pure-perl implementation by 693You can chose to use a pure-perl implementation by loading the
615loading the C<AnyEvent::Impl::Perl> module, which gives you similar 694C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
616behaviour everywhere, but letting AnyEvent chose is generally better. 695everywhere, but letting AnyEvent chose the model is generally better.
696
697=head2 MAINLOOP EMULATION
698
699Sometimes (often for short test scripts, or even standalone programs who
700only want to use AnyEvent), you do not want to run a specific event loop.
701
702In that case, you can use a condition variable like this:
703
704 AnyEvent->condvar->recv;
705
706This has the effect of entering the event loop and looping forever.
707
708Note that usually your program has some exit condition, in which case
709it is better to use the "traditional" approach of storing a condition
710variable somewhere, waiting for it, and sending it when the program should
711exit cleanly.
712
617 713
618=head1 OTHER MODULES 714=head1 OTHER MODULES
619 715
620The following is a non-exhaustive list of additional modules that use 716The following is a non-exhaustive list of additional modules that use
621AnyEvent and can therefore be mixed easily with other AnyEvent modules 717AnyEvent and can therefore be mixed easily with other AnyEvent modules
… …
637 733
638Provides various utility functions for (internet protocol) sockets, 734Provides various utility functions for (internet protocol) sockets,
639addresses and name resolution. Also functions to create non-blocking tcp 735addresses and name resolution. Also functions to create non-blocking tcp
640connections or tcp servers, with IPv6 and SRV record support and more. 736connections or tcp servers, with IPv6 and SRV record support and more.
641 737
738=item L<AnyEvent::DNS>
739
740Provides rich asynchronous DNS resolver capabilities.
741
642=item L<AnyEvent::HTTPD> 742=item L<AnyEvent::HTTPD>
643 743
644Provides a simple web application server framework. 744Provides a simple web application server framework.
645
646=item L<AnyEvent::DNS>
647
648Provides rich asynchronous DNS resolver capabilities.
649 745
650=item L<AnyEvent::FastPing> 746=item L<AnyEvent::FastPing>
651 747
652The fastest ping in the west. 748The fastest ping in the west.
653 749
… …
696no warnings; 792no warnings;
697use strict; 793use strict;
698 794
699use Carp; 795use Carp;
700 796
701our $VERSION = '4.0'; 797our $VERSION = '4.05';
702our $MODEL; 798our $MODEL;
703 799
704our $AUTOLOAD; 800our $AUTOLOAD;
705our @ISA; 801our @ISA;
706 802
803our @REGISTRY;
804
805our $WIN32;
806
807BEGIN {
808 my $win32 = ! ! ($^O =~ /mswin32/i);
809 eval "sub WIN32(){ $win32 }";
810}
811
707our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 812our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
708 813
709our @REGISTRY; 814our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
710
711our %PROTOCOL; # (ipv4|ipv6) => (1|2)
712 815
713{ 816{
714 my $idx; 817 my $idx;
715 $PROTOCOL{$_} = ++$idx 818 $PROTOCOL{$_} = ++$idx
819 for reverse split /\s*,\s*/,
716 for split /\s*,\s*/, $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 820 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
717} 821}
718 822
719my @models = ( 823my @models = (
720 [EV:: => AnyEvent::Impl::EV::], 824 [EV:: => AnyEvent::Impl::EV::],
721 [Event:: => AnyEvent::Impl::Event::], 825 [Event:: => AnyEvent::Impl::Event::],
722 [Tk:: => AnyEvent::Impl::Tk::],
723 [Wx:: => AnyEvent::Impl::POE::],
724 [Prima:: => AnyEvent::Impl::POE::],
725 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 826 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
726 # everything below here will not be autoprobed as the pureperl backend should work everywhere 827 # everything below here will not be autoprobed
727 [Glib:: => AnyEvent::Impl::Glib::], 828 # as the pureperl backend should work everywhere
829 # and is usually faster
830 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
831 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
728 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 832 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
729 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 833 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
730 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 834 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
835 [Wx:: => AnyEvent::Impl::POE::],
836 [Prima:: => AnyEvent::Impl::POE::],
731); 837);
732 838
733our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); 839our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
734 840
735our @post_detect; 841our @post_detect;
736 842
737sub post_detect(&) { 843sub post_detect(&) {
738 my ($cb) = @_; 844 my ($cb) = @_;
… …
755} 861}
756 862
757sub detect() { 863sub detect() {
758 unless ($MODEL) { 864 unless ($MODEL) {
759 no strict 'refs'; 865 no strict 'refs';
866 local $SIG{__DIE__};
760 867
761 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 868 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
762 my $model = "AnyEvent::Impl::$1"; 869 my $model = "AnyEvent::Impl::$1";
763 if (eval "require $model") { 870 if (eval "require $model") {
764 $MODEL = $model; 871 $MODEL = $model;
… …
821 $class->$func (@_); 928 $class->$func (@_);
822} 929}
823 930
824package AnyEvent::Base; 931package AnyEvent::Base;
825 932
933# default implementation for now and time
934
935use Time::HiRes ();
936
937sub time { Time::HiRes::time }
938sub now { Time::HiRes::time }
939
826# default implementation for ->condvar 940# default implementation for ->condvar
827 941
828sub condvar { 942sub condvar {
829 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: 943 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
830} 944}
… …
887 or Carp::croak "required option 'pid' is missing"; 1001 or Carp::croak "required option 'pid' is missing";
888 1002
889 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1003 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
890 1004
891 unless ($WNOHANG) { 1005 unless ($WNOHANG) {
892 $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; 1006 $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
893 } 1007 }
894 1008
895 unless ($CHLD_W) { 1009 unless ($CHLD_W) {
896 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1010 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
897 # child could be a zombie already, so make at least one round 1011 # child could be a zombie already, so make at least one round
… …
913package AnyEvent::CondVar; 1027package AnyEvent::CondVar;
914 1028
915our @ISA = AnyEvent::CondVar::Base::; 1029our @ISA = AnyEvent::CondVar::Base::;
916 1030
917package AnyEvent::CondVar::Base; 1031package AnyEvent::CondVar::Base;
1032
1033use overload
1034 '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1035 fallback => 1;
918 1036
919sub _send { 1037sub _send {
920 # nop 1038 # nop
921} 1039}
922 1040
… …
1072some (broken) firewalls drop such DNS packets, which is why it is off by 1190some (broken) firewalls drop such DNS packets, which is why it is off by
1073default. 1191default.
1074 1192
1075Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce 1193Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1076EDNS0 in its DNS requests. 1194EDNS0 in its DNS requests.
1195
1196=item C<PERL_ANYEVENT_MAX_FORKS>
1197
1198The maximum number of child processes that C<AnyEvent::Util::fork_call>
1199will create in parallel.
1077 1200
1078=back 1201=back
1079 1202
1080=head1 EXAMPLE PROGRAM 1203=head1 EXAMPLE PROGRAM
1081 1204

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines