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Revision 1.135 by root, Sun May 25 04:49:01 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
731no warnings; 792no warnings;
732use strict; 793use strict;
733 794
734use Carp; 795use Carp;
735 796
736our $VERSION = '4.03'; 797our $VERSION = '4.05';
737our $MODEL; 798our $MODEL;
738 799
739our $AUTOLOAD; 800our $AUTOLOAD;
740our @ISA; 801our @ISA;
741 802
742our @REGISTRY; 803our @REGISTRY;
743 804
805our $WIN32;
806
807BEGIN {
808 my $win32 = ! ! ($^O =~ /mswin32/i);
809 eval "sub WIN32(){ $win32 }";
810}
811
744our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 812our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
745 813
746our %PROTOCOL; # (ipv4|ipv6) => (1|2) 814our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
747 815
748{ 816{
749 my $idx; 817 my $idx;
750 $PROTOCOL{$_} = ++$idx 818 $PROTOCOL{$_} = ++$idx
819 for reverse split /\s*,\s*/,
751 for split /\s*,\s*/, $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 820 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
752} 821}
753 822
754my @models = ( 823my @models = (
755 [EV:: => AnyEvent::Impl::EV::], 824 [EV:: => AnyEvent::Impl::EV::],
756 [Event:: => AnyEvent::Impl::Event::], 825 [Event:: => AnyEvent::Impl::Event::],
765 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 834 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
766 [Wx:: => AnyEvent::Impl::POE::], 835 [Wx:: => AnyEvent::Impl::POE::],
767 [Prima:: => AnyEvent::Impl::POE::], 836 [Prima:: => AnyEvent::Impl::POE::],
768); 837);
769 838
770our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); 839our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
771 840
772our @post_detect; 841our @post_detect;
773 842
774sub post_detect(&) { 843sub post_detect(&) {
775 my ($cb) = @_; 844 my ($cb) = @_;
792} 861}
793 862
794sub detect() { 863sub detect() {
795 unless ($MODEL) { 864 unless ($MODEL) {
796 no strict 'refs'; 865 no strict 'refs';
866 local $SIG{__DIE__};
797 867
798 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 868 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
799 my $model = "AnyEvent::Impl::$1"; 869 my $model = "AnyEvent::Impl::$1";
800 if (eval "require $model") { 870 if (eval "require $model") {
801 $MODEL = $model; 871 $MODEL = $model;
858 $class->$func (@_); 928 $class->$func (@_);
859} 929}
860 930
861package AnyEvent::Base; 931package AnyEvent::Base;
862 932
933# default implementation for now and time
934
935use Time::HiRes ();
936
937sub time { Time::HiRes::time }
938sub now { Time::HiRes::time }
939
863# default implementation for ->condvar 940# default implementation for ->condvar
864 941
865sub condvar { 942sub condvar {
866 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: 943 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
867} 944}
924 or Carp::croak "required option 'pid' is missing"; 1001 or Carp::croak "required option 'pid' is missing";
925 1002
926 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1003 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
927 1004
928 unless ($WNOHANG) { 1005 unless ($WNOHANG) {
929 $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; 1006 $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
930 } 1007 }
931 1008
932 unless ($CHLD_W) { 1009 unless ($CHLD_W) {
933 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1010 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
934 # 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
1113some (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
1114default. 1191default.
1115 1192
1116Setting 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
1117EDNS0 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.
1118 1200
1119=back 1201=back
1120 1202
1121=head1 EXAMPLE PROGRAM 1203=head1 EXAMPLE PROGRAM
1122 1204

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