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Revision 1.167 by root, Tue Jul 8 23:44:51 2008 UTC vs.
Revision 1.173 by root, Mon Jul 21 03:47:22 2008 UTC

6 6
7=head1 SYNOPSIS 7=head1 SYNOPSIS
8 8
9 use AnyEvent; 9 use AnyEvent;
10 10
11 my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { 11 my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { ... });
12 ...
13 });
14 12
15 my $w = AnyEvent->timer (after => $seconds, cb => sub { 13 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
14 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
15
16 print AnyEvent->now; # prints current event loop time
17 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
18
19 my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
20
21 my $w = AnyEvent->child (pid => $pid, cb => sub {
22 my ($pid, $status) = @_;
16 ... 23 ...
17 }); 24 });
18 25
19 my $w = AnyEvent->condvar; # stores whether a condition was flagged 26 my $w = AnyEvent->condvar; # stores whether a condition was flagged
20 $w->send; # wake up current and all future recv's 27 $w->send; # wake up current and all future recv's
21 $w->recv; # enters "main loop" till $condvar gets ->send 28 $w->recv; # enters "main loop" till $condvar gets ->send
29 # use a condvar in callback mode:
30 $w->cb (sub { $_[0]->recv });
22 31
23=head1 INTRODUCTION/TUTORIAL 32=head1 INTRODUCTION/TUTORIAL
24 33
25This manpage is mainly a reference manual. If you are interested 34This manpage is mainly a reference manual. If you are interested
26in a tutorial or some gentle introduction, have a look at the 35in a tutorial or some gentle introduction, have a look at the
33 42
34Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of 43Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
35policy> and AnyEvent is I<small and efficient>. 44policy> and AnyEvent is I<small and efficient>.
36 45
37First and foremost, I<AnyEvent is not an event model> itself, it only 46First and foremost, I<AnyEvent is not an event model> itself, it only
38interfaces to whatever event model the main program happens to use in a 47interfaces to whatever event model the main program happens to use, in a
39pragmatic way. For event models and certain classes of immortals alike, 48pragmatic way. For event models and certain classes of immortals alike,
40the statement "there can only be one" is a bitter reality: In general, 49the statement "there can only be one" is a bitter reality: In general,
41only one event loop can be active at the same time in a process. AnyEvent 50only one event loop can be active at the same time in a process. AnyEvent
42helps hiding the differences between those event loops. 51cannot change this, but it can hide the differences between those event
52loops.
43 53
44The goal of AnyEvent is to offer module authors the ability to do event 54The goal of AnyEvent is to offer module authors the ability to do event
45programming (waiting for I/O or timer events) without subscribing to a 55programming (waiting for I/O or timer events) without subscribing to a
46religion, a way of living, and most importantly: without forcing your 56religion, a way of living, and most importantly: without forcing your
47module users into the same thing by forcing them to use the same event 57module users into the same thing by forcing them to use the same event
48model you use. 58model you use.
49 59
50For modules like POE or IO::Async (which is a total misnomer as it is 60For modules like POE or IO::Async (which is a total misnomer as it is
51actually doing all I/O I<synchronously>...), using them in your module is 61actually doing all I/O I<synchronously>...), using them in your module is
52like joining a cult: After you joined, you are dependent on them and you 62like joining a cult: After you joined, you are dependent on them and you
53cannot use anything else, as it is simply incompatible to everything that 63cannot use anything else, as they are simply incompatible to everything
54isn't itself. What's worse, all the potential users of your module are 64that isn't them. What's worse, all the potential users of your
55I<also> forced to use the same event loop you use. 65module are I<also> forced to use the same event loop you use.
56 66
57AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 67AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
58fine. AnyEvent + Tk works fine etc. etc. but none of these work together 68fine. AnyEvent + Tk works fine etc. etc. but none of these work together
59with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if 69with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
60your module uses one of those, every user of your module has to use it, 70your module uses one of those, every user of your module has to use it,
61too. But if your module uses AnyEvent, it works transparently with all 71too. But if your module uses AnyEvent, it works transparently with all
62event models it supports (including stuff like POE and IO::Async, as long 72event models it supports (including stuff like IO::Async, as long as those
63as those use one of the supported event loops. It is trivial to add new 73use one of the supported event loops. It is trivial to add new event loops
64event loops to AnyEvent, too, so it is future-proof). 74to AnyEvent, too, so it is future-proof).
65 75
66In addition to being free of having to use I<the one and only true event 76In addition to being free of having to use I<the one and only true event
67model>, AnyEvent also is free of bloat and policy: with POE or similar 77model>, AnyEvent also is free of bloat and policy: with POE or similar
68modules, you get an enormous amount of code and strict rules you have to 78modules, you get an enormous amount of code and strict rules you have to
69follow. AnyEvent, on the other hand, is lean and up to the point, by only 79follow. AnyEvent, on the other hand, is lean and up to the point, by only
379 389
380The instrument to do that is called a "condition variable", so called 390The instrument to do that is called a "condition variable", so called
381because they represent a condition that must become true. 391because they represent a condition that must become true.
382 392
383Condition variables can be created by calling the C<< AnyEvent->condvar 393Condition variables can be created by calling the C<< AnyEvent->condvar
394
384>> method, usually without arguments. The only argument pair allowed is 395>> method, usually without arguments. The only argument pair allowed is
396
385C<cb>, which specifies a callback to be called when the condition variable 397C<cb>, which specifies a callback to be called when the condition variable
386becomes true. 398becomes true, with the condition variable as the first argument (but not
399the results).
387 400
388After creation, the condition variable is "false" until it becomes "true" 401After creation, the condition variable is "false" until it becomes "true"
389by calling the C<send> method (or calling the condition variable as if it 402by calling the C<send> method (or calling the condition variable as if it
390were a callback, read about the caveats in the description for the C<< 403were a callback, read about the caveats in the description for the C<<
391->send >> method). 404->send >> method).
447 460
448 my $done = AnyEvent->condvar; 461 my $done = AnyEvent->condvar;
449 my $delay = AnyEvent->timer (after => 5, cb => $done); 462 my $delay = AnyEvent->timer (after => 5, cb => $done);
450 $done->recv; 463 $done->recv;
451 464
465Example: Imagine an API that returns a condvar and doesn't support
466callbacks. This is how you make a synchronous call, for example from
467the main program:
468
469 use AnyEvent::CouchDB;
470
471 ...
472
473 my @info = $couchdb->info->recv;
474
475And this is how you would just ste a callback to be called whenever the
476results are available:
477
478 $couchdb->info->cb (sub {
479 my @info = $_[0]->recv;
480 });
481
452=head3 METHODS FOR PRODUCERS 482=head3 METHODS FOR PRODUCERS
453 483
454These methods should only be used by the producing side, i.e. the 484These methods should only be used by the producing side, i.e. the
455code/module that eventually sends the signal. Note that it is also 485code/module that eventually sends the signal. Note that it is also
456the producer side which creates the condvar in most cases, but it isn't 486the producer side which creates the condvar in most cases, but it isn't
589=item $bool = $cv->ready 619=item $bool = $cv->ready
590 620
591Returns true when the condition is "true", i.e. whether C<send> or 621Returns true when the condition is "true", i.e. whether C<send> or
592C<croak> have been called. 622C<croak> have been called.
593 623
594=item $cb = $cv->cb ([new callback]) 624=item $cb = $cv->cb ($cb->($cv))
595 625
596This is a mutator function that returns the callback set and optionally 626This is a mutator function that returns the callback set and optionally
597replaces it before doing so. 627replaces it before doing so.
598 628
599The callback will be called when the condition becomes "true", i.e. when 629The callback will be called when the condition becomes "true", i.e. when
825no warnings; 855no warnings;
826use strict; 856use strict;
827 857
828use Carp; 858use Carp;
829 859
830our $VERSION = 4.2; 860our $VERSION = 4.22;
831our $MODEL; 861our $MODEL;
832 862
833our $AUTOLOAD; 863our $AUTOLOAD;
834our @ISA; 864our @ISA;
835 865
940 } 970 }
941 } 971 }
942 972
943 push @{"$MODEL\::ISA"}, "AnyEvent::Base"; 973 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
944 974
945 if ($ENV{PERL_ANYEVENT_STRICT}) {
946 unshift @AnyEvent::Base::Strict::ISA, $MODEL;
947 unshift @ISA, AnyEvent::Base::Strict::
948 } else {
949 unshift @ISA, $MODEL; 975 unshift @ISA, $MODEL;
950 } 976
977 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
951 978
952 (shift @post_detect)->() while @post_detect; 979 (shift @post_detect)->() while @post_detect;
953 } 980 }
954 981
955 $MODEL 982 $MODEL
963 990
964 detect unless $MODEL; 991 detect unless $MODEL;
965 992
966 my $class = shift; 993 my $class = shift;
967 $class->$func (@_); 994 $class->$func (@_);
995}
996
997# utility function to dup a filehandle. this is used by many backends
998# to support binding more than one watcher per filehandle (they usually
999# allow only one watcher per fd, so we dup it to get a different one).
1000sub _dupfh($$$$) {
1001 my ($poll, $fh, $r, $w) = @_;
1002
1003 require Fcntl;
1004
1005 # cygwin requires the fh mode to be matching, unix doesn't
1006 my ($rw, $mode) = $poll eq "r" ? ($r, "<")
1007 : $poll eq "w" ? ($w, ">")
1008 : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1009
1010 open my $fh2, "$mode&" . fileno $fh
1011 or die "cannot dup() filehandle: $!";
1012
1013 # we assume CLOEXEC is already set by perl in all important cases
1014
1015 ($fh2, $rw)
968} 1016}
969 1017
970package AnyEvent::Base; 1018package AnyEvent::Base;
971 1019
972# default implementation for now and time 1020# default implementation for now and time
1121 1169
1122# undocumented/compatibility with pre-3.4 1170# undocumented/compatibility with pre-3.4
1123*broadcast = \&send; 1171*broadcast = \&send;
1124*wait = \&_wait; 1172*wait = \&_wait;
1125 1173
1126package AnyEvent::Base::Strict;
1127
1128use Carp qw(croak);
1129
1130# supply checks for argument validity for many functions
1131
1132sub io {
1133 my $class = shift;
1134 my %arg = @_;
1135
1136 ref $arg{cb}
1137 or croak "AnyEvent->io called with illegal cb argument '$arg{cb}'";
1138 delete $arg{cb};
1139
1140 fileno $arg{fh}
1141 or croak "AnyEvent->io called with illegal fh argument '$arg{fh}'";
1142 delete $arg{fh};
1143
1144 $arg{poll} =~ /^[rw]$/
1145 or croak "AnyEvent->io called with illegal poll argument '$arg{poll}'";
1146 delete $arg{poll};
1147
1148 croak "AnyEvent->io called with unsupported parameter(s) " . join ", ", keys %arg
1149 if keys %arg;
1150
1151 $class->SUPER::io (@_)
1152}
1153
1154sub timer {
1155 my $class = shift;
1156 my %arg = @_;
1157
1158 ref $arg{cb}
1159 or croak "AnyEvent->timer called with illegal cb argument '$arg{cb}'";
1160 delete $arg{cb};
1161
1162 exists $arg{after}
1163 or croak "AnyEvent->timer called without mandatory 'after' parameter";
1164 delete $arg{after};
1165
1166 $arg{interval} > 0 || !$arg{interval}
1167 or croak "AnyEvent->timer called with illegal interval argument '$arg{interval}'";
1168 delete $arg{interval};
1169
1170 croak "AnyEvent->timer called with unsupported parameter(s) " . join ", ", keys %arg
1171 if keys %arg;
1172
1173 $class->SUPER::timer (@_)
1174}
1175
1176sub signal {
1177 my $class = shift;
1178 my %arg = @_;
1179
1180 ref $arg{cb}
1181 or croak "AnyEvent->signal called with illegal cb argument '$arg{cb}'";
1182 delete $arg{cb};
1183
1184 eval "require POSIX; defined &POSIX::SIG$arg{signal}"
1185 or croak "AnyEvent->signal called with illegal signal name '$arg{signal}'";
1186 delete $arg{signal};
1187
1188 croak "AnyEvent->signal called with unsupported parameter(s) " . join ", ", keys %arg
1189 if keys %arg;
1190
1191 $class->SUPER::signal (@_)
1192}
1193
1194sub child {
1195 my $class = shift;
1196 my %arg = @_;
1197
1198 ref $arg{cb}
1199 or croak "AnyEvent->signal called with illegal cb argument '$arg{cb}'";
1200 delete $arg{cb};
1201
1202 $arg{pid} =~ /^-?\d+$/
1203 or croak "AnyEvent->signal called with illegal pid value '$arg{pid}'";
1204 delete $arg{pid};
1205
1206 croak "AnyEvent->signal called with unsupported parameter(s) " . join ", ", keys %arg
1207 if keys %arg;
1208
1209 $class->SUPER::child (@_)
1210}
1211
1212sub condvar {
1213 my $class = shift;
1214 my %arg = @_;
1215
1216 !exists $arg{cb} or ref $arg{cb}
1217 or croak "AnyEvent->condvar called with illegal cb argument '$arg{cb}'";
1218 delete $arg{cb};
1219
1220 croak "AnyEvent->condvar called with unsupported parameter(s) " . join ", ", keys %arg
1221 if keys %arg;
1222
1223 $class->SUPER::condvar (@_)
1224}
1225
1226sub time {
1227 my $class = shift;
1228
1229 @_
1230 and croak "AnyEvent->time wrongly called with paramaters";
1231
1232 $class->SUPER::time (@_)
1233}
1234
1235sub now {
1236 my $class = shift;
1237
1238 @_
1239 and croak "AnyEvent->now wrongly called with paramaters";
1240
1241 $class->SUPER::now (@_)
1242}
1243
1244=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1174=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1245 1175
1246This is an advanced topic that you do not normally need to use AnyEvent in 1176This is an advanced topic that you do not normally need to use AnyEvent in
1247a module. This section is only of use to event loop authors who want to 1177a module. This section is only of use to event loop authors who want to
1248provide AnyEvent compatibility. 1178provide AnyEvent compatibility.
1305 1235
1306=item C<PERL_ANYEVENT_STRICT> 1236=item C<PERL_ANYEVENT_STRICT>
1307 1237
1308AnyEvent does not do much argument checking by default, as thorough 1238AnyEvent does not do much argument checking by default, as thorough
1309argument checking is very costly. Setting this variable to a true value 1239argument checking is very costly. Setting this variable to a true value
1310will cause AnyEvent to thoroughly check the arguments passed to most 1240will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1311method calls and croaks if it finds any problems. In other words, enables 1241check the arguments passed to most method calls. If it finds any problems
1242it will croak.
1243
1244In other words, enables "strict" mode.
1245
1312"strict" mode. Unlike C<use strict> it is definitely recommended ot keep 1246Unlike C<use strict> it is definitely recommended ot keep it off in
1313it off in production. 1247production.
1314 1248
1315=item C<PERL_ANYEVENT_MODEL> 1249=item C<PERL_ANYEVENT_MODEL>
1316 1250
1317This can be used to specify the event model to be used by AnyEvent, before 1251This can be used to specify the event model to be used by AnyEvent, before
1318auto detection and -probing kicks in. It must be a string consisting 1252auto detection and -probing kicks in. It must be a string consisting

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