… | |
… | |
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 | |
25 | This manpage is mainly a reference manual. If you are interested |
34 | This manpage is mainly a reference manual. If you are interested |
26 | in a tutorial or some gentle introduction, have a look at the |
35 | in a tutorial or some gentle introduction, have a look at the |
… | |
… | |
33 | |
42 | |
34 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
43 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
35 | policy> and AnyEvent is I<small and efficient>. |
44 | policy> and AnyEvent is I<small and efficient>. |
36 | |
45 | |
37 | First and foremost, I<AnyEvent is not an event model> itself, it only |
46 | First and foremost, I<AnyEvent is not an event model> itself, it only |
38 | interfaces to whatever event model the main program happens to use in a |
47 | interfaces to whatever event model the main program happens to use, in a |
39 | pragmatic way. For event models and certain classes of immortals alike, |
48 | pragmatic way. For event models and certain classes of immortals alike, |
40 | the statement "there can only be one" is a bitter reality: In general, |
49 | the statement "there can only be one" is a bitter reality: In general, |
41 | only one event loop can be active at the same time in a process. AnyEvent |
50 | only one event loop can be active at the same time in a process. AnyEvent |
42 | helps hiding the differences between those event loops. |
51 | cannot change this, but it can hide the differences between those event |
|
|
52 | loops. |
43 | |
53 | |
44 | The goal of AnyEvent is to offer module authors the ability to do event |
54 | The goal of AnyEvent is to offer module authors the ability to do event |
45 | programming (waiting for I/O or timer events) without subscribing to a |
55 | programming (waiting for I/O or timer events) without subscribing to a |
46 | religion, a way of living, and most importantly: without forcing your |
56 | religion, a way of living, and most importantly: without forcing your |
47 | module users into the same thing by forcing them to use the same event |
57 | module users into the same thing by forcing them to use the same event |
48 | model you use. |
58 | model you use. |
49 | |
59 | |
50 | For modules like POE or IO::Async (which is a total misnomer as it is |
60 | For modules like POE or IO::Async (which is a total misnomer as it is |
51 | actually doing all I/O I<synchronously>...), using them in your module is |
61 | actually doing all I/O I<synchronously>...), using them in your module is |
52 | like joining a cult: After you joined, you are dependent on them and you |
62 | like joining a cult: After you joined, you are dependent on them and you |
53 | cannot use anything else, as it is simply incompatible to everything that |
63 | cannot use anything else, as they are simply incompatible to everything |
54 | isn't itself. What's worse, all the potential users of your module are |
64 | that isn't them. What's worse, all the potential users of your |
55 | I<also> forced to use the same event loop you use. |
65 | module are I<also> forced to use the same event loop you use. |
56 | |
66 | |
57 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
67 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
58 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
68 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
59 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
69 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
60 | your module uses one of those, every user of your module has to use it, |
70 | your module uses one of those, every user of your module has to use it, |
61 | too. But if your module uses AnyEvent, it works transparently with all |
71 | too. But if your module uses AnyEvent, it works transparently with all |
62 | event models it supports (including stuff like POE and IO::Async, as long |
72 | event models it supports (including stuff like IO::Async, as long as those |
63 | as those use one of the supported event loops. It is trivial to add new |
73 | use one of the supported event loops. It is trivial to add new event loops |
64 | event loops to AnyEvent, too, so it is future-proof). |
74 | to AnyEvent, too, so it is future-proof). |
65 | |
75 | |
66 | In addition to being free of having to use I<the one and only true event |
76 | In addition to being free of having to use I<the one and only true event |
67 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
77 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
68 | modules, you get an enormous amount of code and strict rules you have to |
78 | modules, you get an enormous amount of code and strict rules you have to |
69 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
79 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
… | |
… | |
330 | =head2 CHILD PROCESS WATCHERS |
340 | =head2 CHILD PROCESS WATCHERS |
331 | |
341 | |
332 | You can also watch on a child process exit and catch its exit status. |
342 | You can also watch on a child process exit and catch its exit status. |
333 | |
343 | |
334 | The child process is specified by the C<pid> argument (if set to C<0>, it |
344 | The child process is specified by the C<pid> argument (if set to C<0>, it |
335 | watches for any child process exit). The watcher will trigger as often |
345 | watches for any child process exit). The watcher will triggered only when |
336 | as status change for the child are received. This works by installing a |
346 | the child process has finished and an exit status is available, not on |
337 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
347 | any trace events (stopped/continued). |
338 | and exit status (as returned by waitpid), so unlike other watcher types, |
348 | |
339 | you I<can> rely on child watcher callback arguments. |
349 | The callback will be called with the pid and exit status (as returned by |
|
|
350 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
|
351 | callback arguments. |
|
|
352 | |
|
|
353 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
|
|
354 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
|
|
355 | random child processes (waiting for specific child processes, e.g. inside |
|
|
356 | C<system>, is just fine). |
340 | |
357 | |
341 | There is a slight catch to child watchers, however: you usually start them |
358 | There is a slight catch to child watchers, however: you usually start them |
342 | I<after> the child process was created, and this means the process could |
359 | I<after> the child process was created, and this means the process could |
343 | have exited already (and no SIGCHLD will be sent anymore). |
360 | have exited already (and no SIGCHLD will be sent anymore). |
344 | |
361 | |
… | |
… | |
380 | The instrument to do that is called a "condition variable", so called |
397 | The instrument to do that is called a "condition variable", so called |
381 | because they represent a condition that must become true. |
398 | because they represent a condition that must become true. |
382 | |
399 | |
383 | Condition variables can be created by calling the C<< AnyEvent->condvar |
400 | Condition variables can be created by calling the C<< AnyEvent->condvar |
384 | >> method, usually without arguments. The only argument pair allowed is |
401 | >> method, usually without arguments. The only argument pair allowed is |
|
|
402 | |
385 | C<cb>, which specifies a callback to be called when the condition variable |
403 | C<cb>, which specifies a callback to be called when the condition variable |
386 | becomes true. |
404 | becomes true, with the condition variable as the first argument (but not |
|
|
405 | the results). |
387 | |
406 | |
388 | After creation, the condition variable is "false" until it becomes "true" |
407 | After creation, the condition variable is "false" until it becomes "true" |
389 | by calling the C<send> method (or calling the condition variable as if it |
408 | by calling the C<send> method (or calling the condition variable as if it |
390 | were a callback, read about the caveats in the description for the C<< |
409 | were a callback, read about the caveats in the description for the C<< |
391 | ->send >> method). |
410 | ->send >> method). |
… | |
… | |
447 | |
466 | |
448 | my $done = AnyEvent->condvar; |
467 | my $done = AnyEvent->condvar; |
449 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
468 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
450 | $done->recv; |
469 | $done->recv; |
451 | |
470 | |
|
|
471 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
472 | callbacks. This is how you make a synchronous call, for example from |
|
|
473 | the main program: |
|
|
474 | |
|
|
475 | use AnyEvent::CouchDB; |
|
|
476 | |
|
|
477 | ... |
|
|
478 | |
|
|
479 | my @info = $couchdb->info->recv; |
|
|
480 | |
|
|
481 | And this is how you would just ste a callback to be called whenever the |
|
|
482 | results are available: |
|
|
483 | |
|
|
484 | $couchdb->info->cb (sub { |
|
|
485 | my @info = $_[0]->recv; |
|
|
486 | }); |
|
|
487 | |
452 | =head3 METHODS FOR PRODUCERS |
488 | =head3 METHODS FOR PRODUCERS |
453 | |
489 | |
454 | These methods should only be used by the producing side, i.e. the |
490 | These methods should only be used by the producing side, i.e. the |
455 | code/module that eventually sends the signal. Note that it is also |
491 | code/module that eventually sends the signal. Note that it is also |
456 | the producer side which creates the condvar in most cases, but it isn't |
492 | the producer side which creates the condvar in most cases, but it isn't |
… | |
… | |
589 | =item $bool = $cv->ready |
625 | =item $bool = $cv->ready |
590 | |
626 | |
591 | Returns true when the condition is "true", i.e. whether C<send> or |
627 | Returns true when the condition is "true", i.e. whether C<send> or |
592 | C<croak> have been called. |
628 | C<croak> have been called. |
593 | |
629 | |
594 | =item $cb = $cv->cb ([new callback]) |
630 | =item $cb = $cv->cb ($cb->($cv)) |
595 | |
631 | |
596 | This is a mutator function that returns the callback set and optionally |
632 | This is a mutator function that returns the callback set and optionally |
597 | replaces it before doing so. |
633 | replaces it before doing so. |
598 | |
634 | |
599 | The callback will be called when the condition becomes "true", i.e. when |
635 | The callback will be called when the condition becomes "true", i.e. when |
… | |
… | |
821 | =cut |
857 | =cut |
822 | |
858 | |
823 | package AnyEvent; |
859 | package AnyEvent; |
824 | |
860 | |
825 | no warnings; |
861 | no warnings; |
826 | use strict; |
862 | use strict qw(vars subs); |
827 | |
863 | |
828 | use Carp; |
864 | use Carp; |
829 | |
865 | |
830 | our $VERSION = 4.2; |
866 | our $VERSION = 4.3; |
831 | our $MODEL; |
867 | our $MODEL; |
832 | |
868 | |
833 | our $AUTOLOAD; |
869 | our $AUTOLOAD; |
834 | our @ISA; |
870 | our @ISA; |
835 | |
871 | |
… | |
… | |
940 | } |
976 | } |
941 | } |
977 | } |
942 | |
978 | |
943 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
979 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
944 | |
980 | |
945 | if ($ENV{PERL_ANYEVENT_STRICT}) { |
|
|
946 | unshift @AnyEvent::Base::Strict::ISA, $MODEL; |
|
|
947 | unshift @ISA, AnyEvent::Base::Strict:: |
|
|
948 | } else { |
|
|
949 | unshift @ISA, $MODEL; |
981 | unshift @ISA, $MODEL; |
950 | } |
982 | |
|
|
983 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
951 | |
984 | |
952 | (shift @post_detect)->() while @post_detect; |
985 | (shift @post_detect)->() while @post_detect; |
953 | } |
986 | } |
954 | |
987 | |
955 | $MODEL |
988 | $MODEL |
… | |
… | |
965 | |
998 | |
966 | my $class = shift; |
999 | my $class = shift; |
967 | $class->$func (@_); |
1000 | $class->$func (@_); |
968 | } |
1001 | } |
969 | |
1002 | |
|
|
1003 | # utility function to dup a filehandle. this is used by many backends |
|
|
1004 | # 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). |
|
|
1006 | sub _dupfh($$$$) { |
|
|
1007 | my ($poll, $fh, $r, $w) = @_; |
|
|
1008 | |
|
|
1009 | require Fcntl; |
|
|
1010 | |
|
|
1011 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1012 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
|
|
1013 | : $poll eq "w" ? ($w, ">") |
|
|
1014 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
|
|
1015 | |
|
|
1016 | open my $fh2, "$mode&" . fileno $fh |
|
|
1017 | or die "cannot dup() filehandle: $!"; |
|
|
1018 | |
|
|
1019 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1020 | |
|
|
1021 | ($fh2, $rw) |
|
|
1022 | } |
|
|
1023 | |
970 | package AnyEvent::Base; |
1024 | package AnyEvent::Base; |
971 | |
1025 | |
972 | # default implementation for now and time |
1026 | # default implementation for now and time |
973 | |
1027 | |
974 | use Time::HiRes (); |
1028 | BEGIN { |
|
|
1029 | if (eval "use Time::HiRes (); time (); 1") { |
|
|
1030 | *_time = \&Time::HiRes::time; |
|
|
1031 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1032 | } else { |
|
|
1033 | *_time = sub { time }; # epic fail |
|
|
1034 | } |
|
|
1035 | } |
975 | |
1036 | |
976 | sub time { Time::HiRes::time } |
1037 | sub time { _time } |
977 | sub now { Time::HiRes::time } |
1038 | sub now { _time } |
978 | |
1039 | |
979 | # default implementation for ->condvar |
1040 | # default implementation for ->condvar |
980 | |
1041 | |
981 | sub condvar { |
1042 | sub condvar { |
982 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1043 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
… | |
… | |
1121 | |
1182 | |
1122 | # undocumented/compatibility with pre-3.4 |
1183 | # undocumented/compatibility with pre-3.4 |
1123 | *broadcast = \&send; |
1184 | *broadcast = \&send; |
1124 | *wait = \&_wait; |
1185 | *wait = \&_wait; |
1125 | |
1186 | |
1126 | package AnyEvent::Base::Strict; |
1187 | =head1 ERROR AND EXCEPTION HANDLING |
1127 | |
1188 | |
1128 | use Carp qw(croak); |
1189 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1190 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1191 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1192 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1193 | development. |
1129 | |
1194 | |
1130 | # supply checks for argument validity for many functions |
1195 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1196 | executing a callback), this is not only highly event-loop specific, but |
|
|
1197 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1198 | program. |
1131 | |
1199 | |
1132 | sub io { |
1200 | The pure perl event loop simply re-throws the exception (usually |
1133 | my $class = shift; |
1201 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
1134 | my %arg = @_; |
1202 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1203 | so on. |
1135 | |
1204 | |
1136 | ref $arg{cb} |
1205 | =head1 ENVIRONMENT VARIABLES |
1137 | or croak "AnyEvent->io called with illegal cb argument '$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 | |
1206 | |
1151 | $class->SUPER::io (@_) |
1207 | The following environment variables are used by this module or its |
1152 | } |
1208 | submodules: |
1153 | |
1209 | |
1154 | sub timer { |
1210 | =over 4 |
1155 | my $class = shift; |
|
|
1156 | my %arg = @_; |
|
|
1157 | |
1211 | |
1158 | ref $arg{cb} |
1212 | =item C<PERL_ANYEVENT_VERBOSE> |
1159 | or croak "AnyEvent->timer called with illegal cb argument '$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 | |
1213 | |
1173 | $class->SUPER::timer (@_) |
1214 | By default, AnyEvent will be completely silent except in fatal |
1174 | } |
1215 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1216 | talkative. |
1175 | |
1217 | |
1176 | sub signal { |
1218 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
1177 | my $class = shift; |
1219 | conditions, such as not being able to load the event model specified by |
1178 | my %arg = @_; |
1220 | C<PERL_ANYEVENT_MODEL>. |
1179 | |
1221 | |
1180 | ref $arg{cb} |
1222 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
1181 | or croak "AnyEvent->signal called with illegal cb argument '$arg{cb}'"; |
1223 | model it chooses. |
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 | |
1224 | |
1191 | $class->SUPER::signal (@_) |
1225 | =item C<PERL_ANYEVENT_STRICT> |
1192 | } |
|
|
1193 | |
1226 | |
1194 | sub child { |
1227 | AnyEvent does not do much argument checking by default, as thorough |
1195 | my $class = shift; |
1228 | argument checking is very costly. Setting this variable to a true value |
1196 | my %arg = @_; |
1229 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1230 | check the arguments passed to most method calls. If it finds any problems |
|
|
1231 | it will croak. |
1197 | |
1232 | |
1198 | ref $arg{cb} |
1233 | In other words, enables "strict" mode. |
1199 | or croak "AnyEvent->signal called with illegal cb argument '$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 | |
1234 | |
1209 | $class->SUPER::child (@_) |
1235 | Unlike C<use strict>, it is definitely recommended ot keep it off in |
1210 | } |
1236 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1237 | developing programs can be very useful, however. |
1211 | |
1238 | |
1212 | sub condvar { |
1239 | =item C<PERL_ANYEVENT_MODEL> |
1213 | my $class = shift; |
|
|
1214 | my %arg = @_; |
|
|
1215 | |
1240 | |
1216 | !exists $arg{cb} or ref $arg{cb} |
1241 | This can be used to specify the event model to be used by AnyEvent, before |
1217 | or croak "AnyEvent->condvar called with illegal cb argument '$arg{cb}'"; |
1242 | auto detection and -probing kicks in. It must be a string consisting |
1218 | delete $arg{cb}; |
1243 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
1219 | |
1244 | and the resulting module name is loaded and if the load was successful, |
1220 | croak "AnyEvent->condvar called with unsupported parameter(s) " . join ", ", keys %arg |
1245 | used as event model. If it fails to load AnyEvent will proceed with |
1221 | if keys %arg; |
1246 | auto detection and -probing. |
1222 | |
1247 | |
1223 | $class->SUPER::condvar (@_) |
1248 | This functionality might change in future versions. |
1224 | } |
|
|
1225 | |
1249 | |
1226 | sub time { |
1250 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
1227 | my $class = shift; |
1251 | could start your program like this: |
1228 | |
1252 | |
1229 | @_ |
1253 | PERL_ANYEVENT_MODEL=Perl perl ... |
1230 | and croak "AnyEvent->time wrongly called with paramaters"; |
|
|
1231 | |
1254 | |
1232 | $class->SUPER::time (@_) |
1255 | =item C<PERL_ANYEVENT_PROTOCOLS> |
1233 | } |
|
|
1234 | |
1256 | |
1235 | sub now { |
1257 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
1236 | my $class = shift; |
1258 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1259 | of auto probing). |
1237 | |
1260 | |
1238 | @_ |
1261 | Must be set to a comma-separated list of protocols or address families, |
1239 | and croak "AnyEvent->now wrongly called with paramaters"; |
1262 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1263 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1264 | list. |
1240 | |
1265 | |
1241 | $class->SUPER::now (@_) |
1266 | This variable can effectively be used for denial-of-service attacks |
1242 | } |
1267 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1268 | small, as the program has to handle connection errors already- |
|
|
1269 | |
|
|
1270 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1271 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1272 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1273 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1274 | IPv6, but prefer IPv6 over IPv4. |
|
|
1275 | |
|
|
1276 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1277 | |
|
|
1278 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1279 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1280 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1281 | default. |
|
|
1282 | |
|
|
1283 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1284 | EDNS0 in its DNS requests. |
|
|
1285 | |
|
|
1286 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1287 | |
|
|
1288 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1289 | will create in parallel. |
|
|
1290 | |
|
|
1291 | =back |
1243 | |
1292 | |
1244 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1293 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1245 | |
1294 | |
1246 | This is an advanced topic that you do not normally need to use AnyEvent in |
1295 | This is an advanced topic that you do not normally need to use AnyEvent in |
1247 | a module. This section is only of use to event loop authors who want to |
1296 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1281 | |
1330 | |
1282 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1331 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1283 | condition variables: code blocking while waiting for a condition will |
1332 | condition variables: code blocking while waiting for a condition will |
1284 | C<die>. This still works with most modules/usages, and blocking calls must |
1333 | C<die>. This still works with most modules/usages, and blocking calls must |
1285 | not be done in an interactive application, so it makes sense. |
1334 | not be done in an interactive application, so it makes sense. |
1286 | |
|
|
1287 | =head1 ENVIRONMENT VARIABLES |
|
|
1288 | |
|
|
1289 | The following environment variables are used by this module: |
|
|
1290 | |
|
|
1291 | =over 4 |
|
|
1292 | |
|
|
1293 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1294 | |
|
|
1295 | By default, AnyEvent will be completely silent except in fatal |
|
|
1296 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1297 | talkative. |
|
|
1298 | |
|
|
1299 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1300 | conditions, such as not being able to load the event model specified by |
|
|
1301 | C<PERL_ANYEVENT_MODEL>. |
|
|
1302 | |
|
|
1303 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1304 | model it chooses. |
|
|
1305 | |
|
|
1306 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1307 | |
|
|
1308 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1309 | argument checking is very costly. Setting this variable to a true value |
|
|
1310 | will cause AnyEvent to thoroughly check the arguments passed to most |
|
|
1311 | method calls and croaks if it finds any problems. In other words, enables |
|
|
1312 | "strict" mode. Unlike C<use strict> it is definitely recommended ot keep |
|
|
1313 | it off in production. |
|
|
1314 | |
|
|
1315 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1316 | |
|
|
1317 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1318 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1319 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1320 | and the resulting module name is loaded and if the load was successful, |
|
|
1321 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1322 | auto detection and -probing. |
|
|
1323 | |
|
|
1324 | This functionality might change in future versions. |
|
|
1325 | |
|
|
1326 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1327 | could start your program like this: |
|
|
1328 | |
|
|
1329 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1330 | |
|
|
1331 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1332 | |
|
|
1333 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1334 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1335 | of auto probing). |
|
|
1336 | |
|
|
1337 | Must be set to a comma-separated list of protocols or address families, |
|
|
1338 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1339 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1340 | list. |
|
|
1341 | |
|
|
1342 | This variable can effectively be used for denial-of-service attacks |
|
|
1343 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1344 | small, as the program has to handle connection errors already- |
|
|
1345 | |
|
|
1346 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1347 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1348 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1349 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1350 | IPv6, but prefer IPv6 over IPv4. |
|
|
1351 | |
|
|
1352 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1353 | |
|
|
1354 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1355 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1356 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1357 | default. |
|
|
1358 | |
|
|
1359 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1360 | EDNS0 in its DNS requests. |
|
|
1361 | |
|
|
1362 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1363 | |
|
|
1364 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1365 | will create in parallel. |
|
|
1366 | |
|
|
1367 | =back |
|
|
1368 | |
1335 | |
1369 | =head1 EXAMPLE PROGRAM |
1336 | =head1 EXAMPLE PROGRAM |
1370 | |
1337 | |
1371 | The following program uses an I/O watcher to read data from STDIN, a timer |
1338 | The following program uses an I/O watcher to read data from STDIN, a timer |
1372 | to display a message once per second, and a condition variable to quit the |
1339 | to display a message once per second, and a condition variable to quit the |