… | |
… | |
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 { $_[0]->recv }); |
22 | |
31 | |
23 | =head1 INTRODUCTION/TUTORIAL |
32 | =head1 INTRODUCTION/TUTORIAL |
24 | |
33 | |
25 | This manpage is mainly a reference manual. If you are interested |
34 | This manpage is mainly a reference manual. If you are interested |
26 | in a tutorial or some gentle introduction, have a look at the |
35 | in a tutorial or some gentle introduction, have a look at the |
… | |
… | |
128 | These watchers are normal Perl objects with normal Perl lifetime. After |
137 | These watchers are normal Perl objects with normal Perl lifetime. After |
129 | creating a watcher it will immediately "watch" for events and invoke the |
138 | creating a watcher it will immediately "watch" for events and invoke the |
130 | callback when the event occurs (of course, only when the event model |
139 | callback when the event occurs (of course, only when the event model |
131 | is in control). |
140 | is in control). |
132 | |
141 | |
|
|
142 | Note that B<callbacks must not permanently change global variables> |
|
|
143 | potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< |
|
|
144 | callbacks must not C<die> >>. The former is good programming practise in |
|
|
145 | Perl and the latter stems from the fact that exception handling differs |
|
|
146 | widely between event loops. |
|
|
147 | |
133 | To disable the watcher you have to destroy it (e.g. by setting the |
148 | To disable the watcher you have to destroy it (e.g. by setting the |
134 | variable you store it in to C<undef> or otherwise deleting all references |
149 | variable you store it in to C<undef> or otherwise deleting all references |
135 | to it). |
150 | to it). |
136 | |
151 | |
137 | All watchers are created by calling a method on the C<AnyEvent> class. |
152 | All watchers are created by calling a method on the C<AnyEvent> class. |
… | |
… | |
331 | =head2 CHILD PROCESS WATCHERS |
346 | =head2 CHILD PROCESS WATCHERS |
332 | |
347 | |
333 | You can also watch on a child process exit and catch its exit status. |
348 | You can also watch on a child process exit and catch its exit status. |
334 | |
349 | |
335 | The child process is specified by the C<pid> argument (if set to C<0>, it |
350 | The child process is specified by the C<pid> argument (if set to C<0>, it |
336 | watches for any child process exit). The watcher will trigger as often |
351 | watches for any child process exit). The watcher will triggered only when |
337 | as status change for the child are received. This works by installing a |
352 | the child process has finished and an exit status is available, not on |
338 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
353 | any trace events (stopped/continued). |
339 | and exit status (as returned by waitpid), so unlike other watcher types, |
354 | |
340 | you I<can> rely on child watcher callback arguments. |
355 | The callback will be called with the pid and exit status (as returned by |
|
|
356 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
|
357 | callback arguments. |
|
|
358 | |
|
|
359 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
|
|
360 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
|
|
361 | random child processes (waiting for specific child processes, e.g. inside |
|
|
362 | C<system>, is just fine). |
341 | |
363 | |
342 | There is a slight catch to child watchers, however: you usually start them |
364 | There is a slight catch to child watchers, however: you usually start them |
343 | I<after> the child process was created, and this means the process could |
365 | I<after> the child process was created, and this means the process could |
344 | have exited already (and no SIGCHLD will be sent anymore). |
366 | have exited already (and no SIGCHLD will be sent anymore). |
345 | |
367 | |
… | |
… | |
381 | The instrument to do that is called a "condition variable", so called |
403 | The instrument to do that is called a "condition variable", so called |
382 | because they represent a condition that must become true. |
404 | because they represent a condition that must become true. |
383 | |
405 | |
384 | Condition variables can be created by calling the C<< AnyEvent->condvar |
406 | Condition variables can be created by calling the C<< AnyEvent->condvar |
385 | >> method, usually without arguments. The only argument pair allowed is |
407 | >> method, usually without arguments. The only argument pair allowed is |
|
|
408 | |
386 | C<cb>, which specifies a callback to be called when the condition variable |
409 | C<cb>, which specifies a callback to be called when the condition variable |
387 | becomes true. |
410 | becomes true, with the condition variable as the first argument (but not |
|
|
411 | the results). |
388 | |
412 | |
389 | After creation, the condition variable is "false" until it becomes "true" |
413 | After creation, the condition variable is "false" until it becomes "true" |
390 | by calling the C<send> method (or calling the condition variable as if it |
414 | by calling the C<send> method (or calling the condition variable as if it |
391 | were a callback, read about the caveats in the description for the C<< |
415 | were a callback, read about the caveats in the description for the C<< |
392 | ->send >> method). |
416 | ->send >> method). |
… | |
… | |
448 | |
472 | |
449 | my $done = AnyEvent->condvar; |
473 | my $done = AnyEvent->condvar; |
450 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
474 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
451 | $done->recv; |
475 | $done->recv; |
452 | |
476 | |
|
|
477 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
478 | callbacks. This is how you make a synchronous call, for example from |
|
|
479 | the main program: |
|
|
480 | |
|
|
481 | use AnyEvent::CouchDB; |
|
|
482 | |
|
|
483 | ... |
|
|
484 | |
|
|
485 | my @info = $couchdb->info->recv; |
|
|
486 | |
|
|
487 | And this is how you would just ste a callback to be called whenever the |
|
|
488 | results are available: |
|
|
489 | |
|
|
490 | $couchdb->info->cb (sub { |
|
|
491 | my @info = $_[0]->recv; |
|
|
492 | }); |
|
|
493 | |
453 | =head3 METHODS FOR PRODUCERS |
494 | =head3 METHODS FOR PRODUCERS |
454 | |
495 | |
455 | These methods should only be used by the producing side, i.e. the |
496 | These methods should only be used by the producing side, i.e. the |
456 | code/module that eventually sends the signal. Note that it is also |
497 | code/module that eventually sends the signal. Note that it is also |
457 | the producer side which creates the condvar in most cases, but it isn't |
498 | the producer side which creates the condvar in most cases, but it isn't |
… | |
… | |
590 | =item $bool = $cv->ready |
631 | =item $bool = $cv->ready |
591 | |
632 | |
592 | Returns true when the condition is "true", i.e. whether C<send> or |
633 | Returns true when the condition is "true", i.e. whether C<send> or |
593 | C<croak> have been called. |
634 | C<croak> have been called. |
594 | |
635 | |
595 | =item $cb = $cv->cb ([new callback]) |
636 | =item $cb = $cv->cb ($cb->($cv)) |
596 | |
637 | |
597 | This is a mutator function that returns the callback set and optionally |
638 | This is a mutator function that returns the callback set and optionally |
598 | replaces it before doing so. |
639 | replaces it before doing so. |
599 | |
640 | |
600 | The callback will be called when the condition becomes "true", i.e. when |
641 | The callback will be called when the condition becomes "true", i.e. when |
… | |
… | |
790 | =item L<AnyEvent::IGS> |
831 | =item L<AnyEvent::IGS> |
791 | |
832 | |
792 | A non-blocking interface to the Internet Go Server protocol (used by |
833 | A non-blocking interface to the Internet Go Server protocol (used by |
793 | L<App::IGS>). |
834 | L<App::IGS>). |
794 | |
835 | |
795 | =item L<Net::IRC3> |
836 | =item L<AnyEvent::IRC> |
796 | |
837 | |
797 | AnyEvent based IRC client module family. |
838 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
798 | |
839 | |
799 | =item L<Net::XMPP2> |
840 | =item L<Net::XMPP2> |
800 | |
841 | |
801 | AnyEvent based XMPP (Jabber protocol) module family. |
842 | AnyEvent based XMPP (Jabber protocol) module family. |
802 | |
843 | |
… | |
… | |
822 | =cut |
863 | =cut |
823 | |
864 | |
824 | package AnyEvent; |
865 | package AnyEvent; |
825 | |
866 | |
826 | no warnings; |
867 | no warnings; |
827 | use strict; |
868 | use strict qw(vars subs); |
828 | |
869 | |
829 | use Carp; |
870 | use Carp; |
830 | |
871 | |
831 | our $VERSION = 4.2; |
872 | our $VERSION = 4.341; |
832 | our $MODEL; |
873 | our $MODEL; |
833 | |
874 | |
834 | our $AUTOLOAD; |
875 | our $AUTOLOAD; |
835 | our @ISA; |
876 | our @ISA; |
836 | |
877 | |
… | |
… | |
969 | # to support binding more than one watcher per filehandle (they usually |
1010 | # to support binding more than one watcher per filehandle (they usually |
970 | # allow only one watcher per fd, so we dup it to get a different one). |
1011 | # allow only one watcher per fd, so we dup it to get a different one). |
971 | sub _dupfh($$$$) { |
1012 | sub _dupfh($$$$) { |
972 | my ($poll, $fh, $r, $w) = @_; |
1013 | my ($poll, $fh, $r, $w) = @_; |
973 | |
1014 | |
974 | require Fcntl; |
|
|
975 | |
|
|
976 | # cygwin requires the fh mode to be matching, unix doesn't |
1015 | # cygwin requires the fh mode to be matching, unix doesn't |
977 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1016 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
978 | : $poll eq "w" ? ($w, ">") |
1017 | : $poll eq "w" ? ($w, ">") |
979 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
1018 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
980 | |
1019 | |
… | |
… | |
988 | |
1027 | |
989 | package AnyEvent::Base; |
1028 | package AnyEvent::Base; |
990 | |
1029 | |
991 | # default implementation for now and time |
1030 | # default implementation for now and time |
992 | |
1031 | |
993 | use Time::HiRes (); |
1032 | BEGIN { |
|
|
1033 | if (eval "use Time::HiRes (); time (); 1") { |
|
|
1034 | *_time = \&Time::HiRes::time; |
|
|
1035 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1036 | } else { |
|
|
1037 | *_time = sub { time }; # epic fail |
|
|
1038 | } |
|
|
1039 | } |
994 | |
1040 | |
995 | sub time { Time::HiRes::time } |
1041 | sub time { _time } |
996 | sub now { Time::HiRes::time } |
1042 | sub now { _time } |
997 | |
1043 | |
998 | # default implementation for ->condvar |
1044 | # default implementation for ->condvar |
999 | |
1045 | |
1000 | sub condvar { |
1046 | sub condvar { |
1001 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1047 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1002 | } |
1048 | } |
1003 | |
1049 | |
1004 | # default implementation for ->signal |
1050 | # default implementation for ->signal |
1005 | |
1051 | |
1006 | our %SIG_CB; |
1052 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1053 | |
|
|
1054 | sub _signal_exec { |
|
|
1055 | while (%SIG_EV) { |
|
|
1056 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1057 | for (keys %SIG_EV) { |
|
|
1058 | delete $SIG_EV{$_}; |
|
|
1059 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1060 | } |
|
|
1061 | } |
|
|
1062 | } |
1007 | |
1063 | |
1008 | sub signal { |
1064 | sub signal { |
1009 | my (undef, %arg) = @_; |
1065 | my (undef, %arg) = @_; |
1010 | |
1066 | |
|
|
1067 | unless ($SIGPIPE_R) { |
|
|
1068 | if (AnyEvent::WIN32) { |
|
|
1069 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1070 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1071 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1072 | } else { |
|
|
1073 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1074 | require Fcntl; |
|
|
1075 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1076 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1077 | } |
|
|
1078 | |
|
|
1079 | $SIGPIPE_R |
|
|
1080 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1081 | |
|
|
1082 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1083 | } |
|
|
1084 | |
1011 | my $signal = uc $arg{signal} |
1085 | my $signal = uc $arg{signal} |
1012 | or Carp::croak "required option 'signal' is missing"; |
1086 | or Carp::croak "required option 'signal' is missing"; |
1013 | |
1087 | |
1014 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1088 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1015 | $SIG{$signal} ||= sub { |
1089 | $SIG{$signal} ||= sub { |
1016 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1090 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1091 | undef $SIG_EV{$signal}; |
1017 | }; |
1092 | }; |
1018 | |
1093 | |
1019 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1094 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1020 | } |
1095 | } |
1021 | |
1096 | |
… | |
… | |
1140 | |
1215 | |
1141 | # undocumented/compatibility with pre-3.4 |
1216 | # undocumented/compatibility with pre-3.4 |
1142 | *broadcast = \&send; |
1217 | *broadcast = \&send; |
1143 | *wait = \&_wait; |
1218 | *wait = \&_wait; |
1144 | |
1219 | |
|
|
1220 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1221 | |
|
|
1222 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1223 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1224 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1225 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1226 | development. |
|
|
1227 | |
|
|
1228 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1229 | executing a callback), this is not only highly event-loop specific, but |
|
|
1230 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1231 | program. |
|
|
1232 | |
|
|
1233 | The pure perl event loop simply re-throws the exception (usually |
|
|
1234 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1235 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1236 | so on. |
|
|
1237 | |
|
|
1238 | =head1 ENVIRONMENT VARIABLES |
|
|
1239 | |
|
|
1240 | The following environment variables are used by this module or its |
|
|
1241 | submodules: |
|
|
1242 | |
|
|
1243 | =over 4 |
|
|
1244 | |
|
|
1245 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1246 | |
|
|
1247 | By default, AnyEvent will be completely silent except in fatal |
|
|
1248 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1249 | talkative. |
|
|
1250 | |
|
|
1251 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1252 | conditions, such as not being able to load the event model specified by |
|
|
1253 | C<PERL_ANYEVENT_MODEL>. |
|
|
1254 | |
|
|
1255 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1256 | model it chooses. |
|
|
1257 | |
|
|
1258 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1259 | |
|
|
1260 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1261 | argument checking is very costly. Setting this variable to a true value |
|
|
1262 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1263 | check the arguments passed to most method calls. If it finds any problems |
|
|
1264 | it will croak. |
|
|
1265 | |
|
|
1266 | In other words, enables "strict" mode. |
|
|
1267 | |
|
|
1268 | Unlike C<use strict>, it is definitely recommended ot keep it off in |
|
|
1269 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1270 | developing programs can be very useful, however. |
|
|
1271 | |
|
|
1272 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1273 | |
|
|
1274 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1275 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1276 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1277 | and the resulting module name is loaded and if the load was successful, |
|
|
1278 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1279 | auto detection and -probing. |
|
|
1280 | |
|
|
1281 | This functionality might change in future versions. |
|
|
1282 | |
|
|
1283 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1284 | could start your program like this: |
|
|
1285 | |
|
|
1286 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1287 | |
|
|
1288 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1289 | |
|
|
1290 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1291 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1292 | of auto probing). |
|
|
1293 | |
|
|
1294 | Must be set to a comma-separated list of protocols or address families, |
|
|
1295 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1296 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1297 | list. |
|
|
1298 | |
|
|
1299 | This variable can effectively be used for denial-of-service attacks |
|
|
1300 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1301 | small, as the program has to handle conenction and other failures anyways. |
|
|
1302 | |
|
|
1303 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1304 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1305 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1306 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1307 | IPv6, but prefer IPv6 over IPv4. |
|
|
1308 | |
|
|
1309 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1310 | |
|
|
1311 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1312 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1313 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1314 | default. |
|
|
1315 | |
|
|
1316 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1317 | EDNS0 in its DNS requests. |
|
|
1318 | |
|
|
1319 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1320 | |
|
|
1321 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1322 | will create in parallel. |
|
|
1323 | |
|
|
1324 | =back |
|
|
1325 | |
1145 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1326 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1146 | |
1327 | |
1147 | This is an advanced topic that you do not normally need to use AnyEvent in |
1328 | This is an advanced topic that you do not normally need to use AnyEvent in |
1148 | a module. This section is only of use to event loop authors who want to |
1329 | a module. This section is only of use to event loop authors who want to |
1149 | provide AnyEvent compatibility. |
1330 | provide AnyEvent compatibility. |
… | |
… | |
1182 | |
1363 | |
1183 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1364 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1184 | condition variables: code blocking while waiting for a condition will |
1365 | condition variables: code blocking while waiting for a condition will |
1185 | C<die>. This still works with most modules/usages, and blocking calls must |
1366 | C<die>. This still works with most modules/usages, and blocking calls must |
1186 | not be done in an interactive application, so it makes sense. |
1367 | not be done in an interactive application, so it makes sense. |
1187 | |
|
|
1188 | =head1 ENVIRONMENT VARIABLES |
|
|
1189 | |
|
|
1190 | The following environment variables are used by this module: |
|
|
1191 | |
|
|
1192 | =over 4 |
|
|
1193 | |
|
|
1194 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1195 | |
|
|
1196 | By default, AnyEvent will be completely silent except in fatal |
|
|
1197 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1198 | talkative. |
|
|
1199 | |
|
|
1200 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1201 | conditions, such as not being able to load the event model specified by |
|
|
1202 | C<PERL_ANYEVENT_MODEL>. |
|
|
1203 | |
|
|
1204 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1205 | model it chooses. |
|
|
1206 | |
|
|
1207 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1208 | |
|
|
1209 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1210 | argument checking is very costly. Setting this variable to a true value |
|
|
1211 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1212 | check the arguments passed to most method calls. If it finds any problems |
|
|
1213 | it will croak. |
|
|
1214 | |
|
|
1215 | In other words, enables "strict" mode. |
|
|
1216 | |
|
|
1217 | Unlike C<use strict> it is definitely recommended ot keep it off in |
|
|
1218 | production. |
|
|
1219 | |
|
|
1220 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1221 | |
|
|
1222 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1223 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1224 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1225 | and the resulting module name is loaded and if the load was successful, |
|
|
1226 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1227 | auto detection and -probing. |
|
|
1228 | |
|
|
1229 | This functionality might change in future versions. |
|
|
1230 | |
|
|
1231 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1232 | could start your program like this: |
|
|
1233 | |
|
|
1234 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1235 | |
|
|
1236 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1237 | |
|
|
1238 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1239 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1240 | of auto probing). |
|
|
1241 | |
|
|
1242 | Must be set to a comma-separated list of protocols or address families, |
|
|
1243 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1244 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1245 | list. |
|
|
1246 | |
|
|
1247 | This variable can effectively be used for denial-of-service attacks |
|
|
1248 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1249 | small, as the program has to handle connection errors already- |
|
|
1250 | |
|
|
1251 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1252 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1253 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1254 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1255 | IPv6, but prefer IPv6 over IPv4. |
|
|
1256 | |
|
|
1257 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1258 | |
|
|
1259 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1260 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1261 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1262 | default. |
|
|
1263 | |
|
|
1264 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1265 | EDNS0 in its DNS requests. |
|
|
1266 | |
|
|
1267 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1268 | |
|
|
1269 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1270 | will create in parallel. |
|
|
1271 | |
|
|
1272 | =back |
|
|
1273 | |
1368 | |
1274 | =head1 EXAMPLE PROGRAM |
1369 | =head1 EXAMPLE PROGRAM |
1275 | |
1370 | |
1276 | The following program uses an I/O watcher to read data from STDIN, a timer |
1371 | The following program uses an I/O watcher to read data from STDIN, a timer |
1277 | to display a message once per second, and a condition variable to quit the |
1372 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1471 | watcher. |
1566 | watcher. |
1472 | |
1567 | |
1473 | =head3 Results |
1568 | =head3 Results |
1474 | |
1569 | |
1475 | name watchers bytes create invoke destroy comment |
1570 | name watchers bytes create invoke destroy comment |
1476 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1571 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1477 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1572 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1478 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1573 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1479 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1574 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1480 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1575 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1481 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1576 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
1482 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1577 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1483 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1578 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1484 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1579 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1485 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1580 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1486 | |
1581 | |
1487 | =head3 Discussion |
1582 | =head3 Discussion |
1488 | |
1583 | |
1489 | The benchmark does I<not> measure scalability of the event loop very |
1584 | The benchmark does I<not> measure scalability of the event loop very |
1490 | well. For example, a select-based event loop (such as the pure perl one) |
1585 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1692 | watchers, as the management overhead dominates. |
1787 | watchers, as the management overhead dominates. |
1693 | |
1788 | |
1694 | =back |
1789 | =back |
1695 | |
1790 | |
1696 | |
1791 | |
|
|
1792 | =head1 SIGNALS |
|
|
1793 | |
|
|
1794 | AnyEvent currently installs handlers for these signals: |
|
|
1795 | |
|
|
1796 | =over 4 |
|
|
1797 | |
|
|
1798 | =item SIGCHLD |
|
|
1799 | |
|
|
1800 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
1801 | emulation for event loops that do not support them natively. Also, some |
|
|
1802 | event loops install a similar handler. |
|
|
1803 | |
|
|
1804 | =item SIGPIPE |
|
|
1805 | |
|
|
1806 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
1807 | when AnyEvent gets loaded. |
|
|
1808 | |
|
|
1809 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
1810 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
1811 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
1812 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
1813 | some random socket. |
|
|
1814 | |
|
|
1815 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
1816 | that this way, the handler will be restored to defaults on exec. |
|
|
1817 | |
|
|
1818 | Feel free to install your own handler, or reset it to defaults. |
|
|
1819 | |
|
|
1820 | =back |
|
|
1821 | |
|
|
1822 | =cut |
|
|
1823 | |
|
|
1824 | $SIG{PIPE} = sub { } |
|
|
1825 | unless defined $SIG{PIPE}; |
|
|
1826 | |
|
|
1827 | |
1697 | =head1 FORK |
1828 | =head1 FORK |
1698 | |
1829 | |
1699 | Most event libraries are not fork-safe. The ones who are usually are |
1830 | Most event libraries are not fork-safe. The ones who are usually are |
1700 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1831 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1701 | calls. Only L<EV> is fully fork-aware. |
1832 | calls. Only L<EV> is fully fork-aware. |
… | |
… | |
1729 | =head1 BUGS |
1860 | =head1 BUGS |
1730 | |
1861 | |
1731 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
1862 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
1732 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
1863 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
1733 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
1864 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
1734 | mamleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1865 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1735 | pronounced). |
1866 | pronounced). |
1736 | |
1867 | |
1737 | |
1868 | |
1738 | =head1 SEE ALSO |
1869 | =head1 SEE ALSO |
1739 | |
1870 | |