… | |
… | |
137 | These watchers are normal Perl objects with normal Perl lifetime. After |
137 | These watchers are normal Perl objects with normal Perl lifetime. After |
138 | 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 |
139 | 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 |
140 | is in control). |
140 | is in control). |
141 | |
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 | |
142 | 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 |
143 | 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 |
144 | to it). |
150 | to it). |
145 | |
151 | |
146 | 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. |
… | |
… | |
162 | =head2 I/O WATCHERS |
168 | =head2 I/O WATCHERS |
163 | |
169 | |
164 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
170 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
165 | with the following mandatory key-value pairs as arguments: |
171 | with the following mandatory key-value pairs as arguments: |
166 | |
172 | |
167 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events |
173 | C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch |
168 | (AnyEvent might or might not keep a reference to this file handle). C<poll> |
174 | for events (AnyEvent might or might not keep a reference to this file |
|
|
175 | handle). Note that only file handles pointing to things for which |
|
|
176 | non-blocking operation makes sense are allowed. This includes sockets, |
|
|
177 | most character devices, pipes, fifos and so on, but not for example files |
|
|
178 | or block devices. |
|
|
179 | |
169 | must be a string that is either C<r> or C<w>, which creates a watcher |
180 | C<poll> must be a string that is either C<r> or C<w>, which creates a |
170 | waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the |
181 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
|
|
182 | |
171 | callback to invoke each time the file handle becomes ready. |
183 | C<cb> is the callback to invoke each time the file handle becomes ready. |
172 | |
184 | |
173 | Although the callback might get passed parameters, their value and |
185 | Although the callback might get passed parameters, their value and |
174 | presence is undefined and you cannot rely on them. Portable AnyEvent |
186 | presence is undefined and you cannot rely on them. Portable AnyEvent |
175 | callbacks cannot use arguments passed to I/O watcher callbacks. |
187 | callbacks cannot use arguments passed to I/O watcher callbacks. |
176 | |
188 | |
… | |
… | |
308 | In either case, if you care (and in most cases, you don't), then you |
320 | In either case, if you care (and in most cases, you don't), then you |
309 | can get whatever behaviour you want with any event loop, by taking the |
321 | can get whatever behaviour you want with any event loop, by taking the |
310 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
322 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
311 | account. |
323 | account. |
312 | |
324 | |
|
|
325 | =item AnyEvent->now_update |
|
|
326 | |
|
|
327 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
|
|
328 | the current time for each loop iteration (see the discussion of L<< |
|
|
329 | AnyEvent->now >>, above). |
|
|
330 | |
|
|
331 | When a callback runs for a long time (or when the process sleeps), then |
|
|
332 | this "current" time will differ substantially from the real time, which |
|
|
333 | might affect timers and time-outs. |
|
|
334 | |
|
|
335 | When this is the case, you can call this method, which will update the |
|
|
336 | event loop's idea of "current time". |
|
|
337 | |
|
|
338 | Note that updating the time I<might> cause some events to be handled. |
|
|
339 | |
313 | =back |
340 | =back |
314 | |
341 | |
315 | =head2 SIGNAL WATCHERS |
342 | =head2 SIGNAL WATCHERS |
316 | |
343 | |
317 | You can watch for signals using a signal watcher, C<signal> is the signal |
344 | You can watch for signals using a signal watcher, C<signal> is the signal |
… | |
… | |
340 | =head2 CHILD PROCESS WATCHERS |
367 | =head2 CHILD PROCESS WATCHERS |
341 | |
368 | |
342 | You can also watch on a child process exit and catch its exit status. |
369 | You can also watch on a child process exit and catch its exit status. |
343 | |
370 | |
344 | The child process is specified by the C<pid> argument (if set to C<0>, it |
371 | The child process is specified by the C<pid> argument (if set to C<0>, it |
345 | watches for any child process exit). The watcher will trigger as often |
372 | watches for any child process exit). The watcher will triggered only when |
346 | as status change for the child are received. This works by installing a |
373 | the child process has finished and an exit status is available, not on |
347 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
374 | any trace events (stopped/continued). |
348 | and exit status (as returned by waitpid), so unlike other watcher types, |
375 | |
349 | you I<can> rely on child watcher callback arguments. |
376 | The callback will be called with the pid and exit status (as returned by |
|
|
377 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
|
378 | callback arguments. |
|
|
379 | |
|
|
380 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
|
|
381 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
|
|
382 | random child processes (waiting for specific child processes, e.g. inside |
|
|
383 | C<system>, is just fine). |
350 | |
384 | |
351 | There is a slight catch to child watchers, however: you usually start them |
385 | There is a slight catch to child watchers, however: you usually start them |
352 | I<after> the child process was created, and this means the process could |
386 | I<after> the child process was created, and this means the process could |
353 | have exited already (and no SIGCHLD will be sent anymore). |
387 | have exited already (and no SIGCHLD will be sent anymore). |
354 | |
388 | |
… | |
… | |
818 | =item L<AnyEvent::IGS> |
852 | =item L<AnyEvent::IGS> |
819 | |
853 | |
820 | A non-blocking interface to the Internet Go Server protocol (used by |
854 | A non-blocking interface to the Internet Go Server protocol (used by |
821 | L<App::IGS>). |
855 | L<App::IGS>). |
822 | |
856 | |
823 | =item L<Net::IRC3> |
857 | =item L<AnyEvent::IRC> |
824 | |
858 | |
825 | AnyEvent based IRC client module family. |
859 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
826 | |
860 | |
827 | =item L<Net::XMPP2> |
861 | =item L<Net::XMPP2> |
828 | |
862 | |
829 | AnyEvent based XMPP (Jabber protocol) module family. |
863 | AnyEvent based XMPP (Jabber protocol) module family. |
830 | |
864 | |
… | |
… | |
850 | =cut |
884 | =cut |
851 | |
885 | |
852 | package AnyEvent; |
886 | package AnyEvent; |
853 | |
887 | |
854 | no warnings; |
888 | no warnings; |
855 | use strict; |
889 | use strict qw(vars subs); |
856 | |
890 | |
857 | use Carp; |
891 | use Carp; |
858 | |
892 | |
859 | our $VERSION = 4.231; |
893 | our $VERSION = 4.352; |
860 | our $MODEL; |
894 | our $MODEL; |
861 | |
895 | |
862 | our $AUTOLOAD; |
896 | our $AUTOLOAD; |
863 | our @ISA; |
897 | our @ISA; |
864 | |
898 | |
… | |
… | |
896 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
930 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
897 | [Wx:: => AnyEvent::Impl::POE::], |
931 | [Wx:: => AnyEvent::Impl::POE::], |
898 | [Prima:: => AnyEvent::Impl::POE::], |
932 | [Prima:: => AnyEvent::Impl::POE::], |
899 | ); |
933 | ); |
900 | |
934 | |
901 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
935 | our %method = map +($_ => 1), |
|
|
936 | qw(io timer time now now_update signal child condvar one_event DESTROY); |
902 | |
937 | |
903 | our @post_detect; |
938 | our @post_detect; |
904 | |
939 | |
905 | sub post_detect(&) { |
940 | sub post_detect(&) { |
906 | my ($cb) = @_; |
941 | my ($cb) = @_; |
… | |
… | |
963 | last; |
998 | last; |
964 | } |
999 | } |
965 | } |
1000 | } |
966 | |
1001 | |
967 | $MODEL |
1002 | $MODEL |
968 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1003 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
969 | } |
1004 | } |
970 | } |
1005 | } |
971 | |
1006 | |
972 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1007 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
973 | |
1008 | |
… | |
… | |
997 | # to support binding more than one watcher per filehandle (they usually |
1032 | # to support binding more than one watcher per filehandle (they usually |
998 | # allow only one watcher per fd, so we dup it to get a different one). |
1033 | # allow only one watcher per fd, so we dup it to get a different one). |
999 | sub _dupfh($$$$) { |
1034 | sub _dupfh($$$$) { |
1000 | my ($poll, $fh, $r, $w) = @_; |
1035 | my ($poll, $fh, $r, $w) = @_; |
1001 | |
1036 | |
1002 | require Fcntl; |
|
|
1003 | |
|
|
1004 | # cygwin requires the fh mode to be matching, unix doesn't |
1037 | # cygwin requires the fh mode to be matching, unix doesn't |
1005 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1038 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1006 | : $poll eq "w" ? ($w, ">") |
1039 | : $poll eq "w" ? ($w, ">") |
1007 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
1040 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
1008 | |
1041 | |
1009 | open my $fh2, "$mode&" . fileno $fh |
1042 | open my $fh2, "$mode&" . fileno $fh |
1010 | or die "cannot dup() filehandle: $!"; |
1043 | or die "cannot dup() filehandle: $!,"; |
1011 | |
1044 | |
1012 | # we assume CLOEXEC is already set by perl in all important cases |
1045 | # we assume CLOEXEC is already set by perl in all important cases |
1013 | |
1046 | |
1014 | ($fh2, $rw) |
1047 | ($fh2, $rw) |
1015 | } |
1048 | } |
1016 | |
1049 | |
1017 | package AnyEvent::Base; |
1050 | package AnyEvent::Base; |
1018 | |
1051 | |
1019 | # default implementation for now and time |
1052 | # default implementations for many methods |
1020 | |
1053 | |
1021 | use Time::HiRes (); |
1054 | BEGIN { |
|
|
1055 | if (eval "use Time::HiRes (); time (); 1") { |
|
|
1056 | *_time = \&Time::HiRes::time; |
|
|
1057 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1058 | } else { |
|
|
1059 | *_time = sub { time }; # epic fail |
|
|
1060 | } |
|
|
1061 | } |
1022 | |
1062 | |
1023 | sub time { Time::HiRes::time } |
1063 | sub time { _time } |
1024 | sub now { Time::HiRes::time } |
1064 | sub now { _time } |
|
|
1065 | sub now_update { } |
1025 | |
1066 | |
1026 | # default implementation for ->condvar |
1067 | # default implementation for ->condvar |
1027 | |
1068 | |
1028 | sub condvar { |
1069 | sub condvar { |
1029 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1070 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1030 | } |
1071 | } |
1031 | |
1072 | |
1032 | # default implementation for ->signal |
1073 | # default implementation for ->signal |
1033 | |
1074 | |
1034 | our %SIG_CB; |
1075 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1076 | |
|
|
1077 | sub _signal_exec { |
|
|
1078 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1079 | |
|
|
1080 | while (%SIG_EV) { |
|
|
1081 | for (keys %SIG_EV) { |
|
|
1082 | delete $SIG_EV{$_}; |
|
|
1083 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1084 | } |
|
|
1085 | } |
|
|
1086 | } |
1035 | |
1087 | |
1036 | sub signal { |
1088 | sub signal { |
1037 | my (undef, %arg) = @_; |
1089 | my (undef, %arg) = @_; |
1038 | |
1090 | |
|
|
1091 | unless ($SIGPIPE_R) { |
|
|
1092 | require Fcntl; |
|
|
1093 | |
|
|
1094 | if (AnyEvent::WIN32) { |
|
|
1095 | require AnyEvent::Util; |
|
|
1096 | |
|
|
1097 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1098 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1099 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1100 | } else { |
|
|
1101 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1102 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1103 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1104 | } |
|
|
1105 | |
|
|
1106 | $SIGPIPE_R |
|
|
1107 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1108 | |
|
|
1109 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1110 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1111 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1112 | |
|
|
1113 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1114 | } |
|
|
1115 | |
1039 | my $signal = uc $arg{signal} |
1116 | my $signal = uc $arg{signal} |
1040 | or Carp::croak "required option 'signal' is missing"; |
1117 | or Carp::croak "required option 'signal' is missing"; |
1041 | |
1118 | |
1042 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1119 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1043 | $SIG{$signal} ||= sub { |
1120 | $SIG{$signal} ||= sub { |
1044 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1121 | local $!; |
|
|
1122 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1123 | undef $SIG_EV{$signal}; |
1045 | }; |
1124 | }; |
1046 | |
1125 | |
1047 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1126 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1048 | } |
1127 | } |
1049 | |
1128 | |
… | |
… | |
1168 | |
1247 | |
1169 | # undocumented/compatibility with pre-3.4 |
1248 | # undocumented/compatibility with pre-3.4 |
1170 | *broadcast = \&send; |
1249 | *broadcast = \&send; |
1171 | *wait = \&_wait; |
1250 | *wait = \&_wait; |
1172 | |
1251 | |
|
|
1252 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1253 | |
|
|
1254 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1255 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1256 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1257 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1258 | development. |
|
|
1259 | |
|
|
1260 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1261 | executing a callback), this is not only highly event-loop specific, but |
|
|
1262 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1263 | program. |
|
|
1264 | |
|
|
1265 | The pure perl event loop simply re-throws the exception (usually |
|
|
1266 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1267 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1268 | so on. |
|
|
1269 | |
|
|
1270 | =head1 ENVIRONMENT VARIABLES |
|
|
1271 | |
|
|
1272 | The following environment variables are used by this module or its |
|
|
1273 | submodules: |
|
|
1274 | |
|
|
1275 | =over 4 |
|
|
1276 | |
|
|
1277 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1278 | |
|
|
1279 | By default, AnyEvent will be completely silent except in fatal |
|
|
1280 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1281 | talkative. |
|
|
1282 | |
|
|
1283 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1284 | conditions, such as not being able to load the event model specified by |
|
|
1285 | C<PERL_ANYEVENT_MODEL>. |
|
|
1286 | |
|
|
1287 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1288 | model it chooses. |
|
|
1289 | |
|
|
1290 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1291 | |
|
|
1292 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1293 | argument checking is very costly. Setting this variable to a true value |
|
|
1294 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1295 | check the arguments passed to most method calls. If it finds any problems |
|
|
1296 | it will croak. |
|
|
1297 | |
|
|
1298 | In other words, enables "strict" mode. |
|
|
1299 | |
|
|
1300 | Unlike C<use strict>, it is definitely recommended ot keep it off in |
|
|
1301 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1302 | developing programs can be very useful, however. |
|
|
1303 | |
|
|
1304 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1305 | |
|
|
1306 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1307 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1308 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1309 | and the resulting module name is loaded and if the load was successful, |
|
|
1310 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1311 | auto detection and -probing. |
|
|
1312 | |
|
|
1313 | This functionality might change in future versions. |
|
|
1314 | |
|
|
1315 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1316 | could start your program like this: |
|
|
1317 | |
|
|
1318 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1319 | |
|
|
1320 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1321 | |
|
|
1322 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1323 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1324 | of auto probing). |
|
|
1325 | |
|
|
1326 | Must be set to a comma-separated list of protocols or address families, |
|
|
1327 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1328 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1329 | list. |
|
|
1330 | |
|
|
1331 | This variable can effectively be used for denial-of-service attacks |
|
|
1332 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1333 | small, as the program has to handle conenction and other failures anyways. |
|
|
1334 | |
|
|
1335 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1336 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1337 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1338 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1339 | IPv6, but prefer IPv6 over IPv4. |
|
|
1340 | |
|
|
1341 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1342 | |
|
|
1343 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1344 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1345 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1346 | default. |
|
|
1347 | |
|
|
1348 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1349 | EDNS0 in its DNS requests. |
|
|
1350 | |
|
|
1351 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1352 | |
|
|
1353 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1354 | will create in parallel. |
|
|
1355 | |
|
|
1356 | =back |
|
|
1357 | |
1173 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1358 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1174 | |
1359 | |
1175 | This is an advanced topic that you do not normally need to use AnyEvent in |
1360 | This is an advanced topic that you do not normally need to use AnyEvent in |
1176 | a module. This section is only of use to event loop authors who want to |
1361 | a module. This section is only of use to event loop authors who want to |
1177 | provide AnyEvent compatibility. |
1362 | provide AnyEvent compatibility. |
… | |
… | |
1210 | |
1395 | |
1211 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1396 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1212 | condition variables: code blocking while waiting for a condition will |
1397 | condition variables: code blocking while waiting for a condition will |
1213 | C<die>. This still works with most modules/usages, and blocking calls must |
1398 | C<die>. This still works with most modules/usages, and blocking calls must |
1214 | not be done in an interactive application, so it makes sense. |
1399 | not be done in an interactive application, so it makes sense. |
1215 | |
|
|
1216 | =head1 ENVIRONMENT VARIABLES |
|
|
1217 | |
|
|
1218 | The following environment variables are used by this module: |
|
|
1219 | |
|
|
1220 | =over 4 |
|
|
1221 | |
|
|
1222 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1223 | |
|
|
1224 | By default, AnyEvent will be completely silent except in fatal |
|
|
1225 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1226 | talkative. |
|
|
1227 | |
|
|
1228 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1229 | conditions, such as not being able to load the event model specified by |
|
|
1230 | C<PERL_ANYEVENT_MODEL>. |
|
|
1231 | |
|
|
1232 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1233 | model it chooses. |
|
|
1234 | |
|
|
1235 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1236 | |
|
|
1237 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1238 | argument checking is very costly. Setting this variable to a true value |
|
|
1239 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1240 | check the arguments passed to most method calls. If it finds any problems |
|
|
1241 | it will croak. |
|
|
1242 | |
|
|
1243 | In other words, enables "strict" mode. |
|
|
1244 | |
|
|
1245 | Unlike C<use strict> it is definitely recommended ot keep it off in |
|
|
1246 | production. |
|
|
1247 | |
|
|
1248 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1249 | |
|
|
1250 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1251 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1252 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1253 | and the resulting module name is loaded and if the load was successful, |
|
|
1254 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1255 | auto detection and -probing. |
|
|
1256 | |
|
|
1257 | This functionality might change in future versions. |
|
|
1258 | |
|
|
1259 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1260 | could start your program like this: |
|
|
1261 | |
|
|
1262 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1263 | |
|
|
1264 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1265 | |
|
|
1266 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1267 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1268 | of auto probing). |
|
|
1269 | |
|
|
1270 | Must be set to a comma-separated list of protocols or address families, |
|
|
1271 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1272 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1273 | list. |
|
|
1274 | |
|
|
1275 | This variable can effectively be used for denial-of-service attacks |
|
|
1276 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1277 | small, as the program has to handle connection errors already- |
|
|
1278 | |
|
|
1279 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1280 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1281 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1282 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1283 | IPv6, but prefer IPv6 over IPv4. |
|
|
1284 | |
|
|
1285 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1286 | |
|
|
1287 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1288 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1289 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1290 | default. |
|
|
1291 | |
|
|
1292 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1293 | EDNS0 in its DNS requests. |
|
|
1294 | |
|
|
1295 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1296 | |
|
|
1297 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1298 | will create in parallel. |
|
|
1299 | |
|
|
1300 | =back |
|
|
1301 | |
1400 | |
1302 | =head1 EXAMPLE PROGRAM |
1401 | =head1 EXAMPLE PROGRAM |
1303 | |
1402 | |
1304 | The following program uses an I/O watcher to read data from STDIN, a timer |
1403 | The following program uses an I/O watcher to read data from STDIN, a timer |
1305 | to display a message once per second, and a condition variable to quit the |
1404 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1499 | watcher. |
1598 | watcher. |
1500 | |
1599 | |
1501 | =head3 Results |
1600 | =head3 Results |
1502 | |
1601 | |
1503 | name watchers bytes create invoke destroy comment |
1602 | name watchers bytes create invoke destroy comment |
1504 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1603 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1505 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1604 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1506 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1605 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1507 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1606 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1508 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1607 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1509 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1608 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
1510 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1609 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1511 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1610 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1512 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1611 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1513 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1612 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1514 | |
1613 | |
1515 | =head3 Discussion |
1614 | =head3 Discussion |
1516 | |
1615 | |
1517 | The benchmark does I<not> measure scalability of the event loop very |
1616 | The benchmark does I<not> measure scalability of the event loop very |
1518 | well. For example, a select-based event loop (such as the pure perl one) |
1617 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1720 | watchers, as the management overhead dominates. |
1819 | watchers, as the management overhead dominates. |
1721 | |
1820 | |
1722 | =back |
1821 | =back |
1723 | |
1822 | |
1724 | |
1823 | |
|
|
1824 | =head1 SIGNALS |
|
|
1825 | |
|
|
1826 | AnyEvent currently installs handlers for these signals: |
|
|
1827 | |
|
|
1828 | =over 4 |
|
|
1829 | |
|
|
1830 | =item SIGCHLD |
|
|
1831 | |
|
|
1832 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
1833 | emulation for event loops that do not support them natively. Also, some |
|
|
1834 | event loops install a similar handler. |
|
|
1835 | |
|
|
1836 | =item SIGPIPE |
|
|
1837 | |
|
|
1838 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
1839 | when AnyEvent gets loaded. |
|
|
1840 | |
|
|
1841 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
1842 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
1843 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
1844 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
1845 | some random socket. |
|
|
1846 | |
|
|
1847 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
1848 | that this way, the handler will be restored to defaults on exec. |
|
|
1849 | |
|
|
1850 | Feel free to install your own handler, or reset it to defaults. |
|
|
1851 | |
|
|
1852 | =back |
|
|
1853 | |
|
|
1854 | =cut |
|
|
1855 | |
|
|
1856 | $SIG{PIPE} = sub { } |
|
|
1857 | unless defined $SIG{PIPE}; |
|
|
1858 | |
|
|
1859 | |
1725 | =head1 FORK |
1860 | =head1 FORK |
1726 | |
1861 | |
1727 | Most event libraries are not fork-safe. The ones who are usually are |
1862 | Most event libraries are not fork-safe. The ones who are usually are |
1728 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1863 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1729 | calls. Only L<EV> is fully fork-aware. |
1864 | calls. Only L<EV> is fully fork-aware. |
… | |
… | |
1757 | =head1 BUGS |
1892 | =head1 BUGS |
1758 | |
1893 | |
1759 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
1894 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
1760 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
1895 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
1761 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
1896 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
1762 | mamleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1897 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1763 | pronounced). |
1898 | pronounced). |
1764 | |
1899 | |
1765 | |
1900 | |
1766 | =head1 SEE ALSO |
1901 | =head1 SEE ALSO |
1767 | |
1902 | |