… | |
… | |
361 | invocation, and callback invocation will be synchronous. Synchronous means |
361 | invocation, and callback invocation will be synchronous. Synchronous means |
362 | that it might take a while until the signal gets handled by the process, |
362 | that it might take a while until the signal gets handled by the process, |
363 | but it is guaranteed not to interrupt any other callbacks. |
363 | but it is guaranteed not to interrupt any other callbacks. |
364 | |
364 | |
365 | The main advantage of using these watchers is that you can share a signal |
365 | The main advantage of using these watchers is that you can share a signal |
366 | between multiple watchers. |
366 | between multiple watchers, and AnyEvent will ensure that signals will not |
|
|
367 | interrupt your program at bad times. |
367 | |
368 | |
368 | This watcher might use C<%SIG>, so programs overwriting those signals |
369 | This watcher might use C<%SIG> (depending on the event loop used), |
369 | directly will likely not work correctly. |
370 | so programs overwriting those signals directly will likely not work |
|
|
371 | correctly. |
370 | |
372 | |
371 | Example: exit on SIGINT |
373 | Example: exit on SIGINT |
372 | |
374 | |
373 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
375 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
|
|
376 | |
|
|
377 | =head3 Signal Races, Delays and Workarounds |
|
|
378 | |
|
|
379 | Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching |
|
|
380 | callbacks to signals in a generic way, which is a pity, as you cannot do |
|
|
381 | race-free signal handling in perl. AnyEvent will try to do it's best, but |
|
|
382 | in some cases, signals will be delayed. The maximum time a signal might |
|
|
383 | be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 |
|
|
384 | seconds). This variable can be changed only before the first signal |
|
|
385 | watcher is created, and should be left alone otherwise. Higher values |
|
|
386 | will cause fewer spurious wake-ups, which is better for power and CPU |
|
|
387 | saving. All these problems can be avoided by installing the optional |
|
|
388 | L<Async::Interrupt> module. This will not work with inherently broken |
|
|
389 | event loops such as L<Event> or L<Event::Lib> (and not with L<POE> |
|
|
390 | currently, as POE does it's own workaround with one-second latency). With |
|
|
391 | those, you just have to suffer the delays. |
374 | |
392 | |
375 | =head2 CHILD PROCESS WATCHERS |
393 | =head2 CHILD PROCESS WATCHERS |
376 | |
394 | |
377 | You can also watch on a child process exit and catch its exit status. |
395 | You can also watch on a child process exit and catch its exit status. |
378 | |
396 | |
… | |
… | |
403 | |
421 | |
404 | This means you cannot create a child watcher as the very first |
422 | This means you cannot create a child watcher as the very first |
405 | thing in an AnyEvent program, you I<have> to create at least one |
423 | thing in an AnyEvent program, you I<have> to create at least one |
406 | watcher before you C<fork> the child (alternatively, you can call |
424 | watcher before you C<fork> the child (alternatively, you can call |
407 | C<AnyEvent::detect>). |
425 | C<AnyEvent::detect>). |
|
|
426 | |
|
|
427 | As most event loops do not support waiting for child events, they will be |
|
|
428 | emulated by AnyEvent in most cases, in which the latency and race problems |
|
|
429 | mentioned in the description of signal watchers apply. |
408 | |
430 | |
409 | Example: fork a process and wait for it |
431 | Example: fork a process and wait for it |
410 | |
432 | |
411 | my $done = AnyEvent->condvar; |
433 | my $done = AnyEvent->condvar; |
412 | |
434 | |
… | |
… | |
463 | |
485 | |
464 | If you are familiar with some event loops you will know that all of them |
486 | If you are familiar with some event loops you will know that all of them |
465 | require you to run some blocking "loop", "run" or similar function that |
487 | require you to run some blocking "loop", "run" or similar function that |
466 | will actively watch for new events and call your callbacks. |
488 | will actively watch for new events and call your callbacks. |
467 | |
489 | |
468 | AnyEvent is different, it expects somebody else to run the event loop and |
490 | AnyEvent is slightly different: it expects somebody else to run the event |
469 | will only block when necessary (usually when told by the user). |
491 | loop and will only block when necessary (usually when told by the user). |
470 | |
492 | |
471 | The instrument to do that is called a "condition variable", so called |
493 | The instrument to do that is called a "condition variable", so called |
472 | because they represent a condition that must become true. |
494 | because they represent a condition that must become true. |
473 | |
495 | |
|
|
496 | Now is probably a good time to look at the examples further below. |
|
|
497 | |
474 | Condition variables can be created by calling the C<< AnyEvent->condvar |
498 | Condition variables can be created by calling the C<< AnyEvent->condvar |
475 | >> method, usually without arguments. The only argument pair allowed is |
499 | >> method, usually without arguments. The only argument pair allowed is |
476 | |
|
|
477 | C<cb>, which specifies a callback to be called when the condition variable |
500 | C<cb>, which specifies a callback to be called when the condition variable |
478 | becomes true, with the condition variable as the first argument (but not |
501 | becomes true, with the condition variable as the first argument (but not |
479 | the results). |
502 | the results). |
480 | |
503 | |
481 | After creation, the condition variable is "false" until it becomes "true" |
504 | After creation, the condition variable is "false" until it becomes "true" |
… | |
… | |
530 | after => 1, |
553 | after => 1, |
531 | cb => sub { $result_ready->send }, |
554 | cb => sub { $result_ready->send }, |
532 | ); |
555 | ); |
533 | |
556 | |
534 | # this "blocks" (while handling events) till the callback |
557 | # this "blocks" (while handling events) till the callback |
535 | # calls send |
558 | # calls -<send |
536 | $result_ready->recv; |
559 | $result_ready->recv; |
537 | |
560 | |
538 | Example: wait for a timer, but take advantage of the fact that |
561 | Example: wait for a timer, but take advantage of the fact that condition |
539 | condition variables are also code references. |
562 | variables are also callable directly. |
540 | |
563 | |
541 | my $done = AnyEvent->condvar; |
564 | my $done = AnyEvent->condvar; |
542 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
565 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
543 | $done->recv; |
566 | $done->recv; |
544 | |
567 | |
… | |
… | |
550 | |
573 | |
551 | ... |
574 | ... |
552 | |
575 | |
553 | my @info = $couchdb->info->recv; |
576 | my @info = $couchdb->info->recv; |
554 | |
577 | |
555 | And this is how you would just ste a callback to be called whenever the |
578 | And this is how you would just set a callback to be called whenever the |
556 | results are available: |
579 | results are available: |
557 | |
580 | |
558 | $couchdb->info->cb (sub { |
581 | $couchdb->info->cb (sub { |
559 | my @info = $_[0]->recv; |
582 | my @info = $_[0]->recv; |
560 | }); |
583 | }); |
… | |
… | |
578 | immediately from within send. |
601 | immediately from within send. |
579 | |
602 | |
580 | Any arguments passed to the C<send> call will be returned by all |
603 | Any arguments passed to the C<send> call will be returned by all |
581 | future C<< ->recv >> calls. |
604 | future C<< ->recv >> calls. |
582 | |
605 | |
583 | Condition variables are overloaded so one can call them directly |
606 | Condition variables are overloaded so one can call them directly (as if |
584 | (as a code reference). Calling them directly is the same as calling |
607 | they were a code reference). Calling them directly is the same as calling |
585 | C<send>. Note, however, that many C-based event loops do not handle |
608 | C<send>. |
586 | overloading, so as tempting as it may be, passing a condition variable |
|
|
587 | instead of a callback does not work. Both the pure perl and EV loops |
|
|
588 | support overloading, however, as well as all functions that use perl to |
|
|
589 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
|
|
590 | example). |
|
|
591 | |
609 | |
592 | =item $cv->croak ($error) |
610 | =item $cv->croak ($error) |
593 | |
611 | |
594 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
612 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
595 | C<Carp::croak> with the given error message/object/scalar. |
613 | C<Carp::croak> with the given error message/object/scalar. |
596 | |
614 | |
597 | This can be used to signal any errors to the condition variable |
615 | This can be used to signal any errors to the condition variable |
598 | user/consumer. |
616 | user/consumer. Doing it this way instead of calling C<croak> directly |
|
|
617 | delays the error detetcion, but has the overwhelmign advantage that it |
|
|
618 | diagnoses the error at the place where the result is expected, and not |
|
|
619 | deep in some event clalback without connection to the actual code causing |
|
|
620 | the problem. |
599 | |
621 | |
600 | =item $cv->begin ([group callback]) |
622 | =item $cv->begin ([group callback]) |
601 | |
623 | |
602 | =item $cv->end |
624 | =item $cv->end |
603 | |
625 | |
… | |
… | |
699 | function will call C<croak>. |
721 | function will call C<croak>. |
700 | |
722 | |
701 | In list context, all parameters passed to C<send> will be returned, |
723 | In list context, all parameters passed to C<send> will be returned, |
702 | in scalar context only the first one will be returned. |
724 | in scalar context only the first one will be returned. |
703 | |
725 | |
|
|
726 | Note that doing a blocking wait in a callback is not supported by any |
|
|
727 | event loop, that is, recursive invocation of a blocking C<< ->recv |
|
|
728 | >> is not allowed, and the C<recv> call will C<croak> if such a |
|
|
729 | condition is detected. This condition can be slightly loosened by using |
|
|
730 | L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from |
|
|
731 | any thread that doesn't run the event loop itself. |
|
|
732 | |
704 | Not all event models support a blocking wait - some die in that case |
733 | Not all event models support a blocking wait - some die in that case |
705 | (programs might want to do that to stay interactive), so I<if you are |
734 | (programs might want to do that to stay interactive), so I<if you are |
706 | using this from a module, never require a blocking wait>, but let the |
735 | using this from a module, never require a blocking wait>. Instead, let the |
707 | caller decide whether the call will block or not (for example, by coupling |
736 | caller decide whether the call will block or not (for example, by coupling |
708 | condition variables with some kind of request results and supporting |
737 | condition variables with some kind of request results and supporting |
709 | callbacks so the caller knows that getting the result will not block, |
738 | callbacks so the caller knows that getting the result will not block, |
710 | while still supporting blocking waits if the caller so desires). |
739 | while still supporting blocking waits if the caller so desires). |
711 | |
|
|
712 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
|
|
713 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
|
|
714 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
|
|
715 | can supply. |
|
|
716 | |
|
|
717 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
|
|
718 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
|
|
719 | versions and also integrates coroutines into AnyEvent, making blocking |
|
|
720 | C<< ->recv >> calls perfectly safe as long as they are done from another |
|
|
721 | coroutine (one that doesn't run the event loop). |
|
|
722 | |
740 | |
723 | You can ensure that C<< -recv >> never blocks by setting a callback and |
741 | You can ensure that C<< -recv >> never blocks by setting a callback and |
724 | only calling C<< ->recv >> from within that callback (or at a later |
742 | only calling C<< ->recv >> from within that callback (or at a later |
725 | time). This will work even when the event loop does not support blocking |
743 | time). This will work even when the event loop does not support blocking |
726 | waits otherwise. |
744 | waits otherwise. |
… | |
… | |
1028 | |
1046 | |
1029 | =cut |
1047 | =cut |
1030 | |
1048 | |
1031 | package AnyEvent; |
1049 | package AnyEvent; |
1032 | |
1050 | |
|
|
1051 | # basically a tuned-down version of common::sense |
|
|
1052 | sub common_sense { |
1033 | no warnings; |
1053 | # no warnings |
|
|
1054 | ${^WARNING_BITS} ^= ${^WARNING_BITS}; |
1034 | use strict qw(vars subs); |
1055 | # use strict vars subs |
|
|
1056 | $^H |= 0x00000600; |
|
|
1057 | } |
1035 | |
1058 | |
|
|
1059 | BEGIN { AnyEvent::common_sense } |
|
|
1060 | |
1036 | use Carp; |
1061 | use Carp (); |
1037 | |
1062 | |
1038 | our $VERSION = 4.801; |
1063 | our $VERSION = 4.85; |
1039 | our $MODEL; |
1064 | our $MODEL; |
1040 | |
1065 | |
1041 | our $AUTOLOAD; |
1066 | our $AUTOLOAD; |
1042 | our @ISA; |
1067 | our @ISA; |
1043 | |
1068 | |
1044 | our @REGISTRY; |
1069 | our @REGISTRY; |
1045 | |
1070 | |
1046 | our $WIN32; |
1071 | our $WIN32; |
|
|
1072 | |
|
|
1073 | our $VERBOSE; |
1047 | |
1074 | |
1048 | BEGIN { |
1075 | BEGIN { |
1049 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
1076 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
1050 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
1077 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
1051 | |
1078 | |
1052 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
1079 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
1053 | if ${^TAINT}; |
1080 | if ${^TAINT}; |
1054 | } |
|
|
1055 | |
1081 | |
1056 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
1082 | $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
|
|
1083 | |
|
|
1084 | } |
|
|
1085 | |
|
|
1086 | our $MAX_SIGNAL_LATENCY = 10; |
1057 | |
1087 | |
1058 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
1088 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
1059 | |
1089 | |
1060 | { |
1090 | { |
1061 | my $idx; |
1091 | my $idx; |
… | |
… | |
1072 | # as the pureperl backend should work everywhere |
1102 | # as the pureperl backend should work everywhere |
1073 | # and is usually faster |
1103 | # and is usually faster |
1074 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
1104 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
1075 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
1105 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
1076 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
1106 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
1107 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1077 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1108 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1078 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
|
|
1079 | [Wx:: => AnyEvent::Impl::POE::], |
1109 | [Wx:: => AnyEvent::Impl::POE::], |
1080 | [Prima:: => AnyEvent::Impl::POE::], |
1110 | [Prima:: => AnyEvent::Impl::POE::], |
1081 | # IO::Async is just too broken - we would need workarounds for its |
1111 | # IO::Async is just too broken - we would need workarounds for its |
1082 | # byzantine signal and broken child handling, among others. |
1112 | # byzantine signal and broken child handling, among others. |
1083 | # IO::Async is rather hard to detect, as it doesn't have any |
1113 | # IO::Async is rather hard to detect, as it doesn't have any |
… | |
… | |
1112 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1142 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1113 | } |
1143 | } |
1114 | |
1144 | |
1115 | sub detect() { |
1145 | sub detect() { |
1116 | unless ($MODEL) { |
1146 | unless ($MODEL) { |
1117 | no strict 'refs'; |
|
|
1118 | local $SIG{__DIE__}; |
1147 | local $SIG{__DIE__}; |
1119 | |
1148 | |
1120 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
1149 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
1121 | my $model = "AnyEvent::Impl::$1"; |
1150 | my $model = "AnyEvent::Impl::$1"; |
1122 | if (eval "require $model") { |
1151 | if (eval "require $model") { |
1123 | $MODEL = $model; |
1152 | $MODEL = $model; |
1124 | warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; |
1153 | warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; |
1125 | } else { |
1154 | } else { |
1126 | warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; |
1155 | warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE; |
1127 | } |
1156 | } |
1128 | } |
1157 | } |
1129 | |
1158 | |
1130 | # check for already loaded models |
1159 | # check for already loaded models |
1131 | unless ($MODEL) { |
1160 | unless ($MODEL) { |
1132 | for (@REGISTRY, @models) { |
1161 | for (@REGISTRY, @models) { |
1133 | my ($package, $model) = @$_; |
1162 | my ($package, $model) = @$_; |
1134 | if (${"$package\::VERSION"} > 0) { |
1163 | if (${"$package\::VERSION"} > 0) { |
1135 | if (eval "require $model") { |
1164 | if (eval "require $model") { |
1136 | $MODEL = $model; |
1165 | $MODEL = $model; |
1137 | warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; |
1166 | warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2; |
1138 | last; |
1167 | last; |
1139 | } |
1168 | } |
1140 | } |
1169 | } |
1141 | } |
1170 | } |
1142 | |
1171 | |
… | |
… | |
1147 | my ($package, $model) = @$_; |
1176 | my ($package, $model) = @$_; |
1148 | if (eval "require $package" |
1177 | if (eval "require $package" |
1149 | and ${"$package\::VERSION"} > 0 |
1178 | and ${"$package\::VERSION"} > 0 |
1150 | and eval "require $model") { |
1179 | and eval "require $model") { |
1151 | $MODEL = $model; |
1180 | $MODEL = $model; |
1152 | warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; |
1181 | warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2; |
1153 | last; |
1182 | last; |
1154 | } |
1183 | } |
1155 | } |
1184 | } |
1156 | |
1185 | |
1157 | $MODEL |
1186 | $MODEL |
… | |
… | |
1173 | |
1202 | |
1174 | sub AUTOLOAD { |
1203 | sub AUTOLOAD { |
1175 | (my $func = $AUTOLOAD) =~ s/.*://; |
1204 | (my $func = $AUTOLOAD) =~ s/.*://; |
1176 | |
1205 | |
1177 | $method{$func} |
1206 | $method{$func} |
1178 | or croak "$func: not a valid method for AnyEvent objects"; |
1207 | or Carp::croak "$func: not a valid method for AnyEvent objects"; |
1179 | |
1208 | |
1180 | detect unless $MODEL; |
1209 | detect unless $MODEL; |
1181 | |
1210 | |
1182 | my $class = shift; |
1211 | my $class = shift; |
1183 | $class->$func (@_); |
1212 | $class->$func (@_); |
… | |
… | |
1188 | # allow only one watcher per fd, so we dup it to get a different one). |
1217 | # allow only one watcher per fd, so we dup it to get a different one). |
1189 | sub _dupfh($$;$$) { |
1218 | sub _dupfh($$;$$) { |
1190 | my ($poll, $fh, $r, $w) = @_; |
1219 | my ($poll, $fh, $r, $w) = @_; |
1191 | |
1220 | |
1192 | # cygwin requires the fh mode to be matching, unix doesn't |
1221 | # cygwin requires the fh mode to be matching, unix doesn't |
1193 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">"); |
1222 | my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&"); |
1194 | |
1223 | |
1195 | open my $fh2, "$mode&", $fh |
1224 | open my $fh2, $mode, $fh |
1196 | or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; |
1225 | or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; |
1197 | |
1226 | |
1198 | # we assume CLOEXEC is already set by perl in all important cases |
1227 | # we assume CLOEXEC is already set by perl in all important cases |
1199 | |
1228 | |
1200 | ($fh2, $rw) |
1229 | ($fh2, $rw) |
… | |
… | |
1202 | |
1231 | |
1203 | package AnyEvent::Base; |
1232 | package AnyEvent::Base; |
1204 | |
1233 | |
1205 | # default implementations for many methods |
1234 | # default implementations for many methods |
1206 | |
1235 | |
1207 | BEGIN { |
1236 | sub _time { |
|
|
1237 | # probe for availability of Time::HiRes |
1208 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
1238 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1239 | warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; |
1209 | *_time = \&Time::HiRes::time; |
1240 | *_time = \&Time::HiRes::time; |
1210 | # if (eval "use POSIX (); (POSIX::times())... |
1241 | # if (eval "use POSIX (); (POSIX::times())... |
1211 | } else { |
1242 | } else { |
|
|
1243 | warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; |
1212 | *_time = sub { time }; # epic fail |
1244 | *_time = sub { time }; # epic fail |
1213 | } |
1245 | } |
|
|
1246 | |
|
|
1247 | &_time |
1214 | } |
1248 | } |
1215 | |
1249 | |
1216 | sub time { _time } |
1250 | sub time { _time } |
1217 | sub now { _time } |
1251 | sub now { _time } |
1218 | sub now_update { } |
1252 | sub now_update { } |
… | |
… | |
1223 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
1257 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
1224 | } |
1258 | } |
1225 | |
1259 | |
1226 | # default implementation for ->signal |
1260 | # default implementation for ->signal |
1227 | |
1261 | |
|
|
1262 | our $HAVE_ASYNC_INTERRUPT; |
1228 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
1263 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1264 | our (%SIG_ASY, %SIG_ASY_W); |
|
|
1265 | our ($SIG_COUNT, $SIG_TW); |
1229 | |
1266 | |
1230 | sub _signal_exec { |
1267 | sub _signal_exec { |
|
|
1268 | $HAVE_ASYNC_INTERRUPT |
|
|
1269 | ? $SIGPIPE_R->drain |
1231 | sysread $SIGPIPE_R, my $dummy, 4; |
1270 | : sysread $SIGPIPE_R, my $dummy, 9; |
1232 | |
1271 | |
1233 | while (%SIG_EV) { |
1272 | while (%SIG_EV) { |
1234 | for (keys %SIG_EV) { |
1273 | for (keys %SIG_EV) { |
1235 | delete $SIG_EV{$_}; |
1274 | delete $SIG_EV{$_}; |
1236 | $_->() for values %{ $SIG_CB{$_} || {} }; |
1275 | $_->() for values %{ $SIG_CB{$_} || {} }; |
1237 | } |
1276 | } |
1238 | } |
1277 | } |
1239 | } |
1278 | } |
1240 | |
1279 | |
|
|
1280 | # install a dumym wakeupw atcher to reduce signal catching latency |
|
|
1281 | sub _sig_add() { |
|
|
1282 | unless ($SIG_COUNT++) { |
|
|
1283 | # try to align timer on a full-second boundary, if possible |
|
|
1284 | my $NOW = AnyEvent->now; |
|
|
1285 | |
|
|
1286 | $SIG_TW = AnyEvent->timer ( |
|
|
1287 | after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW), |
|
|
1288 | interval => $MAX_SIGNAL_LATENCY, |
|
|
1289 | cb => sub { }, # just for the PERL_ASYNC_CHECK |
|
|
1290 | ); |
|
|
1291 | } |
|
|
1292 | } |
|
|
1293 | |
|
|
1294 | sub _sig_del { |
|
|
1295 | undef $SIG_TW |
|
|
1296 | unless --$SIG_COUNT; |
|
|
1297 | } |
|
|
1298 | |
|
|
1299 | sub _signal { |
|
|
1300 | my (undef, %arg) = @_; |
|
|
1301 | |
|
|
1302 | my $signal = uc $arg{signal} |
|
|
1303 | or Carp::croak "required option 'signal' is missing"; |
|
|
1304 | |
|
|
1305 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
1306 | |
|
|
1307 | if ($HAVE_ASYNC_INTERRUPT) { |
|
|
1308 | # async::interrupt |
|
|
1309 | |
|
|
1310 | $SIG_ASY{$signal} ||= do { |
|
|
1311 | my $asy = new Async::Interrupt |
|
|
1312 | cb => sub { undef $SIG_EV{$signal} }, |
|
|
1313 | signal => $signal, |
|
|
1314 | pipe => [$SIGPIPE_R->filenos], |
|
|
1315 | ; |
|
|
1316 | $asy->pipe_autodrain (0); |
|
|
1317 | |
|
|
1318 | $asy |
|
|
1319 | }; |
|
|
1320 | |
|
|
1321 | } else { |
|
|
1322 | # pure perl |
|
|
1323 | |
|
|
1324 | $SIG{$signal} ||= sub { |
|
|
1325 | local $!; |
|
|
1326 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1327 | undef $SIG_EV{$signal}; |
|
|
1328 | }; |
|
|
1329 | |
|
|
1330 | # can't do signal processing without introducing races in pure perl, |
|
|
1331 | # so limit the signal latency. |
|
|
1332 | _sig_add; |
|
|
1333 | } |
|
|
1334 | |
|
|
1335 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
|
|
1336 | } |
|
|
1337 | |
1241 | sub signal { |
1338 | sub signal { |
1242 | my (undef, %arg) = @_; |
1339 | # probe for availability of Async::Interrupt |
|
|
1340 | if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") { |
|
|
1341 | warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8; |
1243 | |
1342 | |
1244 | unless ($SIGPIPE_R) { |
1343 | $HAVE_ASYNC_INTERRUPT = 1; |
|
|
1344 | $SIGPIPE_R = new Async::Interrupt::EventPipe; |
|
|
1345 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec); |
|
|
1346 | |
|
|
1347 | } else { |
|
|
1348 | warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; |
|
|
1349 | |
1245 | require Fcntl; |
1350 | require Fcntl; |
1246 | |
1351 | |
1247 | if (AnyEvent::WIN32) { |
1352 | if (AnyEvent::WIN32) { |
1248 | require AnyEvent::Util; |
1353 | require AnyEvent::Util; |
1249 | |
1354 | |
… | |
… | |
1264 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
1369 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
1265 | |
1370 | |
1266 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
1371 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
1267 | } |
1372 | } |
1268 | |
1373 | |
1269 | my $signal = uc $arg{signal} |
1374 | *signal = \&_signal; |
1270 | or Carp::croak "required option 'signal' is missing"; |
1375 | &signal |
1271 | |
|
|
1272 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
1273 | $SIG{$signal} ||= sub { |
|
|
1274 | local $!; |
|
|
1275 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1276 | undef $SIG_EV{$signal}; |
|
|
1277 | }; |
|
|
1278 | |
|
|
1279 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
|
|
1280 | } |
1376 | } |
1281 | |
1377 | |
1282 | sub AnyEvent::Base::signal::DESTROY { |
1378 | sub AnyEvent::Base::signal::DESTROY { |
1283 | my ($signal, $cb) = @{$_[0]}; |
1379 | my ($signal, $cb) = @{$_[0]}; |
1284 | |
1380 | |
|
|
1381 | _sig_del; |
|
|
1382 | |
1285 | delete $SIG_CB{$signal}{$cb}; |
1383 | delete $SIG_CB{$signal}{$cb}; |
1286 | |
1384 | |
|
|
1385 | $HAVE_ASYNC_INTERRUPT |
|
|
1386 | ? delete $SIG_ASY{$signal} |
1287 | # delete doesn't work with older perls - they then |
1387 | : # delete doesn't work with older perls - they then |
1288 | # print weird messages, or just unconditionally exit |
1388 | # print weird messages, or just unconditionally exit |
1289 | # instead of getting the default action. |
1389 | # instead of getting the default action. |
|
|
1390 | undef $SIG{$signal} |
1290 | undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1391 | unless keys %{ $SIG_CB{$signal} }; |
1291 | } |
1392 | } |
1292 | |
1393 | |
1293 | # default implementation for ->child |
1394 | # default implementation for ->child |
1294 | |
1395 | |
1295 | our %PID_CB; |
1396 | our %PID_CB; |
… | |
… | |
1297 | our $CHLD_DELAY_W; |
1398 | our $CHLD_DELAY_W; |
1298 | our $WNOHANG; |
1399 | our $WNOHANG; |
1299 | |
1400 | |
1300 | sub _sigchld { |
1401 | sub _sigchld { |
1301 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1402 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
|
|
1403 | $_->($pid, $?) |
1302 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1404 | for values %{ $PID_CB{$pid} || {} }, |
1303 | (values %{ $PID_CB{0} || {} }); |
1405 | values %{ $PID_CB{0} || {} }; |
1304 | } |
1406 | } |
1305 | } |
1407 | } |
1306 | |
1408 | |
1307 | sub child { |
1409 | sub child { |
1308 | my (undef, %arg) = @_; |
1410 | my (undef, %arg) = @_; |
… | |
… | |
1310 | defined (my $pid = $arg{pid} + 0) |
1412 | defined (my $pid = $arg{pid} + 0) |
1311 | or Carp::croak "required option 'pid' is missing"; |
1413 | or Carp::croak "required option 'pid' is missing"; |
1312 | |
1414 | |
1313 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1415 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1314 | |
1416 | |
|
|
1417 | # WNOHANG is almost cetrainly 1 everywhere |
|
|
1418 | $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ |
|
|
1419 | ? 1 |
1315 | $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1420 | : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1316 | |
1421 | |
1317 | unless ($CHLD_W) { |
1422 | unless ($CHLD_W) { |
1318 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1423 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1319 | # child could be a zombie already, so make at least one round |
1424 | # child could be a zombie already, so make at least one round |
1320 | &_sigchld; |
1425 | &_sigchld; |
… | |
… | |
1372 | |
1477 | |
1373 | our @ISA = AnyEvent::CondVar::Base::; |
1478 | our @ISA = AnyEvent::CondVar::Base::; |
1374 | |
1479 | |
1375 | package AnyEvent::CondVar::Base; |
1480 | package AnyEvent::CondVar::Base; |
1376 | |
1481 | |
1377 | use overload |
1482 | #use overload |
1378 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
1483 | # '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
1379 | fallback => 1; |
1484 | # fallback => 1; |
|
|
1485 | |
|
|
1486 | # save 300+ kilobytes by dirtily hardcoding overloading |
|
|
1487 | ${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching. |
|
|
1488 | *{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod." |
|
|
1489 | *{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{} |
|
|
1490 | ${'AnyEvent::CondVar::Base::()'} = 1; # fallback |
|
|
1491 | |
|
|
1492 | our $WAITING; |
1380 | |
1493 | |
1381 | sub _send { |
1494 | sub _send { |
1382 | # nop |
1495 | # nop |
1383 | } |
1496 | } |
1384 | |
1497 | |
… | |
… | |
1397 | sub ready { |
1510 | sub ready { |
1398 | $_[0]{_ae_sent} |
1511 | $_[0]{_ae_sent} |
1399 | } |
1512 | } |
1400 | |
1513 | |
1401 | sub _wait { |
1514 | sub _wait { |
|
|
1515 | $WAITING |
|
|
1516 | and !$_[0]{_ae_sent} |
|
|
1517 | and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected"; |
|
|
1518 | |
|
|
1519 | local $WAITING = 1; |
1402 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
1520 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
1403 | } |
1521 | } |
1404 | |
1522 | |
1405 | sub recv { |
1523 | sub recv { |
1406 | $_[0]->_wait; |
1524 | $_[0]->_wait; |
… | |
… | |
1468 | C<PERL_ANYEVENT_MODEL>. |
1586 | C<PERL_ANYEVENT_MODEL>. |
1469 | |
1587 | |
1470 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
1588 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
1471 | model it chooses. |
1589 | model it chooses. |
1472 | |
1590 | |
|
|
1591 | When set to C<8> or higher, then AnyEvent will report extra information on |
|
|
1592 | which optional modules it loads and how it implements certain features. |
|
|
1593 | |
1473 | =item C<PERL_ANYEVENT_STRICT> |
1594 | =item C<PERL_ANYEVENT_STRICT> |
1474 | |
1595 | |
1475 | AnyEvent does not do much argument checking by default, as thorough |
1596 | AnyEvent does not do much argument checking by default, as thorough |
1476 | argument checking is very costly. Setting this variable to a true value |
1597 | argument checking is very costly. Setting this variable to a true value |
1477 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
1598 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
1478 | check the arguments passed to most method calls. If it finds any problems, |
1599 | check the arguments passed to most method calls. If it finds any problems, |
1479 | it will croak. |
1600 | it will croak. |
1480 | |
1601 | |
1481 | In other words, enables "strict" mode. |
1602 | In other words, enables "strict" mode. |
1482 | |
1603 | |
1483 | Unlike C<use strict>, it is definitely recommended to keep it off in |
1604 | Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> |
1484 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
1605 | >>, it is definitely recommended to keep it off in production. Keeping |
1485 | developing programs can be very useful, however. |
1606 | C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs |
|
|
1607 | can be very useful, however. |
1486 | |
1608 | |
1487 | =item C<PERL_ANYEVENT_MODEL> |
1609 | =item C<PERL_ANYEVENT_MODEL> |
1488 | |
1610 | |
1489 | This can be used to specify the event model to be used by AnyEvent, before |
1611 | This can be used to specify the event model to be used by AnyEvent, before |
1490 | auto detection and -probing kicks in. It must be a string consisting |
1612 | auto detection and -probing kicks in. It must be a string consisting |
… | |
… | |
1552 | |
1674 | |
1553 | When neither C<ca_file> nor C<ca_path> was specified during |
1675 | When neither C<ca_file> nor C<ca_path> was specified during |
1554 | L<AnyEvent::TLS> context creation, and either of these environment |
1676 | L<AnyEvent::TLS> context creation, and either of these environment |
1555 | variables exist, they will be used to specify CA certificate locations |
1677 | variables exist, they will be used to specify CA certificate locations |
1556 | instead of a system-dependent default. |
1678 | instead of a system-dependent default. |
|
|
1679 | |
|
|
1680 | =item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT> |
|
|
1681 | |
|
|
1682 | When these are set to C<1>, then the respective modules are not |
|
|
1683 | loaded. Mostly good for testing AnyEvent itself. |
1557 | |
1684 | |
1558 | =back |
1685 | =back |
1559 | |
1686 | |
1560 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1687 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1561 | |
1688 | |
… | |
… | |
2100 | |
2227 | |
2101 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
2228 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
2102 | emulation for event loops that do not support them natively. Also, some |
2229 | emulation for event loops that do not support them natively. Also, some |
2103 | event loops install a similar handler. |
2230 | event loops install a similar handler. |
2104 | |
2231 | |
2105 | If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will |
2232 | Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then |
2106 | reset it to default, to avoid losing child exit statuses. |
2233 | AnyEvent will reset it to default, to avoid losing child exit statuses. |
2107 | |
2234 | |
2108 | =item SIGPIPE |
2235 | =item SIGPIPE |
2109 | |
2236 | |
2110 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
2237 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
2111 | when AnyEvent gets loaded. |
2238 | when AnyEvent gets loaded. |
… | |
… | |
2129 | if $SIG{CHLD} eq 'IGNORE'; |
2256 | if $SIG{CHLD} eq 'IGNORE'; |
2130 | |
2257 | |
2131 | $SIG{PIPE} = sub { } |
2258 | $SIG{PIPE} = sub { } |
2132 | unless defined $SIG{PIPE}; |
2259 | unless defined $SIG{PIPE}; |
2133 | |
2260 | |
|
|
2261 | =head1 RECOMMENDED/OPTIONAL MODULES |
|
|
2262 | |
|
|
2263 | One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and |
|
|
2264 | it's built-in modules) are required to use it. |
|
|
2265 | |
|
|
2266 | That does not mean that AnyEvent won't take advantage of some additional |
|
|
2267 | modules if they are installed. |
|
|
2268 | |
|
|
2269 | This section epxlains which additional modules will be used, and how they |
|
|
2270 | affect AnyEvent's operetion. |
|
|
2271 | |
|
|
2272 | =over 4 |
|
|
2273 | |
|
|
2274 | =item L<Async::Interrupt> |
|
|
2275 | |
|
|
2276 | This slightly arcane module is used to implement fast signal handling: To |
|
|
2277 | my knowledge, there is no way to do completely race-free and quick |
|
|
2278 | signal handling in pure perl. To ensure that signals still get |
|
|
2279 | delivered, AnyEvent will start an interval timer to wake up perl (and |
|
|
2280 | catch the signals) with some delay (default is 10 seconds, look for |
|
|
2281 | C<$AnyEvent::MAX_SIGNAL_LATENCY>). |
|
|
2282 | |
|
|
2283 | If this module is available, then it will be used to implement signal |
|
|
2284 | catching, which means that signals will not be delayed, and the event loop |
|
|
2285 | will not be interrupted regularly, which is more efficient (And good for |
|
|
2286 | battery life on laptops). |
|
|
2287 | |
|
|
2288 | This affects not just the pure-perl event loop, but also other event loops |
|
|
2289 | that have no signal handling on their own (e.g. Glib, Tk, Qt). |
|
|
2290 | |
|
|
2291 | Some event loops (POE, Event, Event::Lib) offer signal watchers natively, |
|
|
2292 | and either employ their own workarounds (POE) or use AnyEvent's workaround |
|
|
2293 | (using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt> |
|
|
2294 | does nothing for those backends. |
|
|
2295 | |
|
|
2296 | =item L<EV> |
|
|
2297 | |
|
|
2298 | This module isn't really "optional", as it is simply one of the backend |
|
|
2299 | event loops that AnyEvent can use. However, it is simply the best event |
|
|
2300 | loop available in terms of features, speed and stability: It supports |
|
|
2301 | the AnyEvent API optimally, implements all the watcher types in XS, does |
|
|
2302 | automatic timer adjustments even when no monotonic clock is available, |
|
|
2303 | can take avdantage of advanced kernel interfaces such as C<epoll> and |
|
|
2304 | C<kqueue>, and is the fastest backend I<by far>. You can even embed |
|
|
2305 | L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). |
|
|
2306 | |
|
|
2307 | =item L<Guard> |
|
|
2308 | |
|
|
2309 | The guard module, when used, will be used to implement |
|
|
2310 | C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a |
|
|
2311 | lot less memory), but otherwise doesn't affect guard operation much. It is |
|
|
2312 | purely used for performance. |
|
|
2313 | |
|
|
2314 | =item L<JSON> and L<JSON::XS> |
|
|
2315 | |
|
|
2316 | This module is required when you want to read or write JSON data via |
|
|
2317 | L<AnyEvent::Handle>. It is also written in pure-perl, but can take |
|
|
2318 | advantage of the ulta-high-speed L<JSON::XS> module when it is installed. |
|
|
2319 | |
|
|
2320 | In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is |
|
|
2321 | installed. |
|
|
2322 | |
|
|
2323 | =item L<Net::SSLeay> |
|
|
2324 | |
|
|
2325 | Implementing TLS/SSL in Perl is certainly interesting, but not very |
|
|
2326 | worthwhile: If this module is installed, then L<AnyEvent::Handle> (with |
|
|
2327 | the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. |
|
|
2328 | |
|
|
2329 | =item L<Time::HiRes> |
|
|
2330 | |
|
|
2331 | This module is part of perl since release 5.008. It will be used when the |
|
|
2332 | chosen event library does not come with a timing source on it's own. The |
|
|
2333 | pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to |
|
|
2334 | try to use a monotonic clock for timing stability. |
|
|
2335 | |
|
|
2336 | =back |
|
|
2337 | |
|
|
2338 | |
2134 | =head1 FORK |
2339 | =head1 FORK |
2135 | |
2340 | |
2136 | Most event libraries are not fork-safe. The ones who are usually are |
2341 | Most event libraries are not fork-safe. The ones who are usually are |
2137 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2342 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2138 | calls. Only L<EV> is fully fork-aware. |
2343 | calls. Only L<EV> is fully fork-aware. |
2139 | |
2344 | |
2140 | If you have to fork, you must either do so I<before> creating your first |
2345 | If you have to fork, you must either do so I<before> creating your first |
2141 | watcher OR you must not use AnyEvent at all in the child. |
2346 | watcher OR you must not use AnyEvent at all in the child OR you must do |
|
|
2347 | something completely out of the scope of AnyEvent. |
2142 | |
2348 | |
2143 | |
2349 | |
2144 | =head1 SECURITY CONSIDERATIONS |
2350 | =head1 SECURITY CONSIDERATIONS |
2145 | |
2351 | |
2146 | AnyEvent can be forced to load any event model via |
2352 | AnyEvent can be forced to load any event model via |