… | |
… | |
17 | }); |
17 | }); |
18 | |
18 | |
19 | my $w = AnyEvent->condvar; # stores wether a condition was flagged |
19 | my $w = AnyEvent->condvar; # stores wether a condition was flagged |
20 | $w->wait; # enters "main loop" till $condvar gets ->broadcast |
20 | $w->wait; # enters "main loop" till $condvar gets ->broadcast |
21 | $w->broadcast; # wake up current and all future wait's |
21 | $w->broadcast; # wake up current and all future wait's |
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22 | |
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23 | =head1 WHY YOU SHOULD USE THIS MODULE |
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24 | |
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25 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
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26 | nowadays. So what is different about AnyEvent? |
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27 | |
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28 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
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29 | policy> and AnyEvent is I<small and efficient>. |
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30 | |
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31 | First and foremost, I<AnyEvent is not an event model> itself, it only |
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32 | interfaces to whatever event model the main program happens to use in a |
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33 | pragmatic way. For event models and certain classes of immortals alike, |
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34 | the statement "there can only be one" is a bitter reality, and AnyEvent |
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35 | helps hiding the differences. |
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36 | |
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37 | The goal of AnyEvent is to offer module authors the ability to do event |
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38 | programming (waiting for I/O or timer events) without subscribing to a |
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39 | religion, a way of living, and most importantly: without forcing your |
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40 | module users into the same thing by forcing them to use the same event |
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41 | model you use. |
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42 | |
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43 | For modules like POE or IO::Async (the latter of which is actually |
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44 | named confusingly, as it does neither do I/O nor does it do anything |
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45 | asynchronously...), using them in your module is like joining a |
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46 | cult: After you joined, you are dependent on them and you cannot use |
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47 | anything else, as it is simply incompatible to everything that isn't |
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48 | itself. |
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49 | |
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50 | AnyEvent + POE works fine. AnyEvent + Glib works fine. AnyEvent + Tk |
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51 | works fine etc. etc. but none of these work together with the rest: POE |
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52 | + IO::Async? no go. Tk + Event? no go. If your module uses one of |
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53 | those, every user of your module has to use it, too. If your module |
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54 | uses AnyEvent, it works transparently with all event models it supports |
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55 | (including stuff like POE and IO::Async). |
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56 | |
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57 | In addition of being free of having to use I<the one and only true event |
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58 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
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59 | modules, you get an enourmous amount of code and strict rules you have |
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60 | to follow. AnyEvent, on the other hand, is lean and to the point by only |
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61 | offering the functionality that is useful, in as thin as a wrapper as |
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62 | technically possible. |
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63 | |
22 | |
64 | |
23 | =head1 DESCRIPTION |
65 | =head1 DESCRIPTION |
24 | |
66 | |
25 | L<AnyEvent> provides an identical interface to multiple event loops. This |
67 | L<AnyEvent> provides an identical interface to multiple event loops. This |
26 | allows module authors to utilise an event loop without forcing module |
68 | allows module authors to utilise an event loop without forcing module |
… | |
… | |
70 | You can create I/O watcher by calling the C<< AnyEvent->io >> method with |
112 | You can create I/O watcher by calling the C<< AnyEvent->io >> method with |
71 | the following mandatory arguments: |
113 | the following mandatory arguments: |
72 | |
114 | |
73 | C<fh> the Perl I<filehandle> (not filedescriptor) to watch for |
115 | C<fh> the Perl I<filehandle> (not filedescriptor) to watch for |
74 | events. C<poll> must be a string that is either C<r> or C<w>, that creates |
116 | events. C<poll> must be a string that is either C<r> or C<w>, that creates |
75 | a watcher waiting for "r"eadable or "w"ritable events. C<cb> teh callback |
117 | a watcher waiting for "r"eadable or "w"ritable events. C<cb> the callback |
76 | to invoke everytime the filehandle becomes ready. |
118 | to invoke everytime the filehandle becomes ready. |
77 | |
119 | |
78 | Only one io watcher per C<fh> and C<poll> combination is allowed (i.e. on |
120 | Only one io watcher per C<fh> and C<poll> combination is allowed (i.e. on |
79 | a socket you can have one r + one w, not any more (limitation comes from |
121 | a socket you can have one r + one w, not any more (limitation comes from |
80 | Tk - if you are sure you are not using Tk this limitation is gone). |
122 | Tk - if you are sure you are not using Tk this limitation is gone). |
… | |
… | |
109 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
151 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
110 | warn "timeout\n"; |
152 | warn "timeout\n"; |
111 | }); |
153 | }); |
112 | |
154 | |
113 | # to cancel the timer: |
155 | # to cancel the timer: |
114 | undef $w |
156 | undef $w; |
115 | |
157 | |
116 | =head2 CONDITION WATCHERS |
158 | =head2 CONDITION WATCHERS |
117 | |
159 | |
118 | Condition watchers can be created by calling the C<< AnyEvent->condvar >> |
160 | Condition watchers can be created by calling the C<< AnyEvent->condvar >> |
119 | method without any arguments. |
161 | method without any arguments. |
120 | |
162 | |
121 | A condition watcher watches for a condition - precisely that the C<< |
163 | A condition watcher watches for a condition - precisely that the C<< |
122 | ->broadcast >> method has been called. |
164 | ->broadcast >> method has been called. |
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165 | |
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166 | Note that condition watchers recurse into the event loop - if you have |
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167 | two watchers that call C<< ->wait >> in a round-robbin fashion, you |
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168 | lose. Therefore, condition watchers are good to export to your caller, but |
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169 | you should avoid making a blocking wait, at least in callbacks, as this |
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170 | usually asks for trouble. |
123 | |
171 | |
124 | The watcher has only two methods: |
172 | The watcher has only two methods: |
125 | |
173 | |
126 | =over 4 |
174 | =over 4 |
127 | |
175 | |
… | |
… | |
160 | =back |
208 | =back |
161 | |
209 | |
162 | =head2 SIGNAL WATCHERS |
210 | =head2 SIGNAL WATCHERS |
163 | |
211 | |
164 | You can listen for signals using a signal watcher, C<signal> is the signal |
212 | You can listen for signals using a signal watcher, C<signal> is the signal |
165 | I<name> without any C<SIG> prefix. |
213 | I<name> without any C<SIG> prefix. Multiple signals events can be clumped |
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214 | together into one callback invocation, and callback invocation might or |
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215 | might not be asynchronous. |
166 | |
216 | |
167 | These watchers might use C<%SIG>, so programs overwriting those signals |
217 | These watchers might use C<%SIG>, so programs overwriting those signals |
168 | directly will likely not work correctly. |
218 | directly will likely not work correctly. |
169 | |
219 | |
170 | Example: exit on SIGINT |
220 | Example: exit on SIGINT |
171 | |
221 | |
172 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
222 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
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223 | |
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224 | =head2 CHILD PROCESS WATCHERS |
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225 | |
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226 | You can also listen for the status of a child process specified by the |
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227 | C<pid> argument (or any child if the pid argument is 0). The watcher will |
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228 | trigger as often as status change for the child are received. This works |
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229 | by installing a signal handler for C<SIGCHLD>. The callback will be called with |
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230 | the pid and exit status (as returned by waitpid). |
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231 | |
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232 | Example: wait for pid 1333 |
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233 | |
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234 | my $w = AnyEvent->child (pid => 1333, cb => sub { warn "exit status $?" }); |
173 | |
235 | |
174 | =head1 GLOBALS |
236 | =head1 GLOBALS |
175 | |
237 | |
176 | =over 4 |
238 | =over 4 |
177 | |
239 | |
… | |
… | |
183 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
245 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
184 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
246 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
185 | |
247 | |
186 | The known classes so far are: |
248 | The known classes so far are: |
187 | |
249 | |
188 | AnyEvent::Impl::Coro based on Coro::Event, best choise. |
250 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
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251 | AnyEvent::Impl::EV based on EV (an interface to libev, also best choice). |
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252 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
189 | AnyEvent::Impl::Event based on Event, also best choice :) |
253 | AnyEvent::Impl::Event based on Event, also second best choice :) |
190 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
254 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
191 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
255 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
192 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
256 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
193 | |
257 | |
194 | =item AnyEvent::detect |
258 | =item AnyEvent::detect |
… | |
… | |
233 | |
297 | |
234 | package AnyEvent; |
298 | package AnyEvent; |
235 | |
299 | |
236 | no warnings; |
300 | no warnings; |
237 | use strict; |
301 | use strict; |
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302 | |
238 | use Carp; |
303 | use Carp; |
239 | |
304 | |
240 | our $VERSION = '2.5'; |
305 | our $VERSION = '3.0'; |
241 | our $MODEL; |
306 | our $MODEL; |
242 | |
307 | |
243 | our $AUTOLOAD; |
308 | our $AUTOLOAD; |
244 | our @ISA; |
309 | our @ISA; |
245 | |
310 | |
246 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
311 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
247 | |
312 | |
248 | our @REGISTRY; |
313 | our @REGISTRY; |
249 | |
314 | |
250 | my @models = ( |
315 | my @models = ( |
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316 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
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317 | [EV:: => AnyEvent::Impl::EV::], |
251 | [Coro::Event:: => AnyEvent::Impl::Coro::], |
318 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
252 | [Event:: => AnyEvent::Impl::Event::], |
319 | [Event:: => AnyEvent::Impl::Event::], |
253 | [Glib:: => AnyEvent::Impl::Glib::], |
320 | [Glib:: => AnyEvent::Impl::Glib::], |
254 | [Tk:: => AnyEvent::Impl::Tk::], |
321 | [Tk:: => AnyEvent::Impl::Tk::], |
255 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
322 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
256 | ); |
323 | ); |
… | |
… | |
276 | unless ($MODEL) { |
343 | unless ($MODEL) { |
277 | # try to load a model |
344 | # try to load a model |
278 | |
345 | |
279 | for (@REGISTRY, @models) { |
346 | for (@REGISTRY, @models) { |
280 | my ($package, $model) = @$_; |
347 | my ($package, $model) = @$_; |
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348 | if (eval "require $package" |
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349 | and ${"$package\::VERSION"} > 0 |
281 | if (eval "require $model") { |
350 | and eval "require $model") { |
282 | $MODEL = $model; |
351 | $MODEL = $model; |
283 | warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1; |
352 | warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1; |
284 | last; |
353 | last; |
285 | } |
354 | } |
286 | } |
355 | } |
287 | |
356 | |
288 | $MODEL |
357 | $MODEL |
289 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: Event (or Coro+Event), Glib or Tk."; |
358 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV (or Coro+EV), Event (or Coro+Event), Glib or Tk."; |
290 | } |
359 | } |
291 | |
360 | |
292 | unshift @ISA, $MODEL; |
361 | unshift @ISA, $MODEL; |
293 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
362 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
294 | } |
363 | } |
… | |
… | |
308 | $class->$func (@_); |
377 | $class->$func (@_); |
309 | } |
378 | } |
310 | |
379 | |
311 | package AnyEvent::Base; |
380 | package AnyEvent::Base; |
312 | |
381 | |
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382 | # default implementation for ->condvar, ->wait, ->broadcast |
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383 | |
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384 | sub condvar { |
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385 | bless \my $flag, "AnyEvent::Base::CondVar" |
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386 | } |
|
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387 | |
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388 | sub AnyEvent::Base::CondVar::broadcast { |
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389 | ${$_[0]}++; |
|
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390 | } |
|
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391 | |
|
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392 | sub AnyEvent::Base::CondVar::wait { |
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393 | AnyEvent->one_event while !${$_[0]}; |
|
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394 | } |
|
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395 | |
313 | # default implementation for signal |
396 | # default implementation for ->signal |
314 | |
397 | |
315 | our %SIG_CB; |
398 | our %SIG_CB; |
316 | |
399 | |
317 | sub signal { |
400 | sub signal { |
318 | my (undef, %arg) = @_; |
401 | my (undef, %arg) = @_; |
319 | |
402 | |
320 | my $signal = uc $arg{signal} |
403 | my $signal = uc $arg{signal} |
321 | or Carp::croak "required option 'signal' is missing"; |
404 | or Carp::croak "required option 'signal' is missing"; |
322 | |
405 | |
323 | my $w = bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"; |
|
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324 | |
|
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325 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
406 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
326 | $SIG{$signal} ||= sub { |
407 | $SIG{$signal} ||= sub { |
327 | $_->() for values %{ $SIG_CB{$signal} }; |
408 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
328 | }; |
409 | }; |
329 | |
410 | |
330 | $w |
411 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
331 | } |
412 | } |
332 | |
413 | |
333 | sub AnyEvent::Base::Signal::DESTROY { |
414 | sub AnyEvent::Base::Signal::DESTROY { |
334 | my ($signal, $cb) = @{$_[0]}; |
415 | my ($signal, $cb) = @{$_[0]}; |
335 | |
416 | |
336 | delete $SIG_CB{$signal}{$cb}; |
417 | delete $SIG_CB{$signal}{$cb}; |
337 | |
418 | |
338 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
419 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
|
|
420 | } |
|
|
421 | |
|
|
422 | # default implementation for ->child |
|
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423 | |
|
|
424 | our %PID_CB; |
|
|
425 | our $CHLD_W; |
|
|
426 | our $CHLD_DELAY_W; |
|
|
427 | our $PID_IDLE; |
|
|
428 | our $WNOHANG; |
|
|
429 | |
|
|
430 | sub _child_wait { |
|
|
431 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
|
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432 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
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433 | (values %{ $PID_CB{0} || {} }); |
|
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434 | } |
|
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435 | |
|
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436 | undef $PID_IDLE; |
|
|
437 | } |
|
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438 | |
|
|
439 | sub _sigchld { |
|
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440 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
441 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
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442 | undef $CHLD_DELAY_W; |
|
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443 | &_child_wait; |
|
|
444 | }); |
|
|
445 | } |
|
|
446 | |
|
|
447 | sub child { |
|
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448 | my (undef, %arg) = @_; |
|
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449 | |
|
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450 | defined (my $pid = $arg{pid} + 0) |
|
|
451 | or Carp::croak "required option 'pid' is missing"; |
|
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452 | |
|
|
453 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
|
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454 | |
|
|
455 | unless ($WNOHANG) { |
|
|
456 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
|
|
457 | } |
|
|
458 | |
|
|
459 | unless ($CHLD_W) { |
|
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460 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
|
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461 | # child could be a zombie already, so make at least one round |
|
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462 | &_sigchld; |
|
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463 | } |
|
|
464 | |
|
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465 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
|
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466 | } |
|
|
467 | |
|
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468 | sub AnyEvent::Base::Child::DESTROY { |
|
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469 | my ($pid, $cb) = @{$_[0]}; |
|
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470 | |
|
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471 | delete $PID_CB{$pid}{$cb}; |
|
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472 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
|
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473 | |
|
|
474 | undef $CHLD_W unless keys %PID_CB; |
339 | } |
475 | } |
340 | |
476 | |
341 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
477 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
342 | |
478 | |
343 | If you need to support another event library which isn't directly |
479 | If you need to support another event library which isn't directly |
… | |
… | |
368 | I<rxvt-unicode> distribution. |
504 | I<rxvt-unicode> distribution. |
369 | |
505 | |
370 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
506 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
371 | condition variables: code blocking while waiting for a condition will |
507 | condition variables: code blocking while waiting for a condition will |
372 | C<die>. This still works with most modules/usages, and blocking calls must |
508 | C<die>. This still works with most modules/usages, and blocking calls must |
373 | not be in an interactive appliation, so it makes sense. |
509 | not be in an interactive application, so it makes sense. |
374 | |
510 | |
375 | =head1 ENVIRONMENT VARIABLES |
511 | =head1 ENVIRONMENT VARIABLES |
376 | |
512 | |
377 | The following environment variables are used by this module: |
513 | The following environment variables are used by this module: |
378 | |
514 | |