… | |
… | |
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 (OR NOT) |
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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 (which is actually doing all I/O |
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44 | I<synchronously>...), using them in your module is like joining a |
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45 | cult: After you joined, you are dependent on them and you cannot use |
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46 | anything else, as it is simply incompatible to everything that isn't |
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47 | itself. |
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48 | |
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49 | AnyEvent + POE works fine. AnyEvent + Glib works fine. AnyEvent + Tk |
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50 | works fine etc. etc. but none of these work together with the rest: POE |
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51 | + IO::Async? no go. Tk + Event? no go. If your module uses one of |
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52 | those, every user of your module has to use it, too. If your module |
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53 | uses AnyEvent, it works transparently with all event models it supports |
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54 | (including stuff like POE and IO::Async). |
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55 | |
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56 | In addition of being free of having to use I<the one and only true event |
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57 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
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58 | modules, you get an enourmous amount of code and strict rules you have |
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59 | to follow. AnyEvent, on the other hand, is lean and to the point by only |
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60 | offering the functionality that is useful, in as thin as a wrapper as |
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61 | technically possible. |
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62 | |
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63 | Of course, if you want lots of policy (this can arguably be somewhat |
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64 | useful) and you want to force your users to use the one and only event |
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65 | model, you should I<not> use this module. |
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66 | |
22 | |
67 | |
23 | =head1 DESCRIPTION |
68 | =head1 DESCRIPTION |
24 | |
69 | |
25 | L<AnyEvent> provides an identical interface to multiple event loops. This |
70 | L<AnyEvent> provides an identical interface to multiple event loops. This |
26 | allows module authors to utilise an event loop without forcing module |
71 | 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 |
115 | You can create I/O watcher by calling the C<< AnyEvent->io >> method with |
71 | the following mandatory arguments: |
116 | the following mandatory arguments: |
72 | |
117 | |
73 | C<fh> the Perl I<filehandle> (not filedescriptor) to watch for |
118 | 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 |
119 | 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 |
120 | a watcher waiting for "r"eadable or "w"ritable events. C<cb> the callback |
76 | to invoke everytime the filehandle becomes ready. |
121 | to invoke everytime the filehandle becomes ready. |
77 | |
122 | |
78 | Only one io watcher per C<fh> and C<poll> combination is allowed (i.e. on |
123 | 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 |
124 | 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). |
125 | Tk - if you are sure you are not using Tk this limitation is gone). |
… | |
… | |
109 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
154 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
110 | warn "timeout\n"; |
155 | warn "timeout\n"; |
111 | }); |
156 | }); |
112 | |
157 | |
113 | # to cancel the timer: |
158 | # to cancel the timer: |
114 | undef $w |
159 | undef $w; |
115 | |
160 | |
116 | =head2 CONDITION WATCHERS |
161 | =head2 CONDITION WATCHERS |
117 | |
162 | |
118 | Condition watchers can be created by calling the C<< AnyEvent->condvar >> |
163 | Condition watchers can be created by calling the C<< AnyEvent->condvar >> |
119 | method without any arguments. |
164 | method without any arguments. |
120 | |
165 | |
121 | A condition watcher watches for a condition - precisely that the C<< |
166 | A condition watcher watches for a condition - precisely that the C<< |
122 | ->broadcast >> method has been called. |
167 | ->broadcast >> method has been called. |
123 | |
168 | |
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169 | Note that condition watchers recurse into the event loop - if you have |
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170 | two watchers that call C<< ->wait >> in a round-robbin fashion, you |
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171 | lose. Therefore, condition watchers are good to export to your caller, but |
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172 | you should avoid making a blocking wait, at least in callbacks, as this |
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173 | usually asks for trouble. |
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174 | |
124 | The watcher has only two methods: |
175 | The watcher has only two methods: |
125 | |
176 | |
126 | =over 4 |
177 | =over 4 |
127 | |
178 | |
128 | =item $cv->wait |
179 | =item $cv->wait |
129 | |
180 | |
130 | Wait (blocking if necessary) until the C<< ->broadcast >> method has been |
181 | Wait (blocking if necessary) until the C<< ->broadcast >> method has been |
131 | called on c<$cv>, while servicing other watchers normally. |
182 | called on c<$cv>, while servicing other watchers normally. |
132 | |
183 | |
133 | Not all event models support a blocking wait - some die in that case, so |
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134 | if you are using this from a module, never require a blocking wait, but |
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135 | let the caller decide wether the call will block or not (for example, |
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136 | by coupling condition variables with some kind of request results and |
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137 | supporting callbacks so the caller knows that getting the result will not |
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138 | block, while still suppporting blockign waits if the caller so desires). |
|
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139 | |
|
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140 | You can only wait once on a condition - additional calls will return |
184 | You can only wait once on a condition - additional calls will return |
141 | immediately. |
185 | immediately. |
|
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186 | |
|
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187 | Not all event models support a blocking wait - some die in that case |
|
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188 | (programs might want to do that so they stay interactive), so I<if you |
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189 | are using this from a module, never require a blocking wait>, but let the |
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190 | caller decide wether the call will block or not (for example, by coupling |
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191 | condition variables with some kind of request results and supporting |
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192 | callbacks so the caller knows that getting the result will not block, |
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193 | while still suppporting blocking waits if the caller so desires). |
|
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194 | |
|
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195 | Another reason I<never> to C<< ->wait >> in a module is that you cannot |
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196 | sensibly have two C<< ->wait >>'s in parallel, as that would require |
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197 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
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198 | can supply (the coroutine-aware backends C<Coro::EV> and C<Coro::Event> |
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199 | explicitly support concurrent C<< ->wait >>'s from different coroutines, |
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200 | however). |
142 | |
201 | |
143 | =item $cv->broadcast |
202 | =item $cv->broadcast |
144 | |
203 | |
145 | Flag the condition as ready - a running C<< ->wait >> and all further |
204 | Flag the condition as ready - a running C<< ->wait >> and all further |
146 | calls to C<wait> will return after this method has been called. If nobody |
205 | calls to C<wait> will return after this method has been called. If nobody |
… | |
… | |
160 | =back |
219 | =back |
161 | |
220 | |
162 | =head2 SIGNAL WATCHERS |
221 | =head2 SIGNAL WATCHERS |
163 | |
222 | |
164 | You can listen for signals using a signal watcher, C<signal> is the signal |
223 | You can listen for signals using a signal watcher, C<signal> is the signal |
165 | I<name> without any C<SIG> prefix. |
224 | I<name> without any C<SIG> prefix. Multiple signals events can be clumped |
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225 | together into one callback invocation, and callback invocation might or |
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226 | might not be asynchronous. |
166 | |
227 | |
167 | These watchers might use C<%SIG>, so programs overwriting those signals |
228 | These watchers might use C<%SIG>, so programs overwriting those signals |
168 | directly will likely not work correctly. |
229 | directly will likely not work correctly. |
169 | |
230 | |
170 | Example: exit on SIGINT |
231 | Example: exit on SIGINT |
171 | |
232 | |
172 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
233 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
|
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234 | |
|
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235 | =head2 CHILD PROCESS WATCHERS |
|
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236 | |
|
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237 | You can also listen for the status of a child process specified by the |
|
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238 | C<pid> argument (or any child if the pid argument is 0). The watcher will |
|
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239 | trigger as often as status change for the child are received. This works |
|
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240 | by installing a signal handler for C<SIGCHLD>. The callback will be called with |
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241 | the pid and exit status (as returned by waitpid). |
|
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242 | |
|
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243 | Example: wait for pid 1333 |
|
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244 | |
|
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245 | my $w = AnyEvent->child (pid => 1333, cb => sub { warn "exit status $?" }); |
173 | |
246 | |
174 | =head1 GLOBALS |
247 | =head1 GLOBALS |
175 | |
248 | |
176 | =over 4 |
249 | =over 4 |
177 | |
250 | |
… | |
… | |
183 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
256 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
184 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
257 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
185 | |
258 | |
186 | The known classes so far are: |
259 | The known classes so far are: |
187 | |
260 | |
188 | AnyEvent::Impl::Coro based on Coro::Event, best choise. |
261 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
|
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262 | AnyEvent::Impl::EV based on EV (an interface to libev, also best choice). |
|
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263 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
189 | AnyEvent::Impl::Event based on Event, also best choice :) |
264 | AnyEvent::Impl::Event based on Event, also second best choice :) |
190 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
265 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
191 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
266 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
192 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
267 | AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable. |
193 | |
268 | |
194 | =item AnyEvent::detect |
269 | =item AnyEvent::detect |
195 | |
270 | |
196 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model if |
271 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model if |
197 | necessary. You should only call this function right before you would have |
272 | necessary. You should only call this function right before you would have |
… | |
… | |
233 | |
308 | |
234 | package AnyEvent; |
309 | package AnyEvent; |
235 | |
310 | |
236 | no warnings; |
311 | no warnings; |
237 | use strict; |
312 | use strict; |
|
|
313 | |
238 | use Carp; |
314 | use Carp; |
239 | |
315 | |
240 | our $VERSION = '2.5'; |
316 | our $VERSION = '3.0'; |
241 | our $MODEL; |
317 | our $MODEL; |
242 | |
318 | |
243 | our $AUTOLOAD; |
319 | our $AUTOLOAD; |
244 | our @ISA; |
320 | our @ISA; |
245 | |
321 | |
246 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
322 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
247 | |
323 | |
248 | our @REGISTRY; |
324 | our @REGISTRY; |
249 | |
325 | |
250 | my @models = ( |
326 | my @models = ( |
|
|
327 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
|
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328 | [EV:: => AnyEvent::Impl::EV::], |
251 | [Coro::Event:: => AnyEvent::Impl::Coro::], |
329 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
252 | [Event:: => AnyEvent::Impl::Event::], |
330 | [Event:: => AnyEvent::Impl::Event::], |
253 | [Glib:: => AnyEvent::Impl::Glib::], |
331 | [Glib:: => AnyEvent::Impl::Glib::], |
254 | [Tk:: => AnyEvent::Impl::Tk::], |
332 | [Tk:: => AnyEvent::Impl::Tk::], |
255 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
333 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
256 | ); |
334 | ); |
… | |
… | |
276 | unless ($MODEL) { |
354 | unless ($MODEL) { |
277 | # try to load a model |
355 | # try to load a model |
278 | |
356 | |
279 | for (@REGISTRY, @models) { |
357 | for (@REGISTRY, @models) { |
280 | my ($package, $model) = @$_; |
358 | my ($package, $model) = @$_; |
|
|
359 | if (eval "require $package" |
|
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360 | and ${"$package\::VERSION"} > 0 |
281 | if (eval "require $model") { |
361 | and eval "require $model") { |
282 | $MODEL = $model; |
362 | $MODEL = $model; |
283 | warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1; |
363 | warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1; |
284 | last; |
364 | last; |
285 | } |
365 | } |
286 | } |
366 | } |
287 | |
367 | |
288 | $MODEL |
368 | $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."; |
369 | 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 | } |
370 | } |
291 | |
371 | |
292 | unshift @ISA, $MODEL; |
372 | unshift @ISA, $MODEL; |
293 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
373 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
294 | } |
374 | } |
… | |
… | |
308 | $class->$func (@_); |
388 | $class->$func (@_); |
309 | } |
389 | } |
310 | |
390 | |
311 | package AnyEvent::Base; |
391 | package AnyEvent::Base; |
312 | |
392 | |
|
|
393 | # default implementation for ->condvar, ->wait, ->broadcast |
|
|
394 | |
|
|
395 | sub condvar { |
|
|
396 | bless \my $flag, "AnyEvent::Base::CondVar" |
|
|
397 | } |
|
|
398 | |
|
|
399 | sub AnyEvent::Base::CondVar::broadcast { |
|
|
400 | ${$_[0]}++; |
|
|
401 | } |
|
|
402 | |
|
|
403 | sub AnyEvent::Base::CondVar::wait { |
|
|
404 | AnyEvent->one_event while !${$_[0]}; |
|
|
405 | } |
|
|
406 | |
313 | # default implementation for signal |
407 | # default implementation for ->signal |
314 | |
408 | |
315 | our %SIG_CB; |
409 | our %SIG_CB; |
316 | |
410 | |
317 | sub signal { |
411 | sub signal { |
318 | my (undef, %arg) = @_; |
412 | my (undef, %arg) = @_; |
319 | |
413 | |
320 | my $signal = uc $arg{signal} |
414 | my $signal = uc $arg{signal} |
321 | or Carp::croak "required option 'signal' is missing"; |
415 | or Carp::croak "required option 'signal' is missing"; |
322 | |
416 | |
323 | my $w = bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"; |
|
|
324 | |
|
|
325 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
417 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
326 | $SIG{$signal} ||= sub { |
418 | $SIG{$signal} ||= sub { |
327 | $_->() for values %{ $SIG_CB{$signal} }; |
419 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
328 | }; |
420 | }; |
329 | |
421 | |
330 | $w |
422 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
331 | } |
423 | } |
332 | |
424 | |
333 | sub AnyEvent::Base::Signal::DESTROY { |
425 | sub AnyEvent::Base::Signal::DESTROY { |
334 | my ($signal, $cb) = @{$_[0]}; |
426 | my ($signal, $cb) = @{$_[0]}; |
335 | |
427 | |
336 | delete $SIG_CB{$signal}{$cb}; |
428 | delete $SIG_CB{$signal}{$cb}; |
337 | |
429 | |
338 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
430 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
|
|
431 | } |
|
|
432 | |
|
|
433 | # default implementation for ->child |
|
|
434 | |
|
|
435 | our %PID_CB; |
|
|
436 | our $CHLD_W; |
|
|
437 | our $CHLD_DELAY_W; |
|
|
438 | our $PID_IDLE; |
|
|
439 | our $WNOHANG; |
|
|
440 | |
|
|
441 | sub _child_wait { |
|
|
442 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
|
|
443 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
|
|
444 | (values %{ $PID_CB{0} || {} }); |
|
|
445 | } |
|
|
446 | |
|
|
447 | undef $PID_IDLE; |
|
|
448 | } |
|
|
449 | |
|
|
450 | sub _sigchld { |
|
|
451 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
452 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
453 | undef $CHLD_DELAY_W; |
|
|
454 | &_child_wait; |
|
|
455 | }); |
|
|
456 | } |
|
|
457 | |
|
|
458 | sub child { |
|
|
459 | my (undef, %arg) = @_; |
|
|
460 | |
|
|
461 | defined (my $pid = $arg{pid} + 0) |
|
|
462 | or Carp::croak "required option 'pid' is missing"; |
|
|
463 | |
|
|
464 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
|
|
465 | |
|
|
466 | unless ($WNOHANG) { |
|
|
467 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
|
|
468 | } |
|
|
469 | |
|
|
470 | unless ($CHLD_W) { |
|
|
471 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
|
|
472 | # child could be a zombie already, so make at least one round |
|
|
473 | &_sigchld; |
|
|
474 | } |
|
|
475 | |
|
|
476 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
|
|
477 | } |
|
|
478 | |
|
|
479 | sub AnyEvent::Base::Child::DESTROY { |
|
|
480 | my ($pid, $cb) = @{$_[0]}; |
|
|
481 | |
|
|
482 | delete $PID_CB{$pid}{$cb}; |
|
|
483 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
|
|
484 | |
|
|
485 | undef $CHLD_W unless keys %PID_CB; |
339 | } |
486 | } |
340 | |
487 | |
341 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
488 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
342 | |
489 | |
343 | If you need to support another event library which isn't directly |
490 | If you need to support another event library which isn't directly |
… | |
… | |
368 | I<rxvt-unicode> distribution. |
515 | I<rxvt-unicode> distribution. |
369 | |
516 | |
370 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
517 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
371 | condition variables: code blocking while waiting for a condition will |
518 | condition variables: code blocking while waiting for a condition will |
372 | C<die>. This still works with most modules/usages, and blocking calls must |
519 | C<die>. This still works with most modules/usages, and blocking calls must |
373 | not be in an interactive appliation, so it makes sense. |
520 | not be in an interactive application, so it makes sense. |
374 | |
521 | |
375 | =head1 ENVIRONMENT VARIABLES |
522 | =head1 ENVIRONMENT VARIABLES |
376 | |
523 | |
377 | The following environment variables are used by this module: |
524 | The following environment variables are used by this module: |
378 | |
525 | |