… | |
… | |
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 |
… | |
… | |
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. Multiple signals events can be clumped |
224 | I<name> without any C<SIG> prefix. Multiple signals events can be clumped |
166 | together into one callback invocation, and callbakc invocation might or |
225 | together into one callback invocation, and callback invocation might or |
167 | might not be asynchronous. |
226 | might not be asynchronous. |
168 | |
227 | |
169 | These watchers might use C<%SIG>, so programs overwriting those signals |
228 | These watchers might use C<%SIG>, so programs overwriting those signals |
170 | directly will likely not work correctly. |
229 | directly will likely not work correctly. |
171 | |
230 | |
… | |
… | |
174 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
233 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
175 | |
234 | |
176 | =head2 CHILD PROCESS WATCHERS |
235 | =head2 CHILD PROCESS WATCHERS |
177 | |
236 | |
178 | You can also listen for the status of a child process specified by the |
237 | You can also listen for the status of a child process specified by the |
179 | C<pid> argument. The watcher will only trigger once. This works by |
238 | C<pid> argument (or any child if the pid argument is 0). The watcher will |
180 | installing a signal handler for C<SIGCHLD>. |
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). |
181 | |
242 | |
182 | Example: wait for pid 1333 |
243 | Example: wait for pid 1333 |
183 | |
244 | |
184 | my $w = AnyEvent->child (pid => 1333, cb => sub { warn "exit status $?" }); |
245 | my $w = AnyEvent->child (pid => 1333, cb => sub { warn "exit status $?" }); |
185 | |
246 | |
… | |
… | |
195 | 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 |
196 | 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>). |
197 | |
258 | |
198 | The known classes so far are: |
259 | The known classes so far are: |
199 | |
260 | |
200 | 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. |
201 | AnyEvent::Impl::Event based on Event, also best choice :) |
264 | AnyEvent::Impl::Event based on Event, also second best choice :) |
202 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
265 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
203 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
266 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
204 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
267 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
205 | |
268 | |
206 | =item AnyEvent::detect |
269 | =item AnyEvent::detect |
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245 | |
308 | |
246 | package AnyEvent; |
309 | package AnyEvent; |
247 | |
310 | |
248 | no warnings; |
311 | no warnings; |
249 | use strict; |
312 | use strict; |
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313 | |
250 | use Carp; |
314 | use Carp; |
251 | |
315 | |
252 | our $VERSION = '2.51'; |
316 | our $VERSION = '3.0'; |
253 | our $MODEL; |
317 | our $MODEL; |
254 | |
318 | |
255 | our $AUTOLOAD; |
319 | our $AUTOLOAD; |
256 | our @ISA; |
320 | our @ISA; |
257 | |
321 | |
258 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
322 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
259 | |
323 | |
260 | our @REGISTRY; |
324 | our @REGISTRY; |
261 | |
325 | |
262 | my @models = ( |
326 | my @models = ( |
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327 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
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328 | [EV:: => AnyEvent::Impl::EV::], |
263 | [Coro::Event:: => AnyEvent::Impl::Coro::], |
329 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
264 | [Event:: => AnyEvent::Impl::Event::], |
330 | [Event:: => AnyEvent::Impl::Event::], |
265 | [Glib:: => AnyEvent::Impl::Glib::], |
331 | [Glib:: => AnyEvent::Impl::Glib::], |
266 | [Tk:: => AnyEvent::Impl::Tk::], |
332 | [Tk:: => AnyEvent::Impl::Tk::], |
267 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
333 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
268 | ); |
334 | ); |
… | |
… | |
298 | last; |
364 | last; |
299 | } |
365 | } |
300 | } |
366 | } |
301 | |
367 | |
302 | $MODEL |
368 | $MODEL |
303 | 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."; |
304 | } |
370 | } |
305 | |
371 | |
306 | unshift @ISA, $MODEL; |
372 | unshift @ISA, $MODEL; |
307 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
373 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
308 | } |
374 | } |
… | |
… | |
366 | |
432 | |
367 | # default implementation for ->child |
433 | # default implementation for ->child |
368 | |
434 | |
369 | our %PID_CB; |
435 | our %PID_CB; |
370 | our $CHLD_W; |
436 | our $CHLD_W; |
|
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437 | our $CHLD_DELAY_W; |
371 | our $PID_IDLE; |
438 | our $PID_IDLE; |
372 | our $WNOHANG; |
439 | our $WNOHANG; |
373 | |
440 | |
374 | sub _child_wait { |
441 | sub _child_wait { |
375 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
442 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
376 | $_->() for values %{ (delete $PID_CB{$pid}) || {} }; |
443 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
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444 | (values %{ $PID_CB{0} || {} }); |
377 | } |
445 | } |
378 | |
446 | |
379 | undef $PID_IDLE; |
447 | undef $PID_IDLE; |
|
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448 | } |
|
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449 | |
|
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450 | sub _sigchld { |
|
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451 | # make sure we deliver these changes "synchronous" with the event loop. |
|
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452 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
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453 | undef $CHLD_DELAY_W; |
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454 | &_child_wait; |
|
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455 | }); |
380 | } |
456 | } |
381 | |
457 | |
382 | sub child { |
458 | sub child { |
383 | my (undef, %arg) = @_; |
459 | my (undef, %arg) = @_; |
384 | |
460 | |
385 | my $pid = uc $arg{pid} |
461 | defined (my $pid = $arg{pid} + 0) |
386 | or Carp::croak "required option 'pid' is missing"; |
462 | or Carp::croak "required option 'pid' is missing"; |
387 | |
463 | |
388 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
464 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
389 | |
465 | |
390 | unless ($WNOHANG) { |
466 | unless ($WNOHANG) { |
391 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_child_wait); |
|
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392 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
467 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
393 | } |
468 | } |
394 | |
469 | |
395 | # child could be a zombie already |
470 | unless ($CHLD_W) { |
396 | $PID_IDLE ||= AnyEvent->timer (after => 0, cb => \&_child_wait); |
471 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
|
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472 | # child could be a zombie already, so make at least one round |
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473 | &_sigchld; |
|
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474 | } |
397 | |
475 | |
398 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
476 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
399 | } |
477 | } |
400 | |
478 | |
401 | sub AnyEvent::Base::Child::DESTROY { |
479 | sub AnyEvent::Base::Child::DESTROY { |
… | |
… | |
437 | I<rxvt-unicode> distribution. |
515 | I<rxvt-unicode> distribution. |
438 | |
516 | |
439 | 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 |
440 | condition variables: code blocking while waiting for a condition will |
518 | condition variables: code blocking while waiting for a condition will |
441 | 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 |
442 | not be in an interactive appliation, so it makes sense. |
520 | not be in an interactive application, so it makes sense. |
443 | |
521 | |
444 | =head1 ENVIRONMENT VARIABLES |
522 | =head1 ENVIRONMENT VARIABLES |
445 | |
523 | |
446 | The following environment variables are used by this module: |
524 | The following environment variables are used by this module: |
447 | |
525 | |