… | |
… | |
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 | |
|
|
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 |
|
|
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 |
|
|
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 |
|
|
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 | |
|
|
63 | Of course, if you want lots of policy (this is arguably somewhat useful |
|
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64 | in many cases) and you want to force your users to the one and only event |
|
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65 | model your module forces on them, 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). |
… | |
… | |
89 | chomp (my $input = <STDIN>); |
134 | chomp (my $input = <STDIN>); |
90 | warn "read: $input\n"; |
135 | warn "read: $input\n"; |
91 | undef $w; |
136 | undef $w; |
92 | }); |
137 | }); |
93 | |
138 | |
94 | =head2 TIMER WATCHERS |
139 | =head2 TIME WATCHERS |
95 | |
140 | |
96 | You can create a timer watcher by calling the C<< AnyEvent->timer >> |
141 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
97 | method with the following mandatory arguments: |
142 | method with the following mandatory arguments: |
98 | |
143 | |
99 | C<after> after how many seconds (fractions are supported) should the timer |
144 | C<after> after how many seconds (fractions are supported) should the timer |
100 | activate. C<cb> the callback to invoke. |
145 | activate. C<cb> the callback to invoke. |
101 | |
146 | |
… | |
… | |
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. |
|
|
168 | |
|
|
169 | Note that condition watchers recurse into the event loop - if you have |
|
|
170 | two watchers that call C<< ->wait >> in a round-robbin fashion, you |
|
|
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 |
|
|
173 | usually asks for trouble. |
123 | |
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 | |
… | |
… | |
154 | # do something such as adding a timer |
205 | # do something such as adding a timer |
155 | # or socket watcher the calls $result_ready->broadcast |
206 | # or socket watcher the calls $result_ready->broadcast |
156 | # when the "result" is ready. |
207 | # when the "result" is ready. |
157 | |
208 | |
158 | $result_ready->wait; |
209 | $result_ready->wait; |
|
|
210 | |
|
|
211 | =back |
|
|
212 | |
|
|
213 | =head2 SIGNAL WATCHERS |
|
|
214 | |
|
|
215 | You can listen for signals using a signal watcher, C<signal> is the signal |
|
|
216 | I<name> without any C<SIG> prefix. Multiple signals events can be clumped |
|
|
217 | together into one callback invocation, and callback invocation might or |
|
|
218 | might not be asynchronous. |
|
|
219 | |
|
|
220 | These watchers might use C<%SIG>, so programs overwriting those signals |
|
|
221 | directly will likely not work correctly. |
|
|
222 | |
|
|
223 | Example: exit on SIGINT |
|
|
224 | |
|
|
225 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
|
|
226 | |
|
|
227 | =head2 CHILD PROCESS WATCHERS |
|
|
228 | |
|
|
229 | You can also listen for the status of a child process specified by the |
|
|
230 | C<pid> argument (or any child if the pid argument is 0). The watcher will |
|
|
231 | trigger as often as status change for the child are received. This works |
|
|
232 | by installing a signal handler for C<SIGCHLD>. The callback will be called with |
|
|
233 | the pid and exit status (as returned by waitpid). |
|
|
234 | |
|
|
235 | Example: wait for pid 1333 |
|
|
236 | |
|
|
237 | my $w = AnyEvent->child (pid => 1333, cb => sub { warn "exit status $?" }); |
|
|
238 | |
|
|
239 | =head1 GLOBALS |
|
|
240 | |
|
|
241 | =over 4 |
|
|
242 | |
|
|
243 | =item $AnyEvent::MODEL |
|
|
244 | |
|
|
245 | Contains C<undef> until the first watcher is being created. Then it |
|
|
246 | contains the event model that is being used, which is the name of the |
|
|
247 | Perl class implementing the model. This class is usually one of the |
|
|
248 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
|
|
249 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
|
|
250 | |
|
|
251 | The known classes so far are: |
|
|
252 | |
|
|
253 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
|
|
254 | AnyEvent::Impl::EV based on EV (an interface to libev, also best choice). |
|
|
255 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
|
|
256 | AnyEvent::Impl::Event based on Event, also second best choice :) |
|
|
257 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
|
|
258 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
|
|
259 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
|
|
260 | |
|
|
261 | =item AnyEvent::detect |
|
|
262 | |
|
|
263 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model if |
|
|
264 | necessary. You should only call this function right before you would have |
|
|
265 | created an AnyEvent watcher anyway, that is, very late at runtime. |
159 | |
266 | |
160 | =back |
267 | =back |
161 | |
268 | |
162 | =head1 WHAT TO DO IN A MODULE |
269 | =head1 WHAT TO DO IN A MODULE |
163 | |
270 | |
… | |
… | |
192 | =cut |
299 | =cut |
193 | |
300 | |
194 | package AnyEvent; |
301 | package AnyEvent; |
195 | |
302 | |
196 | no warnings; |
303 | no warnings; |
197 | use strict 'vars'; |
304 | use strict; |
|
|
305 | |
198 | use Carp; |
306 | use Carp; |
199 | |
307 | |
200 | our $VERSION = '2.0'; |
308 | our $VERSION = '3.0'; |
201 | our $MODEL; |
309 | our $MODEL; |
202 | |
310 | |
203 | our $AUTOLOAD; |
311 | our $AUTOLOAD; |
204 | our @ISA; |
312 | our @ISA; |
205 | |
313 | |
206 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
314 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
207 | |
315 | |
208 | our @REGISTRY; |
316 | our @REGISTRY; |
209 | |
317 | |
210 | my @models = ( |
318 | my @models = ( |
|
|
319 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
|
|
320 | [EV:: => AnyEvent::Impl::EV::], |
211 | [Coro::Event:: => AnyEvent::Impl::Coro::], |
321 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
212 | [Event:: => AnyEvent::Impl::Event::], |
322 | [Event:: => AnyEvent::Impl::Event::], |
213 | [Glib:: => AnyEvent::Impl::Glib::], |
323 | [Glib:: => AnyEvent::Impl::Glib::], |
214 | [Tk:: => AnyEvent::Impl::Tk::], |
324 | [Tk:: => AnyEvent::Impl::Tk::], |
215 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
325 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
216 | ); |
326 | ); |
217 | |
327 | |
218 | our %method = map +($_ => 1), qw(io timer condvar broadcast wait DESTROY); |
328 | our %method = map +($_ => 1), qw(io timer condvar broadcast wait signal one_event DESTROY); |
219 | |
329 | |
220 | sub AUTOLOAD { |
330 | sub detect() { |
221 | $AUTOLOAD =~ s/.*://; |
|
|
222 | |
|
|
223 | $method{$AUTOLOAD} |
|
|
224 | or croak "$AUTOLOAD: not a valid method for AnyEvent objects"; |
|
|
225 | |
|
|
226 | unless ($MODEL) { |
331 | unless ($MODEL) { |
|
|
332 | no strict 'refs'; |
|
|
333 | |
227 | # check for already loaded models |
334 | # check for already loaded models |
228 | for (@REGISTRY, @models) { |
335 | for (@REGISTRY, @models) { |
229 | my ($package, $model) = @$_; |
336 | my ($package, $model) = @$_; |
230 | if (${"$package\::VERSION"} > 0) { |
337 | if (${"$package\::VERSION"} > 0) { |
231 | if (eval "require $model") { |
338 | if (eval "require $model") { |
… | |
… | |
239 | unless ($MODEL) { |
346 | unless ($MODEL) { |
240 | # try to load a model |
347 | # try to load a model |
241 | |
348 | |
242 | for (@REGISTRY, @models) { |
349 | for (@REGISTRY, @models) { |
243 | my ($package, $model) = @$_; |
350 | my ($package, $model) = @$_; |
|
|
351 | if (eval "require $package" |
|
|
352 | and ${"$package\::VERSION"} > 0 |
244 | if (eval "require $model") { |
353 | and eval "require $model") { |
245 | $MODEL = $model; |
354 | $MODEL = $model; |
246 | warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1; |
355 | warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1; |
247 | last; |
356 | last; |
248 | } |
357 | } |
249 | } |
358 | } |
250 | |
359 | |
251 | $MODEL |
360 | $MODEL |
252 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: Coro, Event, Glib or Tk."; |
361 | 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."; |
253 | } |
362 | } |
|
|
363 | |
|
|
364 | unshift @ISA, $MODEL; |
|
|
365 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
254 | } |
366 | } |
255 | |
367 | |
256 | @ISA = $MODEL; |
368 | $MODEL |
|
|
369 | } |
|
|
370 | |
|
|
371 | sub AUTOLOAD { |
|
|
372 | (my $func = $AUTOLOAD) =~ s/.*://; |
|
|
373 | |
|
|
374 | $method{$func} |
|
|
375 | or croak "$func: not a valid method for AnyEvent objects"; |
|
|
376 | |
|
|
377 | detect unless $MODEL; |
257 | |
378 | |
258 | my $class = shift; |
379 | my $class = shift; |
259 | $class->$AUTOLOAD (@_); |
380 | $class->$func (@_); |
|
|
381 | } |
|
|
382 | |
|
|
383 | package AnyEvent::Base; |
|
|
384 | |
|
|
385 | # default implementation for ->condvar, ->wait, ->broadcast |
|
|
386 | |
|
|
387 | sub condvar { |
|
|
388 | bless \my $flag, "AnyEvent::Base::CondVar" |
|
|
389 | } |
|
|
390 | |
|
|
391 | sub AnyEvent::Base::CondVar::broadcast { |
|
|
392 | ${$_[0]}++; |
|
|
393 | } |
|
|
394 | |
|
|
395 | sub AnyEvent::Base::CondVar::wait { |
|
|
396 | AnyEvent->one_event while !${$_[0]}; |
|
|
397 | } |
|
|
398 | |
|
|
399 | # default implementation for ->signal |
|
|
400 | |
|
|
401 | our %SIG_CB; |
|
|
402 | |
|
|
403 | sub signal { |
|
|
404 | my (undef, %arg) = @_; |
|
|
405 | |
|
|
406 | my $signal = uc $arg{signal} |
|
|
407 | or Carp::croak "required option 'signal' is missing"; |
|
|
408 | |
|
|
409 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
410 | $SIG{$signal} ||= sub { |
|
|
411 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
|
|
412 | }; |
|
|
413 | |
|
|
414 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
|
|
415 | } |
|
|
416 | |
|
|
417 | sub AnyEvent::Base::Signal::DESTROY { |
|
|
418 | my ($signal, $cb) = @{$_[0]}; |
|
|
419 | |
|
|
420 | delete $SIG_CB{$signal}{$cb}; |
|
|
421 | |
|
|
422 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
|
|
423 | } |
|
|
424 | |
|
|
425 | # default implementation for ->child |
|
|
426 | |
|
|
427 | our %PID_CB; |
|
|
428 | our $CHLD_W; |
|
|
429 | our $CHLD_DELAY_W; |
|
|
430 | our $PID_IDLE; |
|
|
431 | our $WNOHANG; |
|
|
432 | |
|
|
433 | sub _child_wait { |
|
|
434 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
|
|
435 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
|
|
436 | (values %{ $PID_CB{0} || {} }); |
|
|
437 | } |
|
|
438 | |
|
|
439 | undef $PID_IDLE; |
|
|
440 | } |
|
|
441 | |
|
|
442 | sub _sigchld { |
|
|
443 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
444 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
445 | undef $CHLD_DELAY_W; |
|
|
446 | &_child_wait; |
|
|
447 | }); |
|
|
448 | } |
|
|
449 | |
|
|
450 | sub child { |
|
|
451 | my (undef, %arg) = @_; |
|
|
452 | |
|
|
453 | defined (my $pid = $arg{pid} + 0) |
|
|
454 | or Carp::croak "required option 'pid' is missing"; |
|
|
455 | |
|
|
456 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
|
|
457 | |
|
|
458 | unless ($WNOHANG) { |
|
|
459 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
|
|
460 | } |
|
|
461 | |
|
|
462 | unless ($CHLD_W) { |
|
|
463 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
|
|
464 | # child could be a zombie already, so make at least one round |
|
|
465 | &_sigchld; |
|
|
466 | } |
|
|
467 | |
|
|
468 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
|
|
469 | } |
|
|
470 | |
|
|
471 | sub AnyEvent::Base::Child::DESTROY { |
|
|
472 | my ($pid, $cb) = @{$_[0]}; |
|
|
473 | |
|
|
474 | delete $PID_CB{$pid}{$cb}; |
|
|
475 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
|
|
476 | |
|
|
477 | undef $CHLD_W unless keys %PID_CB; |
260 | } |
478 | } |
261 | |
479 | |
262 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
480 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
263 | |
481 | |
264 | If you need to support another event library which isn't directly |
482 | If you need to support another event library which isn't directly |
… | |
… | |
275 | This tells AnyEvent to (literally) use the C<urxvt::anyevent::> |
493 | This tells AnyEvent to (literally) use the C<urxvt::anyevent::> |
276 | package/class when it finds the C<urxvt> package/module is loaded. When |
494 | package/class when it finds the C<urxvt> package/module is loaded. When |
277 | AnyEvent is loaded and asked to find a suitable event model, it will |
495 | AnyEvent is loaded and asked to find a suitable event model, it will |
278 | first check for the presence of urxvt. |
496 | first check for the presence of urxvt. |
279 | |
497 | |
280 | The class should prove implementations for all watcher types (see |
498 | The class should provide implementations for all watcher types (see |
281 | L<AnyEvent::Impl::Event> (source code), L<AnyEvent::Impl::Glib> |
499 | L<AnyEvent::Impl::Event> (source code), L<AnyEvent::Impl::Glib> |
282 | (Source code) and so on for actual examples, use C<perldoc -m |
500 | (Source code) and so on for actual examples, use C<perldoc -m |
283 | AnyEvent::Impl::Glib> to see the sources). |
501 | AnyEvent::Impl::Glib> to see the sources). |
284 | |
502 | |
285 | The above isn't fictitious, the I<rxvt-unicode> (a.k.a. urxvt) |
503 | The above isn't fictitious, the I<rxvt-unicode> (a.k.a. urxvt) |
… | |
… | |
289 | I<rxvt-unicode> distribution. |
507 | I<rxvt-unicode> distribution. |
290 | |
508 | |
291 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
509 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
292 | condition variables: code blocking while waiting for a condition will |
510 | condition variables: code blocking while waiting for a condition will |
293 | C<die>. This still works with most modules/usages, and blocking calls must |
511 | C<die>. This still works with most modules/usages, and blocking calls must |
294 | not be in an interactive appliation, so it makes sense. |
512 | not be in an interactive application, so it makes sense. |
295 | |
513 | |
296 | =head1 ENVIRONMENT VARIABLES |
514 | =head1 ENVIRONMENT VARIABLES |
297 | |
515 | |
298 | The following environment variables are used by this module: |
516 | The following environment variables are used by this module: |
299 | |
517 | |