… | |
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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 | |
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174 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
222 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
175 | |
223 | |
176 | =head2 CHILD PROCESS WATCHERS |
224 | =head2 CHILD PROCESS WATCHERS |
177 | |
225 | |
178 | You can also listen for the status of a child process specified by the |
226 | 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 |
227 | C<pid> argument (or any child if the pid argument is 0). The watcher will |
180 | installing a signal handler for C<SIGCHLD>. |
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). |
181 | |
231 | |
182 | Example: wait for pid 1333 |
232 | Example: wait for pid 1333 |
183 | |
233 | |
184 | my $w = AnyEvent->child (pid => 1333, cb => sub { warn "exit status $?" }); |
234 | my $w = AnyEvent->child (pid => 1333, cb => sub { warn "exit status $?" }); |
185 | |
235 | |
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195 | 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 |
196 | 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>). |
197 | |
247 | |
198 | The known classes so far are: |
248 | The known classes so far are: |
199 | |
249 | |
200 | 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. |
201 | AnyEvent::Impl::Event based on Event, also best choice :) |
253 | AnyEvent::Impl::Event based on Event, also second best choice :) |
202 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
254 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
203 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
255 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
204 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
256 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
205 | |
257 | |
206 | =item AnyEvent::detect |
258 | =item AnyEvent::detect |
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248 | no warnings; |
300 | no warnings; |
249 | use strict; |
301 | use strict; |
250 | |
302 | |
251 | use Carp; |
303 | use Carp; |
252 | |
304 | |
253 | our $VERSION = '2.52'; |
305 | our $VERSION = '3.0'; |
254 | our $MODEL; |
306 | our $MODEL; |
255 | |
307 | |
256 | our $AUTOLOAD; |
308 | our $AUTOLOAD; |
257 | our @ISA; |
309 | our @ISA; |
258 | |
310 | |
259 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
311 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
260 | |
312 | |
261 | our @REGISTRY; |
313 | our @REGISTRY; |
262 | |
314 | |
263 | my @models = ( |
315 | my @models = ( |
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316 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
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317 | [EV:: => AnyEvent::Impl::EV::], |
264 | [Coro::Event:: => AnyEvent::Impl::Coro::], |
318 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
265 | [Event:: => AnyEvent::Impl::Event::], |
319 | [Event:: => AnyEvent::Impl::Event::], |
266 | [Glib:: => AnyEvent::Impl::Glib::], |
320 | [Glib:: => AnyEvent::Impl::Glib::], |
267 | [Tk:: => AnyEvent::Impl::Tk::], |
321 | [Tk:: => AnyEvent::Impl::Tk::], |
268 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
322 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
269 | ); |
323 | ); |
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299 | last; |
353 | last; |
300 | } |
354 | } |
301 | } |
355 | } |
302 | |
356 | |
303 | $MODEL |
357 | $MODEL |
304 | 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."; |
305 | } |
359 | } |
306 | |
360 | |
307 | unshift @ISA, $MODEL; |
361 | unshift @ISA, $MODEL; |
308 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
362 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
309 | } |
363 | } |
… | |
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367 | |
421 | |
368 | # default implementation for ->child |
422 | # default implementation for ->child |
369 | |
423 | |
370 | our %PID_CB; |
424 | our %PID_CB; |
371 | our $CHLD_W; |
425 | our $CHLD_W; |
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426 | our $CHLD_DELAY_W; |
372 | our $PID_IDLE; |
427 | our $PID_IDLE; |
373 | our $WNOHANG; |
428 | our $WNOHANG; |
374 | |
429 | |
375 | sub _child_wait { |
430 | sub _child_wait { |
376 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
431 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
377 | $_->() for values %{ (delete $PID_CB{$pid}) || {} }; |
432 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
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433 | (values %{ $PID_CB{0} || {} }); |
378 | } |
434 | } |
379 | |
435 | |
380 | undef $PID_IDLE; |
436 | undef $PID_IDLE; |
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437 | } |
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438 | |
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439 | sub _sigchld { |
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440 | # make sure we deliver these changes "synchronous" with the event loop. |
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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; |
|
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444 | }); |
381 | } |
445 | } |
382 | |
446 | |
383 | sub child { |
447 | sub child { |
384 | my (undef, %arg) = @_; |
448 | my (undef, %arg) = @_; |
385 | |
449 | |
386 | my $pid = uc $arg{pid} |
450 | defined (my $pid = $arg{pid} + 0) |
387 | or Carp::croak "required option 'pid' is missing"; |
451 | or Carp::croak "required option 'pid' is missing"; |
388 | |
452 | |
389 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
453 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
390 | |
454 | |
391 | unless ($WNOHANG) { |
455 | unless ($WNOHANG) { |
392 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
456 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
393 | } |
457 | } |
394 | |
458 | |
395 | unless ($CHLD_W) { |
459 | unless ($CHLD_W) { |
396 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_child_wait); |
460 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
397 | # child could be a zombie already |
461 | # child could be a zombie already, so make at least one round |
398 | $PID_IDLE ||= AnyEvent->timer (after => 0, cb => \&_child_wait); |
462 | &_sigchld; |
399 | } |
463 | } |
400 | |
464 | |
401 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
465 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
402 | } |
466 | } |
403 | |
467 | |
… | |
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440 | I<rxvt-unicode> distribution. |
504 | I<rxvt-unicode> distribution. |
441 | |
505 | |
442 | 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 |
443 | condition variables: code blocking while waiting for a condition will |
507 | condition variables: code blocking while waiting for a condition will |
444 | 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 |
445 | not be in an interactive appliation, so it makes sense. |
509 | not be in an interactive application, so it makes sense. |
446 | |
510 | |
447 | =head1 ENVIRONMENT VARIABLES |
511 | =head1 ENVIRONMENT VARIABLES |
448 | |
512 | |
449 | The following environment variables are used by this module: |
513 | The following environment variables are used by this module: |
450 | |
514 | |