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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 (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 | |
22 | |
63 | |
23 | =head1 DESCRIPTION |
64 | =head1 DESCRIPTION |
24 | |
65 | |
25 | L<AnyEvent> provides an identical interface to multiple event loops. This |
66 | L<AnyEvent> provides an identical interface to multiple event loops. This |
26 | allows module authors to utilise an event loop without forcing module |
67 | allows module authors to utilise an event loop without forcing module |
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70 | You can create I/O watcher by calling the C<< AnyEvent->io >> method with |
111 | You can create I/O watcher by calling the C<< AnyEvent->io >> method with |
71 | the following mandatory arguments: |
112 | the following mandatory arguments: |
72 | |
113 | |
73 | C<fh> the Perl I<filehandle> (not filedescriptor) to watch for |
114 | 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 |
115 | 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 |
116 | a watcher waiting for "r"eadable or "w"ritable events. C<cb> the callback |
76 | to invoke everytime the filehandle becomes ready. |
117 | to invoke everytime the filehandle becomes ready. |
77 | |
118 | |
78 | Only one io watcher per C<fh> and C<poll> combination is allowed (i.e. on |
119 | 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 |
120 | 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). |
121 | Tk - if you are sure you are not using Tk this limitation is gone). |
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109 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
150 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
110 | warn "timeout\n"; |
151 | warn "timeout\n"; |
111 | }); |
152 | }); |
112 | |
153 | |
113 | # to cancel the timer: |
154 | # to cancel the timer: |
114 | undef $w |
155 | undef $w; |
115 | |
156 | |
116 | =head2 CONDITION WATCHERS |
157 | =head2 CONDITION WATCHERS |
117 | |
158 | |
118 | Condition watchers can be created by calling the C<< AnyEvent->condvar >> |
159 | Condition watchers can be created by calling the C<< AnyEvent->condvar >> |
119 | method without any arguments. |
160 | method without any arguments. |
120 | |
161 | |
121 | A condition watcher watches for a condition - precisely that the C<< |
162 | A condition watcher watches for a condition - precisely that the C<< |
122 | ->broadcast >> method has been called. |
163 | ->broadcast >> method has been called. |
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164 | |
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165 | Note that condition watchers recurse into the event loop - if you have |
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166 | two watchers that call C<< ->wait >> in a round-robbin fashion, you |
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167 | lose. Therefore, condition watchers are good to export to your caller, but |
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168 | you should avoid making a blocking wait, at least in callbacks, as this |
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169 | usually asks for trouble. |
123 | |
170 | |
124 | The watcher has only two methods: |
171 | The watcher has only two methods: |
125 | |
172 | |
126 | =over 4 |
173 | =over 4 |
127 | |
174 | |
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199 | |
246 | |
200 | The known classes so far are: |
247 | The known classes so far are: |
201 | |
248 | |
202 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
249 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
203 | AnyEvent::Impl::EV based on EV (an interface to libev, also best choice). |
250 | AnyEvent::Impl::EV based on EV (an interface to libev, also best choice). |
204 | AnyEvent::Impl::Coro based on Coro::Event, second best choice. |
251 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
205 | AnyEvent::Impl::Event based on Event, also second best choice :) |
252 | AnyEvent::Impl::Event based on Event, also second best choice :) |
206 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
253 | AnyEvent::Impl::Glib based on Glib, second-best choice. |
207 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
254 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
208 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
255 | AnyEvent::Impl::Perl pure-perl implementation, inefficient. |
209 | |
256 | |
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252 | no warnings; |
299 | no warnings; |
253 | use strict; |
300 | use strict; |
254 | |
301 | |
255 | use Carp; |
302 | use Carp; |
256 | |
303 | |
257 | our $VERSION = '2.6'; |
304 | our $VERSION = '3.0'; |
258 | our $MODEL; |
305 | our $MODEL; |
259 | |
306 | |
260 | our $AUTOLOAD; |
307 | our $AUTOLOAD; |
261 | our @ISA; |
308 | our @ISA; |
262 | |
309 | |
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265 | our @REGISTRY; |
312 | our @REGISTRY; |
266 | |
313 | |
267 | my @models = ( |
314 | my @models = ( |
268 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
315 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
269 | [EV:: => AnyEvent::Impl::EV::], |
316 | [EV:: => AnyEvent::Impl::EV::], |
270 | [Coro::Event:: => AnyEvent::Impl::Coro::], |
317 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
271 | [Event:: => AnyEvent::Impl::Event::], |
318 | [Event:: => AnyEvent::Impl::Event::], |
272 | [Glib:: => AnyEvent::Impl::Glib::], |
319 | [Glib:: => AnyEvent::Impl::Glib::], |
273 | [Tk:: => AnyEvent::Impl::Tk::], |
320 | [Tk:: => AnyEvent::Impl::Tk::], |
274 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
321 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
275 | ); |
322 | ); |
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373 | |
420 | |
374 | # default implementation for ->child |
421 | # default implementation for ->child |
375 | |
422 | |
376 | our %PID_CB; |
423 | our %PID_CB; |
377 | our $CHLD_W; |
424 | our $CHLD_W; |
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425 | our $CHLD_DELAY_W; |
378 | our $PID_IDLE; |
426 | our $PID_IDLE; |
379 | our $WNOHANG; |
427 | our $WNOHANG; |
380 | |
428 | |
381 | sub _child_wait { |
429 | sub _child_wait { |
382 | while (0 <= (my $pid = waitpid -1, $WNOHANG)) { |
430 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
383 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
431 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
384 | (values %{ $PID_CB{0} || {} }); |
432 | (values %{ $PID_CB{0} || {} }); |
385 | } |
433 | } |
386 | |
434 | |
387 | undef $PID_IDLE; |
435 | undef $PID_IDLE; |
388 | } |
436 | } |
389 | |
437 | |
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438 | sub _sigchld { |
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439 | # make sure we deliver these changes "synchronous" with the event loop. |
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440 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
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441 | undef $CHLD_DELAY_W; |
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442 | &_child_wait; |
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443 | }); |
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444 | } |
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445 | |
390 | sub child { |
446 | sub child { |
391 | my (undef, %arg) = @_; |
447 | my (undef, %arg) = @_; |
392 | |
448 | |
393 | defined (my $pid = $arg{pid} + 0) |
449 | defined (my $pid = $arg{pid} + 0) |
394 | or Carp::croak "required option 'pid' is missing"; |
450 | or Carp::croak "required option 'pid' is missing"; |
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398 | unless ($WNOHANG) { |
454 | unless ($WNOHANG) { |
399 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
455 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
400 | } |
456 | } |
401 | |
457 | |
402 | unless ($CHLD_W) { |
458 | unless ($CHLD_W) { |
403 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_child_wait); |
459 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
404 | # child could be a zombie already |
460 | # child could be a zombie already, so make at least one round |
405 | $PID_IDLE ||= AnyEvent->timer (after => 0, cb => \&_child_wait); |
461 | &_sigchld; |
406 | } |
462 | } |
407 | |
463 | |
408 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
464 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
409 | } |
465 | } |
410 | |
466 | |