1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - provide framework for multiple event loops |
4 | |
4 | |
5 | Event, Coro, Glib, Tk - various supported event loops |
5 | Event, Coro, Glib, Tk, Perl - various supported event loops |
6 | |
6 | |
7 | =head1 SYNOPSIS |
7 | =head1 SYNOPSIS |
8 | |
8 | |
9 | use AnyEvent; |
9 | use AnyEvent; |
10 | |
10 | |
11 | my $w = AnyEvent->io (fh => ..., poll => "[rw]+", cb => sub { |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { |
12 | my ($poll_got) = @_; |
|
|
13 | ... |
12 | ... |
14 | }); |
13 | }); |
15 | |
|
|
16 | - only one io watcher per $fh and $poll type is allowed |
|
|
17 | (i.e. on a socket you can have one r + one w or one rw |
|
|
18 | watcher, not any more. |
|
|
19 | |
|
|
20 | - AnyEvent will keep filehandles alive, so as long as the watcher exists, |
|
|
21 | the filehandle exists. |
|
|
22 | |
14 | |
23 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
24 | ... |
16 | ... |
25 | }); |
17 | }); |
26 | |
18 | |
27 | - io and time watchers get canceled whenever $w is destroyed, so keep a copy |
19 | my $w = AnyEvent->condvar; # stores wether a condition was flagged |
28 | |
|
|
29 | - timers can only be used once and must be recreated for repeated operation |
|
|
30 | |
|
|
31 | my $w = AnyEvent->condvar; # kind of main loop replacement |
|
|
32 | $w->wait; # enters main loop till $condvar gets ->broadcast |
20 | $w->wait; # enters "main loop" till $condvar gets ->broadcast |
33 | $w->broadcast; # wake up current and all future wait's |
21 | $w->broadcast; # wake up current and all future wait's |
34 | |
22 | |
35 | - condvars are used to give blocking behaviour when neccessary. Create |
23 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
36 | a condvar for any "request" or "event" your module might create, C<< |
24 | |
37 | ->broadcast >> it when the event happens and provide a function that calls |
25 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
38 | C<< ->wait >> for it. See the examples below. |
26 | nowadays. So what is different about AnyEvent? |
|
|
27 | |
|
|
28 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
|
|
29 | policy> and AnyEvent is I<small and efficient>. |
|
|
30 | |
|
|
31 | First and foremost, I<AnyEvent is not an event model> itself, it only |
|
|
32 | interfaces to whatever event model the main program happens to use in a |
|
|
33 | pragmatic way. For event models and certain classes of immortals alike, |
|
|
34 | the statement "there can only be one" is a bitter reality, and AnyEvent |
|
|
35 | helps hiding the differences. |
|
|
36 | |
|
|
37 | The goal of AnyEvent is to offer module authors the ability to do event |
|
|
38 | programming (waiting for I/O or timer events) without subscribing to a |
|
|
39 | religion, a way of living, and most importantly: without forcing your |
|
|
40 | module users into the same thing by forcing them to use the same event |
|
|
41 | model you use. |
|
|
42 | |
|
|
43 | For modules like POE or IO::Async (which is actually doing all I/O |
|
|
44 | I<synchronously>...), using them in your module is like joining a |
|
|
45 | cult: After you joined, you are dependent on them and you cannot use |
|
|
46 | anything else, as it is simply incompatible to everything that isn't |
|
|
47 | itself. |
|
|
48 | |
|
|
49 | AnyEvent + POE works fine. AnyEvent + Glib works fine. AnyEvent + Tk |
|
|
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 |
|
|
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 |
|
|
54 | (including stuff like POE and IO::Async). |
|
|
55 | |
|
|
56 | In addition of being free of having to use I<the one and only true event |
|
|
57 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
|
|
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 |
|
|
60 | offering the functionality that is useful, in as thin as a wrapper as |
|
|
61 | technically possible. |
|
|
62 | |
|
|
63 | Of course, if you want lots of policy (this can arguably be somewhat |
|
|
64 | useful) and you want to force your users to use the one and only event |
|
|
65 | model, you should I<not> use this module. |
|
|
66 | |
39 | |
67 | |
40 | =head1 DESCRIPTION |
68 | =head1 DESCRIPTION |
41 | |
69 | |
42 | L<AnyEvent> provides an identical interface to multiple event loops. This |
70 | L<AnyEvent> provides an identical interface to multiple event loops. This |
43 | allows module authors to utilizy an event loop without forcing module |
71 | allows module authors to utilise an event loop without forcing module |
44 | users to use the same event loop (as only a single event loop can coexist |
72 | users to use the same event loop (as only a single event loop can coexist |
45 | peacefully at any one time). |
73 | peacefully at any one time). |
46 | |
74 | |
47 | The interface itself is vaguely similar but not identical to the Event |
75 | The interface itself is vaguely similar but not identical to the Event |
48 | module. |
76 | module. |
… | |
… | |
50 | On the first call of any method, the module tries to detect the currently |
78 | On the first call of any method, the module tries to detect the currently |
51 | loaded event loop by probing wether any of the following modules is |
79 | loaded event loop by probing wether any of the following modules is |
52 | loaded: L<Coro::Event>, L<Event>, L<Glib>, L<Tk>. The first one found is |
80 | loaded: L<Coro::Event>, L<Event>, L<Glib>, L<Tk>. The first one found is |
53 | used. If none is found, the module tries to load these modules in the |
81 | used. If none is found, the module tries to load these modules in the |
54 | order given. The first one that could be successfully loaded will be |
82 | order given. The first one that could be successfully loaded will be |
55 | used. If still none could be found, it will issue an error. |
83 | used. If still none could be found, AnyEvent will fall back to a pure-perl |
|
|
84 | event loop, which is also not very efficient. |
|
|
85 | |
|
|
86 | Because AnyEvent first checks for modules that are already loaded, loading |
|
|
87 | an Event model explicitly before first using AnyEvent will likely make |
|
|
88 | that model the default. For example: |
|
|
89 | |
|
|
90 | use Tk; |
|
|
91 | use AnyEvent; |
|
|
92 | |
|
|
93 | # .. AnyEvent will likely default to Tk |
|
|
94 | |
|
|
95 | The pure-perl implementation of AnyEvent is called |
|
|
96 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
|
|
97 | explicitly. |
|
|
98 | |
|
|
99 | =head1 WATCHERS |
|
|
100 | |
|
|
101 | AnyEvent has the central concept of a I<watcher>, which is an object that |
|
|
102 | stores relevant data for each kind of event you are waiting for, such as |
|
|
103 | the callback to call, the filehandle to watch, etc. |
|
|
104 | |
|
|
105 | These watchers are normal Perl objects with normal Perl lifetime. After |
|
|
106 | creating a watcher it will immediately "watch" for events and invoke |
|
|
107 | the callback. To disable the watcher you have to destroy it (e.g. by |
|
|
108 | setting the variable that stores it to C<undef> or otherwise deleting all |
|
|
109 | references to it). |
|
|
110 | |
|
|
111 | All watchers are created by calling a method on the C<AnyEvent> class. |
|
|
112 | |
|
|
113 | =head2 IO WATCHERS |
|
|
114 | |
|
|
115 | You can create I/O watcher by calling the C<< AnyEvent->io >> method with |
|
|
116 | the following mandatory arguments: |
|
|
117 | |
|
|
118 | C<fh> the Perl I<filehandle> (not filedescriptor) to watch for |
|
|
119 | events. C<poll> must be a string that is either C<r> or C<w>, that creates |
|
|
120 | a watcher waiting for "r"eadable or "w"ritable events. C<cb> the callback |
|
|
121 | to invoke everytime the filehandle becomes ready. |
|
|
122 | |
|
|
123 | Only one io watcher per C<fh> and C<poll> combination is allowed (i.e. on |
|
|
124 | a socket you can have one r + one w, not any more (limitation comes from |
|
|
125 | Tk - if you are sure you are not using Tk this limitation is gone). |
|
|
126 | |
|
|
127 | Filehandles will be kept alive, so as long as the watcher exists, the |
|
|
128 | filehandle exists, too. |
|
|
129 | |
|
|
130 | Example: |
|
|
131 | |
|
|
132 | # wait for readability of STDIN, then read a line and disable the watcher |
|
|
133 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
|
|
134 | chomp (my $input = <STDIN>); |
|
|
135 | warn "read: $input\n"; |
|
|
136 | undef $w; |
|
|
137 | }); |
|
|
138 | |
|
|
139 | =head2 TIME WATCHERS |
|
|
140 | |
|
|
141 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
|
|
142 | method with the following mandatory arguments: |
|
|
143 | |
|
|
144 | C<after> after how many seconds (fractions are supported) should the timer |
|
|
145 | activate. C<cb> the callback to invoke. |
|
|
146 | |
|
|
147 | The timer callback will be invoked at most once: if you want a repeating |
|
|
148 | timer you have to create a new watcher (this is a limitation by both Tk |
|
|
149 | and Glib). |
|
|
150 | |
|
|
151 | Example: |
|
|
152 | |
|
|
153 | # fire an event after 7.7 seconds |
|
|
154 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
|
|
155 | warn "timeout\n"; |
|
|
156 | }); |
|
|
157 | |
|
|
158 | # to cancel the timer: |
|
|
159 | undef $w; |
|
|
160 | |
|
|
161 | =head2 CONDITION WATCHERS |
|
|
162 | |
|
|
163 | Condition watchers can be created by calling the C<< AnyEvent->condvar >> |
|
|
164 | method without any arguments. |
|
|
165 | |
|
|
166 | A condition watcher watches for a condition - precisely that the C<< |
|
|
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 |
|
|
172 | you should avoid making a blocking wait, at least in callbacks, as this |
|
|
173 | usually asks for trouble. |
|
|
174 | |
|
|
175 | The watcher has only two methods: |
56 | |
176 | |
57 | =over 4 |
177 | =over 4 |
58 | |
178 | |
|
|
179 | =item $cv->wait |
|
|
180 | |
|
|
181 | Wait (blocking if necessary) until the C<< ->broadcast >> method has been |
|
|
182 | called on c<$cv>, while servicing other watchers normally. |
|
|
183 | |
|
|
184 | You can only wait once on a condition - additional calls will return |
|
|
185 | immediately. |
|
|
186 | |
|
|
187 | Not all event models support a blocking wait - some die in that case |
|
|
188 | (programs might want to do that so they stay interactive), so I<if you |
|
|
189 | are using this from a module, never require a blocking wait>, but let the |
|
|
190 | caller decide wether the call will block or not (for example, by coupling |
|
|
191 | condition variables with some kind of request results and supporting |
|
|
192 | callbacks so the caller knows that getting the result will not block, |
|
|
193 | while still suppporting blocking waits if the caller so desires). |
|
|
194 | |
|
|
195 | Another reason I<never> to C<< ->wait >> in a module is that you cannot |
|
|
196 | sensibly have two C<< ->wait >>'s in parallel, as that would require |
|
|
197 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
|
|
198 | can supply (the coroutine-aware backends C<Coro::EV> and C<Coro::Event> |
|
|
199 | explicitly support concurrent C<< ->wait >>'s from different coroutines, |
|
|
200 | however). |
|
|
201 | |
|
|
202 | =item $cv->broadcast |
|
|
203 | |
|
|
204 | Flag the condition as ready - a running C<< ->wait >> and all further |
|
|
205 | calls to C<wait> will return after this method has been called. If nobody |
|
|
206 | is waiting the broadcast will be remembered.. |
|
|
207 | |
|
|
208 | Example: |
|
|
209 | |
|
|
210 | # wait till the result is ready |
|
|
211 | my $result_ready = AnyEvent->condvar; |
|
|
212 | |
|
|
213 | # do something such as adding a timer |
|
|
214 | # or socket watcher the calls $result_ready->broadcast |
|
|
215 | # when the "result" is ready. |
|
|
216 | |
|
|
217 | $result_ready->wait; |
|
|
218 | |
|
|
219 | =back |
|
|
220 | |
|
|
221 | =head2 SIGNAL WATCHERS |
|
|
222 | |
|
|
223 | You can listen for signals using a signal watcher, C<signal> is the signal |
|
|
224 | I<name> without any C<SIG> prefix. Multiple signals events can be clumped |
|
|
225 | together into one callback invocation, and callback invocation might or |
|
|
226 | might not be asynchronous. |
|
|
227 | |
|
|
228 | These watchers might use C<%SIG>, so programs overwriting those signals |
|
|
229 | directly will likely not work correctly. |
|
|
230 | |
|
|
231 | Example: exit on SIGINT |
|
|
232 | |
|
|
233 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
|
|
234 | |
|
|
235 | =head2 CHILD PROCESS WATCHERS |
|
|
236 | |
|
|
237 | You can also listen for the status of a child process specified by the |
|
|
238 | C<pid> argument (or any child if the pid argument is 0). The watcher will |
|
|
239 | trigger as often as status change for the child are received. This works |
|
|
240 | by installing a signal handler for C<SIGCHLD>. The callback will be called with |
|
|
241 | the pid and exit status (as returned by waitpid). |
|
|
242 | |
|
|
243 | Example: wait for pid 1333 |
|
|
244 | |
|
|
245 | my $w = AnyEvent->child (pid => 1333, cb => sub { warn "exit status $?" }); |
|
|
246 | |
|
|
247 | =head1 GLOBALS |
|
|
248 | |
|
|
249 | =over 4 |
|
|
250 | |
|
|
251 | =item $AnyEvent::MODEL |
|
|
252 | |
|
|
253 | Contains C<undef> until the first watcher is being created. Then it |
|
|
254 | contains the event model that is being used, which is the name of the |
|
|
255 | Perl class implementing the model. This class is usually one of the |
|
|
256 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
|
|
257 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
|
|
258 | |
|
|
259 | The known classes so far are: |
|
|
260 | |
|
|
261 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
|
|
262 | AnyEvent::Impl::EV based on EV (an interface to libev, also best choice). |
|
|
263 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
|
|
264 | AnyEvent::Impl::Event based on Event, also second best choice :) |
|
|
265 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
|
|
266 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
|
|
267 | AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable. |
|
|
268 | |
|
|
269 | =item AnyEvent::detect |
|
|
270 | |
|
|
271 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model if |
|
|
272 | necessary. You should only call this function right before you would have |
|
|
273 | created an AnyEvent watcher anyway, that is, very late at runtime. |
|
|
274 | |
|
|
275 | =back |
|
|
276 | |
|
|
277 | =head1 WHAT TO DO IN A MODULE |
|
|
278 | |
|
|
279 | As a module author, you should "use AnyEvent" and call AnyEvent methods |
|
|
280 | freely, but you should not load a specific event module or rely on it. |
|
|
281 | |
|
|
282 | Be careful when you create watchers in the module body - Anyevent will |
|
|
283 | decide which event module to use as soon as the first method is called, so |
|
|
284 | by calling AnyEvent in your module body you force the user of your module |
|
|
285 | to load the event module first. |
|
|
286 | |
|
|
287 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
|
|
288 | |
|
|
289 | There will always be a single main program - the only place that should |
|
|
290 | dictate which event model to use. |
|
|
291 | |
|
|
292 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
|
|
293 | do anything special and let AnyEvent decide which implementation to chose. |
|
|
294 | |
|
|
295 | If the main program relies on a specific event model (for example, in Gtk2 |
|
|
296 | programs you have to rely on either Glib or Glib::Event), you should load |
|
|
297 | it before loading AnyEvent or any module that uses it, generally, as early |
|
|
298 | as possible. The reason is that modules might create watchers when they |
|
|
299 | are loaded, and AnyEvent will decide on the event model to use as soon as |
|
|
300 | it creates watchers, and it might chose the wrong one unless you load the |
|
|
301 | correct one yourself. |
|
|
302 | |
|
|
303 | You can chose to use a rather inefficient pure-perl implementation by |
|
|
304 | loading the C<AnyEvent::Impl::Perl> module, but letting AnyEvent chose is |
|
|
305 | generally better. |
|
|
306 | |
59 | =cut |
307 | =cut |
60 | |
308 | |
61 | package AnyEvent; |
309 | package AnyEvent; |
62 | |
310 | |
63 | no warnings; |
311 | no warnings; |
64 | use strict 'vars'; |
312 | use strict; |
|
|
313 | |
65 | use Carp; |
314 | use Carp; |
66 | |
315 | |
67 | our $VERSION = 0.3; |
316 | our $VERSION = '3.0'; |
68 | our $MODEL; |
317 | our $MODEL; |
69 | |
318 | |
70 | our $AUTOLOAD; |
319 | our $AUTOLOAD; |
71 | our @ISA; |
320 | our @ISA; |
72 | |
321 | |
|
|
322 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
|
|
323 | |
|
|
324 | our @REGISTRY; |
|
|
325 | |
73 | my @models = ( |
326 | my @models = ( |
74 | [Coro => Coro::Event::], |
327 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
75 | [Event => Event::], |
328 | [EV:: => AnyEvent::Impl::EV::], |
76 | [Glib => Glib::], |
329 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
77 | [Tk => Tk::], |
330 | [Event:: => AnyEvent::Impl::Event::], |
|
|
331 | [Glib:: => AnyEvent::Impl::Glib::], |
|
|
332 | [Tk:: => AnyEvent::Impl::Tk::], |
|
|
333 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
78 | ); |
334 | ); |
79 | |
335 | |
80 | our %method = map +($_ => 1), qw(io timer condvar broadcast wait cancel DESTROY); |
336 | our %method = map +($_ => 1), qw(io timer condvar broadcast wait signal one_event DESTROY); |
81 | |
337 | |
82 | sub AUTOLOAD { |
338 | sub detect() { |
83 | $AUTOLOAD =~ s/.*://; |
|
|
84 | |
|
|
85 | $method{$AUTOLOAD} |
|
|
86 | or croak "$AUTOLOAD: not a valid method for AnyEvent objects"; |
|
|
87 | |
|
|
88 | unless ($MODEL) { |
339 | unless ($MODEL) { |
|
|
340 | no strict 'refs'; |
|
|
341 | |
89 | # check for already loaded models |
342 | # check for already loaded models |
90 | for (@models) { |
343 | for (@REGISTRY, @models) { |
91 | my ($model, $package) = @$_; |
344 | my ($package, $model) = @$_; |
92 | if (scalar keys %{ *{"$package\::"} }) { |
345 | if (${"$package\::VERSION"} > 0) { |
93 | eval "require AnyEvent::Impl::$model"; |
346 | if (eval "require $model") { |
94 | last if $MODEL; |
347 | $MODEL = $model; |
|
|
348 | warn "AnyEvent: found model '$model', using it.\n" if $verbose > 1; |
|
|
349 | last; |
|
|
350 | } |
95 | } |
351 | } |
96 | } |
352 | } |
97 | |
353 | |
98 | unless ($MODEL) { |
354 | unless ($MODEL) { |
99 | # try to load a model |
355 | # try to load a model |
100 | |
356 | |
101 | for (@models) { |
357 | for (@REGISTRY, @models) { |
102 | my ($model, $package) = @$_; |
358 | my ($package, $model) = @$_; |
103 | eval "require AnyEvent::Impl::$model"; |
359 | if (eval "require $package" |
104 | last if $MODEL; |
360 | and ${"$package\::VERSION"} > 0 |
|
|
361 | and eval "require $model") { |
|
|
362 | $MODEL = $model; |
|
|
363 | warn "AnyEvent: autoprobed and loaded model '$model', using it.\n" if $verbose > 1; |
|
|
364 | last; |
|
|
365 | } |
105 | } |
366 | } |
106 | |
367 | |
107 | $MODEL |
368 | $MODEL |
108 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: 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."; |
109 | } |
370 | } |
|
|
371 | |
|
|
372 | unshift @ISA, $MODEL; |
|
|
373 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
110 | } |
374 | } |
111 | |
375 | |
112 | @ISA = $MODEL; |
376 | $MODEL |
|
|
377 | } |
|
|
378 | |
|
|
379 | sub AUTOLOAD { |
|
|
380 | (my $func = $AUTOLOAD) =~ s/.*://; |
|
|
381 | |
|
|
382 | $method{$func} |
|
|
383 | or croak "$func: not a valid method for AnyEvent objects"; |
|
|
384 | |
|
|
385 | detect unless $MODEL; |
113 | |
386 | |
114 | my $class = shift; |
387 | my $class = shift; |
115 | $class->$AUTOLOAD (@_); |
388 | $class->$func (@_); |
116 | } |
389 | } |
117 | |
390 | |
118 | =back |
391 | package AnyEvent::Base; |
|
|
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 | |
|
|
407 | # default implementation for ->signal |
|
|
408 | |
|
|
409 | our %SIG_CB; |
|
|
410 | |
|
|
411 | sub signal { |
|
|
412 | my (undef, %arg) = @_; |
|
|
413 | |
|
|
414 | my $signal = uc $arg{signal} |
|
|
415 | or Carp::croak "required option 'signal' is missing"; |
|
|
416 | |
|
|
417 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
418 | $SIG{$signal} ||= sub { |
|
|
419 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
|
|
420 | }; |
|
|
421 | |
|
|
422 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
|
|
423 | } |
|
|
424 | |
|
|
425 | sub AnyEvent::Base::Signal::DESTROY { |
|
|
426 | my ($signal, $cb) = @{$_[0]}; |
|
|
427 | |
|
|
428 | delete $SIG_CB{$signal}{$cb}; |
|
|
429 | |
|
|
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; |
|
|
486 | } |
|
|
487 | |
|
|
488 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
|
|
489 | |
|
|
490 | If you need to support another event library which isn't directly |
|
|
491 | supported by AnyEvent, you can supply your own interface to it by |
|
|
492 | pushing, before the first watcher gets created, the package name of |
|
|
493 | the event module and the package name of the interface to use onto |
|
|
494 | C<@AnyEvent::REGISTRY>. You can do that before and even without loading |
|
|
495 | AnyEvent. |
|
|
496 | |
|
|
497 | Example: |
|
|
498 | |
|
|
499 | push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::]; |
|
|
500 | |
|
|
501 | This tells AnyEvent to (literally) use the C<urxvt::anyevent::> |
|
|
502 | package/class when it finds the C<urxvt> package/module is loaded. When |
|
|
503 | AnyEvent is loaded and asked to find a suitable event model, it will |
|
|
504 | first check for the presence of urxvt. |
|
|
505 | |
|
|
506 | The class should provide implementations for all watcher types (see |
|
|
507 | L<AnyEvent::Impl::Event> (source code), L<AnyEvent::Impl::Glib> |
|
|
508 | (Source code) and so on for actual examples, use C<perldoc -m |
|
|
509 | AnyEvent::Impl::Glib> to see the sources). |
|
|
510 | |
|
|
511 | The above isn't fictitious, the I<rxvt-unicode> (a.k.a. urxvt) |
|
|
512 | uses the above line as-is. An interface isn't included in AnyEvent |
|
|
513 | because it doesn't make sense outside the embedded interpreter inside |
|
|
514 | I<rxvt-unicode>, and it is updated and maintained as part of the |
|
|
515 | I<rxvt-unicode> distribution. |
|
|
516 | |
|
|
517 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
|
|
518 | condition variables: code blocking while waiting for a condition will |
|
|
519 | C<die>. This still works with most modules/usages, and blocking calls must |
|
|
520 | not be in an interactive application, so it makes sense. |
|
|
521 | |
|
|
522 | =head1 ENVIRONMENT VARIABLES |
|
|
523 | |
|
|
524 | The following environment variables are used by this module: |
|
|
525 | |
|
|
526 | C<PERL_ANYEVENT_VERBOSE> when set to C<2> or higher, reports which event |
|
|
527 | model gets used. |
119 | |
528 | |
120 | =head1 EXAMPLE |
529 | =head1 EXAMPLE |
121 | |
530 | |
122 | The following program uses an io watcher to read data from stdin, a timer |
531 | The following program uses an io watcher to read data from stdin, a timer |
123 | to display a message once per second, and a condvar to exit the program |
532 | to display a message once per second, and a condvar to exit the program |
… | |
… | |
183 | connect $txn->{fh}, ... |
592 | connect $txn->{fh}, ... |
184 | and !$!{EWOULDBLOCK} |
593 | and !$!{EWOULDBLOCK} |
185 | and !$!{EINPROGRESS} |
594 | and !$!{EINPROGRESS} |
186 | and Carp::croak "unable to connect: $!\n"; |
595 | and Carp::croak "unable to connect: $!\n"; |
187 | |
596 | |
188 | Then it creates a write-watcher which gets called wehnever an error occurs |
597 | Then it creates a write-watcher which gets called whenever an error occurs |
189 | or the connection succeeds: |
598 | or the connection succeeds: |
190 | |
599 | |
191 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'w', cb => sub { $txn->fh_ready_w }); |
600 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'w', cb => sub { $txn->fh_ready_w }); |
192 | |
601 | |
193 | And returns this transaction object. The C<fh_ready_w> callback gets |
602 | And returns this transaction object. The C<fh_ready_w> callback gets |
… | |
… | |
210 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
619 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
211 | |
620 | |
212 | if (end-of-file or data complete) { |
621 | if (end-of-file or data complete) { |
213 | $txn->{result} = $txn->{buf}; |
622 | $txn->{result} = $txn->{buf}; |
214 | $txn->{finished}->broadcast; |
623 | $txn->{finished}->broadcast; |
|
|
624 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
215 | } |
625 | } |
216 | |
626 | |
217 | The C<result> method, finally, just waits for the finished signal (if the |
627 | The C<result> method, finally, just waits for the finished signal (if the |
218 | request was already finished, it doesn't wait, of course, and returns the |
628 | request was already finished, it doesn't wait, of course, and returns the |
219 | data: |
629 | data: |
220 | |
630 | |
221 | $txn->{finished}->wait; |
631 | $txn->{finished}->wait; |
222 | return $txn->{buf}; |
632 | return $txn->{result}; |
223 | |
633 | |
224 | The actual code goes further and collects all errors (C<die>s, exceptions) |
634 | The actual code goes further and collects all errors (C<die>s, exceptions) |
225 | that occured during request processing. The C<result> method detects |
635 | that occured during request processing. The C<result> method detects |
226 | wether an exception as thrown (it is stored inside the $txn object) |
636 | wether an exception as thrown (it is stored inside the $txn object) |
227 | and just throws the exception, which means connection errors and other |
637 | and just throws the exception, which means connection errors and other |