… | |
… | |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
16 | ... |
16 | ... |
17 | }); |
17 | }); |
18 | |
18 | |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
|
|
20 | $w->send; # wake up current and all future recv's |
20 | $w->wait; # enters "main loop" till $condvar gets ->send |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
21 | $w->send; # wake up current and all future wait's |
22 | |
|
|
23 | =head1 INTRODUCTION/TUTORIAL |
|
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24 | |
|
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25 | This manpage is mainly a reference manual. If you are interested |
|
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26 | in a tutorial or some gentle introduction, have a look at the |
|
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27 | L<AnyEvent::Intro> manpage. |
22 | |
28 | |
23 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
29 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
24 | |
30 | |
25 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
31 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
26 | nowadays. So what is different about AnyEvent? |
32 | nowadays. So what is different about AnyEvent? |
… | |
… | |
48 | isn't itself. What's worse, all the potential users of your module are |
54 | isn't itself. What's worse, all the potential users of your module are |
49 | I<also> forced to use the same event loop you use. |
55 | I<also> forced to use the same event loop you use. |
50 | |
56 | |
51 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
57 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
52 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
58 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
53 | with the rest: POE + IO::Async? no go. Tk + Event? no go. Again: if |
59 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
54 | your module uses one of those, every user of your module has to use it, |
60 | your module uses one of those, every user of your module has to use it, |
55 | too. But if your module uses AnyEvent, it works transparently with all |
61 | too. But if your module uses AnyEvent, it works transparently with all |
56 | event models it supports (including stuff like POE and IO::Async, as long |
62 | event models it supports (including stuff like POE and IO::Async, as long |
57 | as those use one of the supported event loops. It is trivial to add new |
63 | as those use one of the supported event loops. It is trivial to add new |
58 | event loops to AnyEvent, too, so it is future-proof). |
64 | event loops to AnyEvent, too, so it is future-proof). |
59 | |
65 | |
60 | In addition to being free of having to use I<the one and only true event |
66 | In addition to being free of having to use I<the one and only true event |
61 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
67 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
62 | modules, you get an enourmous amount of code and strict rules you have to |
68 | modules, you get an enormous amount of code and strict rules you have to |
63 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
69 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
64 | offering the functionality that is necessary, in as thin as a wrapper as |
70 | offering the functionality that is necessary, in as thin as a wrapper as |
65 | technically possible. |
71 | technically possible. |
66 | |
72 | |
|
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73 | Of course, AnyEvent comes with a big (and fully optional!) toolbox |
|
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74 | of useful functionality, such as an asynchronous DNS resolver, 100% |
|
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75 | non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms |
|
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76 | such as Windows) and lots of real-world knowledge and workarounds for |
|
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77 | platform bugs and differences. |
|
|
78 | |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
79 | Now, if you I<do want> lots of policy (this can arguably be somewhat |
68 | useful) and you want to force your users to use the one and only event |
80 | useful) and you want to force your users to use the one and only event |
69 | model, you should I<not> use this module. |
81 | model, you should I<not> use this module. |
70 | |
82 | |
71 | =head1 DESCRIPTION |
83 | =head1 DESCRIPTION |
72 | |
84 | |
… | |
… | |
102 | starts using it, all bets are off. Maybe you should tell their authors to |
114 | starts using it, all bets are off. Maybe you should tell their authors to |
103 | use AnyEvent so their modules work together with others seamlessly... |
115 | use AnyEvent so their modules work together with others seamlessly... |
104 | |
116 | |
105 | The pure-perl implementation of AnyEvent is called |
117 | The pure-perl implementation of AnyEvent is called |
106 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
118 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
107 | explicitly. |
119 | explicitly and enjoy the high availability of that event loop :) |
108 | |
120 | |
109 | =head1 WATCHERS |
121 | =head1 WATCHERS |
110 | |
122 | |
111 | AnyEvent has the central concept of a I<watcher>, which is an object that |
123 | AnyEvent has the central concept of a I<watcher>, which is an object that |
112 | stores relevant data for each kind of event you are waiting for, such as |
124 | stores relevant data for each kind of event you are waiting for, such as |
113 | the callback to call, the filehandle to watch, etc. |
125 | the callback to call, the file handle to watch, etc. |
114 | |
126 | |
115 | These watchers are normal Perl objects with normal Perl lifetime. After |
127 | These watchers are normal Perl objects with normal Perl lifetime. After |
116 | creating a watcher it will immediately "watch" for events and invoke the |
128 | creating a watcher it will immediately "watch" for events and invoke the |
117 | callback when the event occurs (of course, only when the event model |
129 | callback when the event occurs (of course, only when the event model |
118 | is in control). |
130 | is in control). |
… | |
… | |
126 | Many watchers either are used with "recursion" (repeating timers for |
138 | Many watchers either are used with "recursion" (repeating timers for |
127 | example), or need to refer to their watcher object in other ways. |
139 | example), or need to refer to their watcher object in other ways. |
128 | |
140 | |
129 | An any way to achieve that is this pattern: |
141 | An any way to achieve that is this pattern: |
130 | |
142 | |
131 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
143 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
132 | # you can use $w here, for example to undef it |
144 | # you can use $w here, for example to undef it |
133 | undef $w; |
145 | undef $w; |
134 | }); |
146 | }); |
135 | |
147 | |
136 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
148 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
137 | my variables are only visible after the statement in which they are |
149 | my variables are only visible after the statement in which they are |
138 | declared. |
150 | declared. |
139 | |
151 | |
… | |
… | |
227 | timers. |
239 | timers. |
228 | |
240 | |
229 | AnyEvent always prefers relative timers, if available, matching the |
241 | AnyEvent always prefers relative timers, if available, matching the |
230 | AnyEvent API. |
242 | AnyEvent API. |
231 | |
243 | |
|
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244 | AnyEvent has two additional methods that return the "current time": |
|
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245 | |
|
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246 | =over 4 |
|
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247 | |
|
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248 | =item AnyEvent->time |
|
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249 | |
|
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250 | This returns the "current wallclock time" as a fractional number of |
|
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251 | seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time> |
|
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252 | return, and the result is guaranteed to be compatible with those). |
|
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253 | |
|
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254 | It progresses independently of any event loop processing, i.e. each call |
|
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255 | will check the system clock, which usually gets updated frequently. |
|
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256 | |
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257 | =item AnyEvent->now |
|
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258 | |
|
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259 | This also returns the "current wallclock time", but unlike C<time>, above, |
|
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260 | this value might change only once per event loop iteration, depending on |
|
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261 | the event loop (most return the same time as C<time>, above). This is the |
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262 | time that AnyEvent's timers get scheduled against. |
|
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263 | |
|
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264 | I<In almost all cases (in all cases if you don't care), this is the |
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265 | function to call when you want to know the current time.> |
|
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266 | |
|
|
267 | This function is also often faster then C<< AnyEvent->time >>, and |
|
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268 | thus the preferred method if you want some timestamp (for example, |
|
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269 | L<AnyEvent::Handle> uses this to update it's activity timeouts). |
|
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270 | |
|
|
271 | The rest of this section is only of relevance if you try to be very exact |
|
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272 | with your timing, you can skip it without bad conscience. |
|
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273 | |
|
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274 | For a practical example of when these times differ, consider L<Event::Lib> |
|
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275 | and L<EV> and the following set-up: |
|
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276 | |
|
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277 | The event loop is running and has just invoked one of your callback at |
|
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278 | time=500 (assume no other callbacks delay processing). In your callback, |
|
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279 | you wait a second by executing C<sleep 1> (blocking the process for a |
|
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280 | second) and then (at time=501) you create a relative timer that fires |
|
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281 | after three seconds. |
|
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282 | |
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283 | With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will |
|
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284 | both return C<501>, because that is the current time, and the timer will |
|
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285 | be scheduled to fire at time=504 (C<501> + C<3>). |
|
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286 | |
|
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287 | With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current |
|
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288 | time), but C<< AnyEvent->now >> returns C<500>, as that is the time the |
|
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289 | last event processing phase started. With L<EV>, your timer gets scheduled |
|
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290 | to run at time=503 (C<500> + C<3>). |
|
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291 | |
|
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292 | In one sense, L<Event::Lib> is more exact, as it uses the current time |
|
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293 | regardless of any delays introduced by event processing. However, most |
|
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294 | callbacks do not expect large delays in processing, so this causes a |
|
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295 | higher drift (and a lot more system calls to get the current time). |
|
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296 | |
|
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297 | In another sense, L<EV> is more exact, as your timer will be scheduled at |
|
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298 | the same time, regardless of how long event processing actually took. |
|
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299 | |
|
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300 | In either case, if you care (and in most cases, you don't), then you |
|
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301 | can get whatever behaviour you want with any event loop, by taking the |
|
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302 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
|
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303 | account. |
|
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304 | |
|
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305 | =back |
|
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306 | |
232 | =head2 SIGNAL WATCHERS |
307 | =head2 SIGNAL WATCHERS |
233 | |
308 | |
234 | You can watch for signals using a signal watcher, C<signal> is the signal |
309 | You can watch for signals using a signal watcher, C<signal> is the signal |
235 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
310 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
236 | be invoked whenever a signal occurs. |
311 | be invoked whenever a signal occurs. |
237 | |
312 | |
238 | Although the callback might get passed parameters, their value and |
313 | Although the callback might get passed parameters, their value and |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
314 | presence is undefined and you cannot rely on them. Portable AnyEvent |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
315 | callbacks cannot use arguments passed to signal watcher callbacks. |
241 | |
316 | |
242 | Multiple signal occurances can be clumped together into one callback |
317 | Multiple signal occurrences can be clumped together into one callback |
243 | invocation, and callback invocation will be synchronous. synchronous means |
318 | invocation, and callback invocation will be synchronous. Synchronous means |
244 | that it might take a while until the signal gets handled by the process, |
319 | that it might take a while until the signal gets handled by the process, |
245 | but it is guarenteed not to interrupt any other callbacks. |
320 | but it is guaranteed not to interrupt any other callbacks. |
246 | |
321 | |
247 | The main advantage of using these watchers is that you can share a signal |
322 | The main advantage of using these watchers is that you can share a signal |
248 | between multiple watchers. |
323 | between multiple watchers. |
249 | |
324 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
325 | This watcher might use C<%SIG>, so programs overwriting those signals |
… | |
… | |
277 | AnyEvent program, you I<have> to create at least one watcher before you |
352 | AnyEvent program, you I<have> to create at least one watcher before you |
278 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
353 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
279 | |
354 | |
280 | Example: fork a process and wait for it |
355 | Example: fork a process and wait for it |
281 | |
356 | |
282 | my $done = AnyEvent->condvar; |
357 | my $done = AnyEvent->condvar; |
283 | |
358 | |
284 | AnyEvent::detect; # force event module to be initialised |
|
|
285 | |
|
|
286 | my $pid = fork or exit 5; |
359 | my $pid = fork or exit 5; |
287 | |
360 | |
288 | my $w = AnyEvent->child ( |
361 | my $w = AnyEvent->child ( |
289 | pid => $pid, |
362 | pid => $pid, |
290 | cb => sub { |
363 | cb => sub { |
291 | my ($pid, $status) = @_; |
364 | my ($pid, $status) = @_; |
292 | warn "pid $pid exited with status $status"; |
365 | warn "pid $pid exited with status $status"; |
293 | $done->send; |
366 | $done->send; |
294 | }, |
367 | }, |
295 | ); |
368 | ); |
296 | |
369 | |
297 | # do something else, then wait for process exit |
370 | # do something else, then wait for process exit |
298 | $done->wait; |
371 | $done->recv; |
299 | |
372 | |
300 | =head2 CONDITION VARIABLES |
373 | =head2 CONDITION VARIABLES |
301 | |
374 | |
302 | If you are familiar with some event loops you will know that all of them |
375 | If you are familiar with some event loops you will know that all of them |
303 | require you to run some blocking "loop", "run" or similar function that |
376 | require you to run some blocking "loop", "run" or similar function that |
… | |
… | |
312 | Condition variables can be created by calling the C<< AnyEvent->condvar |
385 | Condition variables can be created by calling the C<< AnyEvent->condvar |
313 | >> method, usually without arguments. The only argument pair allowed is |
386 | >> method, usually without arguments. The only argument pair allowed is |
314 | C<cb>, which specifies a callback to be called when the condition variable |
387 | C<cb>, which specifies a callback to be called when the condition variable |
315 | becomes true. |
388 | becomes true. |
316 | |
389 | |
317 | After creation, the conditon variable is "false" until it becomes "true" |
390 | After creation, the condition variable is "false" until it becomes "true" |
318 | by calling the C<send> method. |
391 | by calling the C<send> method (or calling the condition variable as if it |
|
|
392 | were a callback, read about the caveats in the description for the C<< |
|
|
393 | ->send >> method). |
319 | |
394 | |
320 | Condition variables are similar to callbacks, except that you can |
395 | Condition variables are similar to callbacks, except that you can |
321 | optionally wait for them. They can also be called merge points - points |
396 | optionally wait for them. They can also be called merge points - points |
322 | in time where multiple outstandign events have been processed. And yet |
397 | in time where multiple outstanding events have been processed. And yet |
323 | another way to call them is transations - each condition variable can be |
398 | another way to call them is transactions - each condition variable can be |
324 | used to represent a transaction, which finishes at some point and delivers |
399 | used to represent a transaction, which finishes at some point and delivers |
325 | a result. |
400 | a result. |
326 | |
401 | |
327 | Condition variables are very useful to signal that something has finished, |
402 | Condition variables are very useful to signal that something has finished, |
328 | for example, if you write a module that does asynchronous http requests, |
403 | for example, if you write a module that does asynchronous http requests, |
329 | then a condition variable would be the ideal candidate to signal the |
404 | then a condition variable would be the ideal candidate to signal the |
330 | availability of results. The user can either act when the callback is |
405 | availability of results. The user can either act when the callback is |
331 | called or can synchronously C<< ->wait >> for the results. |
406 | called or can synchronously C<< ->recv >> for the results. |
332 | |
407 | |
333 | You can also use them to simulate traditional event loops - for example, |
408 | You can also use them to simulate traditional event loops - for example, |
334 | you can block your main program until an event occurs - for example, you |
409 | you can block your main program until an event occurs - for example, you |
335 | could C<< ->wait >> in your main program until the user clicks the Quit |
410 | could C<< ->recv >> in your main program until the user clicks the Quit |
336 | button of your app, which would C<< ->send >> the "quit" event. |
411 | button of your app, which would C<< ->send >> the "quit" event. |
337 | |
412 | |
338 | Note that condition variables recurse into the event loop - if you have |
413 | Note that condition variables recurse into the event loop - if you have |
339 | two pieces of code that call C<< ->wait >> in a round-robbin fashion, you |
414 | two pieces of code that call C<< ->recv >> in a round-robin fashion, you |
340 | lose. Therefore, condition variables are good to export to your caller, but |
415 | lose. Therefore, condition variables are good to export to your caller, but |
341 | you should avoid making a blocking wait yourself, at least in callbacks, |
416 | you should avoid making a blocking wait yourself, at least in callbacks, |
342 | as this asks for trouble. |
417 | as this asks for trouble. |
343 | |
418 | |
344 | Condition variables are represented by hash refs in perl, and the keys |
419 | Condition variables are represented by hash refs in perl, and the keys |
… | |
… | |
349 | |
424 | |
350 | There are two "sides" to a condition variable - the "producer side" which |
425 | There are two "sides" to a condition variable - the "producer side" which |
351 | eventually calls C<< -> send >>, and the "consumer side", which waits |
426 | eventually calls C<< -> send >>, and the "consumer side", which waits |
352 | for the send to occur. |
427 | for the send to occur. |
353 | |
428 | |
354 | Example: |
429 | Example: wait for a timer. |
355 | |
430 | |
356 | # wait till the result is ready |
431 | # wait till the result is ready |
357 | my $result_ready = AnyEvent->condvar; |
432 | my $result_ready = AnyEvent->condvar; |
358 | |
433 | |
359 | # do something such as adding a timer |
434 | # do something such as adding a timer |
… | |
… | |
365 | cb => sub { $result_ready->send }, |
440 | cb => sub { $result_ready->send }, |
366 | ); |
441 | ); |
367 | |
442 | |
368 | # this "blocks" (while handling events) till the callback |
443 | # this "blocks" (while handling events) till the callback |
369 | # calls send |
444 | # calls send |
370 | $result_ready->wait; |
445 | $result_ready->recv; |
|
|
446 | |
|
|
447 | Example: wait for a timer, but take advantage of the fact that |
|
|
448 | condition variables are also code references. |
|
|
449 | |
|
|
450 | my $done = AnyEvent->condvar; |
|
|
451 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
|
|
452 | $done->recv; |
371 | |
453 | |
372 | =head3 METHODS FOR PRODUCERS |
454 | =head3 METHODS FOR PRODUCERS |
373 | |
455 | |
374 | These methods should only be used by the producing side, i.e. the |
456 | These methods should only be used by the producing side, i.e. the |
375 | code/module that eventually sends the signal. Note that it is also |
457 | code/module that eventually sends the signal. Note that it is also |
… | |
… | |
378 | |
460 | |
379 | =over 4 |
461 | =over 4 |
380 | |
462 | |
381 | =item $cv->send (...) |
463 | =item $cv->send (...) |
382 | |
464 | |
383 | Flag the condition as ready - a running C<< ->wait >> and all further |
465 | Flag the condition as ready - a running C<< ->recv >> and all further |
384 | calls to C<wait> will (eventually) return after this method has been |
466 | calls to C<recv> will (eventually) return after this method has been |
385 | called. If nobody is waiting the send will be remembered. |
467 | called. If nobody is waiting the send will be remembered. |
386 | |
468 | |
387 | If a callback has been set on the condition variable, it is called |
469 | If a callback has been set on the condition variable, it is called |
388 | immediately from within send. |
470 | immediately from within send. |
389 | |
471 | |
390 | Any arguments passed to the C<send> call will be returned by all |
472 | Any arguments passed to the C<send> call will be returned by all |
391 | future C<< ->wait >> calls. |
473 | future C<< ->recv >> calls. |
|
|
474 | |
|
|
475 | Condition variables are overloaded so one can call them directly |
|
|
476 | (as a code reference). Calling them directly is the same as calling |
|
|
477 | C<send>. Note, however, that many C-based event loops do not handle |
|
|
478 | overloading, so as tempting as it may be, passing a condition variable |
|
|
479 | instead of a callback does not work. Both the pure perl and EV loops |
|
|
480 | support overloading, however, as well as all functions that use perl to |
|
|
481 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
|
|
482 | example). |
392 | |
483 | |
393 | =item $cv->croak ($error) |
484 | =item $cv->croak ($error) |
394 | |
485 | |
395 | Similar to send, but causes all call's wait C<< ->wait >> to invoke |
486 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
396 | C<Carp::croak> with the given error message/object/scalar. |
487 | C<Carp::croak> with the given error message/object/scalar. |
397 | |
488 | |
398 | This can be used to signal any errors to the condition variable |
489 | This can be used to signal any errors to the condition variable |
399 | user/consumer. |
490 | user/consumer. |
400 | |
491 | |
401 | =item $cv->begin ([group callback]) |
492 | =item $cv->begin ([group callback]) |
402 | |
493 | |
403 | =item $cv->end |
494 | =item $cv->end |
|
|
495 | |
|
|
496 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
404 | |
497 | |
405 | These two methods can be used to combine many transactions/events into |
498 | These two methods can be used to combine many transactions/events into |
406 | one. For example, a function that pings many hosts in parallel might want |
499 | one. For example, a function that pings many hosts in parallel might want |
407 | to use a condition variable for the whole process. |
500 | to use a condition variable for the whole process. |
408 | |
501 | |
… | |
… | |
443 | doesn't execute once). |
536 | doesn't execute once). |
444 | |
537 | |
445 | This is the general pattern when you "fan out" into multiple subrequests: |
538 | This is the general pattern when you "fan out" into multiple subrequests: |
446 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
539 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
447 | is called at least once, and then, for each subrequest you start, call |
540 | is called at least once, and then, for each subrequest you start, call |
448 | C<begin> and for eahc subrequest you finish, call C<end>. |
541 | C<begin> and for each subrequest you finish, call C<end>. |
449 | |
542 | |
450 | =back |
543 | =back |
451 | |
544 | |
452 | =head3 METHODS FOR CONSUMERS |
545 | =head3 METHODS FOR CONSUMERS |
453 | |
546 | |
454 | These methods should only be used by the consuming side, i.e. the |
547 | These methods should only be used by the consuming side, i.e. the |
455 | code awaits the condition. |
548 | code awaits the condition. |
456 | |
549 | |
457 | =over 4 |
550 | =over 4 |
458 | |
551 | |
459 | =item $cv->wait |
552 | =item $cv->recv |
460 | |
553 | |
461 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
554 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
462 | >> methods have been called on c<$cv>, while servicing other watchers |
555 | >> methods have been called on c<$cv>, while servicing other watchers |
463 | normally. |
556 | normally. |
464 | |
557 | |
… | |
… | |
475 | (programs might want to do that to stay interactive), so I<if you are |
568 | (programs might want to do that to stay interactive), so I<if you are |
476 | using this from a module, never require a blocking wait>, but let the |
569 | using this from a module, never require a blocking wait>, but let the |
477 | caller decide whether the call will block or not (for example, by coupling |
570 | caller decide whether the call will block or not (for example, by coupling |
478 | condition variables with some kind of request results and supporting |
571 | condition variables with some kind of request results and supporting |
479 | callbacks so the caller knows that getting the result will not block, |
572 | callbacks so the caller knows that getting the result will not block, |
480 | while still suppporting blocking waits if the caller so desires). |
573 | while still supporting blocking waits if the caller so desires). |
481 | |
574 | |
482 | Another reason I<never> to C<< ->wait >> in a module is that you cannot |
575 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
483 | sensibly have two C<< ->wait >>'s in parallel, as that would require |
576 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
484 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
577 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
485 | can supply. |
578 | can supply. |
486 | |
579 | |
487 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
580 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
488 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
581 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
489 | versions and also integrates coroutines into AnyEvent, making blocking |
582 | versions and also integrates coroutines into AnyEvent, making blocking |
490 | C<< ->wait >> calls perfectly safe as long as they are done from another |
583 | C<< ->recv >> calls perfectly safe as long as they are done from another |
491 | coroutine (one that doesn't run the event loop). |
584 | coroutine (one that doesn't run the event loop). |
492 | |
585 | |
493 | You can ensure that C<< -wait >> never blocks by setting a callback and |
586 | You can ensure that C<< -recv >> never blocks by setting a callback and |
494 | only calling C<< ->wait >> from within that callback (or at a later |
587 | only calling C<< ->recv >> from within that callback (or at a later |
495 | time). This will work even when the event loop does not support blocking |
588 | time). This will work even when the event loop does not support blocking |
496 | waits otherwise. |
589 | waits otherwise. |
497 | |
590 | |
498 | =item $bool = $cv->ready |
591 | =item $bool = $cv->ready |
499 | |
592 | |
… | |
… | |
504 | |
597 | |
505 | This is a mutator function that returns the callback set and optionally |
598 | This is a mutator function that returns the callback set and optionally |
506 | replaces it before doing so. |
599 | replaces it before doing so. |
507 | |
600 | |
508 | The callback will be called when the condition becomes "true", i.e. when |
601 | The callback will be called when the condition becomes "true", i.e. when |
509 | C<send> or C<croak> are called. Calling C<wait> inside the callback |
602 | C<send> or C<croak> are called, with the only argument being the condition |
510 | or at any later time is guaranteed not to block. |
603 | variable itself. Calling C<recv> inside the callback or at any later time |
|
|
604 | is guaranteed not to block. |
511 | |
605 | |
512 | =back |
606 | =back |
513 | |
607 | |
514 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
608 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
515 | |
609 | |
… | |
… | |
549 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
643 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
550 | if necessary. You should only call this function right before you would |
644 | if necessary. You should only call this function right before you would |
551 | have created an AnyEvent watcher anyway, that is, as late as possible at |
645 | have created an AnyEvent watcher anyway, that is, as late as possible at |
552 | runtime. |
646 | runtime. |
553 | |
647 | |
554 | =item AnyEvent::on_detect { BLOCK } |
648 | =item $guard = AnyEvent::post_detect { BLOCK } |
555 | |
649 | |
556 | Arranges for the code block to be executed as soon as the event model is |
650 | Arranges for the code block to be executed as soon as the event model is |
557 | autodetected (or immediately if this has already happened). |
651 | autodetected (or immediately if this has already happened). |
558 | |
652 | |
|
|
653 | If called in scalar or list context, then it creates and returns an object |
|
|
654 | that automatically removes the callback again when it is destroyed. See |
|
|
655 | L<Coro::BDB> for a case where this is useful. |
|
|
656 | |
559 | =item @AnyEvent::on_detect |
657 | =item @AnyEvent::post_detect |
560 | |
658 | |
561 | If there are any code references in this array (you can C<push> to it |
659 | If there are any code references in this array (you can C<push> to it |
562 | before or after loading AnyEvent), then they will called directly after |
660 | before or after loading AnyEvent), then they will called directly after |
563 | the event loop has been chosen. |
661 | the event loop has been chosen. |
564 | |
662 | |
565 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
663 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
566 | if it contains a true value then the event loop has already been detected, |
664 | if it contains a true value then the event loop has already been detected, |
567 | and the array will be ignored. |
665 | and the array will be ignored. |
568 | |
666 | |
569 | Best use C<AnyEvent::on_detect { BLOCK }> instead. |
667 | Best use C<AnyEvent::post_detect { BLOCK }> instead. |
570 | |
668 | |
571 | =back |
669 | =back |
572 | |
670 | |
573 | =head1 WHAT TO DO IN A MODULE |
671 | =head1 WHAT TO DO IN A MODULE |
574 | |
672 | |
… | |
… | |
578 | Be careful when you create watchers in the module body - AnyEvent will |
676 | Be careful when you create watchers in the module body - AnyEvent will |
579 | decide which event module to use as soon as the first method is called, so |
677 | decide which event module to use as soon as the first method is called, so |
580 | by calling AnyEvent in your module body you force the user of your module |
678 | by calling AnyEvent in your module body you force the user of your module |
581 | to load the event module first. |
679 | to load the event module first. |
582 | |
680 | |
583 | Never call C<< ->wait >> on a condition variable unless you I<know> that |
681 | Never call C<< ->recv >> on a condition variable unless you I<know> that |
584 | the C<< ->send >> method has been called on it already. This is |
682 | the C<< ->send >> method has been called on it already. This is |
585 | because it will stall the whole program, and the whole point of using |
683 | because it will stall the whole program, and the whole point of using |
586 | events is to stay interactive. |
684 | events is to stay interactive. |
587 | |
685 | |
588 | It is fine, however, to call C<< ->wait >> when the user of your module |
686 | It is fine, however, to call C<< ->recv >> when the user of your module |
589 | requests it (i.e. if you create a http request object ad have a method |
687 | requests it (i.e. if you create a http request object ad have a method |
590 | called C<results> that returns the results, it should call C<< ->wait >> |
688 | called C<results> that returns the results, it should call C<< ->recv >> |
591 | freely, as the user of your module knows what she is doing. always). |
689 | freely, as the user of your module knows what she is doing. always). |
592 | |
690 | |
593 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
691 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
594 | |
692 | |
595 | There will always be a single main program - the only place that should |
693 | There will always be a single main program - the only place that should |
… | |
… | |
597 | |
695 | |
598 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
696 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
599 | do anything special (it does not need to be event-based) and let AnyEvent |
697 | do anything special (it does not need to be event-based) and let AnyEvent |
600 | decide which implementation to chose if some module relies on it. |
698 | decide which implementation to chose if some module relies on it. |
601 | |
699 | |
602 | If the main program relies on a specific event model. For example, in |
700 | If the main program relies on a specific event model - for example, in |
603 | Gtk2 programs you have to rely on the Glib module. You should load the |
701 | Gtk2 programs you have to rely on the Glib module - you should load the |
604 | event module before loading AnyEvent or any module that uses it: generally |
702 | event module before loading AnyEvent or any module that uses it: generally |
605 | speaking, you should load it as early as possible. The reason is that |
703 | speaking, you should load it as early as possible. The reason is that |
606 | modules might create watchers when they are loaded, and AnyEvent will |
704 | modules might create watchers when they are loaded, and AnyEvent will |
607 | decide on the event model to use as soon as it creates watchers, and it |
705 | decide on the event model to use as soon as it creates watchers, and it |
608 | might chose the wrong one unless you load the correct one yourself. |
706 | might chose the wrong one unless you load the correct one yourself. |
609 | |
707 | |
610 | You can chose to use a rather inefficient pure-perl implementation by |
708 | You can chose to use a pure-perl implementation by loading the |
611 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
709 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
612 | behaviour everywhere, but letting AnyEvent chose is generally better. |
710 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
711 | |
|
|
712 | =head2 MAINLOOP EMULATION |
|
|
713 | |
|
|
714 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
715 | only want to use AnyEvent), you do not want to run a specific event loop. |
|
|
716 | |
|
|
717 | In that case, you can use a condition variable like this: |
|
|
718 | |
|
|
719 | AnyEvent->condvar->recv; |
|
|
720 | |
|
|
721 | This has the effect of entering the event loop and looping forever. |
|
|
722 | |
|
|
723 | Note that usually your program has some exit condition, in which case |
|
|
724 | it is better to use the "traditional" approach of storing a condition |
|
|
725 | variable somewhere, waiting for it, and sending it when the program should |
|
|
726 | exit cleanly. |
|
|
727 | |
613 | |
728 | |
614 | =head1 OTHER MODULES |
729 | =head1 OTHER MODULES |
615 | |
730 | |
616 | The following is a non-exhaustive list of additional modules that use |
731 | The following is a non-exhaustive list of additional modules that use |
617 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
732 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
… | |
… | |
629 | |
744 | |
630 | Provide read and write buffers and manages watchers for reads and writes. |
745 | Provide read and write buffers and manages watchers for reads and writes. |
631 | |
746 | |
632 | =item L<AnyEvent::Socket> |
747 | =item L<AnyEvent::Socket> |
633 | |
748 | |
634 | Provides a means to do non-blocking connects, accepts etc. |
749 | Provides various utility functions for (internet protocol) sockets, |
|
|
750 | addresses and name resolution. Also functions to create non-blocking tcp |
|
|
751 | connections or tcp servers, with IPv6 and SRV record support and more. |
|
|
752 | |
|
|
753 | =item L<AnyEvent::DNS> |
|
|
754 | |
|
|
755 | Provides rich asynchronous DNS resolver capabilities. |
|
|
756 | |
|
|
757 | =item L<AnyEvent::HTTP> |
|
|
758 | |
|
|
759 | A simple-to-use HTTP library that is capable of making a lot of concurrent |
|
|
760 | HTTP requests. |
635 | |
761 | |
636 | =item L<AnyEvent::HTTPD> |
762 | =item L<AnyEvent::HTTPD> |
637 | |
763 | |
638 | Provides a simple web application server framework. |
764 | Provides a simple web application server framework. |
639 | |
765 | |
640 | =item L<AnyEvent::DNS> |
|
|
641 | |
|
|
642 | Provides asynchronous DNS resolver capabilities, beyond what |
|
|
643 | L<AnyEvent::Util> offers. |
|
|
644 | |
|
|
645 | =item L<AnyEvent::FastPing> |
766 | =item L<AnyEvent::FastPing> |
646 | |
767 | |
647 | The fastest ping in the west. |
768 | The fastest ping in the west. |
|
|
769 | |
|
|
770 | =item L<AnyEvent::DBI> |
|
|
771 | |
|
|
772 | Executes DBI requests asynchronously in a proxy process. |
648 | |
773 | |
649 | =item L<Net::IRC3> |
774 | =item L<Net::IRC3> |
650 | |
775 | |
651 | AnyEvent based IRC client module family. |
776 | AnyEvent based IRC client module family. |
652 | |
777 | |
… | |
… | |
665 | |
790 | |
666 | =item L<Coro> |
791 | =item L<Coro> |
667 | |
792 | |
668 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
793 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
669 | |
794 | |
|
|
795 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
796 | |
|
|
797 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
798 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
799 | together. |
|
|
800 | |
|
|
801 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
802 | |
|
|
803 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
804 | IO::AIO and AnyEvent together. |
|
|
805 | |
670 | =item L<IO::Lambda> |
806 | =item L<IO::Lambda> |
671 | |
807 | |
672 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
808 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
673 | |
|
|
674 | =item L<IO::AIO> |
|
|
675 | |
|
|
676 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
677 | programmer. Can be trivially made to use AnyEvent. |
|
|
678 | |
|
|
679 | =item L<BDB> |
|
|
680 | |
|
|
681 | Truly asynchronous Berkeley DB access. Can be trivially made to use |
|
|
682 | AnyEvent. |
|
|
683 | |
809 | |
684 | =back |
810 | =back |
685 | |
811 | |
686 | =cut |
812 | =cut |
687 | |
813 | |
… | |
… | |
690 | no warnings; |
816 | no warnings; |
691 | use strict; |
817 | use strict; |
692 | |
818 | |
693 | use Carp; |
819 | use Carp; |
694 | |
820 | |
695 | our $VERSION = '3.4'; |
821 | our $VERSION = 4.160; |
696 | our $MODEL; |
822 | our $MODEL; |
697 | |
823 | |
698 | our $AUTOLOAD; |
824 | our $AUTOLOAD; |
699 | our @ISA; |
825 | our @ISA; |
700 | |
826 | |
|
|
827 | our @REGISTRY; |
|
|
828 | |
|
|
829 | our $WIN32; |
|
|
830 | |
|
|
831 | BEGIN { |
|
|
832 | my $win32 = ! ! ($^O =~ /mswin32/i); |
|
|
833 | eval "sub WIN32(){ $win32 }"; |
|
|
834 | } |
|
|
835 | |
701 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
836 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
702 | |
837 | |
703 | our @REGISTRY; |
838 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
|
|
839 | |
|
|
840 | { |
|
|
841 | my $idx; |
|
|
842 | $PROTOCOL{$_} = ++$idx |
|
|
843 | for reverse split /\s*,\s*/, |
|
|
844 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
|
|
845 | } |
704 | |
846 | |
705 | my @models = ( |
847 | my @models = ( |
706 | [EV:: => AnyEvent::Impl::EV::], |
848 | [EV:: => AnyEvent::Impl::EV::], |
707 | [Event:: => AnyEvent::Impl::Event::], |
849 | [Event:: => AnyEvent::Impl::Event::], |
708 | [Tk:: => AnyEvent::Impl::Tk::], |
|
|
709 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
710 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
711 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
850 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
712 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
851 | # everything below here will not be autoprobed |
713 | [Glib:: => AnyEvent::Impl::Glib::], |
852 | # as the pureperl backend should work everywhere |
|
|
853 | # and is usually faster |
|
|
854 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
855 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
714 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
856 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
715 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
857 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
716 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
858 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
|
|
859 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
860 | [Prima:: => AnyEvent::Impl::POE::], |
717 | ); |
861 | ); |
718 | |
862 | |
719 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
863 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
720 | |
864 | |
721 | our @on_detect; |
865 | our @post_detect; |
722 | |
866 | |
723 | sub on_detect(&) { |
867 | sub post_detect(&) { |
|
|
868 | my ($cb) = @_; |
|
|
869 | |
724 | if ($MODEL) { |
870 | if ($MODEL) { |
725 | $_[0]->(); |
871 | $cb->(); |
|
|
872 | |
|
|
873 | 1 |
726 | } else { |
874 | } else { |
727 | push @on_detect, $_[0]; |
875 | push @post_detect, $cb; |
|
|
876 | |
|
|
877 | defined wantarray |
|
|
878 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
|
|
879 | : () |
728 | } |
880 | } |
|
|
881 | } |
|
|
882 | |
|
|
883 | sub AnyEvent::Util::PostDetect::DESTROY { |
|
|
884 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
729 | } |
885 | } |
730 | |
886 | |
731 | sub detect() { |
887 | sub detect() { |
732 | unless ($MODEL) { |
888 | unless ($MODEL) { |
733 | no strict 'refs'; |
889 | no strict 'refs'; |
|
|
890 | local $SIG{__DIE__}; |
734 | |
891 | |
735 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
892 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
736 | my $model = "AnyEvent::Impl::$1"; |
893 | my $model = "AnyEvent::Impl::$1"; |
737 | if (eval "require $model") { |
894 | if (eval "require $model") { |
738 | $MODEL = $model; |
895 | $MODEL = $model; |
… | |
… | |
775 | } |
932 | } |
776 | |
933 | |
777 | unshift @ISA, $MODEL; |
934 | unshift @ISA, $MODEL; |
778 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
935 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
779 | |
936 | |
780 | (shift @on_detect)->() while @on_detect; |
937 | (shift @post_detect)->() while @post_detect; |
781 | } |
938 | } |
782 | |
939 | |
783 | $MODEL |
940 | $MODEL |
784 | } |
941 | } |
785 | |
942 | |
… | |
… | |
795 | $class->$func (@_); |
952 | $class->$func (@_); |
796 | } |
953 | } |
797 | |
954 | |
798 | package AnyEvent::Base; |
955 | package AnyEvent::Base; |
799 | |
956 | |
|
|
957 | # default implementation for now and time |
|
|
958 | |
|
|
959 | use Time::HiRes (); |
|
|
960 | |
|
|
961 | sub time { Time::HiRes::time } |
|
|
962 | sub now { Time::HiRes::time } |
|
|
963 | |
800 | # default implementation for ->condvar, ->wait, ->broadcast |
964 | # default implementation for ->condvar |
801 | |
965 | |
802 | sub condvar { |
966 | sub condvar { |
803 | bless \my $flag, "AnyEvent::Base::CondVar" |
967 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
804 | } |
|
|
805 | |
|
|
806 | sub AnyEvent::Base::CondVar::broadcast { |
|
|
807 | ${$_[0]}++; |
|
|
808 | } |
|
|
809 | |
|
|
810 | sub AnyEvent::Base::CondVar::wait { |
|
|
811 | AnyEvent->one_event while !${$_[0]}; |
|
|
812 | } |
968 | } |
813 | |
969 | |
814 | # default implementation for ->signal |
970 | # default implementation for ->signal |
815 | |
971 | |
816 | our %SIG_CB; |
972 | our %SIG_CB; |
… | |
… | |
832 | sub AnyEvent::Base::Signal::DESTROY { |
988 | sub AnyEvent::Base::Signal::DESTROY { |
833 | my ($signal, $cb) = @{$_[0]}; |
989 | my ($signal, $cb) = @{$_[0]}; |
834 | |
990 | |
835 | delete $SIG_CB{$signal}{$cb}; |
991 | delete $SIG_CB{$signal}{$cb}; |
836 | |
992 | |
837 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
993 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
838 | } |
994 | } |
839 | |
995 | |
840 | # default implementation for ->child |
996 | # default implementation for ->child |
841 | |
997 | |
842 | our %PID_CB; |
998 | our %PID_CB; |
… | |
… | |
869 | or Carp::croak "required option 'pid' is missing"; |
1025 | or Carp::croak "required option 'pid' is missing"; |
870 | |
1026 | |
871 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1027 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
872 | |
1028 | |
873 | unless ($WNOHANG) { |
1029 | unless ($WNOHANG) { |
874 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
1030 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
875 | } |
1031 | } |
876 | |
1032 | |
877 | unless ($CHLD_W) { |
1033 | unless ($CHLD_W) { |
878 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1034 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
879 | # child could be a zombie already, so make at least one round |
1035 | # child could be a zombie already, so make at least one round |
… | |
… | |
889 | delete $PID_CB{$pid}{$cb}; |
1045 | delete $PID_CB{$pid}{$cb}; |
890 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1046 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
891 | |
1047 | |
892 | undef $CHLD_W unless keys %PID_CB; |
1048 | undef $CHLD_W unless keys %PID_CB; |
893 | } |
1049 | } |
|
|
1050 | |
|
|
1051 | package AnyEvent::CondVar; |
|
|
1052 | |
|
|
1053 | our @ISA = AnyEvent::CondVar::Base::; |
|
|
1054 | |
|
|
1055 | package AnyEvent::CondVar::Base; |
|
|
1056 | |
|
|
1057 | use overload |
|
|
1058 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
|
|
1059 | fallback => 1; |
|
|
1060 | |
|
|
1061 | sub _send { |
|
|
1062 | # nop |
|
|
1063 | } |
|
|
1064 | |
|
|
1065 | sub send { |
|
|
1066 | my $cv = shift; |
|
|
1067 | $cv->{_ae_sent} = [@_]; |
|
|
1068 | (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; |
|
|
1069 | $cv->_send; |
|
|
1070 | } |
|
|
1071 | |
|
|
1072 | sub croak { |
|
|
1073 | $_[0]{_ae_croak} = $_[1]; |
|
|
1074 | $_[0]->send; |
|
|
1075 | } |
|
|
1076 | |
|
|
1077 | sub ready { |
|
|
1078 | $_[0]{_ae_sent} |
|
|
1079 | } |
|
|
1080 | |
|
|
1081 | sub _wait { |
|
|
1082 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
|
|
1083 | } |
|
|
1084 | |
|
|
1085 | sub recv { |
|
|
1086 | $_[0]->_wait; |
|
|
1087 | |
|
|
1088 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
|
|
1089 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
|
|
1090 | } |
|
|
1091 | |
|
|
1092 | sub cb { |
|
|
1093 | $_[0]{_ae_cb} = $_[1] if @_ > 1; |
|
|
1094 | $_[0]{_ae_cb} |
|
|
1095 | } |
|
|
1096 | |
|
|
1097 | sub begin { |
|
|
1098 | ++$_[0]{_ae_counter}; |
|
|
1099 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
|
|
1100 | } |
|
|
1101 | |
|
|
1102 | sub end { |
|
|
1103 | return if --$_[0]{_ae_counter}; |
|
|
1104 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
|
|
1105 | } |
|
|
1106 | |
|
|
1107 | # undocumented/compatibility with pre-3.4 |
|
|
1108 | *broadcast = \&send; |
|
|
1109 | *wait = \&_wait; |
894 | |
1110 | |
895 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1111 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
896 | |
1112 | |
897 | This is an advanced topic that you do not normally need to use AnyEvent in |
1113 | This is an advanced topic that you do not normally need to use AnyEvent in |
898 | a module. This section is only of use to event loop authors who want to |
1114 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
955 | model it chooses. |
1171 | model it chooses. |
956 | |
1172 | |
957 | =item C<PERL_ANYEVENT_MODEL> |
1173 | =item C<PERL_ANYEVENT_MODEL> |
958 | |
1174 | |
959 | This can be used to specify the event model to be used by AnyEvent, before |
1175 | This can be used to specify the event model to be used by AnyEvent, before |
960 | autodetection and -probing kicks in. It must be a string consisting |
1176 | auto detection and -probing kicks in. It must be a string consisting |
961 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
1177 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
962 | and the resulting module name is loaded and if the load was successful, |
1178 | and the resulting module name is loaded and if the load was successful, |
963 | used as event model. If it fails to load AnyEvent will proceed with |
1179 | used as event model. If it fails to load AnyEvent will proceed with |
964 | autodetection and -probing. |
1180 | auto detection and -probing. |
965 | |
1181 | |
966 | This functionality might change in future versions. |
1182 | This functionality might change in future versions. |
967 | |
1183 | |
968 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
1184 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
969 | could start your program like this: |
1185 | could start your program like this: |
970 | |
1186 | |
971 | PERL_ANYEVENT_MODEL=Perl perl ... |
1187 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1188 | |
|
|
1189 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1190 | |
|
|
1191 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1192 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1193 | of auto probing). |
|
|
1194 | |
|
|
1195 | Must be set to a comma-separated list of protocols or address families, |
|
|
1196 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1197 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1198 | list. |
|
|
1199 | |
|
|
1200 | This variable can effectively be used for denial-of-service attacks |
|
|
1201 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1202 | small, as the program has to handle connection errors already- |
|
|
1203 | |
|
|
1204 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1205 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1206 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1207 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1208 | IPv6, but prefer IPv6 over IPv4. |
|
|
1209 | |
|
|
1210 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1211 | |
|
|
1212 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1213 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1214 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1215 | default. |
|
|
1216 | |
|
|
1217 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1218 | EDNS0 in its DNS requests. |
|
|
1219 | |
|
|
1220 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1221 | |
|
|
1222 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1223 | will create in parallel. |
972 | |
1224 | |
973 | =back |
1225 | =back |
974 | |
1226 | |
975 | =head1 EXAMPLE PROGRAM |
1227 | =head1 EXAMPLE PROGRAM |
976 | |
1228 | |
… | |
… | |
987 | poll => 'r', |
1239 | poll => 'r', |
988 | cb => sub { |
1240 | cb => sub { |
989 | warn "io event <$_[0]>\n"; # will always output <r> |
1241 | warn "io event <$_[0]>\n"; # will always output <r> |
990 | chomp (my $input = <STDIN>); # read a line |
1242 | chomp (my $input = <STDIN>); # read a line |
991 | warn "read: $input\n"; # output what has been read |
1243 | warn "read: $input\n"; # output what has been read |
992 | $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i |
1244 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
993 | }, |
1245 | }, |
994 | ); |
1246 | ); |
995 | |
1247 | |
996 | my $time_watcher; # can only be used once |
1248 | my $time_watcher; # can only be used once |
997 | |
1249 | |
… | |
… | |
1002 | }); |
1254 | }); |
1003 | } |
1255 | } |
1004 | |
1256 | |
1005 | new_timer; # create first timer |
1257 | new_timer; # create first timer |
1006 | |
1258 | |
1007 | $cv->wait; # wait until user enters /^q/i |
1259 | $cv->recv; # wait until user enters /^q/i |
1008 | |
1260 | |
1009 | =head1 REAL-WORLD EXAMPLE |
1261 | =head1 REAL-WORLD EXAMPLE |
1010 | |
1262 | |
1011 | Consider the L<Net::FCP> module. It features (among others) the following |
1263 | Consider the L<Net::FCP> module. It features (among others) the following |
1012 | API calls, which are to freenet what HTTP GET requests are to http: |
1264 | API calls, which are to freenet what HTTP GET requests are to http: |
… | |
… | |
1062 | syswrite $txn->{fh}, $txn->{request} |
1314 | syswrite $txn->{fh}, $txn->{request} |
1063 | or die "connection or write error"; |
1315 | or die "connection or write error"; |
1064 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1316 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1065 | |
1317 | |
1066 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1318 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1067 | result and signals any possible waiters that the request ahs finished: |
1319 | result and signals any possible waiters that the request has finished: |
1068 | |
1320 | |
1069 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1321 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1070 | |
1322 | |
1071 | if (end-of-file or data complete) { |
1323 | if (end-of-file or data complete) { |
1072 | $txn->{result} = $txn->{buf}; |
1324 | $txn->{result} = $txn->{buf}; |
1073 | $txn->{finished}->broadcast; |
1325 | $txn->{finished}->send; |
1074 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1326 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1075 | } |
1327 | } |
1076 | |
1328 | |
1077 | The C<result> method, finally, just waits for the finished signal (if the |
1329 | The C<result> method, finally, just waits for the finished signal (if the |
1078 | request was already finished, it doesn't wait, of course, and returns the |
1330 | request was already finished, it doesn't wait, of course, and returns the |
1079 | data: |
1331 | data: |
1080 | |
1332 | |
1081 | $txn->{finished}->wait; |
1333 | $txn->{finished}->recv; |
1082 | return $txn->{result}; |
1334 | return $txn->{result}; |
1083 | |
1335 | |
1084 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1336 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1085 | that occured during request processing. The C<result> method detects |
1337 | that occurred during request processing. The C<result> method detects |
1086 | whether an exception as thrown (it is stored inside the $txn object) |
1338 | whether an exception as thrown (it is stored inside the $txn object) |
1087 | and just throws the exception, which means connection errors and other |
1339 | and just throws the exception, which means connection errors and other |
1088 | problems get reported tot he code that tries to use the result, not in a |
1340 | problems get reported tot he code that tries to use the result, not in a |
1089 | random callback. |
1341 | random callback. |
1090 | |
1342 | |
… | |
… | |
1121 | |
1373 | |
1122 | my $quit = AnyEvent->condvar; |
1374 | my $quit = AnyEvent->condvar; |
1123 | |
1375 | |
1124 | $fcp->txn_client_get ($url)->cb (sub { |
1376 | $fcp->txn_client_get ($url)->cb (sub { |
1125 | ... |
1377 | ... |
1126 | $quit->broadcast; |
1378 | $quit->send; |
1127 | }); |
1379 | }); |
1128 | |
1380 | |
1129 | $quit->wait; |
1381 | $quit->recv; |
1130 | |
1382 | |
1131 | |
1383 | |
1132 | =head1 BENCHMARKS |
1384 | =head1 BENCHMARKS |
1133 | |
1385 | |
1134 | To give you an idea of the performance and overheads that AnyEvent adds |
1386 | To give you an idea of the performance and overheads that AnyEvent adds |
… | |
… | |
1136 | of various event loops I prepared some benchmarks. |
1388 | of various event loops I prepared some benchmarks. |
1137 | |
1389 | |
1138 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1390 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1139 | |
1391 | |
1140 | Here is a benchmark of various supported event models used natively and |
1392 | Here is a benchmark of various supported event models used natively and |
1141 | through anyevent. The benchmark creates a lot of timers (with a zero |
1393 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1142 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1394 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1143 | which it is), lets them fire exactly once and destroys them again. |
1395 | which it is), lets them fire exactly once and destroys them again. |
1144 | |
1396 | |
1145 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1397 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1146 | distribution. |
1398 | distribution. |
… | |
… | |
1163 | all watchers, to avoid adding memory overhead. That means closure creation |
1415 | all watchers, to avoid adding memory overhead. That means closure creation |
1164 | and memory usage is not included in the figures. |
1416 | and memory usage is not included in the figures. |
1165 | |
1417 | |
1166 | I<invoke> is the time, in microseconds, used to invoke a simple |
1418 | I<invoke> is the time, in microseconds, used to invoke a simple |
1167 | callback. The callback simply counts down a Perl variable and after it was |
1419 | callback. The callback simply counts down a Perl variable and after it was |
1168 | invoked "watcher" times, it would C<< ->broadcast >> a condvar once to |
1420 | invoked "watcher" times, it would C<< ->send >> a condvar once to |
1169 | signal the end of this phase. |
1421 | signal the end of this phase. |
1170 | |
1422 | |
1171 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1423 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1172 | watcher. |
1424 | watcher. |
1173 | |
1425 | |
… | |
… | |
1269 | |
1521 | |
1270 | =back |
1522 | =back |
1271 | |
1523 | |
1272 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1524 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1273 | |
1525 | |
1274 | This benchmark atcually benchmarks the event loop itself. It works by |
1526 | This benchmark actually benchmarks the event loop itself. It works by |
1275 | creating a number of "servers": each server consists of a socketpair, a |
1527 | creating a number of "servers": each server consists of a socket pair, a |
1276 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1528 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1277 | watcher waiting for input on one side of the socket. Each time the socket |
1529 | watcher waiting for input on one side of the socket. Each time the socket |
1278 | watcher reads a byte it will write that byte to a random other "server". |
1530 | watcher reads a byte it will write that byte to a random other "server". |
1279 | |
1531 | |
1280 | The effect is that there will be a lot of I/O watchers, only part of which |
1532 | The effect is that there will be a lot of I/O watchers, only part of which |
1281 | are active at any one point (so there is a constant number of active |
1533 | are active at any one point (so there is a constant number of active |
1282 | fds for each loop iterstaion, but which fds these are is random). The |
1534 | fds for each loop iteration, but which fds these are is random). The |
1283 | timeout is reset each time something is read because that reflects how |
1535 | timeout is reset each time something is read because that reflects how |
1284 | most timeouts work (and puts extra pressure on the event loops). |
1536 | most timeouts work (and puts extra pressure on the event loops). |
1285 | |
1537 | |
1286 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 |
1538 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1287 | (1%) are active. This mirrors the activity of large servers with many |
1539 | (1%) are active. This mirrors the activity of large servers with many |
1288 | connections, most of which are idle at any one point in time. |
1540 | connections, most of which are idle at any one point in time. |
1289 | |
1541 | |
1290 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1542 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1291 | distribution. |
1543 | distribution. |
… | |
… | |
1293 | =head3 Explanation of the columns |
1545 | =head3 Explanation of the columns |
1294 | |
1546 | |
1295 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1547 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1296 | each server has a read and write socket end). |
1548 | each server has a read and write socket end). |
1297 | |
1549 | |
1298 | I<create> is the time it takes to create a socketpair (which is |
1550 | I<create> is the time it takes to create a socket pair (which is |
1299 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1551 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1300 | |
1552 | |
1301 | I<request>, the most important value, is the time it takes to handle a |
1553 | I<request>, the most important value, is the time it takes to handle a |
1302 | single "request", that is, reading the token from the pipe and forwarding |
1554 | single "request", that is, reading the token from the pipe and forwarding |
1303 | it to another server. This includes deleting the old timeout and creating |
1555 | it to another server. This includes deleting the old timeout and creating |
… | |
… | |
1376 | speed most when you have lots of watchers, not when you only have a few of |
1628 | speed most when you have lots of watchers, not when you only have a few of |
1377 | them). |
1629 | them). |
1378 | |
1630 | |
1379 | EV is again fastest. |
1631 | EV is again fastest. |
1380 | |
1632 | |
1381 | Perl again comes second. It is noticably faster than the C-based event |
1633 | Perl again comes second. It is noticeably faster than the C-based event |
1382 | loops Event and Glib, although the difference is too small to really |
1634 | loops Event and Glib, although the difference is too small to really |
1383 | matter. |
1635 | matter. |
1384 | |
1636 | |
1385 | POE also performs much better in this case, but is is still far behind the |
1637 | POE also performs much better in this case, but is is still far behind the |
1386 | others. |
1638 | others. |
… | |
… | |
1415 | specified in the variable. |
1667 | specified in the variable. |
1416 | |
1668 | |
1417 | You can make AnyEvent completely ignore this variable by deleting it |
1669 | You can make AnyEvent completely ignore this variable by deleting it |
1418 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1670 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1419 | |
1671 | |
1420 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1672 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1421 | |
1673 | |
1422 | use AnyEvent; |
1674 | use AnyEvent; |
1423 | |
1675 | |
1424 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1676 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1425 | be used to probe what backend is used and gain other information (which is |
1677 | be used to probe what backend is used and gain other information (which is |
1426 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1678 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1427 | |
1679 | |
1428 | |
1680 | |
|
|
1681 | =head1 BUGS |
|
|
1682 | |
|
|
1683 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
|
|
1684 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
|
|
1685 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
|
|
1686 | mamleaks, such as leaking on C<map> and C<grep> but it is usually not as |
|
|
1687 | pronounced). |
|
|
1688 | |
|
|
1689 | |
1429 | =head1 SEE ALSO |
1690 | =head1 SEE ALSO |
|
|
1691 | |
|
|
1692 | Utility functions: L<AnyEvent::Util>. |
1430 | |
1693 | |
1431 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1694 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1432 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1695 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1433 | |
1696 | |
1434 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1697 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1435 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1698 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1436 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1699 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1437 | L<AnyEvent::Impl::POE>. |
1700 | L<AnyEvent::Impl::POE>. |
1438 | |
1701 | |
|
|
1702 | Non-blocking file handles, sockets, TCP clients and |
|
|
1703 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
|
|
1704 | |
|
|
1705 | Asynchronous DNS: L<AnyEvent::DNS>. |
|
|
1706 | |
1439 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1707 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1440 | |
1708 | |
1441 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
1709 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
1442 | |
1710 | |
1443 | |
1711 | |
1444 | =head1 AUTHOR |
1712 | =head1 AUTHOR |
1445 | |
1713 | |
1446 | Marc Lehmann <schmorp@schmorp.de> |
1714 | Marc Lehmann <schmorp@schmorp.de> |
1447 | http://home.schmorp.de/ |
1715 | http://home.schmorp.de/ |
1448 | |
1716 | |
1449 | =cut |
1717 | =cut |
1450 | |
1718 | |
1451 | 1 |
1719 | 1 |
1452 | |
1720 | |