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 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
6 | |
6 | |
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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 |
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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 |
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22 | |
22 | |
23 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
23 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
24 | |
24 | |
25 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
25 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
26 | nowadays. So what is different about AnyEvent? |
26 | nowadays. So what is different about AnyEvent? |
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48 | isn't itself. What's worse, all the potential users of your module are |
48 | 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. |
49 | I<also> forced to use the same event loop you use. |
50 | |
50 | |
51 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
51 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
52 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
52 | 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 |
53 | 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, |
54 | 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 |
55 | 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 |
56 | 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 |
57 | 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). |
58 | event loops to AnyEvent, too, so it is future-proof). |
59 | |
59 | |
60 | In addition to being free of having to use I<the one and only true event |
60 | 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 |
61 | 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 |
62 | 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 |
63 | 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 |
64 | offering the functionality that is necessary, in as thin as a wrapper as |
65 | technically possible. |
65 | technically possible. |
66 | |
66 | |
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67 | Of course, AnyEvent comes with a big (and fully optional!) toolbox |
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68 | of useful functionality, such as an asynchronous DNS resolver, 100% |
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69 | non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms |
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70 | such as Windows) and lots of real-world knowledge and workarounds for |
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71 | platform bugs and differences. |
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72 | |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
73 | 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 |
74 | useful) and you want to force your users to use the one and only event |
69 | model, you should I<not> use this module. |
75 | model, you should I<not> use this module. |
70 | |
76 | |
71 | =head1 DESCRIPTION |
77 | =head1 DESCRIPTION |
72 | |
78 | |
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102 | starts using it, all bets are off. Maybe you should tell their authors to |
108 | 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... |
109 | use AnyEvent so their modules work together with others seamlessly... |
104 | |
110 | |
105 | The pure-perl implementation of AnyEvent is called |
111 | The pure-perl implementation of AnyEvent is called |
106 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
112 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
107 | explicitly. |
113 | explicitly and enjoy the high availability of that event loop :) |
108 | |
114 | |
109 | =head1 WATCHERS |
115 | =head1 WATCHERS |
110 | |
116 | |
111 | AnyEvent has the central concept of a I<watcher>, which is an object that |
117 | 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 |
118 | stores relevant data for each kind of event you are waiting for, such as |
113 | the callback to call, the filehandle to watch, etc. |
119 | the callback to call, the file handle to watch, etc. |
114 | |
120 | |
115 | These watchers are normal Perl objects with normal Perl lifetime. After |
121 | These watchers are normal Perl objects with normal Perl lifetime. After |
116 | creating a watcher it will immediately "watch" for events and invoke the |
122 | 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 |
123 | callback when the event occurs (of course, only when the event model |
118 | is in control). |
124 | is in control). |
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237 | |
243 | |
238 | Although the callback might get passed parameters, their value and |
244 | Although the callback might get passed parameters, their value and |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
245 | presence is undefined and you cannot rely on them. Portable AnyEvent |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
246 | callbacks cannot use arguments passed to signal watcher callbacks. |
241 | |
247 | |
242 | Multiple signal occurances can be clumped together into one callback |
248 | Multiple signal occurrences can be clumped together into one callback |
243 | invocation, and callback invocation will be synchronous. synchronous means |
249 | invocation, and callback invocation will be synchronous. Synchronous means |
244 | that it might take a while until the signal gets handled by the process, |
250 | 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. |
251 | but it is guaranteed not to interrupt any other callbacks. |
246 | |
252 | |
247 | The main advantage of using these watchers is that you can share a signal |
253 | The main advantage of using these watchers is that you can share a signal |
248 | between multiple watchers. |
254 | between multiple watchers. |
249 | |
255 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
256 | This watcher might use C<%SIG>, so programs overwriting those signals |
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278 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
284 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
279 | |
285 | |
280 | Example: fork a process and wait for it |
286 | Example: fork a process and wait for it |
281 | |
287 | |
282 | my $done = AnyEvent->condvar; |
288 | my $done = AnyEvent->condvar; |
283 | |
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284 | AnyEvent::detect; # force event module to be initialised |
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285 | |
289 | |
286 | my $pid = fork or exit 5; |
290 | my $pid = fork or exit 5; |
287 | |
291 | |
288 | my $w = AnyEvent->child ( |
292 | my $w = AnyEvent->child ( |
289 | pid => $pid, |
293 | pid => $pid, |
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293 | $done->send; |
297 | $done->send; |
294 | }, |
298 | }, |
295 | ); |
299 | ); |
296 | |
300 | |
297 | # do something else, then wait for process exit |
301 | # do something else, then wait for process exit |
298 | $done->wait; |
302 | $done->recv; |
299 | |
303 | |
300 | =head2 CONDITION VARIABLES |
304 | =head2 CONDITION VARIABLES |
301 | |
305 | |
302 | If you are familiar with some event loops you will know that all of them |
306 | 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 |
307 | require you to run some blocking "loop", "run" or similar function that |
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312 | Condition variables can be created by calling the C<< AnyEvent->condvar |
316 | Condition variables can be created by calling the C<< AnyEvent->condvar |
313 | >> method, usually without arguments. The only argument pair allowed is |
317 | >> method, usually without arguments. The only argument pair allowed is |
314 | C<cb>, which specifies a callback to be called when the condition variable |
318 | C<cb>, which specifies a callback to be called when the condition variable |
315 | becomes true. |
319 | becomes true. |
316 | |
320 | |
317 | After creation, the conditon variable is "false" until it becomes "true" |
321 | After creation, the condition variable is "false" until it becomes "true" |
318 | by calling the C<send> method. |
322 | by calling the C<send> method (or calling the condition variable as if it |
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323 | were a callback, read about the caveats in the description for the C<< |
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324 | ->send >> method). |
319 | |
325 | |
320 | Condition variables are similar to callbacks, except that you can |
326 | Condition variables are similar to callbacks, except that you can |
321 | optionally wait for them. They can also be called merge points - points |
327 | optionally wait for them. They can also be called merge points - points |
322 | in time where multiple outstandign events have been processed. And yet |
328 | in time where multiple outstanding events have been processed. And yet |
323 | another way to call them is transations - each condition variable can be |
329 | 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 |
330 | used to represent a transaction, which finishes at some point and delivers |
325 | a result. |
331 | a result. |
326 | |
332 | |
327 | Condition variables are very useful to signal that something has finished, |
333 | Condition variables are very useful to signal that something has finished, |
328 | for example, if you write a module that does asynchronous http requests, |
334 | 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 |
335 | 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 |
336 | availability of results. The user can either act when the callback is |
331 | called or can synchronously C<< ->wait >> for the results. |
337 | called or can synchronously C<< ->recv >> for the results. |
332 | |
338 | |
333 | You can also use them to simulate traditional event loops - for example, |
339 | 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 |
340 | 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 |
341 | 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. |
342 | button of your app, which would C<< ->send >> the "quit" event. |
337 | |
343 | |
338 | Note that condition variables recurse into the event loop - if you have |
344 | 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 |
345 | 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 |
346 | 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, |
347 | you should avoid making a blocking wait yourself, at least in callbacks, |
342 | as this asks for trouble. |
348 | as this asks for trouble. |
343 | |
349 | |
344 | Condition variables are represented by hash refs in perl, and the keys |
350 | Condition variables are represented by hash refs in perl, and the keys |
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349 | |
355 | |
350 | There are two "sides" to a condition variable - the "producer side" which |
356 | There are two "sides" to a condition variable - the "producer side" which |
351 | eventually calls C<< -> send >>, and the "consumer side", which waits |
357 | eventually calls C<< -> send >>, and the "consumer side", which waits |
352 | for the send to occur. |
358 | for the send to occur. |
353 | |
359 | |
354 | Example: |
360 | Example: wait for a timer. |
355 | |
361 | |
356 | # wait till the result is ready |
362 | # wait till the result is ready |
357 | my $result_ready = AnyEvent->condvar; |
363 | my $result_ready = AnyEvent->condvar; |
358 | |
364 | |
359 | # do something such as adding a timer |
365 | # do something such as adding a timer |
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365 | cb => sub { $result_ready->send }, |
371 | cb => sub { $result_ready->send }, |
366 | ); |
372 | ); |
367 | |
373 | |
368 | # this "blocks" (while handling events) till the callback |
374 | # this "blocks" (while handling events) till the callback |
369 | # calls send |
375 | # calls send |
370 | $result_ready->wait; |
376 | $result_ready->recv; |
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377 | |
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378 | Example: wait for a timer, but take advantage of the fact that |
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379 | condition variables are also code references. |
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380 | |
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381 | my $done = AnyEvent->condvar; |
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382 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
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383 | $done->recv; |
371 | |
384 | |
372 | =head3 METHODS FOR PRODUCERS |
385 | =head3 METHODS FOR PRODUCERS |
373 | |
386 | |
374 | These methods should only be used by the producing side, i.e. the |
387 | 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 |
388 | code/module that eventually sends the signal. Note that it is also |
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378 | |
391 | |
379 | =over 4 |
392 | =over 4 |
380 | |
393 | |
381 | =item $cv->send (...) |
394 | =item $cv->send (...) |
382 | |
395 | |
383 | Flag the condition as ready - a running C<< ->wait >> and all further |
396 | 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 |
397 | calls to C<recv> will (eventually) return after this method has been |
385 | called. If nobody is waiting the send will be remembered. |
398 | called. If nobody is waiting the send will be remembered. |
386 | |
399 | |
387 | If a callback has been set on the condition variable, it is called |
400 | If a callback has been set on the condition variable, it is called |
388 | immediately from within send. |
401 | immediately from within send. |
389 | |
402 | |
390 | Any arguments passed to the C<send> call will be returned by all |
403 | Any arguments passed to the C<send> call will be returned by all |
391 | future C<< ->wait >> calls. |
404 | future C<< ->recv >> calls. |
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405 | |
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406 | Condition variables are overloaded so one can call them directly |
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407 | (as a code reference). Calling them directly is the same as calling |
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408 | C<send>. Note, however, that many C-based event loops do not handle |
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409 | overloading, so as tempting as it may be, passing a condition variable |
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410 | instead of a callback does not work. Both the pure perl and EV loops |
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411 | support overloading, however, as well as all functions that use perl to |
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412 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
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413 | example). |
392 | |
414 | |
393 | =item $cv->croak ($error) |
415 | =item $cv->croak ($error) |
394 | |
416 | |
395 | Similar to send, but causes all call's wait C<< ->wait >> to invoke |
417 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
396 | C<Carp::croak> with the given error message/object/scalar. |
418 | C<Carp::croak> with the given error message/object/scalar. |
397 | |
419 | |
398 | This can be used to signal any errors to the condition variable |
420 | This can be used to signal any errors to the condition variable |
399 | user/consumer. |
421 | user/consumer. |
400 | |
422 | |
401 | =item $cv->begin ([group callback]) |
423 | =item $cv->begin ([group callback]) |
402 | |
424 | |
403 | =item $cv->end |
425 | =item $cv->end |
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426 | |
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427 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
404 | |
428 | |
405 | These two methods can be used to combine many transactions/events into |
429 | 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 |
430 | one. For example, a function that pings many hosts in parallel might want |
407 | to use a condition variable for the whole process. |
431 | to use a condition variable for the whole process. |
408 | |
432 | |
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443 | doesn't execute once). |
467 | doesn't execute once). |
444 | |
468 | |
445 | This is the general pattern when you "fan out" into multiple subrequests: |
469 | 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> |
470 | 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 |
471 | 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>. |
472 | C<begin> and for each subrequest you finish, call C<end>. |
449 | |
473 | |
450 | =back |
474 | =back |
451 | |
475 | |
452 | =head3 METHODS FOR CONSUMERS |
476 | =head3 METHODS FOR CONSUMERS |
453 | |
477 | |
454 | These methods should only be used by the consuming side, i.e. the |
478 | These methods should only be used by the consuming side, i.e. the |
455 | code awaits the condition. |
479 | code awaits the condition. |
456 | |
480 | |
457 | =over 4 |
481 | =over 4 |
458 | |
482 | |
459 | =item $cv->wait |
483 | =item $cv->recv |
460 | |
484 | |
461 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
485 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
462 | >> methods have been called on c<$cv>, while servicing other watchers |
486 | >> methods have been called on c<$cv>, while servicing other watchers |
463 | normally. |
487 | normally. |
464 | |
488 | |
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475 | (programs might want to do that to stay interactive), so I<if you are |
499 | (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 |
500 | 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 |
501 | caller decide whether the call will block or not (for example, by coupling |
478 | condition variables with some kind of request results and supporting |
502 | condition variables with some kind of request results and supporting |
479 | callbacks so the caller knows that getting the result will not block, |
503 | callbacks so the caller knows that getting the result will not block, |
480 | while still suppporting blocking waits if the caller so desires). |
504 | while still supporting blocking waits if the caller so desires). |
481 | |
505 | |
482 | Another reason I<never> to C<< ->wait >> in a module is that you cannot |
506 | 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 |
507 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
484 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
508 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
485 | can supply. |
509 | can supply. |
486 | |
510 | |
487 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
511 | 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 |
512 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
489 | versions and also integrates coroutines into AnyEvent, making blocking |
513 | versions and also integrates coroutines into AnyEvent, making blocking |
490 | C<< ->wait >> calls perfectly safe as long as they are done from another |
514 | C<< ->recv >> calls perfectly safe as long as they are done from another |
491 | coroutine (one that doesn't run the event loop). |
515 | coroutine (one that doesn't run the event loop). |
492 | |
516 | |
493 | You can ensure that C<< -wait >> never blocks by setting a callback and |
517 | 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 |
518 | 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 |
519 | time). This will work even when the event loop does not support blocking |
496 | waits otherwise. |
520 | waits otherwise. |
497 | |
521 | |
498 | =item $bool = $cv->ready |
522 | =item $bool = $cv->ready |
499 | |
523 | |
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504 | |
528 | |
505 | This is a mutator function that returns the callback set and optionally |
529 | This is a mutator function that returns the callback set and optionally |
506 | replaces it before doing so. |
530 | replaces it before doing so. |
507 | |
531 | |
508 | The callback will be called when the condition becomes "true", i.e. when |
532 | The callback will be called when the condition becomes "true", i.e. when |
509 | C<send> or C<croak> are called. Calling C<wait> inside the callback |
533 | C<send> or C<croak> are called. Calling C<recv> inside the callback |
510 | or at any later time is guaranteed not to block. |
534 | or at any later time is guaranteed not to block. |
511 | |
535 | |
512 | =back |
536 | =back |
513 | |
537 | |
514 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
538 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
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549 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
573 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
550 | if necessary. You should only call this function right before you would |
574 | 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 |
575 | have created an AnyEvent watcher anyway, that is, as late as possible at |
552 | runtime. |
576 | runtime. |
553 | |
577 | |
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578 | =item $guard = AnyEvent::post_detect { BLOCK } |
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579 | |
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580 | Arranges for the code block to be executed as soon as the event model is |
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581 | autodetected (or immediately if this has already happened). |
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582 | |
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583 | If called in scalar or list context, then it creates and returns an object |
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584 | that automatically removes the callback again when it is destroyed. See |
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585 | L<Coro::BDB> for a case where this is useful. |
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586 | |
554 | =item @AnyEvent::detect |
587 | =item @AnyEvent::post_detect |
555 | |
588 | |
556 | If there are any code references in this array (you can C<push> to it |
589 | If there are any code references in this array (you can C<push> to it |
557 | before or after loading AnyEvent), then they will called directly after |
590 | before or after loading AnyEvent), then they will called directly after |
558 | the event loop has been chosen. |
591 | the event loop has been chosen. |
559 | |
592 | |
560 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
593 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
561 | if it contains a true value then the event loop has already been detected, |
594 | if it contains a true value then the event loop has already been detected, |
562 | and the array will be ignored. |
595 | and the array will be ignored. |
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596 | |
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597 | Best use C<AnyEvent::post_detect { BLOCK }> instead. |
563 | |
598 | |
564 | =back |
599 | =back |
565 | |
600 | |
566 | =head1 WHAT TO DO IN A MODULE |
601 | =head1 WHAT TO DO IN A MODULE |
567 | |
602 | |
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571 | Be careful when you create watchers in the module body - AnyEvent will |
606 | Be careful when you create watchers in the module body - AnyEvent will |
572 | decide which event module to use as soon as the first method is called, so |
607 | decide which event module to use as soon as the first method is called, so |
573 | by calling AnyEvent in your module body you force the user of your module |
608 | by calling AnyEvent in your module body you force the user of your module |
574 | to load the event module first. |
609 | to load the event module first. |
575 | |
610 | |
576 | Never call C<< ->wait >> on a condition variable unless you I<know> that |
611 | Never call C<< ->recv >> on a condition variable unless you I<know> that |
577 | the C<< ->send >> method has been called on it already. This is |
612 | the C<< ->send >> method has been called on it already. This is |
578 | because it will stall the whole program, and the whole point of using |
613 | because it will stall the whole program, and the whole point of using |
579 | events is to stay interactive. |
614 | events is to stay interactive. |
580 | |
615 | |
581 | It is fine, however, to call C<< ->wait >> when the user of your module |
616 | It is fine, however, to call C<< ->recv >> when the user of your module |
582 | requests it (i.e. if you create a http request object ad have a method |
617 | requests it (i.e. if you create a http request object ad have a method |
583 | called C<results> that returns the results, it should call C<< ->wait >> |
618 | called C<results> that returns the results, it should call C<< ->recv >> |
584 | freely, as the user of your module knows what she is doing. always). |
619 | freely, as the user of your module knows what she is doing. always). |
585 | |
620 | |
586 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
621 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
587 | |
622 | |
588 | There will always be a single main program - the only place that should |
623 | There will always be a single main program - the only place that should |
… | |
… | |
590 | |
625 | |
591 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
626 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
592 | do anything special (it does not need to be event-based) and let AnyEvent |
627 | do anything special (it does not need to be event-based) and let AnyEvent |
593 | decide which implementation to chose if some module relies on it. |
628 | decide which implementation to chose if some module relies on it. |
594 | |
629 | |
595 | If the main program relies on a specific event model. For example, in |
630 | If the main program relies on a specific event model - for example, in |
596 | Gtk2 programs you have to rely on the Glib module. You should load the |
631 | Gtk2 programs you have to rely on the Glib module - you should load the |
597 | event module before loading AnyEvent or any module that uses it: generally |
632 | event module before loading AnyEvent or any module that uses it: generally |
598 | speaking, you should load it as early as possible. The reason is that |
633 | speaking, you should load it as early as possible. The reason is that |
599 | modules might create watchers when they are loaded, and AnyEvent will |
634 | modules might create watchers when they are loaded, and AnyEvent will |
600 | decide on the event model to use as soon as it creates watchers, and it |
635 | decide on the event model to use as soon as it creates watchers, and it |
601 | might chose the wrong one unless you load the correct one yourself. |
636 | might chose the wrong one unless you load the correct one yourself. |
602 | |
637 | |
603 | You can chose to use a rather inefficient pure-perl implementation by |
638 | You can chose to use a pure-perl implementation by loading the |
604 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
639 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
605 | behaviour everywhere, but letting AnyEvent chose is generally better. |
640 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
641 | |
|
|
642 | =head2 MAINLOOP EMULATION |
|
|
643 | |
|
|
644 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
645 | only want to use AnyEvent), you do not want to run a specific event loop. |
|
|
646 | |
|
|
647 | In that case, you can use a condition variable like this: |
|
|
648 | |
|
|
649 | AnyEvent->condvar->recv; |
|
|
650 | |
|
|
651 | This has the effect of entering the event loop and looping forever. |
|
|
652 | |
|
|
653 | Note that usually your program has some exit condition, in which case |
|
|
654 | it is better to use the "traditional" approach of storing a condition |
|
|
655 | variable somewhere, waiting for it, and sending it when the program should |
|
|
656 | exit cleanly. |
|
|
657 | |
606 | |
658 | |
607 | =head1 OTHER MODULES |
659 | =head1 OTHER MODULES |
608 | |
660 | |
609 | The following is a non-exhaustive list of additional modules that use |
661 | The following is a non-exhaustive list of additional modules that use |
610 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
662 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
… | |
… | |
622 | |
674 | |
623 | Provide read and write buffers and manages watchers for reads and writes. |
675 | Provide read and write buffers and manages watchers for reads and writes. |
624 | |
676 | |
625 | =item L<AnyEvent::Socket> |
677 | =item L<AnyEvent::Socket> |
626 | |
678 | |
627 | Provides a means to do non-blocking connects, accepts etc. |
679 | Provides various utility functions for (internet protocol) sockets, |
|
|
680 | addresses and name resolution. Also functions to create non-blocking tcp |
|
|
681 | connections or tcp servers, with IPv6 and SRV record support and more. |
|
|
682 | |
|
|
683 | =item L<AnyEvent::DNS> |
|
|
684 | |
|
|
685 | Provides rich asynchronous DNS resolver capabilities. |
628 | |
686 | |
629 | =item L<AnyEvent::HTTPD> |
687 | =item L<AnyEvent::HTTPD> |
630 | |
688 | |
631 | Provides a simple web application server framework. |
689 | Provides a simple web application server framework. |
632 | |
|
|
633 | =item L<AnyEvent::DNS> |
|
|
634 | |
|
|
635 | Provides asynchronous DNS resolver capabilities, beyond what |
|
|
636 | L<AnyEvent::Util> offers. |
|
|
637 | |
690 | |
638 | =item L<AnyEvent::FastPing> |
691 | =item L<AnyEvent::FastPing> |
639 | |
692 | |
640 | The fastest ping in the west. |
693 | The fastest ping in the west. |
641 | |
694 | |
… | |
… | |
658 | |
711 | |
659 | =item L<Coro> |
712 | =item L<Coro> |
660 | |
713 | |
661 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
714 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
662 | |
715 | |
|
|
716 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
717 | |
|
|
718 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
719 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
720 | together. |
|
|
721 | |
|
|
722 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
723 | |
|
|
724 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
725 | IO::AIO and AnyEvent together. |
|
|
726 | |
663 | =item L<IO::Lambda> |
727 | =item L<IO::Lambda> |
664 | |
728 | |
665 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
729 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
666 | |
|
|
667 | =item L<IO::AIO> |
|
|
668 | |
|
|
669 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
670 | programmer. Can be trivially made to use AnyEvent. |
|
|
671 | |
|
|
672 | =item L<BDB> |
|
|
673 | |
|
|
674 | Truly asynchronous Berkeley DB access. Can be trivially made to use |
|
|
675 | AnyEvent. |
|
|
676 | |
730 | |
677 | =back |
731 | =back |
678 | |
732 | |
679 | =cut |
733 | =cut |
680 | |
734 | |
… | |
… | |
683 | no warnings; |
737 | no warnings; |
684 | use strict; |
738 | use strict; |
685 | |
739 | |
686 | use Carp; |
740 | use Carp; |
687 | |
741 | |
688 | our $VERSION = '3.4'; |
742 | our $VERSION = '4.05'; |
689 | our $MODEL; |
743 | our $MODEL; |
690 | |
744 | |
691 | our $AUTOLOAD; |
745 | our $AUTOLOAD; |
692 | our @ISA; |
746 | our @ISA; |
693 | |
747 | |
|
|
748 | our @REGISTRY; |
|
|
749 | |
|
|
750 | our $WIN32; |
|
|
751 | |
|
|
752 | BEGIN { |
|
|
753 | my $win32 = ! ! ($^O =~ /mswin32/i); |
|
|
754 | eval "sub WIN32(){ $win32 }"; |
|
|
755 | } |
|
|
756 | |
694 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
757 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
695 | |
758 | |
696 | our @REGISTRY; |
759 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
|
|
760 | |
|
|
761 | { |
|
|
762 | my $idx; |
|
|
763 | $PROTOCOL{$_} = ++$idx |
|
|
764 | for reverse split /\s*,\s*/, |
|
|
765 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
|
|
766 | } |
697 | |
767 | |
698 | my @models = ( |
768 | my @models = ( |
699 | [EV:: => AnyEvent::Impl::EV::], |
769 | [EV:: => AnyEvent::Impl::EV::], |
700 | [Event:: => AnyEvent::Impl::Event::], |
770 | [Event:: => AnyEvent::Impl::Event::], |
701 | [Tk:: => AnyEvent::Impl::Tk::], |
|
|
702 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
703 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
704 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
771 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
705 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
772 | # everything below here will not be autoprobed |
706 | [Glib:: => AnyEvent::Impl::Glib::], |
773 | # as the pureperl backend should work everywhere |
|
|
774 | # and is usually faster |
|
|
775 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
776 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
707 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
777 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
708 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
778 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
709 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
779 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
|
|
780 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
781 | [Prima:: => AnyEvent::Impl::POE::], |
710 | ); |
782 | ); |
711 | |
783 | |
712 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
784 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
713 | |
785 | |
714 | our @detect; |
786 | our @post_detect; |
|
|
787 | |
|
|
788 | sub post_detect(&) { |
|
|
789 | my ($cb) = @_; |
|
|
790 | |
|
|
791 | if ($MODEL) { |
|
|
792 | $cb->(); |
|
|
793 | |
|
|
794 | 1 |
|
|
795 | } else { |
|
|
796 | push @post_detect, $cb; |
|
|
797 | |
|
|
798 | defined wantarray |
|
|
799 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
|
|
800 | : () |
|
|
801 | } |
|
|
802 | } |
|
|
803 | |
|
|
804 | sub AnyEvent::Util::PostDetect::DESTROY { |
|
|
805 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
|
|
806 | } |
715 | |
807 | |
716 | sub detect() { |
808 | sub detect() { |
717 | unless ($MODEL) { |
809 | unless ($MODEL) { |
718 | no strict 'refs'; |
810 | no strict 'refs'; |
|
|
811 | local $SIG{__DIE__}; |
719 | |
812 | |
720 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
813 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
721 | my $model = "AnyEvent::Impl::$1"; |
814 | my $model = "AnyEvent::Impl::$1"; |
722 | if (eval "require $model") { |
815 | if (eval "require $model") { |
723 | $MODEL = $model; |
816 | $MODEL = $model; |
… | |
… | |
760 | } |
853 | } |
761 | |
854 | |
762 | unshift @ISA, $MODEL; |
855 | unshift @ISA, $MODEL; |
763 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
856 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
764 | |
857 | |
765 | (shift @detect)->() while @detect; |
858 | (shift @post_detect)->() while @post_detect; |
766 | } |
859 | } |
767 | |
860 | |
768 | $MODEL |
861 | $MODEL |
769 | } |
862 | } |
770 | |
863 | |
… | |
… | |
780 | $class->$func (@_); |
873 | $class->$func (@_); |
781 | } |
874 | } |
782 | |
875 | |
783 | package AnyEvent::Base; |
876 | package AnyEvent::Base; |
784 | |
877 | |
785 | # default implementation for ->condvar, ->wait, ->broadcast |
878 | # default implementation for ->condvar |
786 | |
879 | |
787 | sub condvar { |
880 | sub condvar { |
788 | bless \my $flag, "AnyEvent::Base::CondVar" |
881 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
789 | } |
|
|
790 | |
|
|
791 | sub AnyEvent::Base::CondVar::broadcast { |
|
|
792 | ${$_[0]}++; |
|
|
793 | } |
|
|
794 | |
|
|
795 | sub AnyEvent::Base::CondVar::wait { |
|
|
796 | AnyEvent->one_event while !${$_[0]}; |
|
|
797 | } |
882 | } |
798 | |
883 | |
799 | # default implementation for ->signal |
884 | # default implementation for ->signal |
800 | |
885 | |
801 | our %SIG_CB; |
886 | our %SIG_CB; |
… | |
… | |
854 | or Carp::croak "required option 'pid' is missing"; |
939 | or Carp::croak "required option 'pid' is missing"; |
855 | |
940 | |
856 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
941 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
857 | |
942 | |
858 | unless ($WNOHANG) { |
943 | unless ($WNOHANG) { |
859 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
944 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
860 | } |
945 | } |
861 | |
946 | |
862 | unless ($CHLD_W) { |
947 | unless ($CHLD_W) { |
863 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
948 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
864 | # child could be a zombie already, so make at least one round |
949 | # child could be a zombie already, so make at least one round |
… | |
… | |
874 | delete $PID_CB{$pid}{$cb}; |
959 | delete $PID_CB{$pid}{$cb}; |
875 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
960 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
876 | |
961 | |
877 | undef $CHLD_W unless keys %PID_CB; |
962 | undef $CHLD_W unless keys %PID_CB; |
878 | } |
963 | } |
|
|
964 | |
|
|
965 | package AnyEvent::CondVar; |
|
|
966 | |
|
|
967 | our @ISA = AnyEvent::CondVar::Base::; |
|
|
968 | |
|
|
969 | package AnyEvent::CondVar::Base; |
|
|
970 | |
|
|
971 | use overload |
|
|
972 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
|
|
973 | fallback => 1; |
|
|
974 | |
|
|
975 | sub _send { |
|
|
976 | # nop |
|
|
977 | } |
|
|
978 | |
|
|
979 | sub send { |
|
|
980 | my $cv = shift; |
|
|
981 | $cv->{_ae_sent} = [@_]; |
|
|
982 | (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; |
|
|
983 | $cv->_send; |
|
|
984 | } |
|
|
985 | |
|
|
986 | sub croak { |
|
|
987 | $_[0]{_ae_croak} = $_[1]; |
|
|
988 | $_[0]->send; |
|
|
989 | } |
|
|
990 | |
|
|
991 | sub ready { |
|
|
992 | $_[0]{_ae_sent} |
|
|
993 | } |
|
|
994 | |
|
|
995 | sub _wait { |
|
|
996 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
|
|
997 | } |
|
|
998 | |
|
|
999 | sub recv { |
|
|
1000 | $_[0]->_wait; |
|
|
1001 | |
|
|
1002 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
|
|
1003 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
|
|
1004 | } |
|
|
1005 | |
|
|
1006 | sub cb { |
|
|
1007 | $_[0]{_ae_cb} = $_[1] if @_ > 1; |
|
|
1008 | $_[0]{_ae_cb} |
|
|
1009 | } |
|
|
1010 | |
|
|
1011 | sub begin { |
|
|
1012 | ++$_[0]{_ae_counter}; |
|
|
1013 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
|
|
1014 | } |
|
|
1015 | |
|
|
1016 | sub end { |
|
|
1017 | return if --$_[0]{_ae_counter}; |
|
|
1018 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
|
|
1019 | } |
|
|
1020 | |
|
|
1021 | # undocumented/compatibility with pre-3.4 |
|
|
1022 | *broadcast = \&send; |
|
|
1023 | *wait = \&_wait; |
879 | |
1024 | |
880 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1025 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
881 | |
1026 | |
882 | This is an advanced topic that you do not normally need to use AnyEvent in |
1027 | This is an advanced topic that you do not normally need to use AnyEvent in |
883 | a module. This section is only of use to event loop authors who want to |
1028 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
940 | model it chooses. |
1085 | model it chooses. |
941 | |
1086 | |
942 | =item C<PERL_ANYEVENT_MODEL> |
1087 | =item C<PERL_ANYEVENT_MODEL> |
943 | |
1088 | |
944 | This can be used to specify the event model to be used by AnyEvent, before |
1089 | This can be used to specify the event model to be used by AnyEvent, before |
945 | autodetection and -probing kicks in. It must be a string consisting |
1090 | auto detection and -probing kicks in. It must be a string consisting |
946 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
1091 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
947 | and the resulting module name is loaded and if the load was successful, |
1092 | and the resulting module name is loaded and if the load was successful, |
948 | used as event model. If it fails to load AnyEvent will proceed with |
1093 | used as event model. If it fails to load AnyEvent will proceed with |
949 | autodetection and -probing. |
1094 | auto detection and -probing. |
950 | |
1095 | |
951 | This functionality might change in future versions. |
1096 | This functionality might change in future versions. |
952 | |
1097 | |
953 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
1098 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
954 | could start your program like this: |
1099 | could start your program like this: |
955 | |
1100 | |
956 | PERL_ANYEVENT_MODEL=Perl perl ... |
1101 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1102 | |
|
|
1103 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1104 | |
|
|
1105 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1106 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1107 | of auto probing). |
|
|
1108 | |
|
|
1109 | Must be set to a comma-separated list of protocols or address families, |
|
|
1110 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1111 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1112 | list. |
|
|
1113 | |
|
|
1114 | This variable can effectively be used for denial-of-service attacks |
|
|
1115 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1116 | small, as the program has to handle connection errors already- |
|
|
1117 | |
|
|
1118 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1119 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1120 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1121 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1122 | IPv6, but prefer IPv6 over IPv4. |
|
|
1123 | |
|
|
1124 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1125 | |
|
|
1126 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1127 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1128 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1129 | default. |
|
|
1130 | |
|
|
1131 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1132 | EDNS0 in its DNS requests. |
|
|
1133 | |
|
|
1134 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1135 | |
|
|
1136 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1137 | will create in parallel. |
957 | |
1138 | |
958 | =back |
1139 | =back |
959 | |
1140 | |
960 | =head1 EXAMPLE PROGRAM |
1141 | =head1 EXAMPLE PROGRAM |
961 | |
1142 | |
… | |
… | |
972 | poll => 'r', |
1153 | poll => 'r', |
973 | cb => sub { |
1154 | cb => sub { |
974 | warn "io event <$_[0]>\n"; # will always output <r> |
1155 | warn "io event <$_[0]>\n"; # will always output <r> |
975 | chomp (my $input = <STDIN>); # read a line |
1156 | chomp (my $input = <STDIN>); # read a line |
976 | warn "read: $input\n"; # output what has been read |
1157 | warn "read: $input\n"; # output what has been read |
977 | $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i |
1158 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
978 | }, |
1159 | }, |
979 | ); |
1160 | ); |
980 | |
1161 | |
981 | my $time_watcher; # can only be used once |
1162 | my $time_watcher; # can only be used once |
982 | |
1163 | |
… | |
… | |
987 | }); |
1168 | }); |
988 | } |
1169 | } |
989 | |
1170 | |
990 | new_timer; # create first timer |
1171 | new_timer; # create first timer |
991 | |
1172 | |
992 | $cv->wait; # wait until user enters /^q/i |
1173 | $cv->recv; # wait until user enters /^q/i |
993 | |
1174 | |
994 | =head1 REAL-WORLD EXAMPLE |
1175 | =head1 REAL-WORLD EXAMPLE |
995 | |
1176 | |
996 | Consider the L<Net::FCP> module. It features (among others) the following |
1177 | Consider the L<Net::FCP> module. It features (among others) the following |
997 | API calls, which are to freenet what HTTP GET requests are to http: |
1178 | API calls, which are to freenet what HTTP GET requests are to http: |
… | |
… | |
1047 | syswrite $txn->{fh}, $txn->{request} |
1228 | syswrite $txn->{fh}, $txn->{request} |
1048 | or die "connection or write error"; |
1229 | or die "connection or write error"; |
1049 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1230 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1050 | |
1231 | |
1051 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1232 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1052 | result and signals any possible waiters that the request ahs finished: |
1233 | result and signals any possible waiters that the request has finished: |
1053 | |
1234 | |
1054 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1235 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1055 | |
1236 | |
1056 | if (end-of-file or data complete) { |
1237 | if (end-of-file or data complete) { |
1057 | $txn->{result} = $txn->{buf}; |
1238 | $txn->{result} = $txn->{buf}; |
1058 | $txn->{finished}->broadcast; |
1239 | $txn->{finished}->send; |
1059 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1240 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1060 | } |
1241 | } |
1061 | |
1242 | |
1062 | The C<result> method, finally, just waits for the finished signal (if the |
1243 | The C<result> method, finally, just waits for the finished signal (if the |
1063 | request was already finished, it doesn't wait, of course, and returns the |
1244 | request was already finished, it doesn't wait, of course, and returns the |
1064 | data: |
1245 | data: |
1065 | |
1246 | |
1066 | $txn->{finished}->wait; |
1247 | $txn->{finished}->recv; |
1067 | return $txn->{result}; |
1248 | return $txn->{result}; |
1068 | |
1249 | |
1069 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1250 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1070 | that occured during request processing. The C<result> method detects |
1251 | that occurred during request processing. The C<result> method detects |
1071 | whether an exception as thrown (it is stored inside the $txn object) |
1252 | whether an exception as thrown (it is stored inside the $txn object) |
1072 | and just throws the exception, which means connection errors and other |
1253 | and just throws the exception, which means connection errors and other |
1073 | problems get reported tot he code that tries to use the result, not in a |
1254 | problems get reported tot he code that tries to use the result, not in a |
1074 | random callback. |
1255 | random callback. |
1075 | |
1256 | |
… | |
… | |
1106 | |
1287 | |
1107 | my $quit = AnyEvent->condvar; |
1288 | my $quit = AnyEvent->condvar; |
1108 | |
1289 | |
1109 | $fcp->txn_client_get ($url)->cb (sub { |
1290 | $fcp->txn_client_get ($url)->cb (sub { |
1110 | ... |
1291 | ... |
1111 | $quit->broadcast; |
1292 | $quit->send; |
1112 | }); |
1293 | }); |
1113 | |
1294 | |
1114 | $quit->wait; |
1295 | $quit->recv; |
1115 | |
1296 | |
1116 | |
1297 | |
1117 | =head1 BENCHMARKS |
1298 | =head1 BENCHMARKS |
1118 | |
1299 | |
1119 | To give you an idea of the performance and overheads that AnyEvent adds |
1300 | To give you an idea of the performance and overheads that AnyEvent adds |
… | |
… | |
1121 | of various event loops I prepared some benchmarks. |
1302 | of various event loops I prepared some benchmarks. |
1122 | |
1303 | |
1123 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1304 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1124 | |
1305 | |
1125 | Here is a benchmark of various supported event models used natively and |
1306 | Here is a benchmark of various supported event models used natively and |
1126 | through anyevent. The benchmark creates a lot of timers (with a zero |
1307 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1127 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1308 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1128 | which it is), lets them fire exactly once and destroys them again. |
1309 | which it is), lets them fire exactly once and destroys them again. |
1129 | |
1310 | |
1130 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1311 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1131 | distribution. |
1312 | distribution. |
… | |
… | |
1148 | all watchers, to avoid adding memory overhead. That means closure creation |
1329 | all watchers, to avoid adding memory overhead. That means closure creation |
1149 | and memory usage is not included in the figures. |
1330 | and memory usage is not included in the figures. |
1150 | |
1331 | |
1151 | I<invoke> is the time, in microseconds, used to invoke a simple |
1332 | I<invoke> is the time, in microseconds, used to invoke a simple |
1152 | callback. The callback simply counts down a Perl variable and after it was |
1333 | callback. The callback simply counts down a Perl variable and after it was |
1153 | invoked "watcher" times, it would C<< ->broadcast >> a condvar once to |
1334 | invoked "watcher" times, it would C<< ->send >> a condvar once to |
1154 | signal the end of this phase. |
1335 | signal the end of this phase. |
1155 | |
1336 | |
1156 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1337 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1157 | watcher. |
1338 | watcher. |
1158 | |
1339 | |
… | |
… | |
1254 | |
1435 | |
1255 | =back |
1436 | =back |
1256 | |
1437 | |
1257 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1438 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1258 | |
1439 | |
1259 | This benchmark atcually benchmarks the event loop itself. It works by |
1440 | This benchmark actually benchmarks the event loop itself. It works by |
1260 | creating a number of "servers": each server consists of a socketpair, a |
1441 | creating a number of "servers": each server consists of a socket pair, a |
1261 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1442 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1262 | watcher waiting for input on one side of the socket. Each time the socket |
1443 | watcher waiting for input on one side of the socket. Each time the socket |
1263 | watcher reads a byte it will write that byte to a random other "server". |
1444 | watcher reads a byte it will write that byte to a random other "server". |
1264 | |
1445 | |
1265 | The effect is that there will be a lot of I/O watchers, only part of which |
1446 | The effect is that there will be a lot of I/O watchers, only part of which |
1266 | are active at any one point (so there is a constant number of active |
1447 | are active at any one point (so there is a constant number of active |
1267 | fds for each loop iterstaion, but which fds these are is random). The |
1448 | fds for each loop iteration, but which fds these are is random). The |
1268 | timeout is reset each time something is read because that reflects how |
1449 | timeout is reset each time something is read because that reflects how |
1269 | most timeouts work (and puts extra pressure on the event loops). |
1450 | most timeouts work (and puts extra pressure on the event loops). |
1270 | |
1451 | |
1271 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 |
1452 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1272 | (1%) are active. This mirrors the activity of large servers with many |
1453 | (1%) are active. This mirrors the activity of large servers with many |
1273 | connections, most of which are idle at any one point in time. |
1454 | connections, most of which are idle at any one point in time. |
1274 | |
1455 | |
1275 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1456 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1276 | distribution. |
1457 | distribution. |
… | |
… | |
1278 | =head3 Explanation of the columns |
1459 | =head3 Explanation of the columns |
1279 | |
1460 | |
1280 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1461 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1281 | each server has a read and write socket end). |
1462 | each server has a read and write socket end). |
1282 | |
1463 | |
1283 | I<create> is the time it takes to create a socketpair (which is |
1464 | I<create> is the time it takes to create a socket pair (which is |
1284 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1465 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1285 | |
1466 | |
1286 | I<request>, the most important value, is the time it takes to handle a |
1467 | I<request>, the most important value, is the time it takes to handle a |
1287 | single "request", that is, reading the token from the pipe and forwarding |
1468 | single "request", that is, reading the token from the pipe and forwarding |
1288 | it to another server. This includes deleting the old timeout and creating |
1469 | it to another server. This includes deleting the old timeout and creating |
… | |
… | |
1361 | speed most when you have lots of watchers, not when you only have a few of |
1542 | speed most when you have lots of watchers, not when you only have a few of |
1362 | them). |
1543 | them). |
1363 | |
1544 | |
1364 | EV is again fastest. |
1545 | EV is again fastest. |
1365 | |
1546 | |
1366 | Perl again comes second. It is noticably faster than the C-based event |
1547 | Perl again comes second. It is noticeably faster than the C-based event |
1367 | loops Event and Glib, although the difference is too small to really |
1548 | loops Event and Glib, although the difference is too small to really |
1368 | matter. |
1549 | matter. |
1369 | |
1550 | |
1370 | POE also performs much better in this case, but is is still far behind the |
1551 | POE also performs much better in this case, but is is still far behind the |
1371 | others. |
1552 | others. |
… | |
… | |
1411 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1592 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1412 | |
1593 | |
1413 | |
1594 | |
1414 | =head1 SEE ALSO |
1595 | =head1 SEE ALSO |
1415 | |
1596 | |
|
|
1597 | Utility functions: L<AnyEvent::Util>. |
|
|
1598 | |
1416 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1599 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1417 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1600 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1418 | |
1601 | |
1419 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1602 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1420 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1603 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1421 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1604 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1422 | L<AnyEvent::Impl::POE>. |
1605 | L<AnyEvent::Impl::POE>. |
1423 | |
1606 | |
|
|
1607 | Non-blocking file handles, sockets, TCP clients and |
|
|
1608 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
|
|
1609 | |
|
|
1610 | Asynchronous DNS: L<AnyEvent::DNS>. |
|
|
1611 | |
1424 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1612 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1425 | |
1613 | |
1426 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
1614 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
1427 | |
1615 | |
1428 | |
1616 | |
1429 | =head1 AUTHOR |
1617 | =head1 AUTHOR |
1430 | |
1618 | |
1431 | Marc Lehmann <schmorp@schmorp.de> |
1619 | Marc Lehmann <schmorp@schmorp.de> |