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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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 | |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
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108 | |
108 | |
109 | =head1 WATCHERS |
109 | =head1 WATCHERS |
110 | |
110 | |
111 | AnyEvent has the central concept of a I<watcher>, which is an object that |
111 | 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 |
112 | stores relevant data for each kind of event you are waiting for, such as |
113 | the callback to call, the filehandle to watch, etc. |
113 | the callback to call, the file handle to watch, etc. |
114 | |
114 | |
115 | These watchers are normal Perl objects with normal Perl lifetime. After |
115 | These watchers are normal Perl objects with normal Perl lifetime. After |
116 | creating a watcher it will immediately "watch" for events and invoke the |
116 | 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 |
117 | callback when the event occurs (of course, only when the event model |
118 | is in control). |
118 | is in control). |
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237 | |
237 | |
238 | Although the callback might get passed parameters, their value and |
238 | Although the callback might get passed parameters, their value and |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
241 | |
241 | |
242 | Multiple signal occurances can be clumped together into one callback |
242 | Multiple signal occurrences can be clumped together into one callback |
243 | invocation, and callback invocation will be synchronous. synchronous means |
243 | invocation, and callback invocation will be synchronous. Synchronous means |
244 | that it might take a while until the signal gets handled by the process, |
244 | 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. |
245 | but it is guaranteed not to interrupt any other callbacks. |
246 | |
246 | |
247 | The main advantage of using these watchers is that you can share a signal |
247 | The main advantage of using these watchers is that you can share a signal |
248 | between multiple watchers. |
248 | between multiple watchers. |
249 | |
249 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
250 | 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>). |
278 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
279 | |
279 | |
280 | Example: fork a process and wait for it |
280 | Example: fork a process and wait for it |
281 | |
281 | |
282 | my $done = AnyEvent->condvar; |
282 | my $done = AnyEvent->condvar; |
283 | |
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284 | AnyEvent::detect; # force event module to be initialised |
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285 | |
283 | |
286 | my $pid = fork or exit 5; |
284 | my $pid = fork or exit 5; |
287 | |
285 | |
288 | my $w = AnyEvent->child ( |
286 | my $w = AnyEvent->child ( |
289 | pid => $pid, |
287 | pid => $pid, |
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293 | $done->send; |
291 | $done->send; |
294 | }, |
292 | }, |
295 | ); |
293 | ); |
296 | |
294 | |
297 | # do something else, then wait for process exit |
295 | # do something else, then wait for process exit |
298 | $done->wait; |
296 | $done->recv; |
299 | |
297 | |
300 | =head2 CONDITION VARIABLES |
298 | =head2 CONDITION VARIABLES |
301 | |
299 | |
302 | If you are familiar with some event loops you will know that all of them |
300 | 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 |
301 | 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 |
310 | Condition variables can be created by calling the C<< AnyEvent->condvar |
313 | >> method, usually without arguments. The only argument pair allowed is |
311 | >> method, usually without arguments. The only argument pair allowed is |
314 | C<cb>, which specifies a callback to be called when the condition variable |
312 | C<cb>, which specifies a callback to be called when the condition variable |
315 | becomes true. |
313 | becomes true. |
316 | |
314 | |
317 | After creation, the conditon variable is "false" until it becomes "true" |
315 | After creation, the condition variable is "false" until it becomes "true" |
318 | by calling the C<send> method. |
316 | by calling the C<send> method (or calling the condition variable as if it |
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317 | were a callback, read about the caveats in the description for the C<< |
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318 | ->send >> method). |
319 | |
319 | |
320 | Condition variables are similar to callbacks, except that you can |
320 | Condition variables are similar to callbacks, except that you can |
321 | optionally wait for them. They can also be called merge points - points |
321 | optionally wait for them. They can also be called merge points - points |
322 | in time where multiple outstandign events have been processed. And yet |
322 | in time where multiple outstanding events have been processed. And yet |
323 | another way to call them is transations - each condition variable can be |
323 | 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 |
324 | used to represent a transaction, which finishes at some point and delivers |
325 | a result. |
325 | a result. |
326 | |
326 | |
327 | Condition variables are very useful to signal that something has finished, |
327 | Condition variables are very useful to signal that something has finished, |
328 | for example, if you write a module that does asynchronous http requests, |
328 | 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 |
329 | 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 |
330 | availability of results. The user can either act when the callback is |
331 | called or can synchronously C<< ->wait >> for the results. |
331 | called or can synchronously C<< ->recv >> for the results. |
332 | |
332 | |
333 | You can also use them to simulate traditional event loops - for example, |
333 | 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 |
334 | 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 |
335 | 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. |
336 | button of your app, which would C<< ->send >> the "quit" event. |
337 | |
337 | |
338 | Note that condition variables recurse into the event loop - if you have |
338 | 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 |
339 | 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 |
340 | 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, |
341 | you should avoid making a blocking wait yourself, at least in callbacks, |
342 | as this asks for trouble. |
342 | as this asks for trouble. |
343 | |
343 | |
344 | Condition variables are represented by hash refs in perl, and the keys |
344 | Condition variables are represented by hash refs in perl, and the keys |
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349 | |
349 | |
350 | There are two "sides" to a condition variable - the "producer side" which |
350 | There are two "sides" to a condition variable - the "producer side" which |
351 | eventually calls C<< -> send >>, and the "consumer side", which waits |
351 | eventually calls C<< -> send >>, and the "consumer side", which waits |
352 | for the send to occur. |
352 | for the send to occur. |
353 | |
353 | |
354 | Example: |
354 | Example: wait for a timer. |
355 | |
355 | |
356 | # wait till the result is ready |
356 | # wait till the result is ready |
357 | my $result_ready = AnyEvent->condvar; |
357 | my $result_ready = AnyEvent->condvar; |
358 | |
358 | |
359 | # do something such as adding a timer |
359 | # do something such as adding a timer |
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365 | cb => sub { $result_ready->send }, |
365 | cb => sub { $result_ready->send }, |
366 | ); |
366 | ); |
367 | |
367 | |
368 | # this "blocks" (while handling events) till the callback |
368 | # this "blocks" (while handling events) till the callback |
369 | # calls send |
369 | # calls send |
370 | $result_ready->wait; |
370 | $result_ready->recv; |
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371 | |
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372 | Example: wait for a timer, but take advantage of the fact that |
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373 | condition variables are also code references. |
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374 | |
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375 | my $done = AnyEvent->condvar; |
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376 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
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377 | $done->recv; |
371 | |
378 | |
372 | =head3 METHODS FOR PRODUCERS |
379 | =head3 METHODS FOR PRODUCERS |
373 | |
380 | |
374 | These methods should only be used by the producing side, i.e. the |
381 | 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 |
382 | code/module that eventually sends the signal. Note that it is also |
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378 | |
385 | |
379 | =over 4 |
386 | =over 4 |
380 | |
387 | |
381 | =item $cv->send (...) |
388 | =item $cv->send (...) |
382 | |
389 | |
383 | Flag the condition as ready - a running C<< ->wait >> and all further |
390 | 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 |
391 | calls to C<recv> will (eventually) return after this method has been |
385 | called. If nobody is waiting the send will be remembered. |
392 | called. If nobody is waiting the send will be remembered. |
386 | |
393 | |
387 | If a callback has been set on the condition variable, it is called |
394 | If a callback has been set on the condition variable, it is called |
388 | immediately from within send. |
395 | immediately from within send. |
389 | |
396 | |
390 | Any arguments passed to the C<send> call will be returned by all |
397 | Any arguments passed to the C<send> call will be returned by all |
391 | future C<< ->wait >> calls. |
398 | future C<< ->recv >> calls. |
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399 | |
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400 | Condition variables are overloaded so one can call them directly |
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401 | (as a code reference). Calling them directly is the same as calling |
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402 | C<send>. Note, however, that many C-based event loops do not handle |
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403 | overloading, so as tempting as it may be, passing a condition variable |
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404 | instead of a callback does not work. Both the pure perl and EV loops |
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405 | support overloading, however, as well as all functions that use perl to |
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406 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
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407 | example). |
392 | |
408 | |
393 | =item $cv->croak ($error) |
409 | =item $cv->croak ($error) |
394 | |
410 | |
395 | Similar to send, but causes all call's wait C<< ->wait >> to invoke |
411 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
396 | C<Carp::croak> with the given error message/object/scalar. |
412 | C<Carp::croak> with the given error message/object/scalar. |
397 | |
413 | |
398 | This can be used to signal any errors to the condition variable |
414 | This can be used to signal any errors to the condition variable |
399 | user/consumer. |
415 | user/consumer. |
400 | |
416 | |
401 | =item $cv->begin ([group callback]) |
417 | =item $cv->begin ([group callback]) |
402 | |
418 | |
403 | =item $cv->end |
419 | =item $cv->end |
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420 | |
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421 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
404 | |
422 | |
405 | These two methods can be used to combine many transactions/events into |
423 | 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 |
424 | one. For example, a function that pings many hosts in parallel might want |
407 | to use a condition variable for the whole process. |
425 | to use a condition variable for the whole process. |
408 | |
426 | |
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443 | doesn't execute once). |
461 | doesn't execute once). |
444 | |
462 | |
445 | This is the general pattern when you "fan out" into multiple subrequests: |
463 | 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> |
464 | 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 |
465 | 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>. |
466 | C<begin> and for each subrequest you finish, call C<end>. |
449 | |
467 | |
450 | =back |
468 | =back |
451 | |
469 | |
452 | =head3 METHODS FOR CONSUMERS |
470 | =head3 METHODS FOR CONSUMERS |
453 | |
471 | |
454 | These methods should only be used by the consuming side, i.e. the |
472 | These methods should only be used by the consuming side, i.e. the |
455 | code awaits the condition. |
473 | code awaits the condition. |
456 | |
474 | |
457 | =over 4 |
475 | =over 4 |
458 | |
476 | |
459 | =item $cv->wait |
477 | =item $cv->recv |
460 | |
478 | |
461 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
479 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
462 | >> methods have been called on c<$cv>, while servicing other watchers |
480 | >> methods have been called on c<$cv>, while servicing other watchers |
463 | normally. |
481 | normally. |
464 | |
482 | |
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475 | (programs might want to do that to stay interactive), so I<if you are |
493 | (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 |
494 | 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 |
495 | caller decide whether the call will block or not (for example, by coupling |
478 | condition variables with some kind of request results and supporting |
496 | condition variables with some kind of request results and supporting |
479 | callbacks so the caller knows that getting the result will not block, |
497 | callbacks so the caller knows that getting the result will not block, |
480 | while still suppporting blocking waits if the caller so desires). |
498 | while still supporting blocking waits if the caller so desires). |
481 | |
499 | |
482 | Another reason I<never> to C<< ->wait >> in a module is that you cannot |
500 | 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 |
501 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
484 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
502 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
485 | can supply. |
503 | can supply. |
486 | |
504 | |
487 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
505 | 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 |
506 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
489 | versions and also integrates coroutines into AnyEvent, making blocking |
507 | versions and also integrates coroutines into AnyEvent, making blocking |
490 | C<< ->wait >> calls perfectly safe as long as they are done from another |
508 | C<< ->recv >> calls perfectly safe as long as they are done from another |
491 | coroutine (one that doesn't run the event loop). |
509 | coroutine (one that doesn't run the event loop). |
492 | |
510 | |
493 | You can ensure that C<< -wait >> never blocks by setting a callback and |
511 | 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 |
512 | 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 |
513 | time). This will work even when the event loop does not support blocking |
496 | waits otherwise. |
514 | waits otherwise. |
497 | |
515 | |
498 | =item $bool = $cv->ready |
516 | =item $bool = $cv->ready |
499 | |
517 | |
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504 | |
522 | |
505 | This is a mutator function that returns the callback set and optionally |
523 | This is a mutator function that returns the callback set and optionally |
506 | replaces it before doing so. |
524 | replaces it before doing so. |
507 | |
525 | |
508 | The callback will be called when the condition becomes "true", i.e. when |
526 | The callback will be called when the condition becomes "true", i.e. when |
509 | C<send> or C<croak> are called. Calling C<wait> inside the callback |
527 | C<send> or C<croak> are called. Calling C<recv> inside the callback |
510 | or at any later time is guaranteed not to block. |
528 | or at any later time is guaranteed not to block. |
511 | |
529 | |
512 | =back |
530 | =back |
513 | |
531 | |
514 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
532 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
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549 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
567 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
550 | if necessary. You should only call this function right before you would |
568 | 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 |
569 | have created an AnyEvent watcher anyway, that is, as late as possible at |
552 | runtime. |
570 | runtime. |
553 | |
571 | |
554 | =item $guard = AnyEvent::on_detect { BLOCK } |
572 | =item $guard = AnyEvent::post_detect { BLOCK } |
555 | |
573 | |
556 | Arranges for the code block to be executed as soon as the event model is |
574 | Arranges for the code block to be executed as soon as the event model is |
557 | autodetected (or immediately if this has already happened). |
575 | autodetected (or immediately if this has already happened). |
558 | |
576 | |
559 | If called in scalar or list context, then it creates and returns an object |
577 | If called in scalar or list context, then it creates and returns an object |
560 | that automatically removes the callback again when it is destroyed. |
578 | that automatically removes the callback again when it is destroyed. See |
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579 | L<Coro::BDB> for a case where this is useful. |
561 | |
580 | |
562 | =item @AnyEvent::on_detect |
581 | =item @AnyEvent::post_detect |
563 | |
582 | |
564 | If there are any code references in this array (you can C<push> to it |
583 | If there are any code references in this array (you can C<push> to it |
565 | before or after loading AnyEvent), then they will called directly after |
584 | before or after loading AnyEvent), then they will called directly after |
566 | the event loop has been chosen. |
585 | the event loop has been chosen. |
567 | |
586 | |
568 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
587 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
569 | if it contains a true value then the event loop has already been detected, |
588 | if it contains a true value then the event loop has already been detected, |
570 | and the array will be ignored. |
589 | and the array will be ignored. |
571 | |
590 | |
572 | Best use C<AnyEvent::on_detect { BLOCK }> instead. |
591 | Best use C<AnyEvent::post_detect { BLOCK }> instead. |
573 | |
592 | |
574 | =back |
593 | =back |
575 | |
594 | |
576 | =head1 WHAT TO DO IN A MODULE |
595 | =head1 WHAT TO DO IN A MODULE |
577 | |
596 | |
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581 | Be careful when you create watchers in the module body - AnyEvent will |
600 | Be careful when you create watchers in the module body - AnyEvent will |
582 | decide which event module to use as soon as the first method is called, so |
601 | decide which event module to use as soon as the first method is called, so |
583 | by calling AnyEvent in your module body you force the user of your module |
602 | by calling AnyEvent in your module body you force the user of your module |
584 | to load the event module first. |
603 | to load the event module first. |
585 | |
604 | |
586 | Never call C<< ->wait >> on a condition variable unless you I<know> that |
605 | Never call C<< ->recv >> on a condition variable unless you I<know> that |
587 | the C<< ->send >> method has been called on it already. This is |
606 | the C<< ->send >> method has been called on it already. This is |
588 | because it will stall the whole program, and the whole point of using |
607 | because it will stall the whole program, and the whole point of using |
589 | events is to stay interactive. |
608 | events is to stay interactive. |
590 | |
609 | |
591 | It is fine, however, to call C<< ->wait >> when the user of your module |
610 | It is fine, however, to call C<< ->recv >> when the user of your module |
592 | requests it (i.e. if you create a http request object ad have a method |
611 | requests it (i.e. if you create a http request object ad have a method |
593 | called C<results> that returns the results, it should call C<< ->wait >> |
612 | called C<results> that returns the results, it should call C<< ->recv >> |
594 | freely, as the user of your module knows what she is doing. always). |
613 | freely, as the user of your module knows what she is doing. always). |
595 | |
614 | |
596 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
615 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
597 | |
616 | |
598 | There will always be a single main program - the only place that should |
617 | There will always be a single main program - the only place that should |
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600 | |
619 | |
601 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
620 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
602 | do anything special (it does not need to be event-based) and let AnyEvent |
621 | do anything special (it does not need to be event-based) and let AnyEvent |
603 | decide which implementation to chose if some module relies on it. |
622 | decide which implementation to chose if some module relies on it. |
604 | |
623 | |
605 | If the main program relies on a specific event model. For example, in |
624 | If the main program relies on a specific event model - for example, in |
606 | Gtk2 programs you have to rely on the Glib module. You should load the |
625 | Gtk2 programs you have to rely on the Glib module - you should load the |
607 | event module before loading AnyEvent or any module that uses it: generally |
626 | event module before loading AnyEvent or any module that uses it: generally |
608 | speaking, you should load it as early as possible. The reason is that |
627 | speaking, you should load it as early as possible. The reason is that |
609 | modules might create watchers when they are loaded, and AnyEvent will |
628 | modules might create watchers when they are loaded, and AnyEvent will |
610 | decide on the event model to use as soon as it creates watchers, and it |
629 | decide on the event model to use as soon as it creates watchers, and it |
611 | might chose the wrong one unless you load the correct one yourself. |
630 | might chose the wrong one unless you load the correct one yourself. |
612 | |
631 | |
613 | You can chose to use a rather inefficient pure-perl implementation by |
632 | You can chose to use a pure-perl implementation by loading the |
614 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
633 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
615 | behaviour everywhere, but letting AnyEvent chose is generally better. |
634 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
635 | |
|
|
636 | =head2 MAINLOOP EMULATION |
|
|
637 | |
|
|
638 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
639 | only want to use AnyEvent), you do not want to run a specific event loop. |
|
|
640 | |
|
|
641 | In that case, you can use a condition variable like this: |
|
|
642 | |
|
|
643 | AnyEvent->condvar->recv; |
|
|
644 | |
|
|
645 | This has the effect of entering the event loop and looping forever. |
|
|
646 | |
|
|
647 | Note that usually your program has some exit condition, in which case |
|
|
648 | it is better to use the "traditional" approach of storing a condition |
|
|
649 | variable somewhere, waiting for it, and sending it when the program should |
|
|
650 | exit cleanly. |
|
|
651 | |
616 | |
652 | |
617 | =head1 OTHER MODULES |
653 | =head1 OTHER MODULES |
618 | |
654 | |
619 | The following is a non-exhaustive list of additional modules that use |
655 | The following is a non-exhaustive list of additional modules that use |
620 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
656 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
… | |
… | |
632 | |
668 | |
633 | Provide read and write buffers and manages watchers for reads and writes. |
669 | Provide read and write buffers and manages watchers for reads and writes. |
634 | |
670 | |
635 | =item L<AnyEvent::Socket> |
671 | =item L<AnyEvent::Socket> |
636 | |
672 | |
637 | Provides a means to do non-blocking connects, accepts etc. |
673 | Provides various utility functions for (internet protocol) sockets, |
|
|
674 | addresses and name resolution. Also functions to create non-blocking tcp |
|
|
675 | connections or tcp servers, with IPv6 and SRV record support and more. |
|
|
676 | |
|
|
677 | =item L<AnyEvent::DNS> |
|
|
678 | |
|
|
679 | Provides rich asynchronous DNS resolver capabilities. |
638 | |
680 | |
639 | =item L<AnyEvent::HTTPD> |
681 | =item L<AnyEvent::HTTPD> |
640 | |
682 | |
641 | Provides a simple web application server framework. |
683 | Provides a simple web application server framework. |
642 | |
|
|
643 | =item L<AnyEvent::DNS> |
|
|
644 | |
|
|
645 | Provides asynchronous DNS resolver capabilities, beyond what |
|
|
646 | L<AnyEvent::Util> offers. |
|
|
647 | |
684 | |
648 | =item L<AnyEvent::FastPing> |
685 | =item L<AnyEvent::FastPing> |
649 | |
686 | |
650 | The fastest ping in the west. |
687 | The fastest ping in the west. |
651 | |
688 | |
… | |
… | |
668 | |
705 | |
669 | =item L<Coro> |
706 | =item L<Coro> |
670 | |
707 | |
671 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
708 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
672 | |
709 | |
|
|
710 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
711 | |
|
|
712 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
713 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
714 | together. |
|
|
715 | |
|
|
716 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
717 | |
|
|
718 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
719 | IO::AIO and AnyEvent together. |
|
|
720 | |
673 | =item L<IO::Lambda> |
721 | =item L<IO::Lambda> |
674 | |
722 | |
675 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
723 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
676 | |
|
|
677 | =item L<IO::AIO> |
|
|
678 | |
|
|
679 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
680 | programmer. Can be trivially made to use AnyEvent. |
|
|
681 | |
|
|
682 | =item L<BDB> |
|
|
683 | |
|
|
684 | Truly asynchronous Berkeley DB access. Can be trivially made to use |
|
|
685 | AnyEvent. |
|
|
686 | |
724 | |
687 | =back |
725 | =back |
688 | |
726 | |
689 | =cut |
727 | =cut |
690 | |
728 | |
… | |
… | |
693 | no warnings; |
731 | no warnings; |
694 | use strict; |
732 | use strict; |
695 | |
733 | |
696 | use Carp; |
734 | use Carp; |
697 | |
735 | |
698 | our $VERSION = '3.4'; |
736 | our $VERSION = '4.05'; |
699 | our $MODEL; |
737 | our $MODEL; |
700 | |
738 | |
701 | our $AUTOLOAD; |
739 | our $AUTOLOAD; |
702 | our @ISA; |
740 | our @ISA; |
703 | |
741 | |
|
|
742 | our @REGISTRY; |
|
|
743 | |
|
|
744 | our $WIN32; |
|
|
745 | |
|
|
746 | BEGIN { |
|
|
747 | my $win32 = ! ! ($^O =~ /mswin32/i); |
|
|
748 | eval "sub WIN32(){ $win32 }"; |
|
|
749 | } |
|
|
750 | |
704 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
751 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
705 | |
752 | |
706 | our @REGISTRY; |
753 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
|
|
754 | |
|
|
755 | { |
|
|
756 | my $idx; |
|
|
757 | $PROTOCOL{$_} = ++$idx |
|
|
758 | for reverse split /\s*,\s*/, |
|
|
759 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
|
|
760 | } |
707 | |
761 | |
708 | my @models = ( |
762 | my @models = ( |
709 | [EV:: => AnyEvent::Impl::EV::], |
763 | [EV:: => AnyEvent::Impl::EV::], |
710 | [Event:: => AnyEvent::Impl::Event::], |
764 | [Event:: => AnyEvent::Impl::Event::], |
711 | [Tk:: => AnyEvent::Impl::Tk::], |
|
|
712 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
713 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
714 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
765 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
715 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
766 | # everything below here will not be autoprobed |
716 | [Glib:: => AnyEvent::Impl::Glib::], |
767 | # as the pureperl backend should work everywhere |
|
|
768 | # and is usually faster |
|
|
769 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
770 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
717 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
771 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
718 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
772 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
719 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
773 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
|
|
774 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
775 | [Prima:: => AnyEvent::Impl::POE::], |
720 | ); |
776 | ); |
721 | |
777 | |
722 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
778 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
723 | |
779 | |
724 | our @on_detect; |
780 | our @post_detect; |
725 | |
781 | |
726 | sub on_detect(&) { |
782 | sub post_detect(&) { |
727 | my ($cb) = @_; |
783 | my ($cb) = @_; |
728 | |
784 | |
729 | if ($MODEL) { |
785 | if ($MODEL) { |
730 | $cb->(); |
786 | $cb->(); |
731 | |
787 | |
732 | 1 |
788 | 1 |
733 | } else { |
789 | } else { |
734 | push @on_detect, $cb; |
790 | push @post_detect, $cb; |
735 | |
791 | |
736 | defined wantarray |
792 | defined wantarray |
737 | ? bless \$cb, "AnyEvent::Util::Guard" |
793 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
738 | : () |
794 | : () |
739 | } |
795 | } |
740 | } |
796 | } |
741 | |
797 | |
742 | sub AnyEvent::Util::Guard::DESTROY { |
798 | sub AnyEvent::Util::PostDetect::DESTROY { |
743 | @on_detect = grep $_ != ${$_[0]}, @on_detect; |
799 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
744 | } |
800 | } |
745 | |
801 | |
746 | sub detect() { |
802 | sub detect() { |
747 | unless ($MODEL) { |
803 | unless ($MODEL) { |
748 | no strict 'refs'; |
804 | no strict 'refs'; |
|
|
805 | local $SIG{__DIE__}; |
749 | |
806 | |
750 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
807 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
751 | my $model = "AnyEvent::Impl::$1"; |
808 | my $model = "AnyEvent::Impl::$1"; |
752 | if (eval "require $model") { |
809 | if (eval "require $model") { |
753 | $MODEL = $model; |
810 | $MODEL = $model; |
… | |
… | |
790 | } |
847 | } |
791 | |
848 | |
792 | unshift @ISA, $MODEL; |
849 | unshift @ISA, $MODEL; |
793 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
850 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
794 | |
851 | |
795 | (shift @on_detect)->() while @on_detect; |
852 | (shift @post_detect)->() while @post_detect; |
796 | } |
853 | } |
797 | |
854 | |
798 | $MODEL |
855 | $MODEL |
799 | } |
856 | } |
800 | |
857 | |
… | |
… | |
810 | $class->$func (@_); |
867 | $class->$func (@_); |
811 | } |
868 | } |
812 | |
869 | |
813 | package AnyEvent::Base; |
870 | package AnyEvent::Base; |
814 | |
871 | |
815 | # default implementation for ->condvar, ->wait, ->broadcast |
872 | # default implementation for ->condvar |
816 | |
873 | |
817 | sub condvar { |
874 | sub condvar { |
818 | bless \my $flag, "AnyEvent::Base::CondVar" |
875 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
819 | } |
|
|
820 | |
|
|
821 | sub AnyEvent::Base::CondVar::broadcast { |
|
|
822 | ${$_[0]}++; |
|
|
823 | } |
|
|
824 | |
|
|
825 | sub AnyEvent::Base::CondVar::wait { |
|
|
826 | AnyEvent->one_event while !${$_[0]}; |
|
|
827 | } |
876 | } |
828 | |
877 | |
829 | # default implementation for ->signal |
878 | # default implementation for ->signal |
830 | |
879 | |
831 | our %SIG_CB; |
880 | our %SIG_CB; |
… | |
… | |
884 | or Carp::croak "required option 'pid' is missing"; |
933 | or Carp::croak "required option 'pid' is missing"; |
885 | |
934 | |
886 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
935 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
887 | |
936 | |
888 | unless ($WNOHANG) { |
937 | unless ($WNOHANG) { |
889 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
938 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
890 | } |
939 | } |
891 | |
940 | |
892 | unless ($CHLD_W) { |
941 | unless ($CHLD_W) { |
893 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
942 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
894 | # child could be a zombie already, so make at least one round |
943 | # child could be a zombie already, so make at least one round |
… | |
… | |
904 | delete $PID_CB{$pid}{$cb}; |
953 | delete $PID_CB{$pid}{$cb}; |
905 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
954 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
906 | |
955 | |
907 | undef $CHLD_W unless keys %PID_CB; |
956 | undef $CHLD_W unless keys %PID_CB; |
908 | } |
957 | } |
|
|
958 | |
|
|
959 | package AnyEvent::CondVar; |
|
|
960 | |
|
|
961 | our @ISA = AnyEvent::CondVar::Base::; |
|
|
962 | |
|
|
963 | package AnyEvent::CondVar::Base; |
|
|
964 | |
|
|
965 | use overload |
|
|
966 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
|
|
967 | fallback => 1; |
|
|
968 | |
|
|
969 | sub _send { |
|
|
970 | # nop |
|
|
971 | } |
|
|
972 | |
|
|
973 | sub send { |
|
|
974 | my $cv = shift; |
|
|
975 | $cv->{_ae_sent} = [@_]; |
|
|
976 | (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; |
|
|
977 | $cv->_send; |
|
|
978 | } |
|
|
979 | |
|
|
980 | sub croak { |
|
|
981 | $_[0]{_ae_croak} = $_[1]; |
|
|
982 | $_[0]->send; |
|
|
983 | } |
|
|
984 | |
|
|
985 | sub ready { |
|
|
986 | $_[0]{_ae_sent} |
|
|
987 | } |
|
|
988 | |
|
|
989 | sub _wait { |
|
|
990 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
|
|
991 | } |
|
|
992 | |
|
|
993 | sub recv { |
|
|
994 | $_[0]->_wait; |
|
|
995 | |
|
|
996 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
|
|
997 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
|
|
998 | } |
|
|
999 | |
|
|
1000 | sub cb { |
|
|
1001 | $_[0]{_ae_cb} = $_[1] if @_ > 1; |
|
|
1002 | $_[0]{_ae_cb} |
|
|
1003 | } |
|
|
1004 | |
|
|
1005 | sub begin { |
|
|
1006 | ++$_[0]{_ae_counter}; |
|
|
1007 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
|
|
1008 | } |
|
|
1009 | |
|
|
1010 | sub end { |
|
|
1011 | return if --$_[0]{_ae_counter}; |
|
|
1012 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
|
|
1013 | } |
|
|
1014 | |
|
|
1015 | # undocumented/compatibility with pre-3.4 |
|
|
1016 | *broadcast = \&send; |
|
|
1017 | *wait = \&_wait; |
909 | |
1018 | |
910 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1019 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
911 | |
1020 | |
912 | This is an advanced topic that you do not normally need to use AnyEvent in |
1021 | This is an advanced topic that you do not normally need to use AnyEvent in |
913 | a module. This section is only of use to event loop authors who want to |
1022 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
970 | model it chooses. |
1079 | model it chooses. |
971 | |
1080 | |
972 | =item C<PERL_ANYEVENT_MODEL> |
1081 | =item C<PERL_ANYEVENT_MODEL> |
973 | |
1082 | |
974 | This can be used to specify the event model to be used by AnyEvent, before |
1083 | This can be used to specify the event model to be used by AnyEvent, before |
975 | autodetection and -probing kicks in. It must be a string consisting |
1084 | auto detection and -probing kicks in. It must be a string consisting |
976 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
1085 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
977 | and the resulting module name is loaded and if the load was successful, |
1086 | and the resulting module name is loaded and if the load was successful, |
978 | used as event model. If it fails to load AnyEvent will proceed with |
1087 | used as event model. If it fails to load AnyEvent will proceed with |
979 | autodetection and -probing. |
1088 | auto detection and -probing. |
980 | |
1089 | |
981 | This functionality might change in future versions. |
1090 | This functionality might change in future versions. |
982 | |
1091 | |
983 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
1092 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
984 | could start your program like this: |
1093 | could start your program like this: |
985 | |
1094 | |
986 | PERL_ANYEVENT_MODEL=Perl perl ... |
1095 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1096 | |
|
|
1097 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1098 | |
|
|
1099 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1100 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1101 | of auto probing). |
|
|
1102 | |
|
|
1103 | Must be set to a comma-separated list of protocols or address families, |
|
|
1104 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1105 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1106 | list. |
|
|
1107 | |
|
|
1108 | This variable can effectively be used for denial-of-service attacks |
|
|
1109 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1110 | small, as the program has to handle connection errors already- |
|
|
1111 | |
|
|
1112 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1113 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1114 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1115 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1116 | IPv6, but prefer IPv6 over IPv4. |
|
|
1117 | |
|
|
1118 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1119 | |
|
|
1120 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1121 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1122 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1123 | default. |
|
|
1124 | |
|
|
1125 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1126 | EDNS0 in its DNS requests. |
987 | |
1127 | |
988 | =back |
1128 | =back |
989 | |
1129 | |
990 | =head1 EXAMPLE PROGRAM |
1130 | =head1 EXAMPLE PROGRAM |
991 | |
1131 | |
… | |
… | |
1002 | poll => 'r', |
1142 | poll => 'r', |
1003 | cb => sub { |
1143 | cb => sub { |
1004 | warn "io event <$_[0]>\n"; # will always output <r> |
1144 | warn "io event <$_[0]>\n"; # will always output <r> |
1005 | chomp (my $input = <STDIN>); # read a line |
1145 | chomp (my $input = <STDIN>); # read a line |
1006 | warn "read: $input\n"; # output what has been read |
1146 | warn "read: $input\n"; # output what has been read |
1007 | $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i |
1147 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
1008 | }, |
1148 | }, |
1009 | ); |
1149 | ); |
1010 | |
1150 | |
1011 | my $time_watcher; # can only be used once |
1151 | my $time_watcher; # can only be used once |
1012 | |
1152 | |
… | |
… | |
1017 | }); |
1157 | }); |
1018 | } |
1158 | } |
1019 | |
1159 | |
1020 | new_timer; # create first timer |
1160 | new_timer; # create first timer |
1021 | |
1161 | |
1022 | $cv->wait; # wait until user enters /^q/i |
1162 | $cv->recv; # wait until user enters /^q/i |
1023 | |
1163 | |
1024 | =head1 REAL-WORLD EXAMPLE |
1164 | =head1 REAL-WORLD EXAMPLE |
1025 | |
1165 | |
1026 | Consider the L<Net::FCP> module. It features (among others) the following |
1166 | Consider the L<Net::FCP> module. It features (among others) the following |
1027 | API calls, which are to freenet what HTTP GET requests are to http: |
1167 | API calls, which are to freenet what HTTP GET requests are to http: |
… | |
… | |
1077 | syswrite $txn->{fh}, $txn->{request} |
1217 | syswrite $txn->{fh}, $txn->{request} |
1078 | or die "connection or write error"; |
1218 | or die "connection or write error"; |
1079 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1219 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1080 | |
1220 | |
1081 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1221 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1082 | result and signals any possible waiters that the request ahs finished: |
1222 | result and signals any possible waiters that the request has finished: |
1083 | |
1223 | |
1084 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1224 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1085 | |
1225 | |
1086 | if (end-of-file or data complete) { |
1226 | if (end-of-file or data complete) { |
1087 | $txn->{result} = $txn->{buf}; |
1227 | $txn->{result} = $txn->{buf}; |
1088 | $txn->{finished}->broadcast; |
1228 | $txn->{finished}->send; |
1089 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1229 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1090 | } |
1230 | } |
1091 | |
1231 | |
1092 | The C<result> method, finally, just waits for the finished signal (if the |
1232 | The C<result> method, finally, just waits for the finished signal (if the |
1093 | request was already finished, it doesn't wait, of course, and returns the |
1233 | request was already finished, it doesn't wait, of course, and returns the |
1094 | data: |
1234 | data: |
1095 | |
1235 | |
1096 | $txn->{finished}->wait; |
1236 | $txn->{finished}->recv; |
1097 | return $txn->{result}; |
1237 | return $txn->{result}; |
1098 | |
1238 | |
1099 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1239 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1100 | that occured during request processing. The C<result> method detects |
1240 | that occurred during request processing. The C<result> method detects |
1101 | whether an exception as thrown (it is stored inside the $txn object) |
1241 | whether an exception as thrown (it is stored inside the $txn object) |
1102 | and just throws the exception, which means connection errors and other |
1242 | and just throws the exception, which means connection errors and other |
1103 | problems get reported tot he code that tries to use the result, not in a |
1243 | problems get reported tot he code that tries to use the result, not in a |
1104 | random callback. |
1244 | random callback. |
1105 | |
1245 | |
… | |
… | |
1136 | |
1276 | |
1137 | my $quit = AnyEvent->condvar; |
1277 | my $quit = AnyEvent->condvar; |
1138 | |
1278 | |
1139 | $fcp->txn_client_get ($url)->cb (sub { |
1279 | $fcp->txn_client_get ($url)->cb (sub { |
1140 | ... |
1280 | ... |
1141 | $quit->broadcast; |
1281 | $quit->send; |
1142 | }); |
1282 | }); |
1143 | |
1283 | |
1144 | $quit->wait; |
1284 | $quit->recv; |
1145 | |
1285 | |
1146 | |
1286 | |
1147 | =head1 BENCHMARKS |
1287 | =head1 BENCHMARKS |
1148 | |
1288 | |
1149 | To give you an idea of the performance and overheads that AnyEvent adds |
1289 | To give you an idea of the performance and overheads that AnyEvent adds |
… | |
… | |
1151 | of various event loops I prepared some benchmarks. |
1291 | of various event loops I prepared some benchmarks. |
1152 | |
1292 | |
1153 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1293 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1154 | |
1294 | |
1155 | Here is a benchmark of various supported event models used natively and |
1295 | Here is a benchmark of various supported event models used natively and |
1156 | through anyevent. The benchmark creates a lot of timers (with a zero |
1296 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1157 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1297 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1158 | which it is), lets them fire exactly once and destroys them again. |
1298 | which it is), lets them fire exactly once and destroys them again. |
1159 | |
1299 | |
1160 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1300 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1161 | distribution. |
1301 | distribution. |
… | |
… | |
1178 | all watchers, to avoid adding memory overhead. That means closure creation |
1318 | all watchers, to avoid adding memory overhead. That means closure creation |
1179 | and memory usage is not included in the figures. |
1319 | and memory usage is not included in the figures. |
1180 | |
1320 | |
1181 | I<invoke> is the time, in microseconds, used to invoke a simple |
1321 | I<invoke> is the time, in microseconds, used to invoke a simple |
1182 | callback. The callback simply counts down a Perl variable and after it was |
1322 | callback. The callback simply counts down a Perl variable and after it was |
1183 | invoked "watcher" times, it would C<< ->broadcast >> a condvar once to |
1323 | invoked "watcher" times, it would C<< ->send >> a condvar once to |
1184 | signal the end of this phase. |
1324 | signal the end of this phase. |
1185 | |
1325 | |
1186 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1326 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1187 | watcher. |
1327 | watcher. |
1188 | |
1328 | |
… | |
… | |
1284 | |
1424 | |
1285 | =back |
1425 | =back |
1286 | |
1426 | |
1287 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1427 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1288 | |
1428 | |
1289 | This benchmark atcually benchmarks the event loop itself. It works by |
1429 | This benchmark actually benchmarks the event loop itself. It works by |
1290 | creating a number of "servers": each server consists of a socketpair, a |
1430 | creating a number of "servers": each server consists of a socket pair, a |
1291 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1431 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1292 | watcher waiting for input on one side of the socket. Each time the socket |
1432 | watcher waiting for input on one side of the socket. Each time the socket |
1293 | watcher reads a byte it will write that byte to a random other "server". |
1433 | watcher reads a byte it will write that byte to a random other "server". |
1294 | |
1434 | |
1295 | The effect is that there will be a lot of I/O watchers, only part of which |
1435 | The effect is that there will be a lot of I/O watchers, only part of which |
1296 | are active at any one point (so there is a constant number of active |
1436 | are active at any one point (so there is a constant number of active |
1297 | fds for each loop iterstaion, but which fds these are is random). The |
1437 | fds for each loop iteration, but which fds these are is random). The |
1298 | timeout is reset each time something is read because that reflects how |
1438 | timeout is reset each time something is read because that reflects how |
1299 | most timeouts work (and puts extra pressure on the event loops). |
1439 | most timeouts work (and puts extra pressure on the event loops). |
1300 | |
1440 | |
1301 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 |
1441 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1302 | (1%) are active. This mirrors the activity of large servers with many |
1442 | (1%) are active. This mirrors the activity of large servers with many |
1303 | connections, most of which are idle at any one point in time. |
1443 | connections, most of which are idle at any one point in time. |
1304 | |
1444 | |
1305 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1445 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1306 | distribution. |
1446 | distribution. |
… | |
… | |
1308 | =head3 Explanation of the columns |
1448 | =head3 Explanation of the columns |
1309 | |
1449 | |
1310 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1450 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1311 | each server has a read and write socket end). |
1451 | each server has a read and write socket end). |
1312 | |
1452 | |
1313 | I<create> is the time it takes to create a socketpair (which is |
1453 | I<create> is the time it takes to create a socket pair (which is |
1314 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1454 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1315 | |
1455 | |
1316 | I<request>, the most important value, is the time it takes to handle a |
1456 | I<request>, the most important value, is the time it takes to handle a |
1317 | single "request", that is, reading the token from the pipe and forwarding |
1457 | single "request", that is, reading the token from the pipe and forwarding |
1318 | it to another server. This includes deleting the old timeout and creating |
1458 | it to another server. This includes deleting the old timeout and creating |
… | |
… | |
1391 | speed most when you have lots of watchers, not when you only have a few of |
1531 | speed most when you have lots of watchers, not when you only have a few of |
1392 | them). |
1532 | them). |
1393 | |
1533 | |
1394 | EV is again fastest. |
1534 | EV is again fastest. |
1395 | |
1535 | |
1396 | Perl again comes second. It is noticably faster than the C-based event |
1536 | Perl again comes second. It is noticeably faster than the C-based event |
1397 | loops Event and Glib, although the difference is too small to really |
1537 | loops Event and Glib, although the difference is too small to really |
1398 | matter. |
1538 | matter. |
1399 | |
1539 | |
1400 | POE also performs much better in this case, but is is still far behind the |
1540 | POE also performs much better in this case, but is is still far behind the |
1401 | others. |
1541 | others. |
… | |
… | |
1441 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1581 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1442 | |
1582 | |
1443 | |
1583 | |
1444 | =head1 SEE ALSO |
1584 | =head1 SEE ALSO |
1445 | |
1585 | |
|
|
1586 | Utility functions: L<AnyEvent::Util>. |
|
|
1587 | |
1446 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1588 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1447 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1589 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1448 | |
1590 | |
1449 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1591 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1450 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1592 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1451 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1593 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1452 | L<AnyEvent::Impl::POE>. |
1594 | L<AnyEvent::Impl::POE>. |
1453 | |
1595 | |
|
|
1596 | Non-blocking file handles, sockets, TCP clients and |
|
|
1597 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
|
|
1598 | |
|
|
1599 | Asynchronous DNS: L<AnyEvent::DNS>. |
|
|
1600 | |
1454 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1601 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1455 | |
1602 | |
1456 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
1603 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
1457 | |
1604 | |
1458 | |
1605 | |
1459 | =head1 AUTHOR |
1606 | =head1 AUTHOR |
1460 | |
1607 | |
1461 | Marc Lehmann <schmorp@schmorp.de> |
1608 | Marc Lehmann <schmorp@schmorp.de> |