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, Coro::EV, Coro::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 | |
7 | =head1 SYNOPSIS |
7 | =head1 SYNOPSIS |
8 | |
8 | |
9 | use AnyEvent; |
9 | use AnyEvent; |
10 | |
10 | |
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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 ->broadcast |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
21 | $w->broadcast; # 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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78 | The interface itself is vaguely similar, but not identical to the L<Event> |
78 | The interface itself is vaguely similar, but not identical to the L<Event> |
79 | module. |
79 | module. |
80 | |
80 | |
81 | During the first call of any watcher-creation method, the module tries |
81 | During the first call of any watcher-creation method, the module tries |
82 | to detect the currently loaded event loop by probing whether one of the |
82 | to detect the currently loaded event loop by probing whether one of the |
83 | following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>, |
83 | following modules is already loaded: L<EV>, |
84 | L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>, |
84 | L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>, |
85 | L<POE>. The first one found is used. If none are found, the module tries |
85 | L<POE>. The first one found is used. If none are found, the module tries |
86 | to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl |
86 | to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl |
87 | adaptor should always succeed) in the order given. The first one that can |
87 | adaptor should always succeed) in the order given. The first one that can |
88 | be successfully loaded will be used. If, after this, still none could be |
88 | be successfully loaded will be used. If, after this, still none could be |
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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 | |
283 | |
284 | AnyEvent::detect; # force event module to be initialised |
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285 | |
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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 => $pid, |
290 | cb => sub { |
288 | cb => sub { |
291 | my ($pid, $status) = @_; |
289 | my ($pid, $status) = @_; |
292 | warn "pid $pid exited with status $status"; |
290 | warn "pid $pid exited with status $status"; |
293 | $done->broadcast; |
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 | |
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300 | If you are familiar with some event loops you will know that all of them |
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301 | require you to run some blocking "loop", "run" or similar function that |
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302 | will actively watch for new events and call your callbacks. |
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303 | |
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304 | AnyEvent is different, it expects somebody else to run the event loop and |
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305 | will only block when necessary (usually when told by the user). |
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306 | |
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307 | The instrument to do that is called a "condition variable", so called |
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308 | because they represent a condition that must become true. |
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309 | |
302 | Condition variables can be created by calling the C<< AnyEvent->condvar >> |
310 | Condition variables can be created by calling the C<< AnyEvent->condvar |
303 | method without any arguments. |
311 | >> method, usually without arguments. The only argument pair allowed is |
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312 | C<cb>, which specifies a callback to be called when the condition variable |
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313 | becomes true. |
304 | |
314 | |
305 | A condition variable waits for a condition - precisely that the C<< |
315 | After creation, the conditon variable is "false" until it becomes "true" |
306 | ->broadcast >> method has been called. |
316 | by calling the C<send> method. |
307 | |
317 | |
308 | They are very useful to signal that a condition has been fulfilled, for |
318 | Condition variables are similar to callbacks, except that you can |
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319 | optionally wait for them. They can also be called merge points - points |
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320 | in time where multiple outstandign events have been processed. And yet |
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321 | another way to call them is transations - each condition variable can be |
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322 | used to represent a transaction, which finishes at some point and delivers |
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323 | a result. |
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324 | |
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325 | Condition variables are very useful to signal that something has finished, |
309 | example, if you write a module that does asynchronous http requests, |
326 | for example, if you write a module that does asynchronous http requests, |
310 | then a condition variable would be the ideal candidate to signal the |
327 | then a condition variable would be the ideal candidate to signal the |
311 | availability of results. |
328 | availability of results. The user can either act when the callback is |
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329 | called or can synchronously C<< ->recv >> for the results. |
312 | |
330 | |
313 | You can also use condition variables to block your main program until |
331 | You can also use them to simulate traditional event loops - for example, |
314 | an event occurs - for example, you could C<< ->wait >> in your main |
332 | you can block your main program until an event occurs - for example, you |
315 | program until the user clicks the Quit button in your app, which would C<< |
333 | could C<< ->recv >> in your main program until the user clicks the Quit |
316 | ->broadcast >> the "quit" event. |
334 | button of your app, which would C<< ->send >> the "quit" event. |
317 | |
335 | |
318 | Note that condition variables recurse into the event loop - if you have |
336 | Note that condition variables recurse into the event loop - if you have |
319 | two pirces of code that call C<< ->wait >> in a round-robbin fashion, you |
337 | two pieces of code that call C<< ->recv >> in a round-robbin fashion, you |
320 | lose. Therefore, condition variables are good to export to your caller, but |
338 | lose. Therefore, condition variables are good to export to your caller, but |
321 | you should avoid making a blocking wait yourself, at least in callbacks, |
339 | you should avoid making a blocking wait yourself, at least in callbacks, |
322 | as this asks for trouble. |
340 | as this asks for trouble. |
323 | |
341 | |
324 | This object has two methods: |
342 | Condition variables are represented by hash refs in perl, and the keys |
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343 | used by AnyEvent itself are all named C<_ae_XXX> to make subclassing |
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344 | easy (it is often useful to build your own transaction class on top of |
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345 | AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call |
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346 | it's C<new> method in your own C<new> method. |
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347 | |
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348 | There are two "sides" to a condition variable - the "producer side" which |
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349 | eventually calls C<< -> send >>, and the "consumer side", which waits |
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350 | for the send to occur. |
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351 | |
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352 | Example: |
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353 | |
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354 | # wait till the result is ready |
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355 | my $result_ready = AnyEvent->condvar; |
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356 | |
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357 | # do something such as adding a timer |
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358 | # or socket watcher the calls $result_ready->send |
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359 | # when the "result" is ready. |
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360 | # in this case, we simply use a timer: |
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361 | my $w = AnyEvent->timer ( |
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362 | after => 1, |
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363 | cb => sub { $result_ready->send }, |
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364 | ); |
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365 | |
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366 | # this "blocks" (while handling events) till the callback |
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367 | # calls send |
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368 | $result_ready->recv; |
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369 | |
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370 | =head3 METHODS FOR PRODUCERS |
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371 | |
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372 | These methods should only be used by the producing side, i.e. the |
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373 | code/module that eventually sends the signal. Note that it is also |
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374 | the producer side which creates the condvar in most cases, but it isn't |
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375 | uncommon for the consumer to create it as well. |
325 | |
376 | |
326 | =over 4 |
377 | =over 4 |
327 | |
378 | |
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379 | =item $cv->send (...) |
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380 | |
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381 | Flag the condition as ready - a running C<< ->recv >> and all further |
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382 | calls to C<recv> will (eventually) return after this method has been |
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383 | called. If nobody is waiting the send will be remembered. |
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384 | |
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385 | If a callback has been set on the condition variable, it is called |
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386 | immediately from within send. |
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387 | |
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388 | Any arguments passed to the C<send> call will be returned by all |
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389 | future C<< ->recv >> calls. |
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390 | |
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391 | =item $cv->croak ($error) |
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392 | |
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393 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
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394 | C<Carp::croak> with the given error message/object/scalar. |
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395 | |
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396 | This can be used to signal any errors to the condition variable |
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397 | user/consumer. |
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398 | |
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399 | =item $cv->begin ([group callback]) |
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400 | |
328 | =item $cv->wait |
401 | =item $cv->end |
329 | |
402 | |
330 | Wait (blocking if necessary) until the C<< ->broadcast >> method has been |
403 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
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404 | |
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405 | These two methods can be used to combine many transactions/events into |
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406 | one. For example, a function that pings many hosts in parallel might want |
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407 | to use a condition variable for the whole process. |
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408 | |
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409 | Every call to C<< ->begin >> will increment a counter, and every call to |
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410 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
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411 | >>, the (last) callback passed to C<begin> will be executed. That callback |
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412 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
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413 | callback was set, C<send> will be called without any arguments. |
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414 | |
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415 | Let's clarify this with the ping example: |
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416 | |
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417 | my $cv = AnyEvent->condvar; |
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418 | |
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419 | my %result; |
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420 | $cv->begin (sub { $cv->send (\%result) }); |
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421 | |
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422 | for my $host (@list_of_hosts) { |
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423 | $cv->begin; |
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424 | ping_host_then_call_callback $host, sub { |
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425 | $result{$host} = ...; |
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426 | $cv->end; |
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427 | }; |
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428 | } |
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429 | |
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430 | $cv->end; |
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431 | |
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432 | This code fragment supposedly pings a number of hosts and calls |
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433 | C<send> after results for all then have have been gathered - in any |
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434 | order. To achieve this, the code issues a call to C<begin> when it starts |
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435 | each ping request and calls C<end> when it has received some result for |
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436 | it. Since C<begin> and C<end> only maintain a counter, the order in which |
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437 | results arrive is not relevant. |
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438 | |
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439 | There is an additional bracketing call to C<begin> and C<end> outside the |
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440 | loop, which serves two important purposes: first, it sets the callback |
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441 | to be called once the counter reaches C<0>, and second, it ensures that |
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442 | C<send> is called even when C<no> hosts are being pinged (the loop |
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443 | doesn't execute once). |
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444 | |
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445 | This is the general pattern when you "fan out" into multiple subrequests: |
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446 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
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447 | is called at least once, and then, for each subrequest you start, call |
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448 | C<begin> and for eahc subrequest you finish, call C<end>. |
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449 | |
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450 | =back |
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451 | |
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452 | =head3 METHODS FOR CONSUMERS |
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453 | |
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454 | These methods should only be used by the consuming side, i.e. the |
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455 | code awaits the condition. |
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456 | |
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457 | =over 4 |
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458 | |
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459 | =item $cv->recv |
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460 | |
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461 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
331 | called on c<$cv>, while servicing other watchers normally. |
462 | >> methods have been called on c<$cv>, while servicing other watchers |
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463 | normally. |
332 | |
464 | |
333 | You can only wait once on a condition - additional calls will return |
465 | You can only wait once on a condition - additional calls are valid but |
334 | immediately. |
466 | will return immediately. |
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467 | |
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468 | If an error condition has been set by calling C<< ->croak >>, then this |
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469 | function will call C<croak>. |
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470 | |
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471 | In list context, all parameters passed to C<send> will be returned, |
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472 | in scalar context only the first one will be returned. |
335 | |
473 | |
336 | Not all event models support a blocking wait - some die in that case |
474 | Not all event models support a blocking wait - some die in that case |
337 | (programs might want to do that to stay interactive), so I<if you are |
475 | (programs might want to do that to stay interactive), so I<if you are |
338 | using this from a module, never require a blocking wait>, but let the |
476 | using this from a module, never require a blocking wait>, but let the |
339 | caller decide whether the call will block or not (for example, by coupling |
477 | caller decide whether the call will block or not (for example, by coupling |
340 | condition variables with some kind of request results and supporting |
478 | condition variables with some kind of request results and supporting |
341 | callbacks so the caller knows that getting the result will not block, |
479 | callbacks so the caller knows that getting the result will not block, |
342 | while still suppporting blocking waits if the caller so desires). |
480 | while still suppporting blocking waits if the caller so desires). |
343 | |
481 | |
344 | Another reason I<never> to C<< ->wait >> in a module is that you cannot |
482 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
345 | sensibly have two C<< ->wait >>'s in parallel, as that would require |
483 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
346 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
484 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
347 | can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and |
485 | can supply. |
348 | L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s |
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349 | from different coroutines, however). |
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350 | |
486 | |
351 | =item $cv->broadcast |
487 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
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488 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
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489 | versions and also integrates coroutines into AnyEvent, making blocking |
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490 | C<< ->recv >> calls perfectly safe as long as they are done from another |
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491 | coroutine (one that doesn't run the event loop). |
352 | |
492 | |
353 | Flag the condition as ready - a running C<< ->wait >> and all further |
493 | You can ensure that C<< -recv >> never blocks by setting a callback and |
354 | calls to C<wait> will (eventually) return after this method has been |
494 | only calling C<< ->recv >> from within that callback (or at a later |
355 | called. If nobody is waiting the broadcast will be remembered.. |
495 | time). This will work even when the event loop does not support blocking |
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496 | waits otherwise. |
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497 | |
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498 | =item $bool = $cv->ready |
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499 | |
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500 | Returns true when the condition is "true", i.e. whether C<send> or |
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501 | C<croak> have been called. |
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502 | |
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503 | =item $cb = $cv->cb ([new callback]) |
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504 | |
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505 | This is a mutator function that returns the callback set and optionally |
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506 | replaces it before doing so. |
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507 | |
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508 | The callback will be called when the condition becomes "true", i.e. when |
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509 | C<send> or C<croak> are called. Calling C<recv> inside the callback |
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510 | or at any later time is guaranteed not to block. |
356 | |
511 | |
357 | =back |
512 | =back |
358 | |
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359 | Example: |
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360 | |
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361 | # wait till the result is ready |
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362 | my $result_ready = AnyEvent->condvar; |
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363 | |
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364 | # do something such as adding a timer |
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365 | # or socket watcher the calls $result_ready->broadcast |
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366 | # when the "result" is ready. |
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367 | # in this case, we simply use a timer: |
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368 | my $w = AnyEvent->timer ( |
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369 | after => 1, |
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370 | cb => sub { $result_ready->broadcast }, |
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371 | ); |
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372 | |
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373 | # this "blocks" (while handling events) till the watcher |
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374 | # calls broadcast |
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375 | $result_ready->wait; |
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376 | |
513 | |
377 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
514 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
378 | |
515 | |
379 | =over 4 |
516 | =over 4 |
380 | |
517 | |
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386 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
523 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
387 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
524 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
388 | |
525 | |
389 | The known classes so far are: |
526 | The known classes so far are: |
390 | |
527 | |
391 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
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392 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
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393 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
528 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
394 | AnyEvent::Impl::Event based on Event, second best choice. |
529 | AnyEvent::Impl::Event based on Event, second best choice. |
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530 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
395 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
531 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
396 | AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable. |
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397 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
532 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
398 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
533 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
399 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
534 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
400 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
535 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
401 | |
536 | |
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414 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
549 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
415 | if necessary. You should only call this function right before you would |
550 | if necessary. You should only call this function right before you would |
416 | have created an AnyEvent watcher anyway, that is, as late as possible at |
551 | have created an AnyEvent watcher anyway, that is, as late as possible at |
417 | runtime. |
552 | runtime. |
418 | |
553 | |
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554 | =item $guard = AnyEvent::post_detect { BLOCK } |
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555 | |
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556 | Arranges for the code block to be executed as soon as the event model is |
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557 | autodetected (or immediately if this has already happened). |
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558 | |
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559 | If called in scalar or list context, then it creates and returns an object |
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560 | that automatically removes the callback again when it is destroyed. See |
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561 | L<Coro::BDB> for a case where this is useful. |
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562 | |
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563 | =item @AnyEvent::post_detect |
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564 | |
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565 | If there are any code references in this array (you can C<push> to it |
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566 | before or after loading AnyEvent), then they will called directly after |
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567 | the event loop has been chosen. |
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568 | |
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569 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
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570 | if it contains a true value then the event loop has already been detected, |
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571 | and the array will be ignored. |
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572 | |
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573 | Best use C<AnyEvent::post_detect { BLOCK }> instead. |
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574 | |
419 | =back |
575 | =back |
420 | |
576 | |
421 | =head1 WHAT TO DO IN A MODULE |
577 | =head1 WHAT TO DO IN A MODULE |
422 | |
578 | |
423 | As a module author, you should C<use AnyEvent> and call AnyEvent methods |
579 | As a module author, you should C<use AnyEvent> and call AnyEvent methods |
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426 | Be careful when you create watchers in the module body - AnyEvent will |
582 | Be careful when you create watchers in the module body - AnyEvent will |
427 | decide which event module to use as soon as the first method is called, so |
583 | decide which event module to use as soon as the first method is called, so |
428 | by calling AnyEvent in your module body you force the user of your module |
584 | by calling AnyEvent in your module body you force the user of your module |
429 | to load the event module first. |
585 | to load the event module first. |
430 | |
586 | |
431 | Never call C<< ->wait >> on a condition variable unless you I<know> that |
587 | Never call C<< ->recv >> on a condition variable unless you I<know> that |
432 | the C<< ->broadcast >> method has been called on it already. This is |
588 | the C<< ->send >> method has been called on it already. This is |
433 | because it will stall the whole program, and the whole point of using |
589 | because it will stall the whole program, and the whole point of using |
434 | events is to stay interactive. |
590 | events is to stay interactive. |
435 | |
591 | |
436 | It is fine, however, to call C<< ->wait >> when the user of your module |
592 | It is fine, however, to call C<< ->recv >> when the user of your module |
437 | requests it (i.e. if you create a http request object ad have a method |
593 | requests it (i.e. if you create a http request object ad have a method |
438 | called C<results> that returns the results, it should call C<< ->wait >> |
594 | called C<results> that returns the results, it should call C<< ->recv >> |
439 | freely, as the user of your module knows what she is doing. always). |
595 | freely, as the user of your module knows what she is doing. always). |
440 | |
596 | |
441 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
597 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
442 | |
598 | |
443 | There will always be a single main program - the only place that should |
599 | There will always be a single main program - the only place that should |
… | |
… | |
475 | |
631 | |
476 | =item L<AnyEvent::Handle> |
632 | =item L<AnyEvent::Handle> |
477 | |
633 | |
478 | Provide read and write buffers and manages watchers for reads and writes. |
634 | Provide read and write buffers and manages watchers for reads and writes. |
479 | |
635 | |
480 | =item L<AnyEvent::Socket> |
|
|
481 | |
|
|
482 | Provides a means to do non-blocking connects, accepts etc. |
|
|
483 | |
|
|
484 | =item L<AnyEvent::HTTPD> |
636 | =item L<AnyEvent::HTTPD> |
485 | |
637 | |
486 | Provides a simple web application server framework. |
638 | Provides a simple web application server framework. |
487 | |
639 | |
488 | =item L<AnyEvent::DNS> |
640 | =item L<AnyEvent::DNS> |
… | |
… | |
511 | |
663 | |
512 | High level API for event-based execution flow control. |
664 | High level API for event-based execution flow control. |
513 | |
665 | |
514 | =item L<Coro> |
666 | =item L<Coro> |
515 | |
667 | |
516 | Has special support for AnyEvent. |
668 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
|
|
669 | |
|
|
670 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
671 | |
|
|
672 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
673 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
674 | together. |
|
|
675 | |
|
|
676 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
677 | |
|
|
678 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
679 | IO::AIO and AnyEvent together. |
517 | |
680 | |
518 | =item L<IO::Lambda> |
681 | =item L<IO::Lambda> |
519 | |
682 | |
520 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
683 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
521 | |
|
|
522 | =item L<IO::AIO> |
|
|
523 | |
|
|
524 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
525 | programmer. Can be trivially made to use AnyEvent. |
|
|
526 | |
|
|
527 | =item L<BDB> |
|
|
528 | |
|
|
529 | Truly asynchronous Berkeley DB access. Can be trivially made to use |
|
|
530 | AnyEvent. |
|
|
531 | |
684 | |
532 | =back |
685 | =back |
533 | |
686 | |
534 | =cut |
687 | =cut |
535 | |
688 | |
… | |
… | |
538 | no warnings; |
691 | no warnings; |
539 | use strict; |
692 | use strict; |
540 | |
693 | |
541 | use Carp; |
694 | use Carp; |
542 | |
695 | |
543 | our $VERSION = '3.3'; |
696 | our $VERSION = '3.6'; |
544 | our $MODEL; |
697 | our $MODEL; |
545 | |
698 | |
546 | our $AUTOLOAD; |
699 | our $AUTOLOAD; |
547 | our @ISA; |
700 | our @ISA; |
548 | |
701 | |
549 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
702 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
550 | |
703 | |
551 | our @REGISTRY; |
704 | our @REGISTRY; |
552 | |
705 | |
553 | my @models = ( |
706 | my @models = ( |
554 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
|
|
555 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
|
|
556 | [EV:: => AnyEvent::Impl::EV::], |
707 | [EV:: => AnyEvent::Impl::EV::], |
557 | [Event:: => AnyEvent::Impl::Event::], |
708 | [Event:: => AnyEvent::Impl::Event::], |
558 | [Glib:: => AnyEvent::Impl::Glib::], |
|
|
559 | [Tk:: => AnyEvent::Impl::Tk::], |
709 | [Tk:: => AnyEvent::Impl::Tk::], |
560 | [Wx:: => AnyEvent::Impl::POE::], |
710 | [Wx:: => AnyEvent::Impl::POE::], |
561 | [Prima:: => AnyEvent::Impl::POE::], |
711 | [Prima:: => AnyEvent::Impl::POE::], |
562 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
712 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
563 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
713 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
|
|
714 | [Glib:: => AnyEvent::Impl::Glib::], |
564 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
715 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
565 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
716 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
566 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
717 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
567 | ); |
718 | ); |
568 | |
719 | |
569 | our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY); |
720 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
|
|
721 | |
|
|
722 | our @post_detect; |
|
|
723 | |
|
|
724 | sub post_detect(&) { |
|
|
725 | my ($cb) = @_; |
|
|
726 | |
|
|
727 | if ($MODEL) { |
|
|
728 | $cb->(); |
|
|
729 | |
|
|
730 | 1 |
|
|
731 | } else { |
|
|
732 | push @post_detect, $cb; |
|
|
733 | |
|
|
734 | defined wantarray |
|
|
735 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
|
|
736 | : () |
|
|
737 | } |
|
|
738 | } |
|
|
739 | |
|
|
740 | sub AnyEvent::Util::PostDetect::DESTROY { |
|
|
741 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
|
|
742 | } |
570 | |
743 | |
571 | sub detect() { |
744 | sub detect() { |
572 | unless ($MODEL) { |
745 | unless ($MODEL) { |
573 | no strict 'refs'; |
746 | no strict 'refs'; |
574 | |
747 | |
… | |
… | |
608 | last; |
781 | last; |
609 | } |
782 | } |
610 | } |
783 | } |
611 | |
784 | |
612 | $MODEL |
785 | $MODEL |
613 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV (or Coro+EV), Event (or Coro+Event) or Glib."; |
786 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
614 | } |
787 | } |
615 | } |
788 | } |
616 | |
789 | |
617 | unshift @ISA, $MODEL; |
790 | unshift @ISA, $MODEL; |
618 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
791 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
792 | |
|
|
793 | (shift @post_detect)->() while @post_detect; |
619 | } |
794 | } |
620 | |
795 | |
621 | $MODEL |
796 | $MODEL |
622 | } |
797 | } |
623 | |
798 | |
… | |
… | |
633 | $class->$func (@_); |
808 | $class->$func (@_); |
634 | } |
809 | } |
635 | |
810 | |
636 | package AnyEvent::Base; |
811 | package AnyEvent::Base; |
637 | |
812 | |
638 | # default implementation for ->condvar, ->wait, ->broadcast |
813 | # default implementation for ->condvar |
639 | |
814 | |
640 | sub condvar { |
815 | sub condvar { |
641 | bless \my $flag, "AnyEvent::Base::CondVar" |
816 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
642 | } |
|
|
643 | |
|
|
644 | sub AnyEvent::Base::CondVar::broadcast { |
|
|
645 | ${$_[0]}++; |
|
|
646 | } |
|
|
647 | |
|
|
648 | sub AnyEvent::Base::CondVar::wait { |
|
|
649 | AnyEvent->one_event while !${$_[0]}; |
|
|
650 | } |
817 | } |
651 | |
818 | |
652 | # default implementation for ->signal |
819 | # default implementation for ->signal |
653 | |
820 | |
654 | our %SIG_CB; |
821 | our %SIG_CB; |
… | |
… | |
727 | delete $PID_CB{$pid}{$cb}; |
894 | delete $PID_CB{$pid}{$cb}; |
728 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
895 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
729 | |
896 | |
730 | undef $CHLD_W unless keys %PID_CB; |
897 | undef $CHLD_W unless keys %PID_CB; |
731 | } |
898 | } |
|
|
899 | |
|
|
900 | package AnyEvent::CondVar; |
|
|
901 | |
|
|
902 | our @ISA = AnyEvent::CondVar::Base::; |
|
|
903 | |
|
|
904 | package AnyEvent::CondVar::Base; |
|
|
905 | |
|
|
906 | sub _send { |
|
|
907 | # nop |
|
|
908 | } |
|
|
909 | |
|
|
910 | sub send { |
|
|
911 | my $cv = shift; |
|
|
912 | $cv->{_ae_sent} = [@_]; |
|
|
913 | (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; |
|
|
914 | $cv->_send; |
|
|
915 | } |
|
|
916 | |
|
|
917 | sub croak { |
|
|
918 | $_[0]{_ae_croak} = $_[1]; |
|
|
919 | $_[0]->send; |
|
|
920 | } |
|
|
921 | |
|
|
922 | sub ready { |
|
|
923 | $_[0]{_ae_sent} |
|
|
924 | } |
|
|
925 | |
|
|
926 | sub _wait { |
|
|
927 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
|
|
928 | } |
|
|
929 | |
|
|
930 | sub recv { |
|
|
931 | $_[0]->_wait; |
|
|
932 | |
|
|
933 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
|
|
934 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
|
|
935 | } |
|
|
936 | |
|
|
937 | sub cb { |
|
|
938 | $_[0]{_ae_cb} = $_[1] if @_ > 1; |
|
|
939 | $_[0]{_ae_cb} |
|
|
940 | } |
|
|
941 | |
|
|
942 | sub begin { |
|
|
943 | ++$_[0]{_ae_counter}; |
|
|
944 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
|
|
945 | } |
|
|
946 | |
|
|
947 | sub end { |
|
|
948 | return if --$_[0]{_ae_counter}; |
|
|
949 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
|
|
950 | } |
|
|
951 | |
|
|
952 | # undocumented/compatibility with pre-3.4 |
|
|
953 | *broadcast = \&send; |
|
|
954 | *wait = \&_wait; |
732 | |
955 | |
733 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
956 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
734 | |
957 | |
735 | This is an advanced topic that you do not normally need to use AnyEvent in |
958 | This is an advanced topic that you do not normally need to use AnyEvent in |
736 | a module. This section is only of use to event loop authors who want to |
959 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
825 | poll => 'r', |
1048 | poll => 'r', |
826 | cb => sub { |
1049 | cb => sub { |
827 | warn "io event <$_[0]>\n"; # will always output <r> |
1050 | warn "io event <$_[0]>\n"; # will always output <r> |
828 | chomp (my $input = <STDIN>); # read a line |
1051 | chomp (my $input = <STDIN>); # read a line |
829 | warn "read: $input\n"; # output what has been read |
1052 | warn "read: $input\n"; # output what has been read |
830 | $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i |
1053 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
831 | }, |
1054 | }, |
832 | ); |
1055 | ); |
833 | |
1056 | |
834 | my $time_watcher; # can only be used once |
1057 | my $time_watcher; # can only be used once |
835 | |
1058 | |
… | |
… | |
840 | }); |
1063 | }); |
841 | } |
1064 | } |
842 | |
1065 | |
843 | new_timer; # create first timer |
1066 | new_timer; # create first timer |
844 | |
1067 | |
845 | $cv->wait; # wait until user enters /^q/i |
1068 | $cv->recv; # wait until user enters /^q/i |
846 | |
1069 | |
847 | =head1 REAL-WORLD EXAMPLE |
1070 | =head1 REAL-WORLD EXAMPLE |
848 | |
1071 | |
849 | Consider the L<Net::FCP> module. It features (among others) the following |
1072 | Consider the L<Net::FCP> module. It features (among others) the following |
850 | API calls, which are to freenet what HTTP GET requests are to http: |
1073 | API calls, which are to freenet what HTTP GET requests are to http: |
… | |
… | |
906 | |
1129 | |
907 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1130 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
908 | |
1131 | |
909 | if (end-of-file or data complete) { |
1132 | if (end-of-file or data complete) { |
910 | $txn->{result} = $txn->{buf}; |
1133 | $txn->{result} = $txn->{buf}; |
911 | $txn->{finished}->broadcast; |
1134 | $txn->{finished}->send; |
912 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1135 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
913 | } |
1136 | } |
914 | |
1137 | |
915 | The C<result> method, finally, just waits for the finished signal (if the |
1138 | The C<result> method, finally, just waits for the finished signal (if the |
916 | request was already finished, it doesn't wait, of course, and returns the |
1139 | request was already finished, it doesn't wait, of course, and returns the |
917 | data: |
1140 | data: |
918 | |
1141 | |
919 | $txn->{finished}->wait; |
1142 | $txn->{finished}->recv; |
920 | return $txn->{result}; |
1143 | return $txn->{result}; |
921 | |
1144 | |
922 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1145 | The actual code goes further and collects all errors (C<die>s, exceptions) |
923 | that occured during request processing. The C<result> method detects |
1146 | that occured during request processing. The C<result> method detects |
924 | whether an exception as thrown (it is stored inside the $txn object) |
1147 | whether an exception as thrown (it is stored inside the $txn object) |
… | |
… | |
959 | |
1182 | |
960 | my $quit = AnyEvent->condvar; |
1183 | my $quit = AnyEvent->condvar; |
961 | |
1184 | |
962 | $fcp->txn_client_get ($url)->cb (sub { |
1185 | $fcp->txn_client_get ($url)->cb (sub { |
963 | ... |
1186 | ... |
964 | $quit->broadcast; |
1187 | $quit->send; |
965 | }); |
1188 | }); |
966 | |
1189 | |
967 | $quit->wait; |
1190 | $quit->recv; |
968 | |
1191 | |
969 | |
1192 | |
970 | =head1 BENCHMARKS |
1193 | =head1 BENCHMARKS |
971 | |
1194 | |
972 | To give you an idea of the performance and overheads that AnyEvent adds |
1195 | To give you an idea of the performance and overheads that AnyEvent adds |
… | |
… | |
1001 | all watchers, to avoid adding memory overhead. That means closure creation |
1224 | all watchers, to avoid adding memory overhead. That means closure creation |
1002 | and memory usage is not included in the figures. |
1225 | and memory usage is not included in the figures. |
1003 | |
1226 | |
1004 | I<invoke> is the time, in microseconds, used to invoke a simple |
1227 | I<invoke> is the time, in microseconds, used to invoke a simple |
1005 | callback. The callback simply counts down a Perl variable and after it was |
1228 | callback. The callback simply counts down a Perl variable and after it was |
1006 | invoked "watcher" times, it would C<< ->broadcast >> a condvar once to |
1229 | invoked "watcher" times, it would C<< ->send >> a condvar once to |
1007 | signal the end of this phase. |
1230 | signal the end of this phase. |
1008 | |
1231 | |
1009 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1232 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1010 | watcher. |
1233 | watcher. |
1011 | |
1234 | |
… | |
… | |
1234 | |
1457 | |
1235 | |
1458 | |
1236 | =head1 FORK |
1459 | =head1 FORK |
1237 | |
1460 | |
1238 | Most event libraries are not fork-safe. The ones who are usually are |
1461 | Most event libraries are not fork-safe. The ones who are usually are |
1239 | because they are so inefficient. Only L<EV> is fully fork-aware. |
1462 | because they rely on inefficient but fork-safe C<select> or C<poll> |
|
|
1463 | calls. Only L<EV> is fully fork-aware. |
1240 | |
1464 | |
1241 | If you have to fork, you must either do so I<before> creating your first |
1465 | If you have to fork, you must either do so I<before> creating your first |
1242 | watcher OR you must not use AnyEvent at all in the child. |
1466 | watcher OR you must not use AnyEvent at all in the child. |
1243 | |
1467 | |
1244 | |
1468 | |
… | |
… | |
1256 | |
1480 | |
1257 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1481 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1258 | |
1482 | |
1259 | use AnyEvent; |
1483 | use AnyEvent; |
1260 | |
1484 | |
|
|
1485 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
|
|
1486 | be used to probe what backend is used and gain other information (which is |
|
|
1487 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
|
|
1488 | |
1261 | |
1489 | |
1262 | =head1 SEE ALSO |
1490 | =head1 SEE ALSO |
1263 | |
1491 | |
1264 | Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>, |
1492 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1265 | L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>, |
|
|
1266 | L<Event::Lib>, L<Qt>, L<POE>. |
1493 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1267 | |
1494 | |
1268 | Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>, |
1495 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1269 | L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>, |
1496 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1270 | L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>, |
1497 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1271 | L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>. |
1498 | L<AnyEvent::Impl::POE>. |
|
|
1499 | |
|
|
1500 | Asynchronous DNS: L<AnyEvent::DNS>. |
|
|
1501 | |
|
|
1502 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1272 | |
1503 | |
1273 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
1504 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
1274 | |
1505 | |
1275 | |
1506 | |
1276 | =head1 AUTHOR |
1507 | =head1 AUTHOR |