1 | NAME |
1 | => NAME |
2 | AnyEvent - provide framework for multiple event loops |
2 | AnyEvent - provide framework for multiple event loops |
3 | |
3 | |
4 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event |
4 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event |
5 | loops |
5 | loops |
6 | |
6 | |
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55 | those use one of the supported event loops. It is trivial to add new |
55 | those use one of the supported event loops. It is trivial to add new |
56 | event loops to AnyEvent, too, so it is future-proof). |
56 | event loops to AnyEvent, too, so it is future-proof). |
57 | |
57 | |
58 | In addition to being free of having to use *the one and only true event |
58 | In addition to being free of having to use *the one and only true event |
59 | model*, AnyEvent also is free of bloat and policy: with POE or similar |
59 | model*, AnyEvent also is free of bloat and policy: with POE or similar |
60 | modules, you get an enourmous amount of code and strict rules you have |
60 | modules, you get an enormous amount of code and strict rules you have to |
61 | to follow. AnyEvent, on the other hand, is lean and up to the point, by |
61 | follow. AnyEvent, on the other hand, is lean and up to the point, by |
62 | only offering the functionality that is necessary, in as thin as a |
62 | only offering the functionality that is necessary, in as thin as a |
63 | wrapper as technically possible. |
63 | wrapper as technically possible. |
64 | |
64 | |
65 | Of course, if you want lots of policy (this can arguably be somewhat |
65 | Of course, if you want lots of policy (this can arguably be somewhat |
66 | useful) and you want to force your users to use the one and only event |
66 | useful) and you want to force your users to use the one and only event |
… | |
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104 | explicitly. |
104 | explicitly. |
105 | |
105 | |
106 | WATCHERS |
106 | WATCHERS |
107 | AnyEvent has the central concept of a *watcher*, which is an object that |
107 | AnyEvent has the central concept of a *watcher*, which is an object that |
108 | stores relevant data for each kind of event you are waiting for, such as |
108 | stores relevant data for each kind of event you are waiting for, such as |
109 | the callback to call, the filehandle to watch, etc. |
109 | the callback to call, the file handle to watch, etc. |
110 | |
110 | |
111 | These watchers are normal Perl objects with normal Perl lifetime. After |
111 | These watchers are normal Perl objects with normal Perl lifetime. After |
112 | creating a watcher it will immediately "watch" for events and invoke the |
112 | creating a watcher it will immediately "watch" for events and invoke the |
113 | callback when the event occurs (of course, only when the event model is |
113 | callback when the event occurs (of course, only when the event model is |
114 | in control). |
114 | in control). |
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229 | |
229 | |
230 | Although the callback might get passed parameters, their value and |
230 | Although the callback might get passed parameters, their value and |
231 | presence is undefined and you cannot rely on them. Portable AnyEvent |
231 | presence is undefined and you cannot rely on them. Portable AnyEvent |
232 | callbacks cannot use arguments passed to signal watcher callbacks. |
232 | callbacks cannot use arguments passed to signal watcher callbacks. |
233 | |
233 | |
234 | Multiple signal occurances can be clumped together into one callback |
234 | Multiple signal occurrences can be clumped together into one callback |
235 | invocation, and callback invocation will be synchronous. synchronous |
235 | invocation, and callback invocation will be synchronous. Synchronous |
236 | means that it might take a while until the signal gets handled by the |
236 | means that it might take a while until the signal gets handled by the |
237 | process, but it is guarenteed not to interrupt any other callbacks. |
237 | process, but it is guaranteed not to interrupt any other callbacks. |
238 | |
238 | |
239 | The main advantage of using these watchers is that you can share a |
239 | The main advantage of using these watchers is that you can share a |
240 | signal between multiple watchers. |
240 | signal between multiple watchers. |
241 | |
241 | |
242 | This watcher might use %SIG, so programs overwriting those signals |
242 | This watcher might use %SIG, so programs overwriting those signals |
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301 | Condition variables can be created by calling the "AnyEvent->condvar" |
301 | Condition variables can be created by calling the "AnyEvent->condvar" |
302 | method, usually without arguments. The only argument pair allowed is |
302 | method, usually without arguments. The only argument pair allowed is |
303 | "cb", which specifies a callback to be called when the condition |
303 | "cb", which specifies a callback to be called when the condition |
304 | variable becomes true. |
304 | variable becomes true. |
305 | |
305 | |
306 | After creation, the conditon variable is "false" until it becomes "true" |
306 | After creation, the condition variable is "false" until it becomes |
307 | by calling the "send" method. |
307 | "true" by calling the "send" method (or calling the condition variable |
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308 | as if it were a callback). |
308 | |
309 | |
309 | Condition variables are similar to callbacks, except that you can |
310 | Condition variables are similar to callbacks, except that you can |
310 | optionally wait for them. They can also be called merge points - points |
311 | optionally wait for them. They can also be called merge points - points |
311 | in time where multiple outstandign events have been processed. And yet |
312 | in time where multiple outstanding events have been processed. And yet |
312 | another way to call them is transations - each condition variable can be |
313 | another way to call them is transactions - each condition variable can |
313 | used to represent a transaction, which finishes at some point and |
314 | be used to represent a transaction, which finishes at some point and |
314 | delivers a result. |
315 | delivers a result. |
315 | |
316 | |
316 | Condition variables are very useful to signal that something has |
317 | Condition variables are very useful to signal that something has |
317 | finished, for example, if you write a module that does asynchronous http |
318 | finished, for example, if you write a module that does asynchronous http |
318 | requests, then a condition variable would be the ideal candidate to |
319 | requests, then a condition variable would be the ideal candidate to |
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323 | you can block your main program until an event occurs - for example, you |
324 | you can block your main program until an event occurs - for example, you |
324 | could "->recv" in your main program until the user clicks the Quit |
325 | could "->recv" in your main program until the user clicks the Quit |
325 | button of your app, which would "->send" the "quit" event. |
326 | button of your app, which would "->send" the "quit" event. |
326 | |
327 | |
327 | Note that condition variables recurse into the event loop - if you have |
328 | Note that condition variables recurse into the event loop - if you have |
328 | two pieces of code that call "->recv" in a round-robbin fashion, you |
329 | two pieces of code that call "->recv" in a round-robin fashion, you |
329 | lose. Therefore, condition variables are good to export to your caller, |
330 | lose. Therefore, condition variables are good to export to your caller, |
330 | but you should avoid making a blocking wait yourself, at least in |
331 | but you should avoid making a blocking wait yourself, at least in |
331 | callbacks, as this asks for trouble. |
332 | callbacks, as this asks for trouble. |
332 | |
333 | |
333 | Condition variables are represented by hash refs in perl, and the keys |
334 | Condition variables are represented by hash refs in perl, and the keys |
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338 | |
339 | |
339 | There are two "sides" to a condition variable - the "producer side" |
340 | There are two "sides" to a condition variable - the "producer side" |
340 | which eventually calls "-> send", and the "consumer side", which waits |
341 | which eventually calls "-> send", and the "consumer side", which waits |
341 | for the send to occur. |
342 | for the send to occur. |
342 | |
343 | |
343 | Example: |
344 | Example: wait for a timer. |
344 | |
345 | |
345 | # wait till the result is ready |
346 | # wait till the result is ready |
346 | my $result_ready = AnyEvent->condvar; |
347 | my $result_ready = AnyEvent->condvar; |
347 | |
348 | |
348 | # do something such as adding a timer |
349 | # do something such as adding a timer |
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356 | |
357 | |
357 | # this "blocks" (while handling events) till the callback |
358 | # this "blocks" (while handling events) till the callback |
358 | # calls send |
359 | # calls send |
359 | $result_ready->recv; |
360 | $result_ready->recv; |
360 | |
361 | |
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362 | Example: wait for a timer, but take advantage of the fact that condition |
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363 | variables are also code references. |
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364 | |
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365 | my $done = AnyEvent->condvar; |
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366 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
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367 | $done->recv; |
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368 | |
361 | METHODS FOR PRODUCERS |
369 | METHODS FOR PRODUCERS |
362 | These methods should only be used by the producing side, i.e. the |
370 | These methods should only be used by the producing side, i.e. the |
363 | code/module that eventually sends the signal. Note that it is also the |
371 | code/module that eventually sends the signal. Note that it is also the |
364 | producer side which creates the condvar in most cases, but it isn't |
372 | producer side which creates the condvar in most cases, but it isn't |
365 | uncommon for the consumer to create it as well. |
373 | uncommon for the consumer to create it as well. |
… | |
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372 | If a callback has been set on the condition variable, it is called |
380 | If a callback has been set on the condition variable, it is called |
373 | immediately from within send. |
381 | immediately from within send. |
374 | |
382 | |
375 | Any arguments passed to the "send" call will be returned by all |
383 | Any arguments passed to the "send" call will be returned by all |
376 | future "->recv" calls. |
384 | future "->recv" calls. |
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385 | |
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386 | Condition variables are overloaded so one can call them directly (as |
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387 | a code reference). Calling them directly is the same as calling |
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388 | "send". |
377 | |
389 | |
378 | $cv->croak ($error) |
390 | $cv->croak ($error) |
379 | Similar to send, but causes all call's to "->recv" to invoke |
391 | Similar to send, but causes all call's to "->recv" to invoke |
380 | "Carp::croak" with the given error message/object/scalar. |
392 | "Carp::croak" with the given error message/object/scalar. |
381 | |
393 | |
… | |
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427 | (the loop doesn't execute once). |
439 | (the loop doesn't execute once). |
428 | |
440 | |
429 | This is the general pattern when you "fan out" into multiple |
441 | This is the general pattern when you "fan out" into multiple |
430 | subrequests: use an outer "begin"/"end" pair to set the callback and |
442 | subrequests: use an outer "begin"/"end" pair to set the callback and |
431 | ensure "end" is called at least once, and then, for each subrequest |
443 | ensure "end" is called at least once, and then, for each subrequest |
432 | you start, call "begin" and for eahc subrequest you finish, call |
444 | you start, call "begin" and for each subrequest you finish, call |
433 | "end". |
445 | "end". |
434 | |
446 | |
435 | METHODS FOR CONSUMERS |
447 | METHODS FOR CONSUMERS |
436 | These methods should only be used by the consuming side, i.e. the code |
448 | These methods should only be used by the consuming side, i.e. the code |
437 | awaits the condition. |
449 | awaits the condition. |
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453 | (programs might want to do that to stay interactive), so *if you are |
465 | (programs might want to do that to stay interactive), so *if you are |
454 | using this from a module, never require a blocking wait*, but let |
466 | using this from a module, never require a blocking wait*, but let |
455 | the caller decide whether the call will block or not (for example, |
467 | the caller decide whether the call will block or not (for example, |
456 | by coupling condition variables with some kind of request results |
468 | by coupling condition variables with some kind of request results |
457 | and supporting callbacks so the caller knows that getting the result |
469 | and supporting callbacks so the caller knows that getting the result |
458 | will not block, while still suppporting blocking waits if the caller |
470 | will not block, while still supporting blocking waits if the caller |
459 | so desires). |
471 | so desires). |
460 | |
472 | |
461 | Another reason *never* to "->recv" in a module is that you cannot |
473 | Another reason *never* to "->recv" in a module is that you cannot |
462 | sensibly have two "->recv"'s in parallel, as that would require |
474 | sensibly have two "->recv"'s in parallel, as that would require |
463 | multiple interpreters or coroutines/threads, none of which |
475 | multiple interpreters or coroutines/threads, none of which |
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594 | |
606 | |
595 | AnyEvent::Handle |
607 | AnyEvent::Handle |
596 | Provide read and write buffers and manages watchers for reads and |
608 | Provide read and write buffers and manages watchers for reads and |
597 | writes. |
609 | writes. |
598 | |
610 | |
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611 | AnyEvent::Socket |
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612 | Provides various utility functions for (internet protocol) sockets, |
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613 | addresses and name resolution. Also functions to create non-blocking |
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614 | tcp connections or tcp servers, with IPv6 and SRV record support and |
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615 | more. |
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616 | |
599 | AnyEvent::HTTPD |
617 | AnyEvent::HTTPD |
600 | Provides a simple web application server framework. |
618 | Provides a simple web application server framework. |
601 | |
619 | |
602 | AnyEvent::DNS |
620 | AnyEvent::DNS |
603 | Provides asynchronous DNS resolver capabilities, beyond what |
621 | Provides rich asynchronous DNS resolver capabilities. |
604 | AnyEvent::Util offers. |
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605 | |
622 | |
606 | AnyEvent::FastPing |
623 | AnyEvent::FastPing |
607 | The fastest ping in the west. |
624 | The fastest ping in the west. |
608 | |
625 | |
609 | Net::IRC3 |
626 | Net::IRC3 |
… | |
… | |
693 | When set to 2 or higher, cause AnyEvent to report to STDERR which |
710 | When set to 2 or higher, cause AnyEvent to report to STDERR which |
694 | event model it chooses. |
711 | event model it chooses. |
695 | |
712 | |
696 | "PERL_ANYEVENT_MODEL" |
713 | "PERL_ANYEVENT_MODEL" |
697 | This can be used to specify the event model to be used by AnyEvent, |
714 | This can be used to specify the event model to be used by AnyEvent, |
698 | before autodetection and -probing kicks in. It must be a string |
715 | before auto detection and -probing kicks in. It must be a string |
699 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
716 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
700 | gets prepended and the resulting module name is loaded and if the |
717 | gets prepended and the resulting module name is loaded and if the |
701 | load was successful, used as event model. If it fails to load |
718 | load was successful, used as event model. If it fails to load |
702 | AnyEvent will proceed with autodetection and -probing. |
719 | AnyEvent will proceed with auto detection and -probing. |
703 | |
720 | |
704 | This functionality might change in future versions. |
721 | This functionality might change in future versions. |
705 | |
722 | |
706 | For example, to force the pure perl model (AnyEvent::Impl::Perl) you |
723 | For example, to force the pure perl model (AnyEvent::Impl::Perl) you |
707 | could start your program like this: |
724 | could start your program like this: |
708 | |
725 | |
709 | PERL_ANYEVENT_MODEL=Perl perl ... |
726 | PERL_ANYEVENT_MODEL=Perl perl ... |
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727 | |
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728 | "PERL_ANYEVENT_PROTOCOLS" |
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729 | Used by both AnyEvent::DNS and AnyEvent::Socket to determine |
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730 | preferences for IPv4 or IPv6. The default is unspecified (and might |
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731 | change, or be the result of auto probing). |
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732 | |
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733 | Must be set to a comma-separated list of protocols or address |
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734 | families, current supported: "ipv4" and "ipv6". Only protocols |
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735 | mentioned will be used, and preference will be given to protocols |
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736 | mentioned earlier in the list. |
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737 | |
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738 | This variable can effectively be used for denial-of-service attacks |
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739 | against local programs (e.g. when setuid), although the impact is |
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740 | likely small, as the program has to handle connection errors |
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741 | already- |
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742 | |
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743 | Examples: "PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6" - prefer IPv4 over |
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744 | IPv6, but support both and try to use both. |
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745 | "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to |
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746 | resolve or contact IPv6 addresses. |
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747 | "PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4" support either IPv4 or IPv6, but |
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748 | prefer IPv6 over IPv4. |
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749 | |
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750 | "PERL_ANYEVENT_EDNS0" |
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751 | Used by AnyEvent::DNS to decide whether to use the EDNS0 extension |
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752 | for DNS. This extension is generally useful to reduce DNS traffic, |
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753 | but some (broken) firewalls drop such DNS packets, which is why it |
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754 | is off by default. |
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755 | |
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756 | Setting this variable to 1 will cause AnyEvent::DNS to announce |
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757 | EDNS0 in its DNS requests. |
710 | |
758 | |
711 | EXAMPLE PROGRAM |
759 | EXAMPLE PROGRAM |
712 | The following program uses an I/O watcher to read data from STDIN, a |
760 | The following program uses an I/O watcher to read data from STDIN, a |
713 | timer to display a message once per second, and a condition variable to |
761 | timer to display a message once per second, and a condition variable to |
714 | quit the program when the user enters quit: |
762 | quit the program when the user enters quit: |
… | |
… | |
722 | poll => 'r', |
770 | poll => 'r', |
723 | cb => sub { |
771 | cb => sub { |
724 | warn "io event <$_[0]>\n"; # will always output <r> |
772 | warn "io event <$_[0]>\n"; # will always output <r> |
725 | chomp (my $input = <STDIN>); # read a line |
773 | chomp (my $input = <STDIN>); # read a line |
726 | warn "read: $input\n"; # output what has been read |
774 | warn "read: $input\n"; # output what has been read |
727 | $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i |
775 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
728 | }, |
776 | }, |
729 | ); |
777 | ); |
730 | |
778 | |
731 | my $time_watcher; # can only be used once |
779 | my $time_watcher; # can only be used once |
732 | |
780 | |
… | |
… | |
737 | }); |
785 | }); |
738 | } |
786 | } |
739 | |
787 | |
740 | new_timer; # create first timer |
788 | new_timer; # create first timer |
741 | |
789 | |
742 | $cv->wait; # wait until user enters /^q/i |
790 | $cv->recv; # wait until user enters /^q/i |
743 | |
791 | |
744 | REAL-WORLD EXAMPLE |
792 | REAL-WORLD EXAMPLE |
745 | Consider the Net::FCP module. It features (among others) the following |
793 | Consider the Net::FCP module. It features (among others) the following |
746 | API calls, which are to freenet what HTTP GET requests are to http: |
794 | API calls, which are to freenet what HTTP GET requests are to http: |
747 | |
795 | |
… | |
… | |
796 | syswrite $txn->{fh}, $txn->{request} |
844 | syswrite $txn->{fh}, $txn->{request} |
797 | or die "connection or write error"; |
845 | or die "connection or write error"; |
798 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
846 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
799 | |
847 | |
800 | Again, "fh_ready_r" waits till all data has arrived, and then stores the |
848 | Again, "fh_ready_r" waits till all data has arrived, and then stores the |
801 | result and signals any possible waiters that the request ahs finished: |
849 | result and signals any possible waiters that the request has finished: |
802 | |
850 | |
803 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
851 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
804 | |
852 | |
805 | if (end-of-file or data complete) { |
853 | if (end-of-file or data complete) { |
806 | $txn->{result} = $txn->{buf}; |
854 | $txn->{result} = $txn->{buf}; |
807 | $txn->{finished}->broadcast; |
855 | $txn->{finished}->send; |
808 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
856 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
809 | } |
857 | } |
810 | |
858 | |
811 | The "result" method, finally, just waits for the finished signal (if the |
859 | The "result" method, finally, just waits for the finished signal (if the |
812 | request was already finished, it doesn't wait, of course, and returns |
860 | request was already finished, it doesn't wait, of course, and returns |
813 | the data: |
861 | the data: |
814 | |
862 | |
815 | $txn->{finished}->wait; |
863 | $txn->{finished}->recv; |
816 | return $txn->{result}; |
864 | return $txn->{result}; |
817 | |
865 | |
818 | The actual code goes further and collects all errors ("die"s, |
866 | The actual code goes further and collects all errors ("die"s, |
819 | exceptions) that occured during request processing. The "result" method |
867 | exceptions) that occurred during request processing. The "result" method |
820 | detects whether an exception as thrown (it is stored inside the $txn |
868 | detects whether an exception as thrown (it is stored inside the $txn |
821 | object) and just throws the exception, which means connection errors and |
869 | object) and just throws the exception, which means connection errors and |
822 | other problems get reported tot he code that tries to use the result, |
870 | other problems get reported tot he code that tries to use the result, |
823 | not in a random callback. |
871 | not in a random callback. |
824 | |
872 | |
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855 | |
903 | |
856 | my $quit = AnyEvent->condvar; |
904 | my $quit = AnyEvent->condvar; |
857 | |
905 | |
858 | $fcp->txn_client_get ($url)->cb (sub { |
906 | $fcp->txn_client_get ($url)->cb (sub { |
859 | ... |
907 | ... |
860 | $quit->broadcast; |
908 | $quit->send; |
861 | }); |
909 | }); |
862 | |
910 | |
863 | $quit->wait; |
911 | $quit->recv; |
864 | |
912 | |
865 | BENCHMARKS |
913 | BENCHMARKS |
866 | To give you an idea of the performance and overheads that AnyEvent adds |
914 | To give you an idea of the performance and overheads that AnyEvent adds |
867 | over the event loops themselves and to give you an impression of the |
915 | over the event loops themselves and to give you an impression of the |
868 | speed of various event loops I prepared some benchmarks. |
916 | speed of various event loops I prepared some benchmarks. |
869 | |
917 | |
870 | BENCHMARKING ANYEVENT OVERHEAD |
918 | BENCHMARKING ANYEVENT OVERHEAD |
871 | Here is a benchmark of various supported event models used natively and |
919 | Here is a benchmark of various supported event models used natively and |
872 | through anyevent. The benchmark creates a lot of timers (with a zero |
920 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
873 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
921 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
874 | which it is), lets them fire exactly once and destroys them again. |
922 | which it is), lets them fire exactly once and destroys them again. |
875 | |
923 | |
876 | Source code for this benchmark is found as eg/bench in the AnyEvent |
924 | Source code for this benchmark is found as eg/bench in the AnyEvent |
877 | distribution. |
925 | distribution. |
… | |
… | |
893 | between all watchers, to avoid adding memory overhead. That means |
941 | between all watchers, to avoid adding memory overhead. That means |
894 | closure creation and memory usage is not included in the figures. |
942 | closure creation and memory usage is not included in the figures. |
895 | |
943 | |
896 | *invoke* is the time, in microseconds, used to invoke a simple callback. |
944 | *invoke* is the time, in microseconds, used to invoke a simple callback. |
897 | The callback simply counts down a Perl variable and after it was invoked |
945 | The callback simply counts down a Perl variable and after it was invoked |
898 | "watcher" times, it would "->broadcast" a condvar once to signal the end |
946 | "watcher" times, it would "->send" a condvar once to signal the end of |
899 | of this phase. |
947 | this phase. |
900 | |
948 | |
901 | *destroy* is the time, in microseconds, that it takes to destroy a |
949 | *destroy* is the time, in microseconds, that it takes to destroy a |
902 | single watcher. |
950 | single watcher. |
903 | |
951 | |
904 | Results |
952 | Results |
… | |
… | |
992 | |
1040 | |
993 | * You should avoid POE like the plague if you want performance or |
1041 | * You should avoid POE like the plague if you want performance or |
994 | reasonable memory usage. |
1042 | reasonable memory usage. |
995 | |
1043 | |
996 | BENCHMARKING THE LARGE SERVER CASE |
1044 | BENCHMARKING THE LARGE SERVER CASE |
997 | This benchmark atcually benchmarks the event loop itself. It works by |
1045 | This benchmark actually benchmarks the event loop itself. It works by |
998 | creating a number of "servers": each server consists of a socketpair, a |
1046 | creating a number of "servers": each server consists of a socket pair, a |
999 | timeout watcher that gets reset on activity (but never fires), and an |
1047 | timeout watcher that gets reset on activity (but never fires), and an |
1000 | I/O watcher waiting for input on one side of the socket. Each time the |
1048 | I/O watcher waiting for input on one side of the socket. Each time the |
1001 | socket watcher reads a byte it will write that byte to a random other |
1049 | socket watcher reads a byte it will write that byte to a random other |
1002 | "server". |
1050 | "server". |
1003 | |
1051 | |
1004 | The effect is that there will be a lot of I/O watchers, only part of |
1052 | The effect is that there will be a lot of I/O watchers, only part of |
1005 | which are active at any one point (so there is a constant number of |
1053 | which are active at any one point (so there is a constant number of |
1006 | active fds for each loop iterstaion, but which fds these are is random). |
1054 | active fds for each loop iteration, but which fds these are is random). |
1007 | The timeout is reset each time something is read because that reflects |
1055 | The timeout is reset each time something is read because that reflects |
1008 | how most timeouts work (and puts extra pressure on the event loops). |
1056 | how most timeouts work (and puts extra pressure on the event loops). |
1009 | |
1057 | |
1010 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which |
1058 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which |
1011 | 100 (1%) are active. This mirrors the activity of large servers with |
1059 | 100 (1%) are active. This mirrors the activity of large servers with |
1012 | many connections, most of which are idle at any one point in time. |
1060 | many connections, most of which are idle at any one point in time. |
1013 | |
1061 | |
1014 | Source code for this benchmark is found as eg/bench2 in the AnyEvent |
1062 | Source code for this benchmark is found as eg/bench2 in the AnyEvent |
1015 | distribution. |
1063 | distribution. |
1016 | |
1064 | |
1017 | Explanation of the columns |
1065 | Explanation of the columns |
1018 | *sockets* is the number of sockets, and twice the number of "servers" |
1066 | *sockets* is the number of sockets, and twice the number of "servers" |
1019 | (as each server has a read and write socket end). |
1067 | (as each server has a read and write socket end). |
1020 | |
1068 | |
1021 | *create* is the time it takes to create a socketpair (which is |
1069 | *create* is the time it takes to create a socket pair (which is |
1022 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1070 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1023 | |
1071 | |
1024 | *request*, the most important value, is the time it takes to handle a |
1072 | *request*, the most important value, is the time it takes to handle a |
1025 | single "request", that is, reading the token from the pipe and |
1073 | single "request", that is, reading the token from the pipe and |
1026 | forwarding it to another server. This includes deleting the old timeout |
1074 | forwarding it to another server. This includes deleting the old timeout |
… | |
… | |
1090 | and speed most when you have lots of watchers, not when you only have a |
1138 | and speed most when you have lots of watchers, not when you only have a |
1091 | few of them). |
1139 | few of them). |
1092 | |
1140 | |
1093 | EV is again fastest. |
1141 | EV is again fastest. |
1094 | |
1142 | |
1095 | Perl again comes second. It is noticably faster than the C-based event |
1143 | Perl again comes second. It is noticeably faster than the C-based event |
1096 | loops Event and Glib, although the difference is too small to really |
1144 | loops Event and Glib, although the difference is too small to really |
1097 | matter. |
1145 | matter. |
1098 | |
1146 | |
1099 | POE also performs much better in this case, but is is still far behind |
1147 | POE also performs much better in this case, but is is still far behind |
1100 | the others. |
1148 | the others. |
… | |
… | |
1129 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1177 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1130 | be used to probe what backend is used and gain other information (which |
1178 | be used to probe what backend is used and gain other information (which |
1131 | is probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1179 | is probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1132 | |
1180 | |
1133 | SEE ALSO |
1181 | SEE ALSO |
|
|
1182 | Utility functions: AnyEvent::Util. |
|
|
1183 | |
1134 | Event modules: EV, EV::Glib, Glib::EV, Event, Glib::Event, Glib, Tk, |
1184 | Event modules: EV, EV::Glib, Glib::EV, Event, Glib::Event, Glib, Tk, |
1135 | Event::Lib, Qt, POE. |
1185 | Event::Lib, Qt, POE. |
1136 | |
1186 | |
1137 | Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event, |
1187 | Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event, |
1138 | AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl, |
1188 | AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl, |
1139 | AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE. |
1189 | AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE. |
1140 | |
1190 | |
|
|
1191 | Non-blocking file handles, sockets, TCP clients and servers: |
|
|
1192 | AnyEvent::Handle, AnyEvent::Socket. |
|
|
1193 | |
|
|
1194 | Asynchronous DNS: AnyEvent::DNS. |
|
|
1195 | |
1141 | Coroutine support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event, |
1196 | Coroutine support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event, |
1142 | |
1197 | |
1143 | Nontrivial usage examples: Net::FCP, Net::XMPP2. |
1198 | Nontrivial usage examples: Net::FCP, Net::XMPP2, AnyEvent::DNS. |
1144 | |
1199 | |
1145 | AUTHOR |
1200 | AUTHOR |
1146 | Marc Lehmann <schmorp@schmorp.de> |
1201 | Marc Lehmann <schmorp@schmorp.de> |
1147 | http://home.schmorp.de/ |
1202 | http://home.schmorp.de/ |
1148 | |
1203 | |