1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - the DBI of event loop programming |
4 | |
4 | |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt |
|
|
6 | and POE are various supported event loops/environments. |
6 | |
7 | |
7 | =head1 SYNOPSIS |
8 | =head1 SYNOPSIS |
8 | |
9 | |
9 | use AnyEvent; |
10 | use AnyEvent; |
10 | |
11 | |
|
|
12 | # file descriptor readable |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { |
13 | my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); |
|
|
14 | |
|
|
15 | # one-shot or repeating timers |
|
|
16 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
|
|
17 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
|
|
18 | |
|
|
19 | print AnyEvent->now; # prints current event loop time |
|
|
20 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
|
|
21 | |
|
|
22 | # POSIX signal |
|
|
23 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
|
|
24 | |
|
|
25 | # child process exit |
|
|
26 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
|
|
27 | my ($pid, $status) = @_; |
12 | ... |
28 | ... |
13 | }); |
29 | }); |
14 | |
30 | |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
31 | # called when event loop idle (if applicable) |
16 | ... |
32 | my $w = AnyEvent->idle (cb => sub { ... }); |
17 | }); |
|
|
18 | |
33 | |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
34 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
20 | $w->send; # wake up current and all future recv's |
35 | $w->send; # wake up current and all future recv's |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
36 | $w->recv; # enters "main loop" till $condvar gets ->send |
|
|
37 | # use a condvar in callback mode: |
|
|
38 | $w->cb (sub { $_[0]->recv }); |
22 | |
39 | |
23 | =head1 INTRODUCTION/TUTORIAL |
40 | =head1 INTRODUCTION/TUTORIAL |
24 | |
41 | |
25 | This manpage is mainly a reference manual. If you are interested |
42 | This manpage is mainly a reference manual. If you are interested |
26 | in a tutorial or some gentle introduction, have a look at the |
43 | in a tutorial or some gentle introduction, have a look at the |
27 | L<AnyEvent::Intro> manpage. |
44 | L<AnyEvent::Intro> manpage. |
|
|
45 | |
|
|
46 | =head1 SUPPORT |
|
|
47 | |
|
|
48 | There is a mailinglist for discussing all things AnyEvent, and an IRC |
|
|
49 | channel, too. |
|
|
50 | |
|
|
51 | See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software |
|
|
52 | Repository>, at L<http://anyevent.schmorp.de>, for more info. |
28 | |
53 | |
29 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
54 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
30 | |
55 | |
31 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
56 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
32 | nowadays. So what is different about AnyEvent? |
57 | nowadays. So what is different about AnyEvent? |
… | |
… | |
128 | These watchers are normal Perl objects with normal Perl lifetime. After |
153 | These watchers are normal Perl objects with normal Perl lifetime. After |
129 | creating a watcher it will immediately "watch" for events and invoke the |
154 | creating a watcher it will immediately "watch" for events and invoke the |
130 | callback when the event occurs (of course, only when the event model |
155 | callback when the event occurs (of course, only when the event model |
131 | is in control). |
156 | is in control). |
132 | |
157 | |
|
|
158 | Note that B<callbacks must not permanently change global variables> |
|
|
159 | potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< |
|
|
160 | callbacks must not C<die> >>. The former is good programming practise in |
|
|
161 | Perl and the latter stems from the fact that exception handling differs |
|
|
162 | widely between event loops. |
|
|
163 | |
133 | To disable the watcher you have to destroy it (e.g. by setting the |
164 | To disable the watcher you have to destroy it (e.g. by setting the |
134 | variable you store it in to C<undef> or otherwise deleting all references |
165 | variable you store it in to C<undef> or otherwise deleting all references |
135 | to it). |
166 | to it). |
136 | |
167 | |
137 | All watchers are created by calling a method on the C<AnyEvent> class. |
168 | All watchers are created by calling a method on the C<AnyEvent> class. |
… | |
… | |
150 | my variables are only visible after the statement in which they are |
181 | my variables are only visible after the statement in which they are |
151 | declared. |
182 | declared. |
152 | |
183 | |
153 | =head2 I/O WATCHERS |
184 | =head2 I/O WATCHERS |
154 | |
185 | |
|
|
186 | $w = AnyEvent->io ( |
|
|
187 | fh => <filehandle_or_fileno>, |
|
|
188 | poll => <"r" or "w">, |
|
|
189 | cb => <callback>, |
|
|
190 | ); |
|
|
191 | |
155 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
192 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
156 | with the following mandatory key-value pairs as arguments: |
193 | with the following mandatory key-value pairs as arguments: |
157 | |
194 | |
158 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events |
195 | C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch |
159 | (AnyEvent might or might not keep a reference to this file handle). C<poll> |
196 | for events (AnyEvent might or might not keep a reference to this file |
|
|
197 | handle). Note that only file handles pointing to things for which |
|
|
198 | non-blocking operation makes sense are allowed. This includes sockets, |
|
|
199 | most character devices, pipes, fifos and so on, but not for example files |
|
|
200 | or block devices. |
|
|
201 | |
160 | must be a string that is either C<r> or C<w>, which creates a watcher |
202 | C<poll> must be a string that is either C<r> or C<w>, which creates a |
161 | waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the |
203 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
|
|
204 | |
162 | callback to invoke each time the file handle becomes ready. |
205 | C<cb> is the callback to invoke each time the file handle becomes ready. |
163 | |
206 | |
164 | Although the callback might get passed parameters, their value and |
207 | Although the callback might get passed parameters, their value and |
165 | presence is undefined and you cannot rely on them. Portable AnyEvent |
208 | presence is undefined and you cannot rely on them. Portable AnyEvent |
166 | callbacks cannot use arguments passed to I/O watcher callbacks. |
209 | callbacks cannot use arguments passed to I/O watcher callbacks. |
167 | |
210 | |
… | |
… | |
182 | undef $w; |
225 | undef $w; |
183 | }); |
226 | }); |
184 | |
227 | |
185 | =head2 TIME WATCHERS |
228 | =head2 TIME WATCHERS |
186 | |
229 | |
|
|
230 | $w = AnyEvent->timer (after => <seconds>, cb => <callback>); |
|
|
231 | |
|
|
232 | $w = AnyEvent->timer ( |
|
|
233 | after => <fractional_seconds>, |
|
|
234 | interval => <fractional_seconds>, |
|
|
235 | cb => <callback>, |
|
|
236 | ); |
|
|
237 | |
187 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
238 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
188 | method with the following mandatory arguments: |
239 | method with the following mandatory arguments: |
189 | |
240 | |
190 | C<after> specifies after how many seconds (fractional values are |
241 | C<after> specifies after how many seconds (fractional values are |
191 | supported) the callback should be invoked. C<cb> is the callback to invoke |
242 | supported) the callback should be invoked. C<cb> is the callback to invoke |
… | |
… | |
299 | In either case, if you care (and in most cases, you don't), then you |
350 | In either case, if you care (and in most cases, you don't), then you |
300 | can get whatever behaviour you want with any event loop, by taking the |
351 | can get whatever behaviour you want with any event loop, by taking the |
301 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
352 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
302 | account. |
353 | account. |
303 | |
354 | |
|
|
355 | =item AnyEvent->now_update |
|
|
356 | |
|
|
357 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
|
|
358 | the current time for each loop iteration (see the discussion of L<< |
|
|
359 | AnyEvent->now >>, above). |
|
|
360 | |
|
|
361 | When a callback runs for a long time (or when the process sleeps), then |
|
|
362 | this "current" time will differ substantially from the real time, which |
|
|
363 | might affect timers and time-outs. |
|
|
364 | |
|
|
365 | When this is the case, you can call this method, which will update the |
|
|
366 | event loop's idea of "current time". |
|
|
367 | |
|
|
368 | A typical example would be a script in a web server (e.g. C<mod_perl>) - |
|
|
369 | when mod_perl executes the script, then the event loop will have the wrong |
|
|
370 | idea about the "current time" (being potentially far in the past, when the |
|
|
371 | script ran the last time). In that case you should arrange a call to C<< |
|
|
372 | AnyEvent->now_update >> each time the web server process wakes up again |
|
|
373 | (e.g. at the start of your script, or in a handler). |
|
|
374 | |
|
|
375 | Note that updating the time I<might> cause some events to be handled. |
|
|
376 | |
304 | =back |
377 | =back |
305 | |
378 | |
306 | =head2 SIGNAL WATCHERS |
379 | =head2 SIGNAL WATCHERS |
|
|
380 | |
|
|
381 | $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>); |
307 | |
382 | |
308 | You can watch for signals using a signal watcher, C<signal> is the signal |
383 | You can watch for signals using a signal watcher, C<signal> is the signal |
309 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
384 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
310 | callback to be invoked whenever a signal occurs. |
385 | callback to be invoked whenever a signal occurs. |
311 | |
386 | |
… | |
… | |
317 | invocation, and callback invocation will be synchronous. Synchronous means |
392 | invocation, and callback invocation will be synchronous. Synchronous means |
318 | that it might take a while until the signal gets handled by the process, |
393 | that it might take a while until the signal gets handled by the process, |
319 | but it is guaranteed not to interrupt any other callbacks. |
394 | but it is guaranteed not to interrupt any other callbacks. |
320 | |
395 | |
321 | The main advantage of using these watchers is that you can share a signal |
396 | The main advantage of using these watchers is that you can share a signal |
322 | between multiple watchers. |
397 | between multiple watchers, and AnyEvent will ensure that signals will not |
|
|
398 | interrupt your program at bad times. |
323 | |
399 | |
324 | This watcher might use C<%SIG>, so programs overwriting those signals |
400 | This watcher might use C<%SIG> (depending on the event loop used), |
325 | directly will likely not work correctly. |
401 | so programs overwriting those signals directly will likely not work |
|
|
402 | correctly. |
326 | |
403 | |
327 | Example: exit on SIGINT |
404 | Example: exit on SIGINT |
328 | |
405 | |
329 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
406 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
330 | |
407 | |
|
|
408 | =head3 Restart Behaviour |
|
|
409 | |
|
|
410 | While restart behaviour is up to the event loop implementation, most will |
|
|
411 | not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's |
|
|
412 | pure perl implementation). |
|
|
413 | |
|
|
414 | =head3 Safe/Unsafe Signals |
|
|
415 | |
|
|
416 | Perl signals can be either "safe" (synchronous to opcode handling) or |
|
|
417 | "unsafe" (asynchronous) - the former might get delayed indefinitely, the |
|
|
418 | latter might corrupt your memory. |
|
|
419 | |
|
|
420 | AnyEvent signal handlers are, in addition, synchronous to the event loop, |
|
|
421 | i.e. they will not interrupt your running perl program but will only be |
|
|
422 | called as part of the normal event handling (just like timer, I/O etc. |
|
|
423 | callbacks, too). |
|
|
424 | |
|
|
425 | =head3 Signal Races, Delays and Workarounds |
|
|
426 | |
|
|
427 | Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching |
|
|
428 | callbacks to signals in a generic way, which is a pity, as you cannot |
|
|
429 | do race-free signal handling in perl, requiring C libraries for |
|
|
430 | this. AnyEvent will try to do it's best, which means in some cases, |
|
|
431 | signals will be delayed. The maximum time a signal might be delayed is |
|
|
432 | specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This |
|
|
433 | variable can be changed only before the first signal watcher is created, |
|
|
434 | and should be left alone otherwise. This variable determines how often |
|
|
435 | AnyEvent polls for signals (in case a wake-up was missed). Higher values |
|
|
436 | will cause fewer spurious wake-ups, which is better for power and CPU |
|
|
437 | saving. |
|
|
438 | |
|
|
439 | All these problems can be avoided by installing the optional |
|
|
440 | L<Async::Interrupt> module, which works with most event loops. It will not |
|
|
441 | work with inherently broken event loops such as L<Event> or L<Event::Lib> |
|
|
442 | (and not with L<POE> currently, as POE does it's own workaround with |
|
|
443 | one-second latency). For those, you just have to suffer the delays. |
|
|
444 | |
331 | =head2 CHILD PROCESS WATCHERS |
445 | =head2 CHILD PROCESS WATCHERS |
332 | |
446 | |
|
|
447 | $w = AnyEvent->child (pid => <process id>, cb => <callback>); |
|
|
448 | |
333 | You can also watch on a child process exit and catch its exit status. |
449 | You can also watch on a child process exit and catch its exit status. |
334 | |
450 | |
335 | The child process is specified by the C<pid> argument (if set to C<0>, it |
451 | The child process is specified by the C<pid> argument (one some backends, |
336 | watches for any child process exit). The watcher will trigger as often |
452 | using C<0> watches for any child process exit, on others this will |
337 | as status change for the child are received. This works by installing a |
453 | croak). The watcher will be triggered only when the child process has |
338 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
454 | finished and an exit status is available, not on any trace events |
339 | and exit status (as returned by waitpid), so unlike other watcher types, |
455 | (stopped/continued). |
340 | you I<can> rely on child watcher callback arguments. |
456 | |
|
|
457 | The callback will be called with the pid and exit status (as returned by |
|
|
458 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
|
459 | callback arguments. |
|
|
460 | |
|
|
461 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
|
|
462 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
|
|
463 | random child processes (waiting for specific child processes, e.g. inside |
|
|
464 | C<system>, is just fine). |
341 | |
465 | |
342 | There is a slight catch to child watchers, however: you usually start them |
466 | There is a slight catch to child watchers, however: you usually start them |
343 | I<after> the child process was created, and this means the process could |
467 | I<after> the child process was created, and this means the process could |
344 | have exited already (and no SIGCHLD will be sent anymore). |
468 | have exited already (and no SIGCHLD will be sent anymore). |
345 | |
469 | |
346 | Not all event models handle this correctly (POE doesn't), but even for |
470 | Not all event models handle this correctly (neither POE nor IO::Async do, |
|
|
471 | see their AnyEvent::Impl manpages for details), but even for event models |
347 | event models that I<do> handle this correctly, they usually need to be |
472 | that I<do> handle this correctly, they usually need to be loaded before |
348 | loaded before the process exits (i.e. before you fork in the first place). |
473 | the process exits (i.e. before you fork in the first place). AnyEvent's |
|
|
474 | pure perl event loop handles all cases correctly regardless of when you |
|
|
475 | start the watcher. |
349 | |
476 | |
350 | This means you cannot create a child watcher as the very first thing in an |
477 | This means you cannot create a child watcher as the very first |
351 | AnyEvent program, you I<have> to create at least one watcher before you |
478 | thing in an AnyEvent program, you I<have> to create at least one |
352 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
479 | watcher before you C<fork> the child (alternatively, you can call |
|
|
480 | C<AnyEvent::detect>). |
|
|
481 | |
|
|
482 | As most event loops do not support waiting for child events, they will be |
|
|
483 | emulated by AnyEvent in most cases, in which the latency and race problems |
|
|
484 | mentioned in the description of signal watchers apply. |
353 | |
485 | |
354 | Example: fork a process and wait for it |
486 | Example: fork a process and wait for it |
355 | |
487 | |
356 | my $done = AnyEvent->condvar; |
488 | my $done = AnyEvent->condvar; |
357 | |
489 | |
… | |
… | |
367 | ); |
499 | ); |
368 | |
500 | |
369 | # do something else, then wait for process exit |
501 | # do something else, then wait for process exit |
370 | $done->recv; |
502 | $done->recv; |
371 | |
503 | |
|
|
504 | =head2 IDLE WATCHERS |
|
|
505 | |
|
|
506 | $w = AnyEvent->idle (cb => <callback>); |
|
|
507 | |
|
|
508 | Sometimes there is a need to do something, but it is not so important |
|
|
509 | to do it instantly, but only when there is nothing better to do. This |
|
|
510 | "nothing better to do" is usually defined to be "no other events need |
|
|
511 | attention by the event loop". |
|
|
512 | |
|
|
513 | Idle watchers ideally get invoked when the event loop has nothing |
|
|
514 | better to do, just before it would block the process to wait for new |
|
|
515 | events. Instead of blocking, the idle watcher is invoked. |
|
|
516 | |
|
|
517 | Most event loops unfortunately do not really support idle watchers (only |
|
|
518 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
|
|
519 | will simply call the callback "from time to time". |
|
|
520 | |
|
|
521 | Example: read lines from STDIN, but only process them when the |
|
|
522 | program is otherwise idle: |
|
|
523 | |
|
|
524 | my @lines; # read data |
|
|
525 | my $idle_w; |
|
|
526 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
|
|
527 | push @lines, scalar <STDIN>; |
|
|
528 | |
|
|
529 | # start an idle watcher, if not already done |
|
|
530 | $idle_w ||= AnyEvent->idle (cb => sub { |
|
|
531 | # handle only one line, when there are lines left |
|
|
532 | if (my $line = shift @lines) { |
|
|
533 | print "handled when idle: $line"; |
|
|
534 | } else { |
|
|
535 | # otherwise disable the idle watcher again |
|
|
536 | undef $idle_w; |
|
|
537 | } |
|
|
538 | }); |
|
|
539 | }); |
|
|
540 | |
372 | =head2 CONDITION VARIABLES |
541 | =head2 CONDITION VARIABLES |
|
|
542 | |
|
|
543 | $cv = AnyEvent->condvar; |
|
|
544 | |
|
|
545 | $cv->send (<list>); |
|
|
546 | my @res = $cv->recv; |
373 | |
547 | |
374 | If you are familiar with some event loops you will know that all of them |
548 | If you are familiar with some event loops you will know that all of them |
375 | require you to run some blocking "loop", "run" or similar function that |
549 | require you to run some blocking "loop", "run" or similar function that |
376 | will actively watch for new events and call your callbacks. |
550 | will actively watch for new events and call your callbacks. |
377 | |
551 | |
378 | AnyEvent is different, it expects somebody else to run the event loop and |
552 | AnyEvent is slightly different: it expects somebody else to run the event |
379 | will only block when necessary (usually when told by the user). |
553 | loop and will only block when necessary (usually when told by the user). |
380 | |
554 | |
381 | The instrument to do that is called a "condition variable", so called |
555 | The instrument to do that is called a "condition variable", so called |
382 | because they represent a condition that must become true. |
556 | because they represent a condition that must become true. |
|
|
557 | |
|
|
558 | Now is probably a good time to look at the examples further below. |
383 | |
559 | |
384 | Condition variables can be created by calling the C<< AnyEvent->condvar |
560 | Condition variables can be created by calling the C<< AnyEvent->condvar |
385 | >> method, usually without arguments. The only argument pair allowed is |
561 | >> method, usually without arguments. The only argument pair allowed is |
386 | C<cb>, which specifies a callback to be called when the condition variable |
562 | C<cb>, which specifies a callback to be called when the condition variable |
387 | becomes true. |
563 | becomes true, with the condition variable as the first argument (but not |
|
|
564 | the results). |
388 | |
565 | |
389 | After creation, the condition variable is "false" until it becomes "true" |
566 | After creation, the condition variable is "false" until it becomes "true" |
390 | by calling the C<send> method (or calling the condition variable as if it |
567 | by calling the C<send> method (or calling the condition variable as if it |
391 | were a callback, read about the caveats in the description for the C<< |
568 | were a callback, read about the caveats in the description for the C<< |
392 | ->send >> method). |
569 | ->send >> method). |
… | |
… | |
394 | Condition variables are similar to callbacks, except that you can |
571 | Condition variables are similar to callbacks, except that you can |
395 | optionally wait for them. They can also be called merge points - points |
572 | optionally wait for them. They can also be called merge points - points |
396 | in time where multiple outstanding events have been processed. And yet |
573 | in time where multiple outstanding events have been processed. And yet |
397 | another way to call them is transactions - each condition variable can be |
574 | another way to call them is transactions - each condition variable can be |
398 | used to represent a transaction, which finishes at some point and delivers |
575 | used to represent a transaction, which finishes at some point and delivers |
399 | a result. |
576 | a result. And yet some people know them as "futures" - a promise to |
|
|
577 | compute/deliver something that you can wait for. |
400 | |
578 | |
401 | Condition variables are very useful to signal that something has finished, |
579 | Condition variables are very useful to signal that something has finished, |
402 | for example, if you write a module that does asynchronous http requests, |
580 | for example, if you write a module that does asynchronous http requests, |
403 | then a condition variable would be the ideal candidate to signal the |
581 | then a condition variable would be the ideal candidate to signal the |
404 | availability of results. The user can either act when the callback is |
582 | availability of results. The user can either act when the callback is |
… | |
… | |
438 | after => 1, |
616 | after => 1, |
439 | cb => sub { $result_ready->send }, |
617 | cb => sub { $result_ready->send }, |
440 | ); |
618 | ); |
441 | |
619 | |
442 | # this "blocks" (while handling events) till the callback |
620 | # this "blocks" (while handling events) till the callback |
443 | # calls send |
621 | # calls ->send |
444 | $result_ready->recv; |
622 | $result_ready->recv; |
445 | |
623 | |
446 | Example: wait for a timer, but take advantage of the fact that |
624 | Example: wait for a timer, but take advantage of the fact that condition |
447 | condition variables are also code references. |
625 | variables are also callable directly. |
448 | |
626 | |
449 | my $done = AnyEvent->condvar; |
627 | my $done = AnyEvent->condvar; |
450 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
628 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
451 | $done->recv; |
629 | $done->recv; |
|
|
630 | |
|
|
631 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
632 | callbacks. This is how you make a synchronous call, for example from |
|
|
633 | the main program: |
|
|
634 | |
|
|
635 | use AnyEvent::CouchDB; |
|
|
636 | |
|
|
637 | ... |
|
|
638 | |
|
|
639 | my @info = $couchdb->info->recv; |
|
|
640 | |
|
|
641 | And this is how you would just set a callback to be called whenever the |
|
|
642 | results are available: |
|
|
643 | |
|
|
644 | $couchdb->info->cb (sub { |
|
|
645 | my @info = $_[0]->recv; |
|
|
646 | }); |
452 | |
647 | |
453 | =head3 METHODS FOR PRODUCERS |
648 | =head3 METHODS FOR PRODUCERS |
454 | |
649 | |
455 | These methods should only be used by the producing side, i.e. the |
650 | These methods should only be used by the producing side, i.e. the |
456 | code/module that eventually sends the signal. Note that it is also |
651 | code/module that eventually sends the signal. Note that it is also |
… | |
… | |
469 | immediately from within send. |
664 | immediately from within send. |
470 | |
665 | |
471 | Any arguments passed to the C<send> call will be returned by all |
666 | Any arguments passed to the C<send> call will be returned by all |
472 | future C<< ->recv >> calls. |
667 | future C<< ->recv >> calls. |
473 | |
668 | |
474 | Condition variables are overloaded so one can call them directly |
669 | Condition variables are overloaded so one can call them directly (as if |
475 | (as a code reference). Calling them directly is the same as calling |
670 | they were a code reference). Calling them directly is the same as calling |
476 | C<send>. Note, however, that many C-based event loops do not handle |
671 | C<send>. |
477 | overloading, so as tempting as it may be, passing a condition variable |
|
|
478 | instead of a callback does not work. Both the pure perl and EV loops |
|
|
479 | support overloading, however, as well as all functions that use perl to |
|
|
480 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
|
|
481 | example). |
|
|
482 | |
672 | |
483 | =item $cv->croak ($error) |
673 | =item $cv->croak ($error) |
484 | |
674 | |
485 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
675 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
486 | C<Carp::croak> with the given error message/object/scalar. |
676 | C<Carp::croak> with the given error message/object/scalar. |
487 | |
677 | |
488 | This can be used to signal any errors to the condition variable |
678 | This can be used to signal any errors to the condition variable |
489 | user/consumer. |
679 | user/consumer. Doing it this way instead of calling C<croak> directly |
|
|
680 | delays the error detetcion, but has the overwhelmign advantage that it |
|
|
681 | diagnoses the error at the place where the result is expected, and not |
|
|
682 | deep in some event clalback without connection to the actual code causing |
|
|
683 | the problem. |
490 | |
684 | |
491 | =item $cv->begin ([group callback]) |
685 | =item $cv->begin ([group callback]) |
492 | |
686 | |
493 | =item $cv->end |
687 | =item $cv->end |
494 | |
|
|
495 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
|
|
496 | |
688 | |
497 | These two methods can be used to combine many transactions/events into |
689 | These two methods can be used to combine many transactions/events into |
498 | one. For example, a function that pings many hosts in parallel might want |
690 | one. For example, a function that pings many hosts in parallel might want |
499 | to use a condition variable for the whole process. |
691 | to use a condition variable for the whole process. |
500 | |
692 | |
501 | Every call to C<< ->begin >> will increment a counter, and every call to |
693 | Every call to C<< ->begin >> will increment a counter, and every call to |
502 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
694 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
503 | >>, the (last) callback passed to C<begin> will be executed. That callback |
695 | >>, the (last) callback passed to C<begin> will be executed, passing the |
504 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
696 | condvar as first argument. That callback is I<supposed> to call C<< ->send |
505 | callback was set, C<send> will be called without any arguments. |
697 | >>, but that is not required. If no group callback was set, C<send> will |
|
|
698 | be called without any arguments. |
506 | |
699 | |
507 | Let's clarify this with the ping example: |
700 | You can think of C<< $cv->send >> giving you an OR condition (one call |
|
|
701 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
|
|
702 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
|
|
703 | |
|
|
704 | Let's start with a simple example: you have two I/O watchers (for example, |
|
|
705 | STDOUT and STDERR for a program), and you want to wait for both streams to |
|
|
706 | close before activating a condvar: |
508 | |
707 | |
509 | my $cv = AnyEvent->condvar; |
708 | my $cv = AnyEvent->condvar; |
510 | |
709 | |
|
|
710 | $cv->begin; # first watcher |
|
|
711 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
|
|
712 | defined sysread $fh1, my $buf, 4096 |
|
|
713 | or $cv->end; |
|
|
714 | }); |
|
|
715 | |
|
|
716 | $cv->begin; # second watcher |
|
|
717 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
718 | defined sysread $fh2, my $buf, 4096 |
|
|
719 | or $cv->end; |
|
|
720 | }); |
|
|
721 | |
|
|
722 | $cv->recv; |
|
|
723 | |
|
|
724 | This works because for every event source (EOF on file handle), there is |
|
|
725 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
|
|
726 | sending. |
|
|
727 | |
|
|
728 | The ping example mentioned above is slightly more complicated, as the |
|
|
729 | there are results to be passwd back, and the number of tasks that are |
|
|
730 | begung can potentially be zero: |
|
|
731 | |
|
|
732 | my $cv = AnyEvent->condvar; |
|
|
733 | |
511 | my %result; |
734 | my %result; |
512 | $cv->begin (sub { $cv->send (\%result) }); |
735 | $cv->begin (sub { shift->send (\%result) }); |
513 | |
736 | |
514 | for my $host (@list_of_hosts) { |
737 | for my $host (@list_of_hosts) { |
515 | $cv->begin; |
738 | $cv->begin; |
516 | ping_host_then_call_callback $host, sub { |
739 | ping_host_then_call_callback $host, sub { |
517 | $result{$host} = ...; |
740 | $result{$host} = ...; |
… | |
… | |
532 | loop, which serves two important purposes: first, it sets the callback |
755 | loop, which serves two important purposes: first, it sets the callback |
533 | to be called once the counter reaches C<0>, and second, it ensures that |
756 | to be called once the counter reaches C<0>, and second, it ensures that |
534 | C<send> is called even when C<no> hosts are being pinged (the loop |
757 | C<send> is called even when C<no> hosts are being pinged (the loop |
535 | doesn't execute once). |
758 | doesn't execute once). |
536 | |
759 | |
537 | This is the general pattern when you "fan out" into multiple subrequests: |
760 | This is the general pattern when you "fan out" into multiple (but |
538 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
761 | potentially none) subrequests: use an outer C<begin>/C<end> pair to set |
539 | is called at least once, and then, for each subrequest you start, call |
762 | the callback and ensure C<end> is called at least once, and then, for each |
540 | C<begin> and for each subrequest you finish, call C<end>. |
763 | subrequest you start, call C<begin> and for each subrequest you finish, |
|
|
764 | call C<end>. |
541 | |
765 | |
542 | =back |
766 | =back |
543 | |
767 | |
544 | =head3 METHODS FOR CONSUMERS |
768 | =head3 METHODS FOR CONSUMERS |
545 | |
769 | |
… | |
… | |
561 | function will call C<croak>. |
785 | function will call C<croak>. |
562 | |
786 | |
563 | In list context, all parameters passed to C<send> will be returned, |
787 | In list context, all parameters passed to C<send> will be returned, |
564 | in scalar context only the first one will be returned. |
788 | in scalar context only the first one will be returned. |
565 | |
789 | |
|
|
790 | Note that doing a blocking wait in a callback is not supported by any |
|
|
791 | event loop, that is, recursive invocation of a blocking C<< ->recv |
|
|
792 | >> is not allowed, and the C<recv> call will C<croak> if such a |
|
|
793 | condition is detected. This condition can be slightly loosened by using |
|
|
794 | L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from |
|
|
795 | any thread that doesn't run the event loop itself. |
|
|
796 | |
566 | Not all event models support a blocking wait - some die in that case |
797 | Not all event models support a blocking wait - some die in that case |
567 | (programs might want to do that to stay interactive), so I<if you are |
798 | (programs might want to do that to stay interactive), so I<if you are |
568 | using this from a module, never require a blocking wait>, but let the |
799 | using this from a module, never require a blocking wait>. Instead, let the |
569 | caller decide whether the call will block or not (for example, by coupling |
800 | caller decide whether the call will block or not (for example, by coupling |
570 | condition variables with some kind of request results and supporting |
801 | condition variables with some kind of request results and supporting |
571 | callbacks so the caller knows that getting the result will not block, |
802 | callbacks so the caller knows that getting the result will not block, |
572 | while still supporting blocking waits if the caller so desires). |
803 | while still supporting blocking waits if the caller so desires). |
573 | |
804 | |
574 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
|
|
575 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
|
|
576 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
|
|
577 | can supply. |
|
|
578 | |
|
|
579 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
|
|
580 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
|
|
581 | versions and also integrates coroutines into AnyEvent, making blocking |
|
|
582 | C<< ->recv >> calls perfectly safe as long as they are done from another |
|
|
583 | coroutine (one that doesn't run the event loop). |
|
|
584 | |
|
|
585 | You can ensure that C<< -recv >> never blocks by setting a callback and |
805 | You can ensure that C<< -recv >> never blocks by setting a callback and |
586 | only calling C<< ->recv >> from within that callback (or at a later |
806 | only calling C<< ->recv >> from within that callback (or at a later |
587 | time). This will work even when the event loop does not support blocking |
807 | time). This will work even when the event loop does not support blocking |
588 | waits otherwise. |
808 | waits otherwise. |
589 | |
809 | |
590 | =item $bool = $cv->ready |
810 | =item $bool = $cv->ready |
591 | |
811 | |
592 | Returns true when the condition is "true", i.e. whether C<send> or |
812 | Returns true when the condition is "true", i.e. whether C<send> or |
593 | C<croak> have been called. |
813 | C<croak> have been called. |
594 | |
814 | |
595 | =item $cb = $cv->cb ([new callback]) |
815 | =item $cb = $cv->cb ($cb->($cv)) |
596 | |
816 | |
597 | This is a mutator function that returns the callback set and optionally |
817 | This is a mutator function that returns the callback set and optionally |
598 | replaces it before doing so. |
818 | replaces it before doing so. |
599 | |
819 | |
600 | The callback will be called when the condition becomes "true", i.e. when |
820 | The callback will be called when the condition becomes (or already was) |
601 | C<send> or C<croak> are called, with the only argument being the condition |
821 | "true", i.e. when C<send> or C<croak> are called (or were called), with |
602 | variable itself. Calling C<recv> inside the callback or at any later time |
822 | the only argument being the condition variable itself. Calling C<recv> |
603 | is guaranteed not to block. |
823 | inside the callback or at any later time is guaranteed not to block. |
604 | |
824 | |
605 | =back |
825 | =back |
606 | |
826 | |
|
|
827 | =head1 SUPPORTED EVENT LOOPS/BACKENDS |
|
|
828 | |
|
|
829 | The available backend classes are (every class has its own manpage): |
|
|
830 | |
|
|
831 | =over 4 |
|
|
832 | |
|
|
833 | =item Backends that are autoprobed when no other event loop can be found. |
|
|
834 | |
|
|
835 | EV is the preferred backend when no other event loop seems to be in |
|
|
836 | use. If EV is not installed, then AnyEvent will fall back to its own |
|
|
837 | pure-perl implementation, which is available everywhere as it comes with |
|
|
838 | AnyEvent itself. |
|
|
839 | |
|
|
840 | AnyEvent::Impl::EV based on EV (interface to libev, best choice). |
|
|
841 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
842 | |
|
|
843 | =item Backends that are transparently being picked up when they are used. |
|
|
844 | |
|
|
845 | These will be used when they are currently loaded when the first watcher |
|
|
846 | is created, in which case it is assumed that the application is using |
|
|
847 | them. This means that AnyEvent will automatically pick the right backend |
|
|
848 | when the main program loads an event module before anything starts to |
|
|
849 | create watchers. Nothing special needs to be done by the main program. |
|
|
850 | |
|
|
851 | AnyEvent::Impl::Event based on Event, very stable, few glitches. |
|
|
852 | AnyEvent::Impl::Glib based on Glib, slow but very stable. |
|
|
853 | AnyEvent::Impl::Tk based on Tk, very broken. |
|
|
854 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
855 | AnyEvent::Impl::POE based on POE, very slow, some limitations. |
|
|
856 | AnyEvent::Impl::Irssi used when running within irssi. |
|
|
857 | |
|
|
858 | =item Backends with special needs. |
|
|
859 | |
|
|
860 | Qt requires the Qt::Application to be instantiated first, but will |
|
|
861 | otherwise be picked up automatically. As long as the main program |
|
|
862 | instantiates the application before any AnyEvent watchers are created, |
|
|
863 | everything should just work. |
|
|
864 | |
|
|
865 | AnyEvent::Impl::Qt based on Qt. |
|
|
866 | |
|
|
867 | Support for IO::Async can only be partial, as it is too broken and |
|
|
868 | architecturally limited to even support the AnyEvent API. It also |
|
|
869 | is the only event loop that needs the loop to be set explicitly, so |
|
|
870 | it can only be used by a main program knowing about AnyEvent. See |
|
|
871 | L<AnyEvent::Impl::Async> for the gory details. |
|
|
872 | |
|
|
873 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed. |
|
|
874 | |
|
|
875 | =item Event loops that are indirectly supported via other backends. |
|
|
876 | |
|
|
877 | Some event loops can be supported via other modules: |
|
|
878 | |
|
|
879 | There is no direct support for WxWidgets (L<Wx>) or L<Prima>. |
|
|
880 | |
|
|
881 | B<WxWidgets> has no support for watching file handles. However, you can |
|
|
882 | use WxWidgets through the POE adaptor, as POE has a Wx backend that simply |
|
|
883 | polls 20 times per second, which was considered to be too horrible to even |
|
|
884 | consider for AnyEvent. |
|
|
885 | |
|
|
886 | B<Prima> is not supported as nobody seems to be using it, but it has a POE |
|
|
887 | backend, so it can be supported through POE. |
|
|
888 | |
|
|
889 | AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to |
|
|
890 | load L<POE> when detecting them, in the hope that POE will pick them up, |
|
|
891 | in which case everything will be automatic. |
|
|
892 | |
|
|
893 | =back |
|
|
894 | |
607 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
895 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
608 | |
896 | |
|
|
897 | These are not normally required to use AnyEvent, but can be useful to |
|
|
898 | write AnyEvent extension modules. |
|
|
899 | |
609 | =over 4 |
900 | =over 4 |
610 | |
901 | |
611 | =item $AnyEvent::MODEL |
902 | =item $AnyEvent::MODEL |
612 | |
903 | |
613 | Contains C<undef> until the first watcher is being created. Then it |
904 | Contains C<undef> until the first watcher is being created, before the |
|
|
905 | backend has been autodetected. |
|
|
906 | |
614 | contains the event model that is being used, which is the name of the |
907 | Afterwards it contains the event model that is being used, which is the |
615 | Perl class implementing the model. This class is usually one of the |
908 | name of the Perl class implementing the model. This class is usually one |
616 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
909 | of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the |
617 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
910 | case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it |
618 | |
911 | will be C<urxvt::anyevent>). |
619 | The known classes so far are: |
|
|
620 | |
|
|
621 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
|
|
622 | AnyEvent::Impl::Event based on Event, second best choice. |
|
|
623 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
624 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
|
|
625 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
|
|
626 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
|
|
627 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
628 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
|
|
629 | |
|
|
630 | There is no support for WxWidgets, as WxWidgets has no support for |
|
|
631 | watching file handles. However, you can use WxWidgets through the |
|
|
632 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
|
|
633 | second, which was considered to be too horrible to even consider for |
|
|
634 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
|
|
635 | it's adaptor. |
|
|
636 | |
|
|
637 | AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when |
|
|
638 | autodetecting them. |
|
|
639 | |
912 | |
640 | =item AnyEvent::detect |
913 | =item AnyEvent::detect |
641 | |
914 | |
642 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
915 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
643 | if necessary. You should only call this function right before you would |
916 | if necessary. You should only call this function right before you would |
644 | have created an AnyEvent watcher anyway, that is, as late as possible at |
917 | have created an AnyEvent watcher anyway, that is, as late as possible at |
645 | runtime. |
918 | runtime, and not e.g. while initialising of your module. |
|
|
919 | |
|
|
920 | If you need to do some initialisation before AnyEvent watchers are |
|
|
921 | created, use C<post_detect>. |
646 | |
922 | |
647 | =item $guard = AnyEvent::post_detect { BLOCK } |
923 | =item $guard = AnyEvent::post_detect { BLOCK } |
648 | |
924 | |
649 | Arranges for the code block to be executed as soon as the event model is |
925 | Arranges for the code block to be executed as soon as the event model is |
650 | autodetected (or immediately if this has already happened). |
926 | autodetected (or immediately if this has already happened). |
651 | |
927 | |
|
|
928 | The block will be executed I<after> the actual backend has been detected |
|
|
929 | (C<$AnyEvent::MODEL> is set), but I<before> any watchers have been |
|
|
930 | created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do |
|
|
931 | other initialisations - see the sources of L<AnyEvent::Strict> or |
|
|
932 | L<AnyEvent::AIO> to see how this is used. |
|
|
933 | |
|
|
934 | The most common usage is to create some global watchers, without forcing |
|
|
935 | event module detection too early, for example, L<AnyEvent::AIO> creates |
|
|
936 | and installs the global L<IO::AIO> watcher in a C<post_detect> block to |
|
|
937 | avoid autodetecting the event module at load time. |
|
|
938 | |
652 | If called in scalar or list context, then it creates and returns an object |
939 | If called in scalar or list context, then it creates and returns an object |
653 | that automatically removes the callback again when it is destroyed. See |
940 | that automatically removes the callback again when it is destroyed (or |
|
|
941 | C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for |
654 | L<Coro::BDB> for a case where this is useful. |
942 | a case where this is useful. |
|
|
943 | |
|
|
944 | Example: Create a watcher for the IO::AIO module and store it in |
|
|
945 | C<$WATCHER>. Only do so after the event loop is initialised, though. |
|
|
946 | |
|
|
947 | our WATCHER; |
|
|
948 | |
|
|
949 | my $guard = AnyEvent::post_detect { |
|
|
950 | $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb); |
|
|
951 | }; |
|
|
952 | |
|
|
953 | # the ||= is important in case post_detect immediately runs the block, |
|
|
954 | # as to not clobber the newly-created watcher. assigning both watcher and |
|
|
955 | # post_detect guard to the same variable has the advantage of users being |
|
|
956 | # able to just C<undef $WATCHER> if the watcher causes them grief. |
|
|
957 | |
|
|
958 | $WATCHER ||= $guard; |
655 | |
959 | |
656 | =item @AnyEvent::post_detect |
960 | =item @AnyEvent::post_detect |
657 | |
961 | |
658 | If there are any code references in this array (you can C<push> to it |
962 | If there are any code references in this array (you can C<push> to it |
659 | before or after loading AnyEvent), then they will called directly after |
963 | before or after loading AnyEvent), then they will called directly after |
660 | the event loop has been chosen. |
964 | the event loop has been chosen. |
661 | |
965 | |
662 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
966 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
663 | if it contains a true value then the event loop has already been detected, |
967 | if it is defined then the event loop has already been detected, and the |
664 | and the array will be ignored. |
968 | array will be ignored. |
665 | |
969 | |
666 | Best use C<AnyEvent::post_detect { BLOCK }> instead. |
970 | Best use C<AnyEvent::post_detect { BLOCK }> when your application allows |
|
|
971 | it, as it takes care of these details. |
|
|
972 | |
|
|
973 | This variable is mainly useful for modules that can do something useful |
|
|
974 | when AnyEvent is used and thus want to know when it is initialised, but do |
|
|
975 | not need to even load it by default. This array provides the means to hook |
|
|
976 | into AnyEvent passively, without loading it. |
|
|
977 | |
|
|
978 | Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used |
|
|
979 | together, you could put this into Coro (this is the actual code used by |
|
|
980 | Coro to accomplish this): |
|
|
981 | |
|
|
982 | if (defined $AnyEvent::MODEL) { |
|
|
983 | # AnyEvent already initialised, so load Coro::AnyEvent |
|
|
984 | require Coro::AnyEvent; |
|
|
985 | } else { |
|
|
986 | # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent |
|
|
987 | # as soon as it is |
|
|
988 | push @AnyEvent::post_detect, sub { require Coro::AnyEvent }; |
|
|
989 | } |
667 | |
990 | |
668 | =back |
991 | =back |
669 | |
992 | |
670 | =head1 WHAT TO DO IN A MODULE |
993 | =head1 WHAT TO DO IN A MODULE |
671 | |
994 | |
… | |
… | |
726 | |
1049 | |
727 | |
1050 | |
728 | =head1 OTHER MODULES |
1051 | =head1 OTHER MODULES |
729 | |
1052 | |
730 | The following is a non-exhaustive list of additional modules that use |
1053 | The following is a non-exhaustive list of additional modules that use |
731 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
1054 | AnyEvent as a client and can therefore be mixed easily with other AnyEvent |
732 | in the same program. Some of the modules come with AnyEvent, some are |
1055 | modules and other event loops in the same program. Some of the modules |
733 | available via CPAN. |
1056 | come with AnyEvent, most are available via CPAN. |
734 | |
1057 | |
735 | =over 4 |
1058 | =over 4 |
736 | |
1059 | |
737 | =item L<AnyEvent::Util> |
1060 | =item L<AnyEvent::Util> |
738 | |
1061 | |
… | |
… | |
747 | |
1070 | |
748 | =item L<AnyEvent::Handle> |
1071 | =item L<AnyEvent::Handle> |
749 | |
1072 | |
750 | Provide read and write buffers, manages watchers for reads and writes, |
1073 | Provide read and write buffers, manages watchers for reads and writes, |
751 | supports raw and formatted I/O, I/O queued and fully transparent and |
1074 | supports raw and formatted I/O, I/O queued and fully transparent and |
752 | non-blocking SSL/TLS. |
1075 | non-blocking SSL/TLS (via L<AnyEvent::TLS>. |
753 | |
1076 | |
754 | =item L<AnyEvent::DNS> |
1077 | =item L<AnyEvent::DNS> |
755 | |
1078 | |
756 | Provides rich asynchronous DNS resolver capabilities. |
1079 | Provides rich asynchronous DNS resolver capabilities. |
757 | |
1080 | |
… | |
… | |
785 | |
1108 | |
786 | =item L<AnyEvent::GPSD> |
1109 | =item L<AnyEvent::GPSD> |
787 | |
1110 | |
788 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
1111 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
789 | |
1112 | |
|
|
1113 | =item L<AnyEvent::IRC> |
|
|
1114 | |
|
|
1115 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
|
|
1116 | |
|
|
1117 | =item L<AnyEvent::XMPP> |
|
|
1118 | |
|
|
1119 | AnyEvent based XMPP (Jabber protocol) module family (replacing the older |
|
|
1120 | Net::XMPP2>. |
|
|
1121 | |
790 | =item L<AnyEvent::IGS> |
1122 | =item L<AnyEvent::IGS> |
791 | |
1123 | |
792 | A non-blocking interface to the Internet Go Server protocol (used by |
1124 | A non-blocking interface to the Internet Go Server protocol (used by |
793 | L<App::IGS>). |
1125 | L<App::IGS>). |
794 | |
1126 | |
795 | =item L<Net::IRC3> |
|
|
796 | |
|
|
797 | AnyEvent based IRC client module family. |
|
|
798 | |
|
|
799 | =item L<Net::XMPP2> |
|
|
800 | |
|
|
801 | AnyEvent based XMPP (Jabber protocol) module family. |
|
|
802 | |
|
|
803 | =item L<Net::FCP> |
1127 | =item L<Net::FCP> |
804 | |
1128 | |
805 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
1129 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
806 | of AnyEvent. |
1130 | of AnyEvent. |
807 | |
1131 | |
… | |
… | |
811 | |
1135 | |
812 | =item L<Coro> |
1136 | =item L<Coro> |
813 | |
1137 | |
814 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
1138 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
815 | |
1139 | |
816 | =item L<IO::Lambda> |
|
|
817 | |
|
|
818 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
|
|
819 | |
|
|
820 | =back |
1140 | =back |
821 | |
1141 | |
822 | =cut |
1142 | =cut |
823 | |
1143 | |
824 | package AnyEvent; |
1144 | package AnyEvent; |
825 | |
1145 | |
826 | no warnings; |
1146 | # basically a tuned-down version of common::sense |
827 | use strict; |
1147 | sub common_sense { |
|
|
1148 | # from common:.sense 1.0 |
|
|
1149 | ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00"; |
|
|
1150 | # use strict vars subs |
|
|
1151 | $^H |= 0x00000600; |
|
|
1152 | } |
828 | |
1153 | |
|
|
1154 | BEGIN { AnyEvent::common_sense } |
|
|
1155 | |
829 | use Carp; |
1156 | use Carp (); |
830 | |
1157 | |
831 | our $VERSION = 4.22; |
1158 | our $VERSION = '5.22'; |
832 | our $MODEL; |
1159 | our $MODEL; |
833 | |
1160 | |
834 | our $AUTOLOAD; |
1161 | our $AUTOLOAD; |
835 | our @ISA; |
1162 | our @ISA; |
836 | |
1163 | |
837 | our @REGISTRY; |
1164 | our @REGISTRY; |
838 | |
1165 | |
839 | our $WIN32; |
1166 | our $VERBOSE; |
840 | |
1167 | |
841 | BEGIN { |
1168 | BEGIN { |
842 | my $win32 = ! ! ($^O =~ /mswin32/i); |
1169 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
843 | eval "sub WIN32(){ $win32 }"; |
1170 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
844 | } |
|
|
845 | |
1171 | |
|
|
1172 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
1173 | if ${^TAINT}; |
|
|
1174 | |
846 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
1175 | $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
|
|
1176 | |
|
|
1177 | } |
|
|
1178 | |
|
|
1179 | our $MAX_SIGNAL_LATENCY = 10; |
847 | |
1180 | |
848 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
1181 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
849 | |
1182 | |
850 | { |
1183 | { |
851 | my $idx; |
1184 | my $idx; |
… | |
… | |
853 | for reverse split /\s*,\s*/, |
1186 | for reverse split /\s*,\s*/, |
854 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
1187 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
855 | } |
1188 | } |
856 | |
1189 | |
857 | my @models = ( |
1190 | my @models = ( |
858 | [EV:: => AnyEvent::Impl::EV::], |
1191 | [EV:: => AnyEvent::Impl::EV:: , 1], |
859 | [Event:: => AnyEvent::Impl::Event::], |
|
|
860 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
1192 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1], |
861 | # everything below here will not be autoprobed |
1193 | # everything below here will not (normally) be autoprobed |
862 | # as the pureperl backend should work everywhere |
1194 | # as the pureperl backend should work everywhere |
863 | # and is usually faster |
1195 | # and is usually faster |
|
|
1196 | [Event:: => AnyEvent::Impl::Event::, 1], |
|
|
1197 | [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers |
|
|
1198 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
|
|
1199 | [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package |
864 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
1200 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
865 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
|
|
866 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
|
|
867 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1201 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
868 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1202 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
869 | [Wx:: => AnyEvent::Impl::POE::], |
1203 | [Wx:: => AnyEvent::Impl::POE::], |
870 | [Prima:: => AnyEvent::Impl::POE::], |
1204 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
1205 | # IO::Async is just too broken - we would need workarounds for its |
|
|
1206 | # byzantine signal and broken child handling, among others. |
|
|
1207 | # IO::Async is rather hard to detect, as it doesn't have any |
|
|
1208 | # obvious default class. |
|
|
1209 | [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1210 | [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1211 | [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1212 | [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program |
871 | ); |
1213 | ); |
872 | |
1214 | |
873 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
1215 | our %method = map +($_ => 1), |
|
|
1216 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
874 | |
1217 | |
875 | our @post_detect; |
1218 | our @post_detect; |
876 | |
1219 | |
877 | sub post_detect(&) { |
1220 | sub post_detect(&) { |
878 | my ($cb) = @_; |
1221 | my ($cb) = @_; |
879 | |
1222 | |
880 | if ($MODEL) { |
1223 | if ($MODEL) { |
881 | $cb->(); |
1224 | $cb->(); |
882 | |
1225 | |
883 | 1 |
1226 | undef |
884 | } else { |
1227 | } else { |
885 | push @post_detect, $cb; |
1228 | push @post_detect, $cb; |
886 | |
1229 | |
887 | defined wantarray |
1230 | defined wantarray |
888 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
1231 | ? bless \$cb, "AnyEvent::Util::postdetect" |
889 | : () |
1232 | : () |
890 | } |
1233 | } |
891 | } |
1234 | } |
892 | |
1235 | |
893 | sub AnyEvent::Util::PostDetect::DESTROY { |
1236 | sub AnyEvent::Util::postdetect::DESTROY { |
894 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1237 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
895 | } |
1238 | } |
896 | |
1239 | |
897 | sub detect() { |
1240 | sub detect() { |
898 | unless ($MODEL) { |
1241 | unless ($MODEL) { |
899 | no strict 'refs'; |
|
|
900 | local $SIG{__DIE__}; |
1242 | local $SIG{__DIE__}; |
901 | |
1243 | |
902 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
1244 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
903 | my $model = "AnyEvent::Impl::$1"; |
1245 | my $model = "AnyEvent::Impl::$1"; |
904 | if (eval "require $model") { |
1246 | if (eval "require $model") { |
905 | $MODEL = $model; |
1247 | $MODEL = $model; |
906 | warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; |
1248 | warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; |
907 | } else { |
1249 | } else { |
908 | warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; |
1250 | warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE; |
909 | } |
1251 | } |
910 | } |
1252 | } |
911 | |
1253 | |
912 | # check for already loaded models |
1254 | # check for already loaded models |
913 | unless ($MODEL) { |
1255 | unless ($MODEL) { |
914 | for (@REGISTRY, @models) { |
1256 | for (@REGISTRY, @models) { |
915 | my ($package, $model) = @$_; |
1257 | my ($package, $model) = @$_; |
916 | if (${"$package\::VERSION"} > 0) { |
1258 | if (${"$package\::VERSION"} > 0) { |
917 | if (eval "require $model") { |
1259 | if (eval "require $model") { |
918 | $MODEL = $model; |
1260 | $MODEL = $model; |
919 | warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; |
1261 | warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2; |
920 | last; |
1262 | last; |
921 | } |
1263 | } |
922 | } |
1264 | } |
923 | } |
1265 | } |
924 | |
1266 | |
925 | unless ($MODEL) { |
1267 | unless ($MODEL) { |
926 | # try to load a model |
1268 | # try to autoload a model |
927 | |
|
|
928 | for (@REGISTRY, @models) { |
1269 | for (@REGISTRY, @models) { |
929 | my ($package, $model) = @$_; |
1270 | my ($package, $model, $autoload) = @$_; |
|
|
1271 | if ( |
|
|
1272 | $autoload |
930 | if (eval "require $package" |
1273 | and eval "require $package" |
931 | and ${"$package\::VERSION"} > 0 |
1274 | and ${"$package\::VERSION"} > 0 |
932 | and eval "require $model") { |
1275 | and eval "require $model" |
|
|
1276 | ) { |
933 | $MODEL = $model; |
1277 | $MODEL = $model; |
934 | warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; |
1278 | warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2; |
935 | last; |
1279 | last; |
936 | } |
1280 | } |
937 | } |
1281 | } |
938 | |
1282 | |
939 | $MODEL |
1283 | $MODEL |
940 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1284 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
941 | } |
1285 | } |
942 | } |
1286 | } |
943 | |
1287 | |
944 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1288 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
945 | |
1289 | |
… | |
… | |
955 | |
1299 | |
956 | sub AUTOLOAD { |
1300 | sub AUTOLOAD { |
957 | (my $func = $AUTOLOAD) =~ s/.*://; |
1301 | (my $func = $AUTOLOAD) =~ s/.*://; |
958 | |
1302 | |
959 | $method{$func} |
1303 | $method{$func} |
960 | or croak "$func: not a valid method for AnyEvent objects"; |
1304 | or Carp::croak "$func: not a valid method for AnyEvent objects"; |
961 | |
1305 | |
962 | detect unless $MODEL; |
1306 | detect unless $MODEL; |
963 | |
1307 | |
964 | my $class = shift; |
1308 | my $class = shift; |
965 | $class->$func (@_); |
1309 | $class->$func (@_); |
966 | } |
1310 | } |
967 | |
1311 | |
968 | # utility function to dup a filehandle. this is used by many backends |
1312 | # utility function to dup a filehandle. this is used by many backends |
969 | # to support binding more than one watcher per filehandle (they usually |
1313 | # to support binding more than one watcher per filehandle (they usually |
970 | # allow only one watcher per fd, so we dup it to get a different one). |
1314 | # allow only one watcher per fd, so we dup it to get a different one). |
971 | sub _dupfh($$$$) { |
1315 | sub _dupfh($$;$$) { |
972 | my ($poll, $fh, $r, $w) = @_; |
1316 | my ($poll, $fh, $r, $w) = @_; |
973 | |
1317 | |
974 | require Fcntl; |
|
|
975 | |
|
|
976 | # cygwin requires the fh mode to be matching, unix doesn't |
1318 | # cygwin requires the fh mode to be matching, unix doesn't |
977 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1319 | my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&"); |
978 | : $poll eq "w" ? ($w, ">") |
|
|
979 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
|
|
980 | |
1320 | |
981 | open my $fh2, "$mode&" . fileno $fh |
1321 | open my $fh2, $mode, $fh |
982 | or die "cannot dup() filehandle: $!"; |
1322 | or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; |
983 | |
1323 | |
984 | # we assume CLOEXEC is already set by perl in all important cases |
1324 | # we assume CLOEXEC is already set by perl in all important cases |
985 | |
1325 | |
986 | ($fh2, $rw) |
1326 | ($fh2, $rw) |
987 | } |
1327 | } |
988 | |
1328 | |
|
|
1329 | =head1 SIMPLIFIED AE API |
|
|
1330 | |
|
|
1331 | Starting with version 5.0, AnyEvent officially supports a second, much |
|
|
1332 | simpler, API that is designed to reduce the calling, typing and memory |
|
|
1333 | overhead. |
|
|
1334 | |
|
|
1335 | See the L<AE> manpage for details. |
|
|
1336 | |
|
|
1337 | =cut |
|
|
1338 | |
|
|
1339 | package AE; |
|
|
1340 | |
|
|
1341 | our $VERSION = $AnyEvent::VERSION; |
|
|
1342 | |
|
|
1343 | sub io($$$) { |
|
|
1344 | AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2]) |
|
|
1345 | } |
|
|
1346 | |
|
|
1347 | sub timer($$$) { |
|
|
1348 | AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]) |
|
|
1349 | } |
|
|
1350 | |
|
|
1351 | sub signal($$) { |
|
|
1352 | AnyEvent->signal (signal => $_[0], cb => $_[1]) |
|
|
1353 | } |
|
|
1354 | |
|
|
1355 | sub child($$) { |
|
|
1356 | AnyEvent->child (pid => $_[0], cb => $_[1]) |
|
|
1357 | } |
|
|
1358 | |
|
|
1359 | sub idle($) { |
|
|
1360 | AnyEvent->idle (cb => $_[0]) |
|
|
1361 | } |
|
|
1362 | |
|
|
1363 | sub cv(;&) { |
|
|
1364 | AnyEvent->condvar (@_ ? (cb => $_[0]) : ()) |
|
|
1365 | } |
|
|
1366 | |
|
|
1367 | sub now() { |
|
|
1368 | AnyEvent->now |
|
|
1369 | } |
|
|
1370 | |
|
|
1371 | sub now_update() { |
|
|
1372 | AnyEvent->now_update |
|
|
1373 | } |
|
|
1374 | |
|
|
1375 | sub time() { |
|
|
1376 | AnyEvent->time |
|
|
1377 | } |
|
|
1378 | |
989 | package AnyEvent::Base; |
1379 | package AnyEvent::Base; |
990 | |
1380 | |
991 | # default implementation for now and time |
1381 | # default implementations for many methods |
992 | |
1382 | |
993 | use Time::HiRes (); |
1383 | sub _time() { |
|
|
1384 | # probe for availability of Time::HiRes |
|
|
1385 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1386 | warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; |
|
|
1387 | *_time = \&Time::HiRes::time; |
|
|
1388 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1389 | } else { |
|
|
1390 | warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; |
|
|
1391 | *_time = sub { time }; # epic fail |
|
|
1392 | } |
994 | |
1393 | |
995 | sub time { Time::HiRes::time } |
1394 | &_time |
996 | sub now { Time::HiRes::time } |
1395 | } |
|
|
1396 | |
|
|
1397 | sub time { _time } |
|
|
1398 | sub now { _time } |
|
|
1399 | sub now_update { } |
997 | |
1400 | |
998 | # default implementation for ->condvar |
1401 | # default implementation for ->condvar |
999 | |
1402 | |
1000 | sub condvar { |
1403 | sub condvar { |
1001 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1404 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
1002 | } |
1405 | } |
1003 | |
1406 | |
1004 | # default implementation for ->signal |
1407 | # default implementation for ->signal |
1005 | |
1408 | |
1006 | our %SIG_CB; |
1409 | our $HAVE_ASYNC_INTERRUPT; |
|
|
1410 | |
|
|
1411 | sub _have_async_interrupt() { |
|
|
1412 | $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} |
|
|
1413 | && eval "use Async::Interrupt 1.02 (); 1") |
|
|
1414 | unless defined $HAVE_ASYNC_INTERRUPT; |
|
|
1415 | |
|
|
1416 | $HAVE_ASYNC_INTERRUPT |
|
|
1417 | } |
|
|
1418 | |
|
|
1419 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1420 | our (%SIG_ASY, %SIG_ASY_W); |
|
|
1421 | our ($SIG_COUNT, $SIG_TW); |
|
|
1422 | |
|
|
1423 | sub _signal_exec { |
|
|
1424 | $HAVE_ASYNC_INTERRUPT |
|
|
1425 | ? $SIGPIPE_R->drain |
|
|
1426 | : sysread $SIGPIPE_R, (my $dummy), 9; |
|
|
1427 | |
|
|
1428 | while (%SIG_EV) { |
|
|
1429 | for (keys %SIG_EV) { |
|
|
1430 | delete $SIG_EV{$_}; |
|
|
1431 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1432 | } |
|
|
1433 | } |
|
|
1434 | } |
|
|
1435 | |
|
|
1436 | # install a dummy wakeup watcher to reduce signal catching latency |
|
|
1437 | sub _sig_add() { |
|
|
1438 | unless ($SIG_COUNT++) { |
|
|
1439 | # try to align timer on a full-second boundary, if possible |
|
|
1440 | my $NOW = AE::now; |
|
|
1441 | |
|
|
1442 | $SIG_TW = AE::timer |
|
|
1443 | $MAX_SIGNAL_LATENCY - ($NOW - int $NOW), |
|
|
1444 | $MAX_SIGNAL_LATENCY, |
|
|
1445 | sub { } # just for the PERL_ASYNC_CHECK |
|
|
1446 | ; |
|
|
1447 | } |
|
|
1448 | } |
|
|
1449 | |
|
|
1450 | sub _sig_del { |
|
|
1451 | undef $SIG_TW |
|
|
1452 | unless --$SIG_COUNT; |
|
|
1453 | } |
|
|
1454 | |
|
|
1455 | our $_sig_name_init; $_sig_name_init = sub { |
|
|
1456 | eval q{ # poor man's autoloading |
|
|
1457 | undef $_sig_name_init; |
|
|
1458 | |
|
|
1459 | if (_have_async_interrupt) { |
|
|
1460 | *sig2num = \&Async::Interrupt::sig2num; |
|
|
1461 | *sig2name = \&Async::Interrupt::sig2name; |
|
|
1462 | } else { |
|
|
1463 | require Config; |
|
|
1464 | |
|
|
1465 | my %signame2num; |
|
|
1466 | @signame2num{ split ' ', $Config::Config{sig_name} } |
|
|
1467 | = split ' ', $Config::Config{sig_num}; |
|
|
1468 | |
|
|
1469 | my @signum2name; |
|
|
1470 | @signum2name[values %signame2num] = keys %signame2num; |
|
|
1471 | |
|
|
1472 | *sig2num = sub($) { |
|
|
1473 | $_[0] > 0 ? shift : $signame2num{+shift} |
|
|
1474 | }; |
|
|
1475 | *sig2name = sub ($) { |
|
|
1476 | $_[0] > 0 ? $signum2name[+shift] : shift |
|
|
1477 | }; |
|
|
1478 | } |
|
|
1479 | }; |
|
|
1480 | die if $@; |
|
|
1481 | }; |
|
|
1482 | |
|
|
1483 | sub sig2num ($) { &$_sig_name_init; &sig2num } |
|
|
1484 | sub sig2name($) { &$_sig_name_init; &sig2name } |
1007 | |
1485 | |
1008 | sub signal { |
1486 | sub signal { |
|
|
1487 | eval q{ # poor man's autoloading {} |
|
|
1488 | # probe for availability of Async::Interrupt |
|
|
1489 | if (_have_async_interrupt) { |
|
|
1490 | warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8; |
|
|
1491 | |
|
|
1492 | $SIGPIPE_R = new Async::Interrupt::EventPipe; |
|
|
1493 | $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec; |
|
|
1494 | |
|
|
1495 | } else { |
|
|
1496 | warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; |
|
|
1497 | |
|
|
1498 | require Fcntl; |
|
|
1499 | |
|
|
1500 | if (AnyEvent::WIN32) { |
|
|
1501 | require AnyEvent::Util; |
|
|
1502 | |
|
|
1503 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1504 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R; |
|
|
1505 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case |
|
|
1506 | } else { |
|
|
1507 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1508 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1509 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1510 | |
|
|
1511 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1512 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1513 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1514 | } |
|
|
1515 | |
|
|
1516 | $SIGPIPE_R |
|
|
1517 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1518 | |
|
|
1519 | $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec; |
|
|
1520 | } |
|
|
1521 | |
|
|
1522 | *signal = sub { |
1009 | my (undef, %arg) = @_; |
1523 | my (undef, %arg) = @_; |
1010 | |
1524 | |
1011 | my $signal = uc $arg{signal} |
1525 | my $signal = uc $arg{signal} |
1012 | or Carp::croak "required option 'signal' is missing"; |
1526 | or Carp::croak "required option 'signal' is missing"; |
1013 | |
1527 | |
|
|
1528 | if ($HAVE_ASYNC_INTERRUPT) { |
|
|
1529 | # async::interrupt |
|
|
1530 | |
|
|
1531 | $signal = sig2num $signal; |
1014 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1532 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
1533 | |
|
|
1534 | $SIG_ASY{$signal} ||= new Async::Interrupt |
|
|
1535 | cb => sub { undef $SIG_EV{$signal} }, |
|
|
1536 | signal => $signal, |
|
|
1537 | pipe => [$SIGPIPE_R->filenos], |
|
|
1538 | pipe_autodrain => 0, |
|
|
1539 | ; |
|
|
1540 | |
|
|
1541 | } else { |
|
|
1542 | # pure perl |
|
|
1543 | |
|
|
1544 | # AE::Util has been loaded in signal |
|
|
1545 | $signal = sig2name $signal; |
|
|
1546 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
1547 | |
1015 | $SIG{$signal} ||= sub { |
1548 | $SIG{$signal} ||= sub { |
1016 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1549 | local $!; |
|
|
1550 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1551 | undef $SIG_EV{$signal}; |
|
|
1552 | }; |
|
|
1553 | |
|
|
1554 | # can't do signal processing without introducing races in pure perl, |
|
|
1555 | # so limit the signal latency. |
|
|
1556 | _sig_add; |
|
|
1557 | } |
|
|
1558 | |
|
|
1559 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
|
|
1560 | }; |
|
|
1561 | |
|
|
1562 | *AnyEvent::Base::signal::DESTROY = sub { |
|
|
1563 | my ($signal, $cb) = @{$_[0]}; |
|
|
1564 | |
|
|
1565 | _sig_del; |
|
|
1566 | |
|
|
1567 | delete $SIG_CB{$signal}{$cb}; |
|
|
1568 | |
|
|
1569 | $HAVE_ASYNC_INTERRUPT |
|
|
1570 | ? delete $SIG_ASY{$signal} |
|
|
1571 | : # delete doesn't work with older perls - they then |
|
|
1572 | # print weird messages, or just unconditionally exit |
|
|
1573 | # instead of getting the default action. |
|
|
1574 | undef $SIG{$signal} |
|
|
1575 | unless keys %{ $SIG_CB{$signal} }; |
|
|
1576 | }; |
1017 | }; |
1577 | }; |
1018 | |
1578 | die if $@; |
1019 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1579 | &signal |
1020 | } |
|
|
1021 | |
|
|
1022 | sub AnyEvent::Base::Signal::DESTROY { |
|
|
1023 | my ($signal, $cb) = @{$_[0]}; |
|
|
1024 | |
|
|
1025 | delete $SIG_CB{$signal}{$cb}; |
|
|
1026 | |
|
|
1027 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
|
|
1028 | } |
1580 | } |
1029 | |
1581 | |
1030 | # default implementation for ->child |
1582 | # default implementation for ->child |
1031 | |
1583 | |
1032 | our %PID_CB; |
1584 | our %PID_CB; |
1033 | our $CHLD_W; |
1585 | our $CHLD_W; |
1034 | our $CHLD_DELAY_W; |
1586 | our $CHLD_DELAY_W; |
1035 | our $PID_IDLE; |
|
|
1036 | our $WNOHANG; |
1587 | our $WNOHANG; |
1037 | |
1588 | |
1038 | sub _child_wait { |
1589 | sub _emit_childstatus($$) { |
1039 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1590 | my (undef, $rpid, $rstatus) = @_; |
|
|
1591 | |
|
|
1592 | $_->($rpid, $rstatus) |
1040 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1593 | for values %{ $PID_CB{$rpid} || {} }, |
1041 | (values %{ $PID_CB{0} || {} }); |
1594 | values %{ $PID_CB{0} || {} }; |
1042 | } |
|
|
1043 | |
|
|
1044 | undef $PID_IDLE; |
|
|
1045 | } |
1595 | } |
1046 | |
1596 | |
1047 | sub _sigchld { |
1597 | sub _sigchld { |
1048 | # make sure we deliver these changes "synchronous" with the event loop. |
1598 | my $pid; |
1049 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
1599 | |
1050 | undef $CHLD_DELAY_W; |
1600 | AnyEvent->_emit_childstatus ($pid, $?) |
1051 | &_child_wait; |
1601 | while ($pid = waitpid -1, $WNOHANG) > 0; |
1052 | }); |
|
|
1053 | } |
1602 | } |
1054 | |
1603 | |
1055 | sub child { |
1604 | sub child { |
1056 | my (undef, %arg) = @_; |
1605 | my (undef, %arg) = @_; |
1057 | |
1606 | |
1058 | defined (my $pid = $arg{pid} + 0) |
1607 | defined (my $pid = $arg{pid} + 0) |
1059 | or Carp::croak "required option 'pid' is missing"; |
1608 | or Carp::croak "required option 'pid' is missing"; |
1060 | |
1609 | |
1061 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1610 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1062 | |
1611 | |
1063 | unless ($WNOHANG) { |
1612 | # WNOHANG is almost cetrainly 1 everywhere |
|
|
1613 | $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ |
|
|
1614 | ? 1 |
1064 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1615 | : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1065 | } |
|
|
1066 | |
1616 | |
1067 | unless ($CHLD_W) { |
1617 | unless ($CHLD_W) { |
1068 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1618 | $CHLD_W = AE::signal CHLD => \&_sigchld; |
1069 | # child could be a zombie already, so make at least one round |
1619 | # child could be a zombie already, so make at least one round |
1070 | &_sigchld; |
1620 | &_sigchld; |
1071 | } |
1621 | } |
1072 | |
1622 | |
1073 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1623 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
1074 | } |
1624 | } |
1075 | |
1625 | |
1076 | sub AnyEvent::Base::Child::DESTROY { |
1626 | sub AnyEvent::Base::child::DESTROY { |
1077 | my ($pid, $cb) = @{$_[0]}; |
1627 | my ($pid, $cb) = @{$_[0]}; |
1078 | |
1628 | |
1079 | delete $PID_CB{$pid}{$cb}; |
1629 | delete $PID_CB{$pid}{$cb}; |
1080 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1630 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1081 | |
1631 | |
1082 | undef $CHLD_W unless keys %PID_CB; |
1632 | undef $CHLD_W unless keys %PID_CB; |
1083 | } |
1633 | } |
1084 | |
1634 | |
|
|
1635 | # idle emulation is done by simply using a timer, regardless |
|
|
1636 | # of whether the process is idle or not, and not letting |
|
|
1637 | # the callback use more than 50% of the time. |
|
|
1638 | sub idle { |
|
|
1639 | my (undef, %arg) = @_; |
|
|
1640 | |
|
|
1641 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1642 | |
|
|
1643 | $rcb = sub { |
|
|
1644 | if ($cb) { |
|
|
1645 | $w = _time; |
|
|
1646 | &$cb; |
|
|
1647 | $w = _time - $w; |
|
|
1648 | |
|
|
1649 | # never use more then 50% of the time for the idle watcher, |
|
|
1650 | # within some limits |
|
|
1651 | $w = 0.0001 if $w < 0.0001; |
|
|
1652 | $w = 5 if $w > 5; |
|
|
1653 | |
|
|
1654 | $w = AE::timer $w, 0, $rcb; |
|
|
1655 | } else { |
|
|
1656 | # clean up... |
|
|
1657 | undef $w; |
|
|
1658 | undef $rcb; |
|
|
1659 | } |
|
|
1660 | }; |
|
|
1661 | |
|
|
1662 | $w = AE::timer 0.05, 0, $rcb; |
|
|
1663 | |
|
|
1664 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1665 | } |
|
|
1666 | |
|
|
1667 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1668 | undef $${$_[0]}; |
|
|
1669 | } |
|
|
1670 | |
1085 | package AnyEvent::CondVar; |
1671 | package AnyEvent::CondVar; |
1086 | |
1672 | |
1087 | our @ISA = AnyEvent::CondVar::Base::; |
1673 | our @ISA = AnyEvent::CondVar::Base::; |
1088 | |
1674 | |
1089 | package AnyEvent::CondVar::Base; |
1675 | package AnyEvent::CondVar::Base; |
1090 | |
1676 | |
1091 | use overload |
1677 | #use overload |
1092 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
1678 | # '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
1093 | fallback => 1; |
1679 | # fallback => 1; |
|
|
1680 | |
|
|
1681 | # save 300+ kilobytes by dirtily hardcoding overloading |
|
|
1682 | ${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching. |
|
|
1683 | *{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod." |
|
|
1684 | *{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{} |
|
|
1685 | ${'AnyEvent::CondVar::Base::()'} = 1; # fallback |
|
|
1686 | |
|
|
1687 | our $WAITING; |
1094 | |
1688 | |
1095 | sub _send { |
1689 | sub _send { |
1096 | # nop |
1690 | # nop |
1097 | } |
1691 | } |
1098 | |
1692 | |
… | |
… | |
1111 | sub ready { |
1705 | sub ready { |
1112 | $_[0]{_ae_sent} |
1706 | $_[0]{_ae_sent} |
1113 | } |
1707 | } |
1114 | |
1708 | |
1115 | sub _wait { |
1709 | sub _wait { |
|
|
1710 | $WAITING |
|
|
1711 | and !$_[0]{_ae_sent} |
|
|
1712 | and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected"; |
|
|
1713 | |
|
|
1714 | local $WAITING = 1; |
1116 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
1715 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
1117 | } |
1716 | } |
1118 | |
1717 | |
1119 | sub recv { |
1718 | sub recv { |
1120 | $_[0]->_wait; |
1719 | $_[0]->_wait; |
… | |
… | |
1122 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
1721 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
1123 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
1722 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
1124 | } |
1723 | } |
1125 | |
1724 | |
1126 | sub cb { |
1725 | sub cb { |
1127 | $_[0]{_ae_cb} = $_[1] if @_ > 1; |
1726 | my $cv = shift; |
|
|
1727 | |
|
|
1728 | @_ |
|
|
1729 | and $cv->{_ae_cb} = shift |
|
|
1730 | and $cv->{_ae_sent} |
|
|
1731 | and (delete $cv->{_ae_cb})->($cv); |
|
|
1732 | |
1128 | $_[0]{_ae_cb} |
1733 | $cv->{_ae_cb} |
1129 | } |
1734 | } |
1130 | |
1735 | |
1131 | sub begin { |
1736 | sub begin { |
1132 | ++$_[0]{_ae_counter}; |
1737 | ++$_[0]{_ae_counter}; |
1133 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
1738 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
… | |
… | |
1139 | } |
1744 | } |
1140 | |
1745 | |
1141 | # undocumented/compatibility with pre-3.4 |
1746 | # undocumented/compatibility with pre-3.4 |
1142 | *broadcast = \&send; |
1747 | *broadcast = \&send; |
1143 | *wait = \&_wait; |
1748 | *wait = \&_wait; |
|
|
1749 | |
|
|
1750 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1751 | |
|
|
1752 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1753 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1754 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1755 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1756 | development. |
|
|
1757 | |
|
|
1758 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1759 | executing a callback), this is not only highly event-loop specific, but |
|
|
1760 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1761 | program. |
|
|
1762 | |
|
|
1763 | The pure perl event loop simply re-throws the exception (usually |
|
|
1764 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1765 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1766 | so on. |
|
|
1767 | |
|
|
1768 | =head1 ENVIRONMENT VARIABLES |
|
|
1769 | |
|
|
1770 | The following environment variables are used by this module or its |
|
|
1771 | submodules. |
|
|
1772 | |
|
|
1773 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1774 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1775 | enabled. |
|
|
1776 | |
|
|
1777 | =over 4 |
|
|
1778 | |
|
|
1779 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1780 | |
|
|
1781 | By default, AnyEvent will be completely silent except in fatal |
|
|
1782 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1783 | talkative. |
|
|
1784 | |
|
|
1785 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1786 | conditions, such as not being able to load the event model specified by |
|
|
1787 | C<PERL_ANYEVENT_MODEL>. |
|
|
1788 | |
|
|
1789 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1790 | model it chooses. |
|
|
1791 | |
|
|
1792 | When set to C<8> or higher, then AnyEvent will report extra information on |
|
|
1793 | which optional modules it loads and how it implements certain features. |
|
|
1794 | |
|
|
1795 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1796 | |
|
|
1797 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1798 | argument checking is very costly. Setting this variable to a true value |
|
|
1799 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1800 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1801 | it will croak. |
|
|
1802 | |
|
|
1803 | In other words, enables "strict" mode. |
|
|
1804 | |
|
|
1805 | Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> |
|
|
1806 | >>, it is definitely recommended to keep it off in production. Keeping |
|
|
1807 | C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs |
|
|
1808 | can be very useful, however. |
|
|
1809 | |
|
|
1810 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1811 | |
|
|
1812 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1813 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1814 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1815 | and the resulting module name is loaded and if the load was successful, |
|
|
1816 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1817 | auto detection and -probing. |
|
|
1818 | |
|
|
1819 | This functionality might change in future versions. |
|
|
1820 | |
|
|
1821 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1822 | could start your program like this: |
|
|
1823 | |
|
|
1824 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1825 | |
|
|
1826 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1827 | |
|
|
1828 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1829 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1830 | of auto probing). |
|
|
1831 | |
|
|
1832 | Must be set to a comma-separated list of protocols or address families, |
|
|
1833 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1834 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1835 | list. |
|
|
1836 | |
|
|
1837 | This variable can effectively be used for denial-of-service attacks |
|
|
1838 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1839 | small, as the program has to handle conenction and other failures anyways. |
|
|
1840 | |
|
|
1841 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1842 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1843 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1844 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1845 | IPv6, but prefer IPv6 over IPv4. |
|
|
1846 | |
|
|
1847 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1848 | |
|
|
1849 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1850 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1851 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1852 | default. |
|
|
1853 | |
|
|
1854 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1855 | EDNS0 in its DNS requests. |
|
|
1856 | |
|
|
1857 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1858 | |
|
|
1859 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1860 | will create in parallel. |
|
|
1861 | |
|
|
1862 | =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> |
|
|
1863 | |
|
|
1864 | The default value for the C<max_outstanding> parameter for the default DNS |
|
|
1865 | resolver - this is the maximum number of parallel DNS requests that are |
|
|
1866 | sent to the DNS server. |
|
|
1867 | |
|
|
1868 | =item C<PERL_ANYEVENT_RESOLV_CONF> |
|
|
1869 | |
|
|
1870 | The file to use instead of F</etc/resolv.conf> (or OS-specific |
|
|
1871 | configuration) in the default resolver. When set to the empty string, no |
|
|
1872 | default config will be used. |
|
|
1873 | |
|
|
1874 | =item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. |
|
|
1875 | |
|
|
1876 | When neither C<ca_file> nor C<ca_path> was specified during |
|
|
1877 | L<AnyEvent::TLS> context creation, and either of these environment |
|
|
1878 | variables exist, they will be used to specify CA certificate locations |
|
|
1879 | instead of a system-dependent default. |
|
|
1880 | |
|
|
1881 | =item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT> |
|
|
1882 | |
|
|
1883 | When these are set to C<1>, then the respective modules are not |
|
|
1884 | loaded. Mostly good for testing AnyEvent itself. |
|
|
1885 | |
|
|
1886 | =back |
1144 | |
1887 | |
1145 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1888 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1146 | |
1889 | |
1147 | This is an advanced topic that you do not normally need to use AnyEvent in |
1890 | This is an advanced topic that you do not normally need to use AnyEvent in |
1148 | a module. This section is only of use to event loop authors who want to |
1891 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1182 | |
1925 | |
1183 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1926 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1184 | condition variables: code blocking while waiting for a condition will |
1927 | condition variables: code blocking while waiting for a condition will |
1185 | C<die>. This still works with most modules/usages, and blocking calls must |
1928 | C<die>. This still works with most modules/usages, and blocking calls must |
1186 | not be done in an interactive application, so it makes sense. |
1929 | not be done in an interactive application, so it makes sense. |
1187 | |
|
|
1188 | =head1 ENVIRONMENT VARIABLES |
|
|
1189 | |
|
|
1190 | The following environment variables are used by this module: |
|
|
1191 | |
|
|
1192 | =over 4 |
|
|
1193 | |
|
|
1194 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1195 | |
|
|
1196 | By default, AnyEvent will be completely silent except in fatal |
|
|
1197 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1198 | talkative. |
|
|
1199 | |
|
|
1200 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1201 | conditions, such as not being able to load the event model specified by |
|
|
1202 | C<PERL_ANYEVENT_MODEL>. |
|
|
1203 | |
|
|
1204 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1205 | model it chooses. |
|
|
1206 | |
|
|
1207 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1208 | |
|
|
1209 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1210 | argument checking is very costly. Setting this variable to a true value |
|
|
1211 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1212 | check the arguments passed to most method calls. If it finds any problems |
|
|
1213 | it will croak. |
|
|
1214 | |
|
|
1215 | In other words, enables "strict" mode. |
|
|
1216 | |
|
|
1217 | Unlike C<use strict> it is definitely recommended ot keep it off in |
|
|
1218 | production. |
|
|
1219 | |
|
|
1220 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1221 | |
|
|
1222 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1223 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1224 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1225 | and the resulting module name is loaded and if the load was successful, |
|
|
1226 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1227 | auto detection and -probing. |
|
|
1228 | |
|
|
1229 | This functionality might change in future versions. |
|
|
1230 | |
|
|
1231 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1232 | could start your program like this: |
|
|
1233 | |
|
|
1234 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1235 | |
|
|
1236 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1237 | |
|
|
1238 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1239 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1240 | of auto probing). |
|
|
1241 | |
|
|
1242 | Must be set to a comma-separated list of protocols or address families, |
|
|
1243 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1244 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1245 | list. |
|
|
1246 | |
|
|
1247 | This variable can effectively be used for denial-of-service attacks |
|
|
1248 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1249 | small, as the program has to handle connection errors already- |
|
|
1250 | |
|
|
1251 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1252 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1253 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1254 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1255 | IPv6, but prefer IPv6 over IPv4. |
|
|
1256 | |
|
|
1257 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1258 | |
|
|
1259 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1260 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1261 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1262 | default. |
|
|
1263 | |
|
|
1264 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1265 | EDNS0 in its DNS requests. |
|
|
1266 | |
|
|
1267 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1268 | |
|
|
1269 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1270 | will create in parallel. |
|
|
1271 | |
|
|
1272 | =back |
|
|
1273 | |
1930 | |
1274 | =head1 EXAMPLE PROGRAM |
1931 | =head1 EXAMPLE PROGRAM |
1275 | |
1932 | |
1276 | The following program uses an I/O watcher to read data from STDIN, a timer |
1933 | The following program uses an I/O watcher to read data from STDIN, a timer |
1277 | to display a message once per second, and a condition variable to quit the |
1934 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1290 | warn "read: $input\n"; # output what has been read |
1947 | warn "read: $input\n"; # output what has been read |
1291 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
1948 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
1292 | }, |
1949 | }, |
1293 | ); |
1950 | ); |
1294 | |
1951 | |
1295 | my $time_watcher; # can only be used once |
|
|
1296 | |
|
|
1297 | sub new_timer { |
|
|
1298 | $timer = AnyEvent->timer (after => 1, cb => sub { |
1952 | my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub { |
1299 | warn "timeout\n"; # print 'timeout' about every second |
1953 | warn "timeout\n"; # print 'timeout' at most every second |
1300 | &new_timer; # and restart the time |
|
|
1301 | }); |
1954 | }); |
1302 | } |
|
|
1303 | |
|
|
1304 | new_timer; # create first timer |
|
|
1305 | |
1955 | |
1306 | $cv->recv; # wait until user enters /^q/i |
1956 | $cv->recv; # wait until user enters /^q/i |
1307 | |
1957 | |
1308 | =head1 REAL-WORLD EXAMPLE |
1958 | =head1 REAL-WORLD EXAMPLE |
1309 | |
1959 | |
… | |
… | |
1440 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
2090 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1441 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
2091 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1442 | which it is), lets them fire exactly once and destroys them again. |
2092 | which it is), lets them fire exactly once and destroys them again. |
1443 | |
2093 | |
1444 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
2094 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1445 | distribution. |
2095 | distribution. It uses the L<AE> interface, which makes a real difference |
|
|
2096 | for the EV and Perl backends only. |
1446 | |
2097 | |
1447 | =head3 Explanation of the columns |
2098 | =head3 Explanation of the columns |
1448 | |
2099 | |
1449 | I<watcher> is the number of event watchers created/destroyed. Since |
2100 | I<watcher> is the number of event watchers created/destroyed. Since |
1450 | different event models feature vastly different performances, each event |
2101 | different event models feature vastly different performances, each event |
… | |
… | |
1471 | watcher. |
2122 | watcher. |
1472 | |
2123 | |
1473 | =head3 Results |
2124 | =head3 Results |
1474 | |
2125 | |
1475 | name watchers bytes create invoke destroy comment |
2126 | name watchers bytes create invoke destroy comment |
1476 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
2127 | EV/EV 100000 223 0.47 0.43 0.27 EV native interface |
1477 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
2128 | EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers |
1478 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
2129 | Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal |
1479 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
2130 | Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation |
1480 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
2131 | Event/Event 16000 516 31.16 31.84 0.82 Event native interface |
1481 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
2132 | Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers |
|
|
2133 | IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll |
|
|
2134 | IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll |
1482 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
2135 | Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour |
1483 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
2136 | Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers |
1484 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
2137 | POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event |
1485 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
2138 | POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select |
1486 | |
2139 | |
1487 | =head3 Discussion |
2140 | =head3 Discussion |
1488 | |
2141 | |
1489 | The benchmark does I<not> measure scalability of the event loop very |
2142 | The benchmark does I<not> measure scalability of the event loop very |
1490 | well. For example, a select-based event loop (such as the pure perl one) |
2143 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1502 | benchmark machine, handling an event takes roughly 1600 CPU cycles with |
2155 | benchmark machine, handling an event takes roughly 1600 CPU cycles with |
1503 | EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU |
2156 | EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU |
1504 | cycles with POE. |
2157 | cycles with POE. |
1505 | |
2158 | |
1506 | C<EV> is the sole leader regarding speed and memory use, which are both |
2159 | C<EV> is the sole leader regarding speed and memory use, which are both |
1507 | maximal/minimal, respectively. Even when going through AnyEvent, it uses |
2160 | maximal/minimal, respectively. When using the L<AE> API there is zero |
|
|
2161 | overhead (when going through the AnyEvent API create is about 5-6 times |
|
|
2162 | slower, with other times being equal, so still uses far less memory than |
1508 | far less memory than any other event loop and is still faster than Event |
2163 | any other event loop and is still faster than Event natively). |
1509 | natively. |
|
|
1510 | |
2164 | |
1511 | The pure perl implementation is hit in a few sweet spots (both the |
2165 | The pure perl implementation is hit in a few sweet spots (both the |
1512 | constant timeout and the use of a single fd hit optimisations in the perl |
2166 | constant timeout and the use of a single fd hit optimisations in the perl |
1513 | interpreter and the backend itself). Nevertheless this shows that it |
2167 | interpreter and the backend itself). Nevertheless this shows that it |
1514 | adds very little overhead in itself. Like any select-based backend its |
2168 | adds very little overhead in itself. Like any select-based backend its |
1515 | performance becomes really bad with lots of file descriptors (and few of |
2169 | performance becomes really bad with lots of file descriptors (and few of |
1516 | them active), of course, but this was not subject of this benchmark. |
2170 | them active), of course, but this was not subject of this benchmark. |
1517 | |
2171 | |
1518 | The C<Event> module has a relatively high setup and callback invocation |
2172 | The C<Event> module has a relatively high setup and callback invocation |
1519 | cost, but overall scores in on the third place. |
2173 | cost, but overall scores in on the third place. |
|
|
2174 | |
|
|
2175 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
2176 | when using its pure perl backend. |
1520 | |
2177 | |
1521 | C<Glib>'s memory usage is quite a bit higher, but it features a |
2178 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1522 | faster callback invocation and overall ends up in the same class as |
2179 | faster callback invocation and overall ends up in the same class as |
1523 | C<Event>. However, Glib scales extremely badly, doubling the number of |
2180 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1524 | watchers increases the processing time by more than a factor of four, |
2181 | watchers increases the processing time by more than a factor of four, |
… | |
… | |
1585 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
2242 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1586 | (1%) are active. This mirrors the activity of large servers with many |
2243 | (1%) are active. This mirrors the activity of large servers with many |
1587 | connections, most of which are idle at any one point in time. |
2244 | connections, most of which are idle at any one point in time. |
1588 | |
2245 | |
1589 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
2246 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1590 | distribution. |
2247 | distribution. It uses the L<AE> interface, which makes a real difference |
|
|
2248 | for the EV and Perl backends only. |
1591 | |
2249 | |
1592 | =head3 Explanation of the columns |
2250 | =head3 Explanation of the columns |
1593 | |
2251 | |
1594 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
2252 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1595 | each server has a read and write socket end). |
2253 | each server has a read and write socket end). |
… | |
… | |
1602 | it to another server. This includes deleting the old timeout and creating |
2260 | it to another server. This includes deleting the old timeout and creating |
1603 | a new one that moves the timeout into the future. |
2261 | a new one that moves the timeout into the future. |
1604 | |
2262 | |
1605 | =head3 Results |
2263 | =head3 Results |
1606 | |
2264 | |
1607 | name sockets create request |
2265 | name sockets create request |
1608 | EV 20000 69.01 11.16 |
2266 | EV 20000 62.66 7.99 |
1609 | Perl 20000 73.32 35.87 |
2267 | Perl 20000 68.32 32.64 |
1610 | Event 20000 212.62 257.32 |
2268 | IOAsync 20000 174.06 101.15 epoll |
1611 | Glib 20000 651.16 1896.30 |
2269 | IOAsync 20000 174.67 610.84 poll |
|
|
2270 | Event 20000 202.69 242.91 |
|
|
2271 | Glib 20000 557.01 1689.52 |
1612 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
2272 | POE 20000 341.54 12086.32 uses POE::Loop::Event |
1613 | |
2273 | |
1614 | =head3 Discussion |
2274 | =head3 Discussion |
1615 | |
2275 | |
1616 | This benchmark I<does> measure scalability and overall performance of the |
2276 | This benchmark I<does> measure scalability and overall performance of the |
1617 | particular event loop. |
2277 | particular event loop. |
… | |
… | |
1619 | EV is again fastest. Since it is using epoll on my system, the setup time |
2279 | EV is again fastest. Since it is using epoll on my system, the setup time |
1620 | is relatively high, though. |
2280 | is relatively high, though. |
1621 | |
2281 | |
1622 | Perl surprisingly comes second. It is much faster than the C-based event |
2282 | Perl surprisingly comes second. It is much faster than the C-based event |
1623 | loops Event and Glib. |
2283 | loops Event and Glib. |
|
|
2284 | |
|
|
2285 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
2286 | good compared to Glib when using its pure perl backend. |
1624 | |
2287 | |
1625 | Event suffers from high setup time as well (look at its code and you will |
2288 | Event suffers from high setup time as well (look at its code and you will |
1626 | understand why). Callback invocation also has a high overhead compared to |
2289 | understand why). Callback invocation also has a high overhead compared to |
1627 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
2290 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1628 | uses select or poll in basically all documented configurations. |
2291 | uses select or poll in basically all documented configurations. |
… | |
… | |
1691 | =item * C-based event loops perform very well with small number of |
2354 | =item * C-based event loops perform very well with small number of |
1692 | watchers, as the management overhead dominates. |
2355 | watchers, as the management overhead dominates. |
1693 | |
2356 | |
1694 | =back |
2357 | =back |
1695 | |
2358 | |
|
|
2359 | =head2 THE IO::Lambda BENCHMARK |
|
|
2360 | |
|
|
2361 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
2362 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
2363 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
2364 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
2365 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
2366 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
2367 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
2368 | |
|
|
2369 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
2370 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
2371 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
2372 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
2373 | benchmark nevertheless. |
|
|
2374 | |
|
|
2375 | name runtime |
|
|
2376 | Lambda/select 0.330 sec |
|
|
2377 | + optimized 0.122 sec |
|
|
2378 | Lambda/AnyEvent 0.327 sec |
|
|
2379 | + optimized 0.138 sec |
|
|
2380 | Raw sockets/select 0.077 sec |
|
|
2381 | POE/select, components 0.662 sec |
|
|
2382 | POE/select, raw sockets 0.226 sec |
|
|
2383 | POE/select, optimized 0.404 sec |
|
|
2384 | |
|
|
2385 | AnyEvent/select/nb 0.085 sec |
|
|
2386 | AnyEvent/EV/nb 0.068 sec |
|
|
2387 | +state machine 0.134 sec |
|
|
2388 | |
|
|
2389 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
2390 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
2391 | defeating the purpose of an event-based solution. All of the newly |
|
|
2392 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
2393 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
2394 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
2395 | generally require a lot more bookkeeping and event handling than blocking |
|
|
2396 | connects (which involve a single syscall only). |
|
|
2397 | |
|
|
2398 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
2399 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
2400 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
2401 | non-blocking, further placing it at a disadvantage. |
|
|
2402 | |
|
|
2403 | As you can see, the AnyEvent + EV combination even beats the |
|
|
2404 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
2405 | backend easily beats IO::Lambda and POE. |
|
|
2406 | |
|
|
2407 | And even the 100% non-blocking version written using the high-level (and |
|
|
2408 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda |
|
|
2409 | higher level ("unoptimised") abstractions by a large margin, even though |
|
|
2410 | it does all of DNS, tcp-connect and socket I/O in a non-blocking way. |
|
|
2411 | |
|
|
2412 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2413 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2414 | part of the IO::Lambda distribution and were used without any changes. |
|
|
2415 | |
|
|
2416 | |
|
|
2417 | =head1 SIGNALS |
|
|
2418 | |
|
|
2419 | AnyEvent currently installs handlers for these signals: |
|
|
2420 | |
|
|
2421 | =over 4 |
|
|
2422 | |
|
|
2423 | =item SIGCHLD |
|
|
2424 | |
|
|
2425 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2426 | emulation for event loops that do not support them natively. Also, some |
|
|
2427 | event loops install a similar handler. |
|
|
2428 | |
|
|
2429 | Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then |
|
|
2430 | AnyEvent will reset it to default, to avoid losing child exit statuses. |
|
|
2431 | |
|
|
2432 | =item SIGPIPE |
|
|
2433 | |
|
|
2434 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2435 | when AnyEvent gets loaded. |
|
|
2436 | |
|
|
2437 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2438 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2439 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2440 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2441 | some random socket. |
|
|
2442 | |
|
|
2443 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2444 | that this way, the handler will be restored to defaults on exec. |
|
|
2445 | |
|
|
2446 | Feel free to install your own handler, or reset it to defaults. |
|
|
2447 | |
|
|
2448 | =back |
|
|
2449 | |
|
|
2450 | =cut |
|
|
2451 | |
|
|
2452 | undef $SIG{CHLD} |
|
|
2453 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2454 | |
|
|
2455 | $SIG{PIPE} = sub { } |
|
|
2456 | unless defined $SIG{PIPE}; |
|
|
2457 | |
|
|
2458 | =head1 RECOMMENDED/OPTIONAL MODULES |
|
|
2459 | |
|
|
2460 | One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and |
|
|
2461 | it's built-in modules) are required to use it. |
|
|
2462 | |
|
|
2463 | That does not mean that AnyEvent won't take advantage of some additional |
|
|
2464 | modules if they are installed. |
|
|
2465 | |
|
|
2466 | This section explains which additional modules will be used, and how they |
|
|
2467 | affect AnyEvent's operation. |
|
|
2468 | |
|
|
2469 | =over 4 |
|
|
2470 | |
|
|
2471 | =item L<Async::Interrupt> |
|
|
2472 | |
|
|
2473 | This slightly arcane module is used to implement fast signal handling: To |
|
|
2474 | my knowledge, there is no way to do completely race-free and quick |
|
|
2475 | signal handling in pure perl. To ensure that signals still get |
|
|
2476 | delivered, AnyEvent will start an interval timer to wake up perl (and |
|
|
2477 | catch the signals) with some delay (default is 10 seconds, look for |
|
|
2478 | C<$AnyEvent::MAX_SIGNAL_LATENCY>). |
|
|
2479 | |
|
|
2480 | If this module is available, then it will be used to implement signal |
|
|
2481 | catching, which means that signals will not be delayed, and the event loop |
|
|
2482 | will not be interrupted regularly, which is more efficient (and good for |
|
|
2483 | battery life on laptops). |
|
|
2484 | |
|
|
2485 | This affects not just the pure-perl event loop, but also other event loops |
|
|
2486 | that have no signal handling on their own (e.g. Glib, Tk, Qt). |
|
|
2487 | |
|
|
2488 | Some event loops (POE, Event, Event::Lib) offer signal watchers natively, |
|
|
2489 | and either employ their own workarounds (POE) or use AnyEvent's workaround |
|
|
2490 | (using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt> |
|
|
2491 | does nothing for those backends. |
|
|
2492 | |
|
|
2493 | =item L<EV> |
|
|
2494 | |
|
|
2495 | This module isn't really "optional", as it is simply one of the backend |
|
|
2496 | event loops that AnyEvent can use. However, it is simply the best event |
|
|
2497 | loop available in terms of features, speed and stability: It supports |
|
|
2498 | the AnyEvent API optimally, implements all the watcher types in XS, does |
|
|
2499 | automatic timer adjustments even when no monotonic clock is available, |
|
|
2500 | can take avdantage of advanced kernel interfaces such as C<epoll> and |
|
|
2501 | C<kqueue>, and is the fastest backend I<by far>. You can even embed |
|
|
2502 | L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). |
|
|
2503 | |
|
|
2504 | =item L<Guard> |
|
|
2505 | |
|
|
2506 | The guard module, when used, will be used to implement |
|
|
2507 | C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a |
|
|
2508 | lot less memory), but otherwise doesn't affect guard operation much. It is |
|
|
2509 | purely used for performance. |
|
|
2510 | |
|
|
2511 | =item L<JSON> and L<JSON::XS> |
|
|
2512 | |
|
|
2513 | One of these modules is required when you want to read or write JSON data |
|
|
2514 | via L<AnyEvent::Handle>. It is also written in pure-perl, but can take |
|
|
2515 | advantage of the ultra-high-speed L<JSON::XS> module when it is installed. |
|
|
2516 | |
|
|
2517 | In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is |
|
|
2518 | installed. |
|
|
2519 | |
|
|
2520 | =item L<Net::SSLeay> |
|
|
2521 | |
|
|
2522 | Implementing TLS/SSL in Perl is certainly interesting, but not very |
|
|
2523 | worthwhile: If this module is installed, then L<AnyEvent::Handle> (with |
|
|
2524 | the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. |
|
|
2525 | |
|
|
2526 | =item L<Time::HiRes> |
|
|
2527 | |
|
|
2528 | This module is part of perl since release 5.008. It will be used when the |
|
|
2529 | chosen event library does not come with a timing source on it's own. The |
|
|
2530 | pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to |
|
|
2531 | try to use a monotonic clock for timing stability. |
|
|
2532 | |
|
|
2533 | =back |
|
|
2534 | |
1696 | |
2535 | |
1697 | =head1 FORK |
2536 | =head1 FORK |
1698 | |
2537 | |
1699 | Most event libraries are not fork-safe. The ones who are usually are |
2538 | Most event libraries are not fork-safe. The ones who are usually are |
1700 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2539 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1701 | calls. Only L<EV> is fully fork-aware. |
2540 | calls. Only L<EV> is fully fork-aware. |
1702 | |
2541 | |
|
|
2542 | This means that, in general, you cannot fork and do event processing |
|
|
2543 | in the child if a watcher was created before the fork (which in turn |
|
|
2544 | initialises the event library). |
|
|
2545 | |
1703 | If you have to fork, you must either do so I<before> creating your first |
2546 | If you have to fork, you must either do so I<before> creating your first |
1704 | watcher OR you must not use AnyEvent at all in the child. |
2547 | watcher OR you must not use AnyEvent at all in the child OR you must do |
|
|
2548 | something completely out of the scope of AnyEvent. |
|
|
2549 | |
|
|
2550 | The problem of doing event processing in the parent I<and> the child |
|
|
2551 | is much more complicated: even for backends that I<are> fork-aware or |
|
|
2552 | fork-safe, their behaviour is not usually what you want: fork clones all |
|
|
2553 | watchers, that means all timers, I/O watchers etc. are active in both |
|
|
2554 | parent and child, which is almost never what you want. |
1705 | |
2555 | |
1706 | |
2556 | |
1707 | =head1 SECURITY CONSIDERATIONS |
2557 | =head1 SECURITY CONSIDERATIONS |
1708 | |
2558 | |
1709 | AnyEvent can be forced to load any event model via |
2559 | AnyEvent can be forced to load any event model via |
… | |
… | |
1721 | use AnyEvent; |
2571 | use AnyEvent; |
1722 | |
2572 | |
1723 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2573 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1724 | be used to probe what backend is used and gain other information (which is |
2574 | be used to probe what backend is used and gain other information (which is |
1725 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
2575 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
1726 | $ENV{PERL_ANYEGENT_STRICT}. |
2576 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2577 | |
|
|
2578 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2579 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2580 | enabled. |
1727 | |
2581 | |
1728 | |
2582 | |
1729 | =head1 BUGS |
2583 | =head1 BUGS |
1730 | |
2584 | |
1731 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
2585 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
1732 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
2586 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
1733 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
2587 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
1734 | mamleaks, such as leaking on C<map> and C<grep> but it is usually not as |
2588 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1735 | pronounced). |
2589 | pronounced). |
1736 | |
2590 | |
1737 | |
2591 | |
1738 | =head1 SEE ALSO |
2592 | =head1 SEE ALSO |
1739 | |
2593 | |
… | |
… | |
1743 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
2597 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1744 | |
2598 | |
1745 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
2599 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1746 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
2600 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1747 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
2601 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1748 | L<AnyEvent::Impl::POE>. |
2602 | L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>. |
1749 | |
2603 | |
1750 | Non-blocking file handles, sockets, TCP clients and |
2604 | Non-blocking file handles, sockets, TCP clients and |
1751 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
2605 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. |
1752 | |
2606 | |
1753 | Asynchronous DNS: L<AnyEvent::DNS>. |
2607 | Asynchronous DNS: L<AnyEvent::DNS>. |
1754 | |
2608 | |
1755 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
2609 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, |
|
|
2610 | L<Coro::Event>, |
1756 | |
2611 | |
1757 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
2612 | Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, |
|
|
2613 | L<AnyEvent::HTTP>. |
1758 | |
2614 | |
1759 | |
2615 | |
1760 | =head1 AUTHOR |
2616 | =head1 AUTHOR |
1761 | |
2617 | |
1762 | Marc Lehmann <schmorp@schmorp.de> |
2618 | Marc Lehmann <schmorp@schmorp.de> |