1 | NAME |
1 | NAME |
2 | AnyEvent - provide framework for multiple event loops |
2 | AnyEvent - provide framework for multiple event loops |
3 | |
3 | |
4 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event |
4 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported |
5 | loops |
5 | event loops. |
6 | |
6 | |
7 | SYNOPSIS |
7 | SYNOPSIS |
8 | use AnyEvent; |
8 | use AnyEvent; |
9 | |
9 | |
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10 | # file descriptor readable |
10 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); |
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12 | |
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13 | # one-shot or repeating timers |
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14 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
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15 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
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16 | |
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17 | print AnyEvent->now; # prints current event loop time |
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18 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
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19 | |
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20 | # POSIX signal |
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21 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
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22 | |
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23 | # child process exit |
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24 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
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25 | my ($pid, $status) = @_; |
11 | ... |
26 | ... |
12 | }); |
27 | }); |
13 | |
28 | |
14 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
29 | # called when event loop idle (if applicable) |
15 | ... |
30 | my $w = AnyEvent->idle (cb => sub { ... }); |
16 | }); |
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17 | |
31 | |
18 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
32 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
19 | $w->send; # wake up current and all future recv's |
33 | $w->send; # wake up current and all future recv's |
20 | $w->recv; # enters "main loop" till $condvar gets ->send |
34 | $w->recv; # enters "main loop" till $condvar gets ->send |
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35 | # use a condvar in callback mode: |
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36 | $w->cb (sub { $_[0]->recv }); |
21 | |
37 | |
22 | INTRODUCTION/TUTORIAL |
38 | INTRODUCTION/TUTORIAL |
23 | This manpage is mainly a reference manual. If you are interested in a |
39 | This manpage is mainly a reference manual. If you are interested in a |
24 | tutorial or some gentle introduction, have a look at the AnyEvent::Intro |
40 | tutorial or some gentle introduction, have a look at the AnyEvent::Intro |
25 | manpage. |
41 | manpage. |
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123 | These watchers are normal Perl objects with normal Perl lifetime. After |
139 | These watchers are normal Perl objects with normal Perl lifetime. After |
124 | creating a watcher it will immediately "watch" for events and invoke the |
140 | creating a watcher it will immediately "watch" for events and invoke the |
125 | callback when the event occurs (of course, only when the event model is |
141 | callback when the event occurs (of course, only when the event model is |
126 | in control). |
142 | in control). |
127 | |
143 | |
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144 | Note that callbacks must not permanently change global variables |
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145 | potentially in use by the event loop (such as $_ or $[) and that |
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146 | callbacks must not "die". The former is good programming practise in |
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147 | Perl and the latter stems from the fact that exception handling differs |
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148 | widely between event loops. |
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149 | |
128 | To disable the watcher you have to destroy it (e.g. by setting the |
150 | To disable the watcher you have to destroy it (e.g. by setting the |
129 | variable you store it in to "undef" or otherwise deleting all references |
151 | variable you store it in to "undef" or otherwise deleting all references |
130 | to it). |
152 | to it). |
131 | |
153 | |
132 | All watchers are created by calling a method on the "AnyEvent" class. |
154 | All watchers are created by calling a method on the "AnyEvent" class. |
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147 | |
169 | |
148 | I/O WATCHERS |
170 | I/O WATCHERS |
149 | You can create an I/O watcher by calling the "AnyEvent->io" method with |
171 | You can create an I/O watcher by calling the "AnyEvent->io" method with |
150 | the following mandatory key-value pairs as arguments: |
172 | the following mandatory key-value pairs as arguments: |
151 | |
173 | |
152 | "fh" the Perl *file handle* (*not* file descriptor) to watch for events |
174 | "fh" is the Perl *file handle* (*not* file descriptor) to watch for |
153 | (AnyEvent might or might not keep a reference to this file handle). |
175 | events (AnyEvent might or might not keep a reference to this file |
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176 | handle). Note that only file handles pointing to things for which |
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177 | non-blocking operation makes sense are allowed. This includes sockets, |
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178 | most character devices, pipes, fifos and so on, but not for example |
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179 | files or block devices. |
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180 | |
154 | "poll" must be a string that is either "r" or "w", which creates a |
181 | "poll" must be a string that is either "r" or "w", which creates a |
155 | watcher waiting for "r"eadable or "w"ritable events, respectively. "cb" |
182 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
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183 | |
156 | is the callback to invoke each time the file handle becomes ready. |
184 | "cb" is the callback to invoke each time the file handle becomes ready. |
157 | |
185 | |
158 | Although the callback might get passed parameters, their value and |
186 | Although the callback might get passed parameters, their value and |
159 | presence is undefined and you cannot rely on them. Portable AnyEvent |
187 | presence is undefined and you cannot rely on them. Portable AnyEvent |
160 | callbacks cannot use arguments passed to I/O watcher callbacks. |
188 | callbacks cannot use arguments passed to I/O watcher callbacks. |
161 | |
189 | |
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293 | In either case, if you care (and in most cases, you don't), then you |
321 | In either case, if you care (and in most cases, you don't), then you |
294 | can get whatever behaviour you want with any event loop, by taking |
322 | can get whatever behaviour you want with any event loop, by taking |
295 | the difference between "AnyEvent->time" and "AnyEvent->now" into |
323 | the difference between "AnyEvent->time" and "AnyEvent->now" into |
296 | account. |
324 | account. |
297 | |
325 | |
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326 | AnyEvent->now_update |
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327 | Some event loops (such as EV or AnyEvent::Impl::Perl) cache the |
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328 | current time for each loop iteration (see the discussion of |
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329 | AnyEvent->now, above). |
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330 | |
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331 | When a callback runs for a long time (or when the process sleeps), |
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332 | then this "current" time will differ substantially from the real |
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333 | time, which might affect timers and time-outs. |
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334 | |
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335 | When this is the case, you can call this method, which will update |
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336 | the event loop's idea of "current time". |
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337 | |
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338 | Note that updating the time *might* cause some events to be handled. |
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339 | |
298 | SIGNAL WATCHERS |
340 | SIGNAL WATCHERS |
299 | You can watch for signals using a signal watcher, "signal" is the signal |
341 | You can watch for signals using a signal watcher, "signal" is the signal |
300 | *name* in uppercase and without any "SIG" prefix, "cb" is the Perl |
342 | *name* in uppercase and without any "SIG" prefix, "cb" is the Perl |
301 | callback to be invoked whenever a signal occurs. |
343 | callback to be invoked whenever a signal occurs. |
302 | |
344 | |
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321 | |
363 | |
322 | CHILD PROCESS WATCHERS |
364 | CHILD PROCESS WATCHERS |
323 | You can also watch on a child process exit and catch its exit status. |
365 | You can also watch on a child process exit and catch its exit status. |
324 | |
366 | |
325 | The child process is specified by the "pid" argument (if set to 0, it |
367 | The child process is specified by the "pid" argument (if set to 0, it |
326 | watches for any child process exit). The watcher will trigger as often |
368 | watches for any child process exit). The watcher will triggered only |
327 | as status change for the child are received. This works by installing a |
369 | when the child process has finished and an exit status is available, not |
328 | signal handler for "SIGCHLD". The callback will be called with the pid |
370 | on any trace events (stopped/continued). |
329 | and exit status (as returned by waitpid), so unlike other watcher types, |
371 | |
330 | you *can* rely on child watcher callback arguments. |
372 | The callback will be called with the pid and exit status (as returned by |
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373 | waitpid), so unlike other watcher types, you *can* rely on child watcher |
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374 | callback arguments. |
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375 | |
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376 | This watcher type works by installing a signal handler for "SIGCHLD", |
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377 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
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378 | random child processes (waiting for specific child processes, e.g. |
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379 | inside "system", is just fine). |
331 | |
380 | |
332 | There is a slight catch to child watchers, however: you usually start |
381 | There is a slight catch to child watchers, however: you usually start |
333 | them *after* the child process was created, and this means the process |
382 | them *after* the child process was created, and this means the process |
334 | could have exited already (and no SIGCHLD will be sent anymore). |
383 | could have exited already (and no SIGCHLD will be sent anymore). |
335 | |
384 | |
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358 | ); |
407 | ); |
359 | |
408 | |
360 | # do something else, then wait for process exit |
409 | # do something else, then wait for process exit |
361 | $done->recv; |
410 | $done->recv; |
362 | |
411 | |
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412 | IDLE WATCHERS |
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413 | Sometimes there is a need to do something, but it is not so important to |
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414 | do it instantly, but only when there is nothing better to do. This |
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415 | "nothing better to do" is usually defined to be "no other events need |
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416 | attention by the event loop". |
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417 | |
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418 | Idle watchers ideally get invoked when the event loop has nothing better |
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419 | to do, just before it would block the process to wait for new events. |
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420 | Instead of blocking, the idle watcher is invoked. |
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421 | |
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422 | Most event loops unfortunately do not really support idle watchers (only |
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423 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
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424 | will simply call the callback "from time to time". |
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425 | |
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426 | Example: read lines from STDIN, but only process them when the program |
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427 | is otherwise idle: |
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428 | |
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429 | my @lines; # read data |
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430 | my $idle_w; |
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431 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
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432 | push @lines, scalar <STDIN>; |
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433 | |
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434 | # start an idle watcher, if not already done |
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435 | $idle_w ||= AnyEvent->idle (cb => sub { |
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436 | # handle only one line, when there are lines left |
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437 | if (my $line = shift @lines) { |
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438 | print "handled when idle: $line"; |
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439 | } else { |
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440 | # otherwise disable the idle watcher again |
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441 | undef $idle_w; |
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442 | } |
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443 | }); |
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444 | }); |
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445 | |
363 | CONDITION VARIABLES |
446 | CONDITION VARIABLES |
364 | If you are familiar with some event loops you will know that all of them |
447 | If you are familiar with some event loops you will know that all of them |
365 | require you to run some blocking "loop", "run" or similar function that |
448 | require you to run some blocking "loop", "run" or similar function that |
366 | will actively watch for new events and call your callbacks. |
449 | will actively watch for new events and call your callbacks. |
367 | |
450 | |
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371 | The instrument to do that is called a "condition variable", so called |
454 | The instrument to do that is called a "condition variable", so called |
372 | because they represent a condition that must become true. |
455 | because they represent a condition that must become true. |
373 | |
456 | |
374 | Condition variables can be created by calling the "AnyEvent->condvar" |
457 | Condition variables can be created by calling the "AnyEvent->condvar" |
375 | method, usually without arguments. The only argument pair allowed is |
458 | method, usually without arguments. The only argument pair allowed is |
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459 | |
376 | "cb", which specifies a callback to be called when the condition |
460 | "cb", which specifies a callback to be called when the condition |
377 | variable becomes true. |
461 | variable becomes true, with the condition variable as the first argument |
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462 | (but not the results). |
378 | |
463 | |
379 | After creation, the condition variable is "false" until it becomes |
464 | After creation, the condition variable is "false" until it becomes |
380 | "true" by calling the "send" method (or calling the condition variable |
465 | "true" by calling the "send" method (or calling the condition variable |
381 | as if it were a callback, read about the caveats in the description for |
466 | as if it were a callback, read about the caveats in the description for |
382 | the "->send" method). |
467 | the "->send" method). |
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438 | |
523 | |
439 | my $done = AnyEvent->condvar; |
524 | my $done = AnyEvent->condvar; |
440 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
525 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
441 | $done->recv; |
526 | $done->recv; |
442 | |
527 | |
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528 | Example: Imagine an API that returns a condvar and doesn't support |
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529 | callbacks. This is how you make a synchronous call, for example from the |
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530 | main program: |
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531 | |
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532 | use AnyEvent::CouchDB; |
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533 | |
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534 | ... |
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535 | |
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536 | my @info = $couchdb->info->recv; |
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537 | |
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538 | And this is how you would just ste a callback to be called whenever the |
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539 | results are available: |
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540 | |
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541 | $couchdb->info->cb (sub { |
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542 | my @info = $_[0]->recv; |
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543 | }); |
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544 | |
443 | METHODS FOR PRODUCERS |
545 | METHODS FOR PRODUCERS |
444 | These methods should only be used by the producing side, i.e. the |
546 | These methods should only be used by the producing side, i.e. the |
445 | code/module that eventually sends the signal. Note that it is also the |
547 | code/module that eventually sends the signal. Note that it is also the |
446 | producer side which creates the condvar in most cases, but it isn't |
548 | producer side which creates the condvar in most cases, but it isn't |
447 | uncommon for the consumer to create it as well. |
549 | uncommon for the consumer to create it as well. |
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567 | |
669 | |
568 | $bool = $cv->ready |
670 | $bool = $cv->ready |
569 | Returns true when the condition is "true", i.e. whether "send" or |
671 | Returns true when the condition is "true", i.e. whether "send" or |
570 | "croak" have been called. |
672 | "croak" have been called. |
571 | |
673 | |
572 | $cb = $cv->cb ([new callback]) |
674 | $cb = $cv->cb ($cb->($cv)) |
573 | This is a mutator function that returns the callback set and |
675 | This is a mutator function that returns the callback set and |
574 | optionally replaces it before doing so. |
676 | optionally replaces it before doing so. |
575 | |
677 | |
576 | The callback will be called when the condition becomes "true", i.e. |
678 | The callback will be called when the condition becomes "true", i.e. |
577 | when "send" or "croak" are called, with the only argument being the |
679 | when "send" or "croak" are called, with the only argument being the |
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742 | |
844 | |
743 | AnyEvent::IGS |
845 | AnyEvent::IGS |
744 | A non-blocking interface to the Internet Go Server protocol (used by |
846 | A non-blocking interface to the Internet Go Server protocol (used by |
745 | App::IGS). |
847 | App::IGS). |
746 | |
848 | |
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849 | AnyEvent::IRC |
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850 | AnyEvent based IRC client module family (replacing the older |
747 | Net::IRC3 |
851 | Net::IRC3). |
748 | AnyEvent based IRC client module family. |
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749 | |
852 | |
750 | Net::XMPP2 |
853 | Net::XMPP2 |
751 | AnyEvent based XMPP (Jabber protocol) module family. |
854 | AnyEvent based XMPP (Jabber protocol) module family. |
752 | |
855 | |
753 | Net::FCP |
856 | Net::FCP |
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762 | |
865 | |
763 | IO::Lambda |
866 | IO::Lambda |
764 | The lambda approach to I/O - don't ask, look there. Can use |
867 | The lambda approach to I/O - don't ask, look there. Can use |
765 | AnyEvent. |
868 | AnyEvent. |
766 | |
869 | |
767 | SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
870 | ERROR AND EXCEPTION HANDLING |
768 | This is an advanced topic that you do not normally need to use AnyEvent |
871 | In general, AnyEvent does not do any error handling - it relies on the |
769 | in a module. This section is only of use to event loop authors who want |
872 | caller to do that if required. The AnyEvent::Strict module (see also the |
770 | to provide AnyEvent compatibility. |
873 | "PERL_ANYEVENT_STRICT" environment variable, below) provides strict |
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874 | checking of all AnyEvent methods, however, which is highly useful during |
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875 | development. |
771 | |
876 | |
772 | If you need to support another event library which isn't directly |
877 | As for exception handling (i.e. runtime errors and exceptions thrown |
773 | supported by AnyEvent, you can supply your own interface to it by |
878 | while executing a callback), this is not only highly event-loop |
774 | pushing, before the first watcher gets created, the package name of the |
879 | specific, but also not in any way wrapped by this module, as this is the |
775 | event module and the package name of the interface to use onto |
880 | job of the main program. |
776 | @AnyEvent::REGISTRY. You can do that before and even without loading |
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777 | AnyEvent, so it is reasonably cheap. |
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778 | |
881 | |
779 | Example: |
882 | The pure perl event loop simply re-throws the exception (usually within |
780 | |
883 | "condvar->recv"), the Event and EV modules call "$Event/EV::DIED->()", |
781 | push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::]; |
884 | Glib uses "install_exception_handler" and so on. |
782 | |
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783 | This tells AnyEvent to (literally) use the "urxvt::anyevent::" |
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784 | package/class when it finds the "urxvt" package/module is already |
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785 | loaded. |
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786 | |
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787 | When AnyEvent is loaded and asked to find a suitable event model, it |
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788 | will first check for the presence of urxvt by trying to "use" the |
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789 | "urxvt::anyevent" module. |
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790 | |
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791 | The class should provide implementations for all watcher types. See |
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792 | AnyEvent::Impl::EV (source code), AnyEvent::Impl::Glib (Source code) and |
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793 | so on for actual examples. Use "perldoc -m AnyEvent::Impl::Glib" to see |
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794 | the sources. |
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795 | |
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796 | If you don't provide "signal" and "child" watchers than AnyEvent will |
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797 | provide suitable (hopefully) replacements. |
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798 | |
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799 | The above example isn't fictitious, the *rxvt-unicode* (a.k.a. urxvt) |
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800 | terminal emulator uses the above line as-is. An interface isn't included |
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801 | in AnyEvent because it doesn't make sense outside the embedded |
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802 | interpreter inside *rxvt-unicode*, and it is updated and maintained as |
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803 | part of the *rxvt-unicode* distribution. |
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804 | |
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805 | *rxvt-unicode* also cheats a bit by not providing blocking access to |
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806 | condition variables: code blocking while waiting for a condition will |
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807 | "die". This still works with most modules/usages, and blocking calls |
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808 | must not be done in an interactive application, so it makes sense. |
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809 | |
885 | |
810 | ENVIRONMENT VARIABLES |
886 | ENVIRONMENT VARIABLES |
811 | The following environment variables are used by this module: |
887 | The following environment variables are used by this module or its |
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888 | submodules: |
812 | |
889 | |
813 | "PERL_ANYEVENT_VERBOSE" |
890 | "PERL_ANYEVENT_VERBOSE" |
814 | By default, AnyEvent will be completely silent except in fatal |
891 | By default, AnyEvent will be completely silent except in fatal |
815 | conditions. You can set this environment variable to make AnyEvent |
892 | conditions. You can set this environment variable to make AnyEvent |
816 | more talkative. |
893 | more talkative. |
… | |
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829 | thoroughly check the arguments passed to most method calls. If it |
906 | thoroughly check the arguments passed to most method calls. If it |
830 | finds any problems it will croak. |
907 | finds any problems it will croak. |
831 | |
908 | |
832 | In other words, enables "strict" mode. |
909 | In other words, enables "strict" mode. |
833 | |
910 | |
834 | Unlike "use strict" it is definitely recommended ot keep it off in |
911 | Unlike "use strict", it is definitely recommended ot keep it off in |
835 | production. |
912 | production. Keeping "PERL_ANYEVENT_STRICT=1" in your environment |
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913 | while developing programs can be very useful, however. |
836 | |
914 | |
837 | "PERL_ANYEVENT_MODEL" |
915 | "PERL_ANYEVENT_MODEL" |
838 | This can be used to specify the event model to be used by AnyEvent, |
916 | This can be used to specify the event model to be used by AnyEvent, |
839 | before auto detection and -probing kicks in. It must be a string |
917 | before auto detection and -probing kicks in. It must be a string |
840 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
918 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
… | |
… | |
859 | mentioned will be used, and preference will be given to protocols |
937 | mentioned will be used, and preference will be given to protocols |
860 | mentioned earlier in the list. |
938 | mentioned earlier in the list. |
861 | |
939 | |
862 | This variable can effectively be used for denial-of-service attacks |
940 | This variable can effectively be used for denial-of-service attacks |
863 | against local programs (e.g. when setuid), although the impact is |
941 | against local programs (e.g. when setuid), although the impact is |
864 | likely small, as the program has to handle connection errors |
942 | likely small, as the program has to handle conenction and other |
865 | already- |
943 | failures anyways. |
866 | |
944 | |
867 | Examples: "PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6" - prefer IPv4 over |
945 | Examples: "PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6" - prefer IPv4 over |
868 | IPv6, but support both and try to use both. |
946 | IPv6, but support both and try to use both. |
869 | "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to |
947 | "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to |
870 | resolve or contact IPv6 addresses. |
948 | resolve or contact IPv6 addresses. |
… | |
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881 | EDNS0 in its DNS requests. |
959 | EDNS0 in its DNS requests. |
882 | |
960 | |
883 | "PERL_ANYEVENT_MAX_FORKS" |
961 | "PERL_ANYEVENT_MAX_FORKS" |
884 | The maximum number of child processes that |
962 | The maximum number of child processes that |
885 | "AnyEvent::Util::fork_call" will create in parallel. |
963 | "AnyEvent::Util::fork_call" will create in parallel. |
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964 | |
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965 | SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
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966 | This is an advanced topic that you do not normally need to use AnyEvent |
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967 | in a module. This section is only of use to event loop authors who want |
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968 | to provide AnyEvent compatibility. |
|
|
969 | |
|
|
970 | If you need to support another event library which isn't directly |
|
|
971 | supported by AnyEvent, you can supply your own interface to it by |
|
|
972 | pushing, before the first watcher gets created, the package name of the |
|
|
973 | event module and the package name of the interface to use onto |
|
|
974 | @AnyEvent::REGISTRY. You can do that before and even without loading |
|
|
975 | AnyEvent, so it is reasonably cheap. |
|
|
976 | |
|
|
977 | Example: |
|
|
978 | |
|
|
979 | push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::]; |
|
|
980 | |
|
|
981 | This tells AnyEvent to (literally) use the "urxvt::anyevent::" |
|
|
982 | package/class when it finds the "urxvt" package/module is already |
|
|
983 | loaded. |
|
|
984 | |
|
|
985 | When AnyEvent is loaded and asked to find a suitable event model, it |
|
|
986 | will first check for the presence of urxvt by trying to "use" the |
|
|
987 | "urxvt::anyevent" module. |
|
|
988 | |
|
|
989 | The class should provide implementations for all watcher types. See |
|
|
990 | AnyEvent::Impl::EV (source code), AnyEvent::Impl::Glib (Source code) and |
|
|
991 | so on for actual examples. Use "perldoc -m AnyEvent::Impl::Glib" to see |
|
|
992 | the sources. |
|
|
993 | |
|
|
994 | If you don't provide "signal" and "child" watchers than AnyEvent will |
|
|
995 | provide suitable (hopefully) replacements. |
|
|
996 | |
|
|
997 | The above example isn't fictitious, the *rxvt-unicode* (a.k.a. urxvt) |
|
|
998 | terminal emulator uses the above line as-is. An interface isn't included |
|
|
999 | in AnyEvent because it doesn't make sense outside the embedded |
|
|
1000 | interpreter inside *rxvt-unicode*, and it is updated and maintained as |
|
|
1001 | part of the *rxvt-unicode* distribution. |
|
|
1002 | |
|
|
1003 | *rxvt-unicode* also cheats a bit by not providing blocking access to |
|
|
1004 | condition variables: code blocking while waiting for a condition will |
|
|
1005 | "die". This still works with most modules/usages, and blocking calls |
|
|
1006 | must not be done in an interactive application, so it makes sense. |
886 | |
1007 | |
887 | EXAMPLE PROGRAM |
1008 | EXAMPLE PROGRAM |
888 | The following program uses an I/O watcher to read data from STDIN, a |
1009 | The following program uses an I/O watcher to read data from STDIN, a |
889 | timer to display a message once per second, and a condition variable to |
1010 | timer to display a message once per second, and a condition variable to |
890 | quit the program when the user enters quit: |
1011 | quit the program when the user enters quit: |
… | |
… | |
1077 | *destroy* is the time, in microseconds, that it takes to destroy a |
1198 | *destroy* is the time, in microseconds, that it takes to destroy a |
1078 | single watcher. |
1199 | single watcher. |
1079 | |
1200 | |
1080 | Results |
1201 | Results |
1081 | name watchers bytes create invoke destroy comment |
1202 | name watchers bytes create invoke destroy comment |
1082 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1203 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1083 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1204 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1084 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1205 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1085 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1206 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1086 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1207 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1087 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1208 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
1088 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1209 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1089 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1210 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1090 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1211 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1091 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1212 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1092 | |
1213 | |
1093 | Discussion |
1214 | Discussion |
1094 | The benchmark does *not* measure scalability of the event loop very |
1215 | The benchmark does *not* measure scalability of the event loop very |
1095 | well. For example, a select-based event loop (such as the pure perl one) |
1216 | well. For example, a select-based event loop (such as the pure perl one) |
1096 | can never compete with an event loop that uses epoll when the number of |
1217 | can never compete with an event loop that uses epoll when the number of |
… | |
… | |
1277 | |
1398 | |
1278 | Summary |
1399 | Summary |
1279 | * C-based event loops perform very well with small number of watchers, |
1400 | * C-based event loops perform very well with small number of watchers, |
1280 | as the management overhead dominates. |
1401 | as the management overhead dominates. |
1281 | |
1402 | |
|
|
1403 | SIGNALS |
|
|
1404 | AnyEvent currently installs handlers for these signals: |
|
|
1405 | |
|
|
1406 | SIGCHLD |
|
|
1407 | A handler for "SIGCHLD" is installed by AnyEvent's child watcher |
|
|
1408 | emulation for event loops that do not support them natively. Also, |
|
|
1409 | some event loops install a similar handler. |
|
|
1410 | |
|
|
1411 | SIGPIPE |
|
|
1412 | A no-op handler is installed for "SIGPIPE" when $SIG{PIPE} is |
|
|
1413 | "undef" when AnyEvent gets loaded. |
|
|
1414 | |
|
|
1415 | The rationale for this is that AnyEvent users usually do not really |
|
|
1416 | depend on SIGPIPE delivery (which is purely an optimisation for |
|
|
1417 | shell use, or badly-written programs), but "SIGPIPE" can cause |
|
|
1418 | spurious and rare program exits as a lot of people do not expect |
|
|
1419 | "SIGPIPE" when writing to some random socket. |
|
|
1420 | |
|
|
1421 | The rationale for installing a no-op handler as opposed to ignoring |
|
|
1422 | it is that this way, the handler will be restored to defaults on |
|
|
1423 | exec. |
|
|
1424 | |
|
|
1425 | Feel free to install your own handler, or reset it to defaults. |
|
|
1426 | |
1282 | FORK |
1427 | FORK |
1283 | Most event libraries are not fork-safe. The ones who are usually are |
1428 | Most event libraries are not fork-safe. The ones who are usually are |
1284 | because they rely on inefficient but fork-safe "select" or "poll" calls. |
1429 | because they rely on inefficient but fork-safe "select" or "poll" calls. |
1285 | Only EV is fully fork-aware. |
1430 | Only EV is fully fork-aware. |
1286 | |
1431 | |
… | |
… | |
1309 | |
1454 | |
1310 | BUGS |
1455 | BUGS |
1311 | Perl 5.8 has numerous memleaks that sometimes hit this module and are |
1456 | Perl 5.8 has numerous memleaks that sometimes hit this module and are |
1312 | hard to work around. If you suffer from memleaks, first upgrade to Perl |
1457 | hard to work around. If you suffer from memleaks, first upgrade to Perl |
1313 | 5.10 and check wether the leaks still show up. (Perl 5.10.0 has other |
1458 | 5.10 and check wether the leaks still show up. (Perl 5.10.0 has other |
1314 | annoying mamleaks, such as leaking on "map" and "grep" but it is usually |
1459 | annoying memleaks, such as leaking on "map" and "grep" but it is usually |
1315 | not as pronounced). |
1460 | not as pronounced). |
1316 | |
1461 | |
1317 | SEE ALSO |
1462 | SEE ALSO |
1318 | Utility functions: AnyEvent::Util. |
1463 | Utility functions: AnyEvent::Util. |
1319 | |
1464 | |