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* (or a naked 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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308 | invocation, and callback invocation will be synchronous. Synchronous |
350 | invocation, and callback invocation will be synchronous. Synchronous |
309 | means that it might take a while until the signal gets handled by the |
351 | means that it might take a while until the signal gets handled by the |
310 | process, but it is guaranteed not to interrupt any other callbacks. |
352 | process, but it is guaranteed not to interrupt any other callbacks. |
311 | |
353 | |
312 | The main advantage of using these watchers is that you can share a |
354 | The main advantage of using these watchers is that you can share a |
313 | signal between multiple watchers. |
355 | signal between multiple watchers, and AnyEvent will ensure that signals |
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356 | will not interrupt your program at bad times. |
314 | |
357 | |
315 | This watcher might use %SIG, so programs overwriting those signals |
358 | This watcher might use %SIG (depending on the event loop used), so |
316 | directly will likely not work correctly. |
359 | programs overwriting those signals directly will likely not work |
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360 | correctly. |
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361 | |
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362 | Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not |
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363 | support attaching callbacks to signals, which is a pity, as you cannot |
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364 | do race-free signal handling in perl. AnyEvent will try to do it's best, |
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365 | but in some cases, signals will be delayed. The maximum time a signal |
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366 | might be delayed is specified in $AnyEvent::MAX_SIGNAL_LATENCY (default: |
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367 | 10 seconds). This variable can be changed only before the first signal |
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368 | watcher is created, and should be left alone otherwise. Higher values |
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369 | will cause fewer spurious wake-ups, which is better for power and CPU |
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370 | saving. All these problems can be avoided by installing the optional |
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371 | Async::Interrupt module. |
317 | |
372 | |
318 | Example: exit on SIGINT |
373 | Example: exit on SIGINT |
319 | |
374 | |
320 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
375 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
321 | |
376 | |
322 | CHILD PROCESS WATCHERS |
377 | CHILD PROCESS WATCHERS |
323 | You can also watch on a child process exit and catch its exit status. |
378 | You can also watch on a child process exit and catch its exit status. |
324 | |
379 | |
325 | The child process is specified by the "pid" argument (if set to 0, it |
380 | 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 |
381 | 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 |
382 | 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 |
383 | on any trace events (stopped/continued). |
329 | and exit status (as returned by waitpid), so unlike other watcher types, |
384 | |
330 | you *can* rely on child watcher callback arguments. |
385 | The callback will be called with the pid and exit status (as returned by |
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386 | waitpid), so unlike other watcher types, you *can* rely on child watcher |
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387 | callback arguments. |
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388 | |
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389 | This watcher type works by installing a signal handler for "SIGCHLD", |
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390 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
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391 | random child processes (waiting for specific child processes, e.g. |
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392 | inside "system", is just fine). |
331 | |
393 | |
332 | There is a slight catch to child watchers, however: you usually start |
394 | 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 |
395 | them *after* the child process was created, and this means the process |
334 | could have exited already (and no SIGCHLD will be sent anymore). |
396 | could have exited already (and no SIGCHLD will be sent anymore). |
335 | |
397 | |
336 | Not all event models handle this correctly (POE doesn't), but even for |
398 | Not all event models handle this correctly (neither POE nor IO::Async |
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399 | do, see their AnyEvent::Impl manpages for details), but even for event |
337 | event models that *do* handle this correctly, they usually need to be |
400 | models that *do* handle this correctly, they usually need to be loaded |
338 | loaded before the process exits (i.e. before you fork in the first |
401 | before the process exits (i.e. before you fork in the first place). |
339 | place). |
402 | AnyEvent's pure perl event loop handles all cases correctly regardless |
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403 | of when you start the watcher. |
340 | |
404 | |
341 | This means you cannot create a child watcher as the very first thing in |
405 | This means you cannot create a child watcher as the very first thing in |
342 | an AnyEvent program, you *have* to create at least one watcher before |
406 | an AnyEvent program, you *have* to create at least one watcher before |
343 | you "fork" the child (alternatively, you can call "AnyEvent::detect"). |
407 | you "fork" the child (alternatively, you can call "AnyEvent::detect"). |
344 | |
408 | |
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409 | As most event loops do not support waiting for child events, they will |
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410 | be emulated by AnyEvent in most cases, in which the latency and race |
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411 | problems mentioned in the description of signal watchers apply. |
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412 | |
345 | Example: fork a process and wait for it |
413 | Example: fork a process and wait for it |
346 | |
414 | |
347 | my $done = AnyEvent->condvar; |
415 | my $done = AnyEvent->condvar; |
348 | |
416 | |
349 | my $pid = fork or exit 5; |
417 | my $pid = fork or exit 5; |
350 | |
418 | |
351 | my $w = AnyEvent->child ( |
419 | my $w = AnyEvent->child ( |
352 | pid => $pid, |
420 | pid => $pid, |
353 | cb => sub { |
421 | cb => sub { |
354 | my ($pid, $status) = @_; |
422 | my ($pid, $status) = @_; |
355 | warn "pid $pid exited with status $status"; |
423 | warn "pid $pid exited with status $status"; |
356 | $done->send; |
424 | $done->send; |
357 | }, |
425 | }, |
358 | ); |
426 | ); |
359 | |
427 | |
360 | # do something else, then wait for process exit |
428 | # do something else, then wait for process exit |
361 | $done->recv; |
429 | $done->recv; |
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430 | |
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431 | IDLE WATCHERS |
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432 | Sometimes there is a need to do something, but it is not so important to |
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433 | do it instantly, but only when there is nothing better to do. This |
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434 | "nothing better to do" is usually defined to be "no other events need |
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435 | attention by the event loop". |
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436 | |
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437 | Idle watchers ideally get invoked when the event loop has nothing better |
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438 | to do, just before it would block the process to wait for new events. |
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439 | Instead of blocking, the idle watcher is invoked. |
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440 | |
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441 | Most event loops unfortunately do not really support idle watchers (only |
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442 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
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443 | will simply call the callback "from time to time". |
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444 | |
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445 | Example: read lines from STDIN, but only process them when the program |
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446 | is otherwise idle: |
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447 | |
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448 | my @lines; # read data |
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449 | my $idle_w; |
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450 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
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451 | push @lines, scalar <STDIN>; |
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452 | |
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453 | # start an idle watcher, if not already done |
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454 | $idle_w ||= AnyEvent->idle (cb => sub { |
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455 | # handle only one line, when there are lines left |
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456 | if (my $line = shift @lines) { |
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457 | print "handled when idle: $line"; |
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458 | } else { |
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459 | # otherwise disable the idle watcher again |
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460 | undef $idle_w; |
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461 | } |
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462 | }); |
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463 | }); |
362 | |
464 | |
363 | CONDITION VARIABLES |
465 | CONDITION VARIABLES |
364 | If you are familiar with some event loops you will know that all of them |
466 | 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 |
467 | require you to run some blocking "loop", "run" or similar function that |
366 | will actively watch for new events and call your callbacks. |
468 | will actively watch for new events and call your callbacks. |
367 | |
469 | |
368 | AnyEvent is different, it expects somebody else to run the event loop |
470 | AnyEvent is slightly different: it expects somebody else to run the |
369 | and will only block when necessary (usually when told by the user). |
471 | event loop and will only block when necessary (usually when told by the |
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472 | user). |
370 | |
473 | |
371 | The instrument to do that is called a "condition variable", so called |
474 | The instrument to do that is called a "condition variable", so called |
372 | because they represent a condition that must become true. |
475 | because they represent a condition that must become true. |
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476 | |
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477 | Now is probably a good time to look at the examples further below. |
373 | |
478 | |
374 | Condition variables can be created by calling the "AnyEvent->condvar" |
479 | Condition variables can be created by calling the "AnyEvent->condvar" |
375 | method, usually without arguments. The only argument pair allowed is |
480 | method, usually without arguments. The only argument pair allowed is |
376 | "cb", which specifies a callback to be called when the condition |
481 | "cb", which specifies a callback to be called when the condition |
377 | variable becomes true. |
482 | variable becomes true, with the condition variable as the first argument |
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483 | (but not the results). |
378 | |
484 | |
379 | After creation, the condition variable is "false" until it becomes |
485 | After creation, the condition variable is "false" until it becomes |
380 | "true" by calling the "send" method (or calling the condition variable |
486 | "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 |
487 | as if it were a callback, read about the caveats in the description for |
382 | the "->send" method). |
488 | the "->send" method). |
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428 | after => 1, |
534 | after => 1, |
429 | cb => sub { $result_ready->send }, |
535 | cb => sub { $result_ready->send }, |
430 | ); |
536 | ); |
431 | |
537 | |
432 | # this "blocks" (while handling events) till the callback |
538 | # this "blocks" (while handling events) till the callback |
433 | # calls send |
539 | # calls -<send |
434 | $result_ready->recv; |
540 | $result_ready->recv; |
435 | |
541 | |
436 | Example: wait for a timer, but take advantage of the fact that condition |
542 | Example: wait for a timer, but take advantage of the fact that condition |
437 | variables are also code references. |
543 | variables are also callable directly. |
438 | |
544 | |
439 | my $done = AnyEvent->condvar; |
545 | my $done = AnyEvent->condvar; |
440 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
546 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
441 | $done->recv; |
547 | $done->recv; |
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548 | |
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549 | Example: Imagine an API that returns a condvar and doesn't support |
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550 | callbacks. This is how you make a synchronous call, for example from the |
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551 | main program: |
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552 | |
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553 | use AnyEvent::CouchDB; |
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554 | |
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555 | ... |
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556 | |
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557 | my @info = $couchdb->info->recv; |
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558 | |
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559 | And this is how you would just set a callback to be called whenever the |
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560 | results are available: |
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561 | |
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562 | $couchdb->info->cb (sub { |
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563 | my @info = $_[0]->recv; |
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564 | }); |
442 | |
565 | |
443 | METHODS FOR PRODUCERS |
566 | METHODS FOR PRODUCERS |
444 | These methods should only be used by the producing side, i.e. the |
567 | 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 |
568 | 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 |
569 | producer side which creates the condvar in most cases, but it isn't |
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456 | |
579 | |
457 | Any arguments passed to the "send" call will be returned by all |
580 | Any arguments passed to the "send" call will be returned by all |
458 | future "->recv" calls. |
581 | future "->recv" calls. |
459 | |
582 | |
460 | Condition variables are overloaded so one can call them directly (as |
583 | Condition variables are overloaded so one can call them directly (as |
461 | a code reference). Calling them directly is the same as calling |
584 | if they were a code reference). Calling them directly is the same as |
462 | "send". Note, however, that many C-based event loops do not handle |
585 | calling "send". |
463 | overloading, so as tempting as it may be, passing a condition |
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464 | variable instead of a callback does not work. Both the pure perl and |
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465 | EV loops support overloading, however, as well as all functions that |
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466 | use perl to invoke a callback (as in AnyEvent::Socket and |
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467 | AnyEvent::DNS for example). |
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468 | |
586 | |
469 | $cv->croak ($error) |
587 | $cv->croak ($error) |
470 | Similar to send, but causes all call's to "->recv" to invoke |
588 | Similar to send, but causes all call's to "->recv" to invoke |
471 | "Carp::croak" with the given error message/object/scalar. |
589 | "Carp::croak" with the given error message/object/scalar. |
472 | |
590 | |
473 | This can be used to signal any errors to the condition variable |
591 | This can be used to signal any errors to the condition variable |
474 | user/consumer. |
592 | user/consumer. Doing it this way instead of calling "croak" directly |
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593 | delays the error detetcion, but has the overwhelmign advantage that |
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594 | it diagnoses the error at the place where the result is expected, |
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595 | and not deep in some event clalback without connection to the actual |
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596 | code causing the problem. |
475 | |
597 | |
476 | $cv->begin ([group callback]) |
598 | $cv->begin ([group callback]) |
477 | $cv->end |
599 | $cv->end |
478 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
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479 | |
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480 | These two methods can be used to combine many transactions/events |
600 | These two methods can be used to combine many transactions/events |
481 | into one. For example, a function that pings many hosts in parallel |
601 | into one. For example, a function that pings many hosts in parallel |
482 | might want to use a condition variable for the whole process. |
602 | might want to use a condition variable for the whole process. |
483 | |
603 | |
484 | Every call to "->begin" will increment a counter, and every call to |
604 | Every call to "->begin" will increment a counter, and every call to |
485 | "->end" will decrement it. If the counter reaches 0 in "->end", the |
605 | "->end" will decrement it. If the counter reaches 0 in "->end", the |
486 | (last) callback passed to "begin" will be executed. That callback is |
606 | (last) callback passed to "begin" will be executed. That callback is |
487 | *supposed* to call "->send", but that is not required. If no |
607 | *supposed* to call "->send", but that is not required. If no |
488 | callback was set, "send" will be called without any arguments. |
608 | callback was set, "send" will be called without any arguments. |
489 | |
609 | |
490 | Let's clarify this with the ping example: |
610 | You can think of "$cv->send" giving you an OR condition (one call |
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611 | sends), while "$cv->begin" and "$cv->end" giving you an AND |
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612 | condition (all "begin" calls must be "end"'ed before the condvar |
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613 | sends). |
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614 | |
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615 | Let's start with a simple example: you have two I/O watchers (for |
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616 | example, STDOUT and STDERR for a program), and you want to wait for |
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617 | both streams to close before activating a condvar: |
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618 | |
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619 | my $cv = AnyEvent->condvar; |
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620 | |
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621 | $cv->begin; # first watcher |
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622 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
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623 | defined sysread $fh1, my $buf, 4096 |
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624 | or $cv->end; |
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625 | }); |
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626 | |
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627 | $cv->begin; # second watcher |
|
|
628 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
629 | defined sysread $fh2, my $buf, 4096 |
|
|
630 | or $cv->end; |
|
|
631 | }); |
|
|
632 | |
|
|
633 | $cv->recv; |
|
|
634 | |
|
|
635 | This works because for every event source (EOF on file handle), |
|
|
636 | there is one call to "begin", so the condvar waits for all calls to |
|
|
637 | "end" before sending. |
|
|
638 | |
|
|
639 | The ping example mentioned above is slightly more complicated, as |
|
|
640 | the there are results to be passwd back, and the number of tasks |
|
|
641 | that are begung can potentially be zero: |
491 | |
642 | |
492 | my $cv = AnyEvent->condvar; |
643 | my $cv = AnyEvent->condvar; |
493 | |
644 | |
494 | my %result; |
645 | my %result; |
495 | $cv->begin (sub { $cv->send (\%result) }); |
646 | $cv->begin (sub { $cv->send (\%result) }); |
… | |
… | |
515 | the loop, which serves two important purposes: first, it sets the |
666 | the loop, which serves two important purposes: first, it sets the |
516 | callback to be called once the counter reaches 0, and second, it |
667 | callback to be called once the counter reaches 0, and second, it |
517 | ensures that "send" is called even when "no" hosts are being pinged |
668 | ensures that "send" is called even when "no" hosts are being pinged |
518 | (the loop doesn't execute once). |
669 | (the loop doesn't execute once). |
519 | |
670 | |
520 | This is the general pattern when you "fan out" into multiple |
671 | This is the general pattern when you "fan out" into multiple (but |
521 | subrequests: use an outer "begin"/"end" pair to set the callback and |
672 | potentially none) subrequests: use an outer "begin"/"end" pair to |
522 | ensure "end" is called at least once, and then, for each subrequest |
673 | set the callback and ensure "end" is called at least once, and then, |
523 | you start, call "begin" and for each subrequest you finish, call |
674 | for each subrequest you start, call "begin" and for each subrequest |
524 | "end". |
675 | you finish, call "end". |
525 | |
676 | |
526 | METHODS FOR CONSUMERS |
677 | METHODS FOR CONSUMERS |
527 | These methods should only be used by the consuming side, i.e. the code |
678 | These methods should only be used by the consuming side, i.e. the code |
528 | awaits the condition. |
679 | awaits the condition. |
529 | |
680 | |
… | |
… | |
538 | function will call "croak". |
689 | function will call "croak". |
539 | |
690 | |
540 | In list context, all parameters passed to "send" will be returned, |
691 | In list context, all parameters passed to "send" will be returned, |
541 | in scalar context only the first one will be returned. |
692 | in scalar context only the first one will be returned. |
542 | |
693 | |
|
|
694 | Note that doing a blocking wait in a callback is not supported by |
|
|
695 | any event loop, that is, recursive invocation of a blocking "->recv" |
|
|
696 | is not allowed, and the "recv" call will "croak" if such a condition |
|
|
697 | is detected. This condition can be slightly loosened by using |
|
|
698 | Coro::AnyEvent, which allows you to do a blocking "->recv" from any |
|
|
699 | thread that doesn't run the event loop itself. |
|
|
700 | |
543 | Not all event models support a blocking wait - some die in that case |
701 | Not all event models support a blocking wait - some die in that case |
544 | (programs might want to do that to stay interactive), so *if you are |
702 | (programs might want to do that to stay interactive), so *if you are |
545 | using this from a module, never require a blocking wait*, but let |
703 | using this from a module, never require a blocking wait*. Instead, |
546 | the caller decide whether the call will block or not (for example, |
704 | let the caller decide whether the call will block or not (for |
547 | by coupling condition variables with some kind of request results |
705 | example, by coupling condition variables with some kind of request |
548 | and supporting callbacks so the caller knows that getting the result |
706 | results and supporting callbacks so the caller knows that getting |
549 | will not block, while still supporting blocking waits if the caller |
707 | the result will not block, while still supporting blocking waits if |
550 | so desires). |
708 | the caller so desires). |
551 | |
|
|
552 | Another reason *never* to "->recv" in a module is that you cannot |
|
|
553 | sensibly have two "->recv"'s in parallel, as that would require |
|
|
554 | multiple interpreters or coroutines/threads, none of which |
|
|
555 | "AnyEvent" can supply. |
|
|
556 | |
|
|
557 | The Coro module, however, *can* and *does* supply coroutines and, in |
|
|
558 | fact, Coro::AnyEvent replaces AnyEvent's condvars by coroutine-safe |
|
|
559 | versions and also integrates coroutines into AnyEvent, making |
|
|
560 | blocking "->recv" calls perfectly safe as long as they are done from |
|
|
561 | another coroutine (one that doesn't run the event loop). |
|
|
562 | |
709 | |
563 | You can ensure that "-recv" never blocks by setting a callback and |
710 | You can ensure that "-recv" never blocks by setting a callback and |
564 | only calling "->recv" from within that callback (or at a later |
711 | only calling "->recv" from within that callback (or at a later |
565 | time). This will work even when the event loop does not support |
712 | time). This will work even when the event loop does not support |
566 | blocking waits otherwise. |
713 | blocking waits otherwise. |
567 | |
714 | |
568 | $bool = $cv->ready |
715 | $bool = $cv->ready |
569 | Returns true when the condition is "true", i.e. whether "send" or |
716 | Returns true when the condition is "true", i.e. whether "send" or |
570 | "croak" have been called. |
717 | "croak" have been called. |
571 | |
718 | |
572 | $cb = $cv->cb ([new callback]) |
719 | $cb = $cv->cb ($cb->($cv)) |
573 | This is a mutator function that returns the callback set and |
720 | This is a mutator function that returns the callback set and |
574 | optionally replaces it before doing so. |
721 | optionally replaces it before doing so. |
575 | |
722 | |
576 | The callback will be called when the condition becomes "true", i.e. |
723 | 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 |
724 | when "send" or "croak" are called, with the only argument being the |
578 | condition variable itself. Calling "recv" inside the callback or at |
725 | condition variable itself. Calling "recv" inside the callback or at |
579 | any later time is guaranteed not to block. |
726 | any later time is guaranteed not to block. |
580 | |
727 | |
|
|
728 | SUPPORTED EVENT LOOPS/BACKENDS |
|
|
729 | The available backend classes are (every class has its own manpage): |
|
|
730 | |
|
|
731 | Backends that are autoprobed when no other event loop can be found. |
|
|
732 | EV is the preferred backend when no other event loop seems to be in |
|
|
733 | use. If EV is not installed, then AnyEvent will try Event, and, |
|
|
734 | failing that, will fall back to its own pure-perl implementation, |
|
|
735 | which is available everywhere as it comes with AnyEvent itself. |
|
|
736 | |
|
|
737 | AnyEvent::Impl::EV based on EV (interface to libev, best choice). |
|
|
738 | AnyEvent::Impl::Event based on Event, very stable, few glitches. |
|
|
739 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
740 | |
|
|
741 | Backends that are transparently being picked up when they are used. |
|
|
742 | These will be used when they are currently loaded when the first |
|
|
743 | watcher is created, in which case it is assumed that the application |
|
|
744 | is using them. This means that AnyEvent will automatically pick the |
|
|
745 | right backend when the main program loads an event module before |
|
|
746 | anything starts to create watchers. Nothing special needs to be done |
|
|
747 | by the main program. |
|
|
748 | |
|
|
749 | AnyEvent::Impl::Glib based on Glib, slow but very stable. |
|
|
750 | AnyEvent::Impl::Tk based on Tk, very broken. |
|
|
751 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
752 | AnyEvent::Impl::POE based on POE, very slow, some limitations. |
|
|
753 | |
|
|
754 | Backends with special needs. |
|
|
755 | Qt requires the Qt::Application to be instantiated first, but will |
|
|
756 | otherwise be picked up automatically. As long as the main program |
|
|
757 | instantiates the application before any AnyEvent watchers are |
|
|
758 | created, everything should just work. |
|
|
759 | |
|
|
760 | AnyEvent::Impl::Qt based on Qt. |
|
|
761 | |
|
|
762 | Support for IO::Async can only be partial, as it is too broken and |
|
|
763 | architecturally limited to even support the AnyEvent API. It also is |
|
|
764 | the only event loop that needs the loop to be set explicitly, so it |
|
|
765 | can only be used by a main program knowing about AnyEvent. See |
|
|
766 | AnyEvent::Impl::Async for the gory details. |
|
|
767 | |
|
|
768 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed. |
|
|
769 | |
|
|
770 | Event loops that are indirectly supported via other backends. |
|
|
771 | Some event loops can be supported via other modules: |
|
|
772 | |
|
|
773 | There is no direct support for WxWidgets (Wx) or Prima. |
|
|
774 | |
|
|
775 | WxWidgets has no support for watching file handles. However, you can |
|
|
776 | use WxWidgets through the POE adaptor, as POE has a Wx backend that |
|
|
777 | simply polls 20 times per second, which was considered to be too |
|
|
778 | horrible to even consider for AnyEvent. |
|
|
779 | |
|
|
780 | Prima is not supported as nobody seems to be using it, but it has a |
|
|
781 | POE backend, so it can be supported through POE. |
|
|
782 | |
|
|
783 | AnyEvent knows about both Prima and Wx, however, and will try to |
|
|
784 | load POE when detecting them, in the hope that POE will pick them |
|
|
785 | up, in which case everything will be automatic. |
|
|
786 | |
581 | GLOBAL VARIABLES AND FUNCTIONS |
787 | GLOBAL VARIABLES AND FUNCTIONS |
|
|
788 | These are not normally required to use AnyEvent, but can be useful to |
|
|
789 | write AnyEvent extension modules. |
|
|
790 | |
582 | $AnyEvent::MODEL |
791 | $AnyEvent::MODEL |
583 | Contains "undef" until the first watcher is being created. Then it |
792 | Contains "undef" until the first watcher is being created, before |
|
|
793 | the backend has been autodetected. |
|
|
794 | |
584 | contains the event model that is being used, which is the name of |
795 | Afterwards it contains the event model that is being used, which is |
585 | the Perl class implementing the model. This class is usually one of |
796 | the name of the Perl class implementing the model. This class is |
586 | the "AnyEvent::Impl:xxx" modules, but can be any other class in the |
797 | usually one of the "AnyEvent::Impl:xxx" modules, but can be any |
587 | case AnyEvent has been extended at runtime (e.g. in *rxvt-unicode*). |
798 | other class in the case AnyEvent has been extended at runtime (e.g. |
588 | |
799 | in *rxvt-unicode* it will be "urxvt::anyevent"). |
589 | The known classes so far are: |
|
|
590 | |
|
|
591 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
|
|
592 | AnyEvent::Impl::Event based on Event, second best choice. |
|
|
593 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
594 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
|
|
595 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
|
|
596 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
|
|
597 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
598 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
|
|
599 | |
|
|
600 | There is no support for WxWidgets, as WxWidgets has no support for |
|
|
601 | watching file handles. However, you can use WxWidgets through the |
|
|
602 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
|
|
603 | second, which was considered to be too horrible to even consider for |
|
|
604 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by |
|
|
605 | using it's adaptor. |
|
|
606 | |
|
|
607 | AnyEvent knows about Prima and Wx and will try to use POE when |
|
|
608 | autodetecting them. |
|
|
609 | |
800 | |
610 | AnyEvent::detect |
801 | AnyEvent::detect |
611 | Returns $AnyEvent::MODEL, forcing autodetection of the event model |
802 | Returns $AnyEvent::MODEL, forcing autodetection of the event model |
612 | if necessary. You should only call this function right before you |
803 | if necessary. You should only call this function right before you |
613 | would have created an AnyEvent watcher anyway, that is, as late as |
804 | would have created an AnyEvent watcher anyway, that is, as late as |
614 | possible at runtime. |
805 | possible at runtime, and not e.g. while initialising of your module. |
|
|
806 | |
|
|
807 | If you need to do some initialisation before AnyEvent watchers are |
|
|
808 | created, use "post_detect". |
615 | |
809 | |
616 | $guard = AnyEvent::post_detect { BLOCK } |
810 | $guard = AnyEvent::post_detect { BLOCK } |
617 | Arranges for the code block to be executed as soon as the event |
811 | Arranges for the code block to be executed as soon as the event |
618 | model is autodetected (or immediately if this has already happened). |
812 | model is autodetected (or immediately if this has already happened). |
|
|
813 | |
|
|
814 | The block will be executed *after* the actual backend has been |
|
|
815 | detected ($AnyEvent::MODEL is set), but *before* any watchers have |
|
|
816 | been created, so it is possible to e.g. patch @AnyEvent::ISA or do |
|
|
817 | other initialisations - see the sources of AnyEvent::Strict or |
|
|
818 | AnyEvent::AIO to see how this is used. |
|
|
819 | |
|
|
820 | The most common usage is to create some global watchers, without |
|
|
821 | forcing event module detection too early, for example, AnyEvent::AIO |
|
|
822 | creates and installs the global IO::AIO watcher in a "post_detect" |
|
|
823 | block to avoid autodetecting the event module at load time. |
619 | |
824 | |
620 | If called in scalar or list context, then it creates and returns an |
825 | If called in scalar or list context, then it creates and returns an |
621 | object that automatically removes the callback again when it is |
826 | object that automatically removes the callback again when it is |
622 | destroyed. See Coro::BDB for a case where this is useful. |
827 | destroyed. See Coro::BDB for a case where this is useful. |
623 | |
828 | |
… | |
… | |
625 | If there are any code references in this array (you can "push" to it |
830 | If there are any code references in this array (you can "push" to it |
626 | before or after loading AnyEvent), then they will called directly |
831 | before or after loading AnyEvent), then they will called directly |
627 | after the event loop has been chosen. |
832 | after the event loop has been chosen. |
628 | |
833 | |
629 | You should check $AnyEvent::MODEL before adding to this array, |
834 | You should check $AnyEvent::MODEL before adding to this array, |
630 | though: if it contains a true value then the event loop has already |
835 | though: if it is defined then the event loop has already been |
631 | been detected, and the array will be ignored. |
836 | detected, and the array will be ignored. |
632 | |
837 | |
633 | Best use "AnyEvent::post_detect { BLOCK }" instead. |
838 | Best use "AnyEvent::post_detect { BLOCK }" when your application |
|
|
839 | allows it,as it takes care of these details. |
|
|
840 | |
|
|
841 | This variable is mainly useful for modules that can do something |
|
|
842 | useful when AnyEvent is used and thus want to know when it is |
|
|
843 | initialised, but do not need to even load it by default. This array |
|
|
844 | provides the means to hook into AnyEvent passively, without loading |
|
|
845 | it. |
634 | |
846 | |
635 | WHAT TO DO IN A MODULE |
847 | WHAT TO DO IN A MODULE |
636 | As a module author, you should "use AnyEvent" and call AnyEvent methods |
848 | As a module author, you should "use AnyEvent" and call AnyEvent methods |
637 | freely, but you should not load a specific event module or rely on it. |
849 | freely, but you should not load a specific event module or rely on it. |
638 | |
850 | |
… | |
… | |
689 | variable somewhere, waiting for it, and sending it when the program |
901 | variable somewhere, waiting for it, and sending it when the program |
690 | should exit cleanly. |
902 | should exit cleanly. |
691 | |
903 | |
692 | OTHER MODULES |
904 | OTHER MODULES |
693 | The following is a non-exhaustive list of additional modules that use |
905 | The following is a non-exhaustive list of additional modules that use |
694 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
906 | AnyEvent as a client and can therefore be mixed easily with other |
695 | in the same program. Some of the modules come with AnyEvent, some are |
907 | AnyEvent modules and other event loops in the same program. Some of the |
696 | available via CPAN. |
908 | modules come with AnyEvent, most are available via CPAN. |
697 | |
909 | |
698 | AnyEvent::Util |
910 | AnyEvent::Util |
699 | Contains various utility functions that replace often-used but |
911 | Contains various utility functions that replace often-used but |
700 | blocking functions such as "inet_aton" by event-/callback-based |
912 | blocking functions such as "inet_aton" by event-/callback-based |
701 | versions. |
913 | versions. |
… | |
… | |
707 | more. |
919 | more. |
708 | |
920 | |
709 | AnyEvent::Handle |
921 | AnyEvent::Handle |
710 | Provide read and write buffers, manages watchers for reads and |
922 | Provide read and write buffers, manages watchers for reads and |
711 | writes, supports raw and formatted I/O, I/O queued and fully |
923 | writes, supports raw and formatted I/O, I/O queued and fully |
712 | transparent and non-blocking SSL/TLS. |
924 | transparent and non-blocking SSL/TLS (via AnyEvent::TLS. |
713 | |
925 | |
714 | AnyEvent::DNS |
926 | AnyEvent::DNS |
715 | Provides rich asynchronous DNS resolver capabilities. |
927 | Provides rich asynchronous DNS resolver capabilities. |
716 | |
928 | |
717 | AnyEvent::HTTP |
929 | AnyEvent::HTTP |
… | |
… | |
738 | |
950 | |
739 | AnyEvent::GPSD |
951 | AnyEvent::GPSD |
740 | A non-blocking interface to gpsd, a daemon delivering GPS |
952 | A non-blocking interface to gpsd, a daemon delivering GPS |
741 | information. |
953 | information. |
742 | |
954 | |
|
|
955 | AnyEvent::IRC |
|
|
956 | AnyEvent based IRC client module family (replacing the older |
|
|
957 | Net::IRC3). |
|
|
958 | |
|
|
959 | AnyEvent::XMPP |
|
|
960 | AnyEvent based XMPP (Jabber protocol) module family (replacing the |
|
|
961 | older Net::XMPP2>. |
|
|
962 | |
743 | AnyEvent::IGS |
963 | AnyEvent::IGS |
744 | A non-blocking interface to the Internet Go Server protocol (used by |
964 | A non-blocking interface to the Internet Go Server protocol (used by |
745 | App::IGS). |
965 | App::IGS). |
746 | |
966 | |
747 | Net::IRC3 |
|
|
748 | AnyEvent based IRC client module family. |
|
|
749 | |
|
|
750 | Net::XMPP2 |
|
|
751 | AnyEvent based XMPP (Jabber protocol) module family. |
|
|
752 | |
|
|
753 | Net::FCP |
967 | Net::FCP |
754 | AnyEvent-based implementation of the Freenet Client Protocol, |
968 | AnyEvent-based implementation of the Freenet Client Protocol, |
755 | birthplace of AnyEvent. |
969 | birthplace of AnyEvent. |
756 | |
970 | |
757 | Event::ExecFlow |
971 | Event::ExecFlow |
758 | High level API for event-based execution flow control. |
972 | High level API for event-based execution flow control. |
759 | |
973 | |
760 | Coro |
974 | Coro |
761 | Has special support for AnyEvent via Coro::AnyEvent. |
975 | Has special support for AnyEvent via Coro::AnyEvent. |
762 | |
976 | |
763 | IO::Lambda |
977 | ERROR AND EXCEPTION HANDLING |
764 | The lambda approach to I/O - don't ask, look there. Can use |
978 | In general, AnyEvent does not do any error handling - it relies on the |
765 | AnyEvent. |
979 | caller to do that if required. The AnyEvent::Strict module (see also the |
|
|
980 | "PERL_ANYEVENT_STRICT" environment variable, below) provides strict |
|
|
981 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
982 | development. |
766 | |
983 | |
767 | SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
984 | As for exception handling (i.e. runtime errors and exceptions thrown |
768 | This is an advanced topic that you do not normally need to use AnyEvent |
985 | while executing a callback), this is not only highly event-loop |
769 | in a module. This section is only of use to event loop authors who want |
986 | specific, but also not in any way wrapped by this module, as this is the |
770 | to provide AnyEvent compatibility. |
987 | job of the main program. |
771 | |
988 | |
772 | If you need to support another event library which isn't directly |
989 | The pure perl event loop simply re-throws the exception (usually within |
773 | supported by AnyEvent, you can supply your own interface to it by |
990 | "condvar->recv"), the Event and EV modules call "$Event/EV::DIED->()", |
774 | pushing, before the first watcher gets created, the package name of the |
991 | Glib uses "install_exception_handler" and so on. |
775 | event module and the package name of the interface to use onto |
|
|
776 | @AnyEvent::REGISTRY. You can do that before and even without loading |
|
|
777 | AnyEvent, so it is reasonably cheap. |
|
|
778 | |
|
|
779 | Example: |
|
|
780 | |
|
|
781 | push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::]; |
|
|
782 | |
|
|
783 | This tells AnyEvent to (literally) use the "urxvt::anyevent::" |
|
|
784 | package/class when it finds the "urxvt" package/module is already |
|
|
785 | loaded. |
|
|
786 | |
|
|
787 | When AnyEvent is loaded and asked to find a suitable event model, it |
|
|
788 | will first check for the presence of urxvt by trying to "use" the |
|
|
789 | "urxvt::anyevent" module. |
|
|
790 | |
|
|
791 | The class should provide implementations for all watcher types. See |
|
|
792 | AnyEvent::Impl::EV (source code), AnyEvent::Impl::Glib (Source code) and |
|
|
793 | so on for actual examples. Use "perldoc -m AnyEvent::Impl::Glib" to see |
|
|
794 | the sources. |
|
|
795 | |
|
|
796 | If you don't provide "signal" and "child" watchers than AnyEvent will |
|
|
797 | provide suitable (hopefully) replacements. |
|
|
798 | |
|
|
799 | The above example isn't fictitious, the *rxvt-unicode* (a.k.a. urxvt) |
|
|
800 | terminal emulator uses the above line as-is. An interface isn't included |
|
|
801 | in AnyEvent because it doesn't make sense outside the embedded |
|
|
802 | interpreter inside *rxvt-unicode*, and it is updated and maintained as |
|
|
803 | part of the *rxvt-unicode* distribution. |
|
|
804 | |
|
|
805 | *rxvt-unicode* also cheats a bit by not providing blocking access to |
|
|
806 | condition variables: code blocking while waiting for a condition will |
|
|
807 | "die". This still works with most modules/usages, and blocking calls |
|
|
808 | must not be done in an interactive application, so it makes sense. |
|
|
809 | |
992 | |
810 | ENVIRONMENT VARIABLES |
993 | ENVIRONMENT VARIABLES |
811 | The following environment variables are used by this module: |
994 | The following environment variables are used by this module or its |
|
|
995 | submodules. |
|
|
996 | |
|
|
997 | Note that AnyEvent will remove *all* environment variables starting with |
|
|
998 | "PERL_ANYEVENT_" from %ENV when it is loaded while taint mode is |
|
|
999 | enabled. |
812 | |
1000 | |
813 | "PERL_ANYEVENT_VERBOSE" |
1001 | "PERL_ANYEVENT_VERBOSE" |
814 | By default, AnyEvent will be completely silent except in fatal |
1002 | By default, AnyEvent will be completely silent except in fatal |
815 | conditions. You can set this environment variable to make AnyEvent |
1003 | conditions. You can set this environment variable to make AnyEvent |
816 | more talkative. |
1004 | more talkative. |
… | |
… | |
819 | conditions, such as not being able to load the event model specified |
1007 | conditions, such as not being able to load the event model specified |
820 | by "PERL_ANYEVENT_MODEL". |
1008 | by "PERL_ANYEVENT_MODEL". |
821 | |
1009 | |
822 | When set to 2 or higher, cause AnyEvent to report to STDERR which |
1010 | When set to 2 or higher, cause AnyEvent to report to STDERR which |
823 | event model it chooses. |
1011 | event model it chooses. |
|
|
1012 | |
|
|
1013 | When set to 8 or higher, then AnyEvent will report extra information |
|
|
1014 | on which optional modules it loads and how it implements certain |
|
|
1015 | features. |
824 | |
1016 | |
825 | "PERL_ANYEVENT_STRICT" |
1017 | "PERL_ANYEVENT_STRICT" |
826 | AnyEvent does not do much argument checking by default, as thorough |
1018 | AnyEvent does not do much argument checking by default, as thorough |
827 | argument checking is very costly. Setting this variable to a true |
1019 | argument checking is very costly. Setting this variable to a true |
828 | value will cause AnyEvent to load "AnyEvent::Strict" and then to |
1020 | value will cause AnyEvent to load "AnyEvent::Strict" and then to |
829 | thoroughly check the arguments passed to most method calls. If it |
1021 | thoroughly check the arguments passed to most method calls. If it |
830 | finds any problems it will croak. |
1022 | finds any problems, it will croak. |
831 | |
1023 | |
832 | In other words, enables "strict" mode. |
1024 | In other words, enables "strict" mode. |
833 | |
1025 | |
834 | Unlike "use strict" it is definitely recommended ot keep it off in |
1026 | Unlike "use strict" (or it's modern cousin, "use common::sense", it |
835 | production. |
1027 | is definitely recommended to keep it off in production. Keeping |
|
|
1028 | "PERL_ANYEVENT_STRICT=1" in your environment while developing |
|
|
1029 | programs can be very useful, however. |
836 | |
1030 | |
837 | "PERL_ANYEVENT_MODEL" |
1031 | "PERL_ANYEVENT_MODEL" |
838 | This can be used to specify the event model to be used by AnyEvent, |
1032 | 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 |
1033 | before auto detection and -probing kicks in. It must be a string |
840 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
1034 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
… | |
… | |
859 | mentioned will be used, and preference will be given to protocols |
1053 | mentioned will be used, and preference will be given to protocols |
860 | mentioned earlier in the list. |
1054 | mentioned earlier in the list. |
861 | |
1055 | |
862 | This variable can effectively be used for denial-of-service attacks |
1056 | This variable can effectively be used for denial-of-service attacks |
863 | against local programs (e.g. when setuid), although the impact is |
1057 | against local programs (e.g. when setuid), although the impact is |
864 | likely small, as the program has to handle connection errors |
1058 | likely small, as the program has to handle conenction and other |
865 | already- |
1059 | failures anyways. |
866 | |
1060 | |
867 | Examples: "PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6" - prefer IPv4 over |
1061 | Examples: "PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6" - prefer IPv4 over |
868 | IPv6, but support both and try to use both. |
1062 | IPv6, but support both and try to use both. |
869 | "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to |
1063 | "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to |
870 | resolve or contact IPv6 addresses. |
1064 | resolve or contact IPv6 addresses. |
… | |
… | |
881 | EDNS0 in its DNS requests. |
1075 | EDNS0 in its DNS requests. |
882 | |
1076 | |
883 | "PERL_ANYEVENT_MAX_FORKS" |
1077 | "PERL_ANYEVENT_MAX_FORKS" |
884 | The maximum number of child processes that |
1078 | The maximum number of child processes that |
885 | "AnyEvent::Util::fork_call" will create in parallel. |
1079 | "AnyEvent::Util::fork_call" will create in parallel. |
|
|
1080 | |
|
|
1081 | "PERL_ANYEVENT_MAX_OUTSTANDING_DNS" |
|
|
1082 | The default value for the "max_outstanding" parameter for the |
|
|
1083 | default DNS resolver - this is the maximum number of parallel DNS |
|
|
1084 | requests that are sent to the DNS server. |
|
|
1085 | |
|
|
1086 | "PERL_ANYEVENT_RESOLV_CONF" |
|
|
1087 | The file to use instead of /etc/resolv.conf (or OS-specific |
|
|
1088 | configuration) in the default resolver. When set to the empty |
|
|
1089 | string, no default config will be used. |
|
|
1090 | |
|
|
1091 | "PERL_ANYEVENT_CA_FILE", "PERL_ANYEVENT_CA_PATH". |
|
|
1092 | When neither "ca_file" nor "ca_path" was specified during |
|
|
1093 | AnyEvent::TLS context creation, and either of these environment |
|
|
1094 | variables exist, they will be used to specify CA certificate |
|
|
1095 | locations instead of a system-dependent default. |
|
|
1096 | |
|
|
1097 | "PERL_ANYEVENT_AVOID_GUARD" and "PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT" |
|
|
1098 | When these are set to 1, then the respective modules are not loaded. |
|
|
1099 | Mostly good for testing AnyEvent itself. |
|
|
1100 | |
|
|
1101 | SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
|
|
1102 | This is an advanced topic that you do not normally need to use AnyEvent |
|
|
1103 | in a module. This section is only of use to event loop authors who want |
|
|
1104 | to provide AnyEvent compatibility. |
|
|
1105 | |
|
|
1106 | If you need to support another event library which isn't directly |
|
|
1107 | supported by AnyEvent, you can supply your own interface to it by |
|
|
1108 | pushing, before the first watcher gets created, the package name of the |
|
|
1109 | event module and the package name of the interface to use onto |
|
|
1110 | @AnyEvent::REGISTRY. You can do that before and even without loading |
|
|
1111 | AnyEvent, so it is reasonably cheap. |
|
|
1112 | |
|
|
1113 | Example: |
|
|
1114 | |
|
|
1115 | push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::]; |
|
|
1116 | |
|
|
1117 | This tells AnyEvent to (literally) use the "urxvt::anyevent::" |
|
|
1118 | package/class when it finds the "urxvt" package/module is already |
|
|
1119 | loaded. |
|
|
1120 | |
|
|
1121 | When AnyEvent is loaded and asked to find a suitable event model, it |
|
|
1122 | will first check for the presence of urxvt by trying to "use" the |
|
|
1123 | "urxvt::anyevent" module. |
|
|
1124 | |
|
|
1125 | The class should provide implementations for all watcher types. See |
|
|
1126 | AnyEvent::Impl::EV (source code), AnyEvent::Impl::Glib (Source code) and |
|
|
1127 | so on for actual examples. Use "perldoc -m AnyEvent::Impl::Glib" to see |
|
|
1128 | the sources. |
|
|
1129 | |
|
|
1130 | If you don't provide "signal" and "child" watchers than AnyEvent will |
|
|
1131 | provide suitable (hopefully) replacements. |
|
|
1132 | |
|
|
1133 | The above example isn't fictitious, the *rxvt-unicode* (a.k.a. urxvt) |
|
|
1134 | terminal emulator uses the above line as-is. An interface isn't included |
|
|
1135 | in AnyEvent because it doesn't make sense outside the embedded |
|
|
1136 | interpreter inside *rxvt-unicode*, and it is updated and maintained as |
|
|
1137 | part of the *rxvt-unicode* distribution. |
|
|
1138 | |
|
|
1139 | *rxvt-unicode* also cheats a bit by not providing blocking access to |
|
|
1140 | condition variables: code blocking while waiting for a condition will |
|
|
1141 | "die". This still works with most modules/usages, and blocking calls |
|
|
1142 | must not be done in an interactive application, so it makes sense. |
886 | |
1143 | |
887 | EXAMPLE PROGRAM |
1144 | EXAMPLE PROGRAM |
888 | The following program uses an I/O watcher to read data from STDIN, a |
1145 | 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 |
1146 | timer to display a message once per second, and a condition variable to |
890 | quit the program when the user enters quit: |
1147 | quit the program when the user enters quit: |
… | |
… | |
1077 | *destroy* is the time, in microseconds, that it takes to destroy a |
1334 | *destroy* is the time, in microseconds, that it takes to destroy a |
1078 | single watcher. |
1335 | single watcher. |
1079 | |
1336 | |
1080 | Results |
1337 | Results |
1081 | name watchers bytes create invoke destroy comment |
1338 | name watchers bytes create invoke destroy comment |
1082 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1339 | 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 |
1340 | 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 |
1341 | 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 |
1342 | 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 |
1343 | 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 |
1344 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1345 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1346 | IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll |
1088 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1347 | 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 |
1348 | 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 |
1349 | 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 |
1350 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1092 | |
1351 | |
1093 | Discussion |
1352 | Discussion |
1094 | The benchmark does *not* measure scalability of the event loop very |
1353 | 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) |
1354 | 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 |
1355 | can never compete with an event loop that uses epoll when the number of |
… | |
… | |
1121 | few of them active), of course, but this was not subject of this |
1380 | few of them active), of course, but this was not subject of this |
1122 | benchmark. |
1381 | benchmark. |
1123 | |
1382 | |
1124 | The "Event" module has a relatively high setup and callback invocation |
1383 | The "Event" module has a relatively high setup and callback invocation |
1125 | cost, but overall scores in on the third place. |
1384 | cost, but overall scores in on the third place. |
|
|
1385 | |
|
|
1386 | "IO::Async" performs admirably well, about on par with "Event", even |
|
|
1387 | when using its pure perl backend. |
1126 | |
1388 | |
1127 | "Glib"'s memory usage is quite a bit higher, but it features a faster |
1389 | "Glib"'s memory usage is quite a bit higher, but it features a faster |
1128 | callback invocation and overall ends up in the same class as "Event". |
1390 | callback invocation and overall ends up in the same class as "Event". |
1129 | However, Glib scales extremely badly, doubling the number of watchers |
1391 | However, Glib scales extremely badly, doubling the number of watchers |
1130 | increases the processing time by more than a factor of four, making it |
1392 | increases the processing time by more than a factor of four, making it |
… | |
… | |
1201 | single "request", that is, reading the token from the pipe and |
1463 | single "request", that is, reading the token from the pipe and |
1202 | forwarding it to another server. This includes deleting the old timeout |
1464 | forwarding it to another server. This includes deleting the old timeout |
1203 | and creating a new one that moves the timeout into the future. |
1465 | and creating a new one that moves the timeout into the future. |
1204 | |
1466 | |
1205 | Results |
1467 | Results |
1206 | name sockets create request |
1468 | name sockets create request |
1207 | EV 20000 69.01 11.16 |
1469 | EV 20000 69.01 11.16 |
1208 | Perl 20000 73.32 35.87 |
1470 | Perl 20000 73.32 35.87 |
|
|
1471 | IOAsync 20000 157.00 98.14 epoll |
|
|
1472 | IOAsync 20000 159.31 616.06 poll |
1209 | Event 20000 212.62 257.32 |
1473 | Event 20000 212.62 257.32 |
1210 | Glib 20000 651.16 1896.30 |
1474 | Glib 20000 651.16 1896.30 |
1211 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1475 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1212 | |
1476 | |
1213 | Discussion |
1477 | Discussion |
1214 | This benchmark *does* measure scalability and overall performance of the |
1478 | This benchmark *does* measure scalability and overall performance of the |
1215 | particular event loop. |
1479 | particular event loop. |
1216 | |
1480 | |
1217 | EV is again fastest. Since it is using epoll on my system, the setup |
1481 | EV is again fastest. Since it is using epoll on my system, the setup |
1218 | time is relatively high, though. |
1482 | time is relatively high, though. |
1219 | |
1483 | |
1220 | Perl surprisingly comes second. It is much faster than the C-based event |
1484 | Perl surprisingly comes second. It is much faster than the C-based event |
1221 | loops Event and Glib. |
1485 | loops Event and Glib. |
|
|
1486 | |
|
|
1487 | IO::Async performs very well when using its epoll backend, and still |
|
|
1488 | quite good compared to Glib when using its pure perl backend. |
1222 | |
1489 | |
1223 | Event suffers from high setup time as well (look at its code and you |
1490 | Event suffers from high setup time as well (look at its code and you |
1224 | will understand why). Callback invocation also has a high overhead |
1491 | will understand why). Callback invocation also has a high overhead |
1225 | compared to the "$_->() for .."-style loop that the Perl event loop |
1492 | compared to the "$_->() for .."-style loop that the Perl event loop |
1226 | uses. Event uses select or poll in basically all documented |
1493 | uses. Event uses select or poll in basically all documented |
… | |
… | |
1277 | |
1544 | |
1278 | Summary |
1545 | Summary |
1279 | * C-based event loops perform very well with small number of watchers, |
1546 | * C-based event loops perform very well with small number of watchers, |
1280 | as the management overhead dominates. |
1547 | as the management overhead dominates. |
1281 | |
1548 | |
|
|
1549 | THE IO::Lambda BENCHMARK |
|
|
1550 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
1551 | could be misinterpreted to make AnyEvent look bad. In fact, the |
|
|
1552 | benchmark simply compares IO::Lambda with POE, and IO::Lambda looks |
|
|
1553 | better (which shouldn't come as a surprise to anybody). As such, the |
|
|
1554 | benchmark is fine, and mostly shows that the AnyEvent backend from |
|
|
1555 | IO::Lambda isn't very optimal. But how would AnyEvent compare when used |
|
|
1556 | without the extra baggage? To explore this, I wrote the equivalent |
|
|
1557 | benchmark for AnyEvent. |
|
|
1558 | |
|
|
1559 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
1560 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
1561 | creates the next connection. This is a rather bad benchmark, as it |
|
|
1562 | doesn't test the efficiency of the framework or much non-blocking I/O, |
|
|
1563 | but it is a benchmark nevertheless. |
|
|
1564 | |
|
|
1565 | name runtime |
|
|
1566 | Lambda/select 0.330 sec |
|
|
1567 | + optimized 0.122 sec |
|
|
1568 | Lambda/AnyEvent 0.327 sec |
|
|
1569 | + optimized 0.138 sec |
|
|
1570 | Raw sockets/select 0.077 sec |
|
|
1571 | POE/select, components 0.662 sec |
|
|
1572 | POE/select, raw sockets 0.226 sec |
|
|
1573 | POE/select, optimized 0.404 sec |
|
|
1574 | |
|
|
1575 | AnyEvent/select/nb 0.085 sec |
|
|
1576 | AnyEvent/EV/nb 0.068 sec |
|
|
1577 | +state machine 0.134 sec |
|
|
1578 | |
|
|
1579 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
1580 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
1581 | defeating the purpose of an event-based solution. All of the newly |
|
|
1582 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
1583 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
1584 | resolver), so AnyEvent is at a disadvantage here, as non-blocking |
|
|
1585 | connects generally require a lot more bookkeeping and event handling |
|
|
1586 | than blocking connects (which involve a single syscall only). |
|
|
1587 | |
|
|
1588 | The last AnyEvent benchmark additionally uses AnyEvent::Handle, which |
|
|
1589 | offers similar expressive power as POE and IO::Lambda, using |
|
|
1590 | conventional Perl syntax. This means that both the echo server and the |
|
|
1591 | client are 100% non-blocking, further placing it at a disadvantage. |
|
|
1592 | |
|
|
1593 | As you can see, the AnyEvent + EV combination even beats the |
|
|
1594 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
1595 | backend easily beats IO::Lambda and POE. |
|
|
1596 | |
|
|
1597 | And even the 100% non-blocking version written using the high-level (and |
|
|
1598 | slow :) AnyEvent::Handle abstraction beats both POE and IO::Lambda by a |
|
|
1599 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
1600 | in a non-blocking way. |
|
|
1601 | |
|
|
1602 | The two AnyEvent benchmarks programs can be found as eg/ae0.pl and |
|
|
1603 | eg/ae2.pl in the AnyEvent distribution, the remaining benchmarks are |
|
|
1604 | part of the IO::lambda distribution and were used without any changes. |
|
|
1605 | |
|
|
1606 | SIGNALS |
|
|
1607 | AnyEvent currently installs handlers for these signals: |
|
|
1608 | |
|
|
1609 | SIGCHLD |
|
|
1610 | A handler for "SIGCHLD" is installed by AnyEvent's child watcher |
|
|
1611 | emulation for event loops that do not support them natively. Also, |
|
|
1612 | some event loops install a similar handler. |
|
|
1613 | |
|
|
1614 | Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, |
|
|
1615 | then AnyEvent will reset it to default, to avoid losing child exit |
|
|
1616 | statuses. |
|
|
1617 | |
|
|
1618 | SIGPIPE |
|
|
1619 | A no-op handler is installed for "SIGPIPE" when $SIG{PIPE} is |
|
|
1620 | "undef" when AnyEvent gets loaded. |
|
|
1621 | |
|
|
1622 | The rationale for this is that AnyEvent users usually do not really |
|
|
1623 | depend on SIGPIPE delivery (which is purely an optimisation for |
|
|
1624 | shell use, or badly-written programs), but "SIGPIPE" can cause |
|
|
1625 | spurious and rare program exits as a lot of people do not expect |
|
|
1626 | "SIGPIPE" when writing to some random socket. |
|
|
1627 | |
|
|
1628 | The rationale for installing a no-op handler as opposed to ignoring |
|
|
1629 | it is that this way, the handler will be restored to defaults on |
|
|
1630 | exec. |
|
|
1631 | |
|
|
1632 | Feel free to install your own handler, or reset it to defaults. |
|
|
1633 | |
|
|
1634 | RECOMMENDED/OPTIONAL MODULES |
|
|
1635 | One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and |
|
|
1636 | it's built-in modules) are required to use it. |
|
|
1637 | |
|
|
1638 | That does not mean that AnyEvent won't take advantage of some additional |
|
|
1639 | modules if they are installed. |
|
|
1640 | |
|
|
1641 | This section epxlains which additional modules will be used, and how |
|
|
1642 | they affect AnyEvent's operetion. |
|
|
1643 | |
|
|
1644 | Async::Interrupt |
|
|
1645 | This slightly arcane module is used to implement fast signal |
|
|
1646 | handling: To my knowledge, there is no way to do completely |
|
|
1647 | race-free and quick signal handling in pure perl. To ensure that |
|
|
1648 | signals still get delivered, AnyEvent will start an interval timer |
|
|
1649 | to wake up perl (and catch the signals) with soemd elay (default is |
|
|
1650 | 10 seconds, look for $AnyEvent::MAX_SIGNAL_LATENCY). |
|
|
1651 | |
|
|
1652 | If this module is available, then it will be used to implement |
|
|
1653 | signal catching, which means that signals will not be delayed, and |
|
|
1654 | the event loop will not be interrupted regularly, which is more |
|
|
1655 | efficient (And good for battery life on laptops). |
|
|
1656 | |
|
|
1657 | This affects not just the pure-perl event loop, but also other event |
|
|
1658 | loops that have no signal handling on their own (e.g. Glib, Tk, Qt). |
|
|
1659 | |
|
|
1660 | EV This module isn't really "optional", as it is simply one of the |
|
|
1661 | backend event loops that AnyEvent can use. However, it is simply the |
|
|
1662 | best event loop available in terms of features, speed and stability: |
|
|
1663 | It supports the AnyEvent API optimally, implements all the watcher |
|
|
1664 | types in XS, does automatic timer adjustments even when no monotonic |
|
|
1665 | clock is available, can take avdantage of advanced kernel interfaces |
|
|
1666 | such as "epoll" and "kqueue", and is the fastest backend *by far*. |
|
|
1667 | You can even embed Glib/Gtk2 in it (or vice versa, see EV::Glib and |
|
|
1668 | Glib::EV). |
|
|
1669 | |
|
|
1670 | Guard |
|
|
1671 | The guard module, when used, will be used to implement |
|
|
1672 | "AnyEvent::Util::guard". This speeds up guards considerably (and |
|
|
1673 | uses a lot less memory), but otherwise doesn't affect guard |
|
|
1674 | operation much. It is purely used for performance. |
|
|
1675 | |
|
|
1676 | JSON and JSON::XS |
|
|
1677 | This module is required when you want to read or write JSON data via |
|
|
1678 | AnyEvent::Handle. It is also written in pure-perl, but can take |
|
|
1679 | advantage of the ulta-high-speed JSON::XS module when it is |
|
|
1680 | installed. |
|
|
1681 | |
|
|
1682 | In fact, AnyEvent::Handle will use JSON::XS by default if it is |
|
|
1683 | installed. |
|
|
1684 | |
|
|
1685 | Net::SSLeay |
|
|
1686 | Implementing TLS/SSL in Perl is certainly interesting, but not very |
|
|
1687 | worthwhile: If this module is installed, then AnyEvent::Handle (with |
|
|
1688 | the help of AnyEvent::TLS), gains the ability to do TLS/SSL. |
|
|
1689 | |
|
|
1690 | Time::HiRes |
|
|
1691 | This module is part of perl since release 5.008. It will be used |
|
|
1692 | when the chosen event library does not come with a timing source on |
|
|
1693 | it's own. The pure-perl event loop (AnyEvent::Impl::Perl) will |
|
|
1694 | additionally use it to try to use a monotonic clock for timing |
|
|
1695 | stability. |
|
|
1696 | |
1282 | FORK |
1697 | FORK |
1283 | Most event libraries are not fork-safe. The ones who are usually are |
1698 | 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. |
1699 | because they rely on inefficient but fork-safe "select" or "poll" calls. |
1285 | Only EV is fully fork-aware. |
1700 | Only EV is fully fork-aware. |
1286 | |
1701 | |
1287 | If you have to fork, you must either do so *before* creating your first |
1702 | If you have to fork, you must either do so *before* creating your first |
1288 | watcher OR you must not use AnyEvent at all in the child. |
1703 | watcher OR you must not use AnyEvent at all in the child OR you must do |
|
|
1704 | something completely out of the scope of AnyEvent. |
1289 | |
1705 | |
1290 | SECURITY CONSIDERATIONS |
1706 | SECURITY CONSIDERATIONS |
1291 | AnyEvent can be forced to load any event model via |
1707 | AnyEvent can be forced to load any event model via |
1292 | $ENV{PERL_ANYEVENT_MODEL}. While this cannot (to my knowledge) be used |
1708 | $ENV{PERL_ANYEVENT_MODEL}. While this cannot (to my knowledge) be used |
1293 | to execute arbitrary code or directly gain access, it can easily be used |
1709 | to execute arbitrary code or directly gain access, it can easily be used |
… | |
… | |
1297 | |
1713 | |
1298 | You can make AnyEvent completely ignore this variable by deleting it |
1714 | You can make AnyEvent completely ignore this variable by deleting it |
1299 | before the first watcher gets created, e.g. with a "BEGIN" block: |
1715 | before the first watcher gets created, e.g. with a "BEGIN" block: |
1300 | |
1716 | |
1301 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1717 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1302 | |
1718 | |
1303 | use AnyEvent; |
1719 | use AnyEvent; |
1304 | |
1720 | |
1305 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1721 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1306 | be used to probe what backend is used and gain other information (which |
1722 | be used to probe what backend is used and gain other information (which |
1307 | is probably even less useful to an attacker than PERL_ANYEVENT_MODEL), |
1723 | is probably even less useful to an attacker than PERL_ANYEVENT_MODEL), |
1308 | and $ENV{PERL_ANYEGENT_STRICT}. |
1724 | and $ENV{PERL_ANYEVENT_STRICT}. |
|
|
1725 | |
|
|
1726 | Note that AnyEvent will remove *all* environment variables starting with |
|
|
1727 | "PERL_ANYEVENT_" from %ENV when it is loaded while taint mode is |
|
|
1728 | enabled. |
1309 | |
1729 | |
1310 | BUGS |
1730 | BUGS |
1311 | Perl 5.8 has numerous memleaks that sometimes hit this module and are |
1731 | 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 |
1732 | 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 |
1733 | 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 |
1734 | annoying memleaks, such as leaking on "map" and "grep" but it is usually |
1315 | not as pronounced). |
1735 | not as pronounced). |
1316 | |
1736 | |
1317 | SEE ALSO |
1737 | SEE ALSO |
1318 | Utility functions: AnyEvent::Util. |
1738 | Utility functions: AnyEvent::Util. |
1319 | |
1739 | |
1320 | Event modules: EV, EV::Glib, Glib::EV, Event, Glib::Event, Glib, Tk, |
1740 | Event modules: EV, EV::Glib, Glib::EV, Event, Glib::Event, Glib, Tk, |
1321 | Event::Lib, Qt, POE. |
1741 | Event::Lib, Qt, POE. |
1322 | |
1742 | |
1323 | Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event, |
1743 | Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event, |
1324 | AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl, |
1744 | AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl, |
1325 | AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE. |
1745 | AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE, |
|
|
1746 | AnyEvent::Impl::IOAsync. |
1326 | |
1747 | |
1327 | Non-blocking file handles, sockets, TCP clients and servers: |
1748 | Non-blocking file handles, sockets, TCP clients and servers: |
1328 | AnyEvent::Handle, AnyEvent::Socket. |
1749 | AnyEvent::Handle, AnyEvent::Socket, AnyEvent::TLS. |
1329 | |
1750 | |
1330 | Asynchronous DNS: AnyEvent::DNS. |
1751 | Asynchronous DNS: AnyEvent::DNS. |
1331 | |
1752 | |
1332 | Coroutine support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event, |
1753 | Coroutine support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event, |
1333 | |
1754 | |
1334 | Nontrivial usage examples: Net::FCP, Net::XMPP2, AnyEvent::DNS. |
1755 | Nontrivial usage examples: AnyEvent::GPSD, AnyEvent::XMPP, |
|
|
1756 | AnyEvent::HTTP. |
1335 | |
1757 | |
1336 | AUTHOR |
1758 | AUTHOR |
1337 | Marc Lehmann <schmorp@schmorp.de> |
1759 | Marc Lehmann <schmorp@schmorp.de> |
1338 | http://home.schmorp.de/ |
1760 | http://home.schmorp.de/ |
1339 | |
1761 | |