1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - provide framework for multiple event loops |
4 | |
4 | |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported |
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6 | event loops. |
6 | |
7 | |
7 | =head1 SYNOPSIS |
8 | =head1 SYNOPSIS |
8 | |
9 | |
9 | use AnyEvent; |
10 | use AnyEvent; |
10 | |
11 | |
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12 | # file descriptor readable |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { ... }); |
13 | my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); |
12 | |
14 | |
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15 | # one-shot or repeating timers |
13 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
16 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
14 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
17 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
15 | |
18 | |
16 | print AnyEvent->now; # prints current event loop time |
19 | print AnyEvent->now; # prints current event loop time |
17 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
20 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
18 | |
21 | |
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22 | # POSIX signal |
19 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
23 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
20 | |
24 | |
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25 | # child process exit |
21 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
26 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
22 | my ($pid, $status) = @_; |
27 | my ($pid, $status) = @_; |
23 | ... |
28 | ... |
24 | }); |
29 | }); |
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30 | |
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31 | # called when event loop idle (if applicable) |
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32 | my $w = AnyEvent->idle (cb => sub { ... }); |
25 | |
33 | |
26 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
34 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
27 | $w->send; # wake up current and all future recv's |
35 | $w->send; # wake up current and all future recv's |
28 | $w->recv; # enters "main loop" till $condvar gets ->send |
36 | $w->recv; # enters "main loop" till $condvar gets ->send |
29 | # use a condvar in callback mode: |
37 | # use a condvar in callback mode: |
… | |
… | |
137 | These watchers are normal Perl objects with normal Perl lifetime. After |
145 | These watchers are normal Perl objects with normal Perl lifetime. After |
138 | creating a watcher it will immediately "watch" for events and invoke the |
146 | creating a watcher it will immediately "watch" for events and invoke the |
139 | callback when the event occurs (of course, only when the event model |
147 | callback when the event occurs (of course, only when the event model |
140 | is in control). |
148 | is in control). |
141 | |
149 | |
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150 | Note that B<callbacks must not permanently change global variables> |
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151 | potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< |
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152 | callbacks must not C<die> >>. The former is good programming practise in |
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153 | Perl and the latter stems from the fact that exception handling differs |
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154 | widely between event loops. |
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155 | |
142 | To disable the watcher you have to destroy it (e.g. by setting the |
156 | To disable the watcher you have to destroy it (e.g. by setting the |
143 | variable you store it in to C<undef> or otherwise deleting all references |
157 | variable you store it in to C<undef> or otherwise deleting all references |
144 | to it). |
158 | to it). |
145 | |
159 | |
146 | All watchers are created by calling a method on the C<AnyEvent> class. |
160 | All watchers are created by calling a method on the C<AnyEvent> class. |
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162 | =head2 I/O WATCHERS |
176 | =head2 I/O WATCHERS |
163 | |
177 | |
164 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
178 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
165 | with the following mandatory key-value pairs as arguments: |
179 | with the following mandatory key-value pairs as arguments: |
166 | |
180 | |
167 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events |
181 | C<fh> is the Perl I<file handle> (I<not> file descriptor, see below) to |
168 | (AnyEvent might or might not keep a reference to this file handle). C<poll> |
182 | watch for events (AnyEvent might or might not keep a reference to this |
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183 | file handle). Note that only file handles pointing to things for which |
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184 | non-blocking operation makes sense are allowed. This includes sockets, |
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185 | most character devices, pipes, fifos and so on, but not for example files |
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186 | or block devices. |
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187 | |
169 | must be a string that is either C<r> or C<w>, which creates a watcher |
188 | C<poll> must be a string that is either C<r> or C<w>, which creates a |
170 | waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the |
189 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
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190 | |
171 | callback to invoke each time the file handle becomes ready. |
191 | C<cb> is the callback to invoke each time the file handle becomes ready. |
172 | |
192 | |
173 | Although the callback might get passed parameters, their value and |
193 | Although the callback might get passed parameters, their value and |
174 | presence is undefined and you cannot rely on them. Portable AnyEvent |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
175 | callbacks cannot use arguments passed to I/O watcher callbacks. |
195 | callbacks cannot use arguments passed to I/O watcher callbacks. |
176 | |
196 | |
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189 | chomp (my $input = <STDIN>); |
209 | chomp (my $input = <STDIN>); |
190 | warn "read: $input\n"; |
210 | warn "read: $input\n"; |
191 | undef $w; |
211 | undef $w; |
192 | }); |
212 | }); |
193 | |
213 | |
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214 | =head3 GETTING A FILE HANDLE FROM A FILE DESCRIPTOR |
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215 | |
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216 | It is not uncommon to only have a file descriptor, while AnyEvent requires |
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217 | a Perl file handle. |
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218 | |
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219 | There are basically two methods to convert a file descriptor into a file handle. If you own |
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220 | the file descriptor, you can open it with C<&=>, as in: |
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221 | |
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222 | open my $fh, "<&=$fileno" or die "xxx: ยง!"; |
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223 | |
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224 | This will "own" the file descriptor, meaning that when C<$fh> is |
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225 | destroyed, it will automatically close the C<$fileno>. Also, note that |
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226 | the open mode (read, write, read/write) must correspond with how the |
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227 | underlying file descriptor was opened. |
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228 | |
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229 | In many cases, taking over the file descriptor is now what you want, in |
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230 | which case the only alternative is to dup the file descriptor: |
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231 | |
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232 | open my $fh, "<&$fileno" or die "xxx: $!"; |
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233 | |
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234 | This has the advantage of not closing the file descriptor and the |
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235 | disadvantage of making a slow copy. |
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236 | |
194 | =head2 TIME WATCHERS |
237 | =head2 TIME WATCHERS |
195 | |
238 | |
196 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
239 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
197 | method with the following mandatory arguments: |
240 | method with the following mandatory arguments: |
198 | |
241 | |
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308 | In either case, if you care (and in most cases, you don't), then you |
351 | In either case, if you care (and in most cases, you don't), then you |
309 | can get whatever behaviour you want with any event loop, by taking the |
352 | can get whatever behaviour you want with any event loop, by taking the |
310 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
353 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
311 | account. |
354 | account. |
312 | |
355 | |
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356 | =item AnyEvent->now_update |
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357 | |
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358 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
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359 | the current time for each loop iteration (see the discussion of L<< |
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360 | AnyEvent->now >>, above). |
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361 | |
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362 | When a callback runs for a long time (or when the process sleeps), then |
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363 | this "current" time will differ substantially from the real time, which |
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364 | might affect timers and time-outs. |
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365 | |
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366 | When this is the case, you can call this method, which will update the |
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367 | event loop's idea of "current time". |
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368 | |
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369 | Note that updating the time I<might> cause some events to be handled. |
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370 | |
313 | =back |
371 | =back |
314 | |
372 | |
315 | =head2 SIGNAL WATCHERS |
373 | =head2 SIGNAL WATCHERS |
316 | |
374 | |
317 | You can watch for signals using a signal watcher, C<signal> is the signal |
375 | You can watch for signals using a signal watcher, C<signal> is the signal |
… | |
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340 | =head2 CHILD PROCESS WATCHERS |
398 | =head2 CHILD PROCESS WATCHERS |
341 | |
399 | |
342 | You can also watch on a child process exit and catch its exit status. |
400 | You can also watch on a child process exit and catch its exit status. |
343 | |
401 | |
344 | The child process is specified by the C<pid> argument (if set to C<0>, it |
402 | The child process is specified by the C<pid> argument (if set to C<0>, it |
345 | watches for any child process exit). The watcher will trigger as often |
403 | watches for any child process exit). The watcher will triggered only when |
346 | as status change for the child are received. This works by installing a |
404 | the child process has finished and an exit status is available, not on |
347 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
405 | any trace events (stopped/continued). |
348 | and exit status (as returned by waitpid), so unlike other watcher types, |
406 | |
349 | you I<can> rely on child watcher callback arguments. |
407 | The callback will be called with the pid and exit status (as returned by |
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408 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
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409 | callback arguments. |
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410 | |
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411 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
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412 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
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413 | random child processes (waiting for specific child processes, e.g. inside |
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414 | C<system>, is just fine). |
350 | |
415 | |
351 | There is a slight catch to child watchers, however: you usually start them |
416 | There is a slight catch to child watchers, however: you usually start them |
352 | I<after> the child process was created, and this means the process could |
417 | I<after> the child process was created, and this means the process could |
353 | have exited already (and no SIGCHLD will be sent anymore). |
418 | have exited already (and no SIGCHLD will be sent anymore). |
354 | |
419 | |
355 | Not all event models handle this correctly (POE doesn't), but even for |
420 | Not all event models handle this correctly (neither POE nor IO::Async do, |
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421 | see their AnyEvent::Impl manpages for details), but even for event models |
356 | event models that I<do> handle this correctly, they usually need to be |
422 | that I<do> handle this correctly, they usually need to be loaded before |
357 | loaded before the process exits (i.e. before you fork in the first place). |
423 | the process exits (i.e. before you fork in the first place). AnyEvent's |
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424 | pure perl event loop handles all cases correctly regardless of when you |
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425 | start the watcher. |
358 | |
426 | |
359 | This means you cannot create a child watcher as the very first thing in an |
427 | This means you cannot create a child watcher as the very first |
360 | AnyEvent program, you I<have> to create at least one watcher before you |
428 | thing in an AnyEvent program, you I<have> to create at least one |
361 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
429 | watcher before you C<fork> the child (alternatively, you can call |
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430 | C<AnyEvent::detect>). |
362 | |
431 | |
363 | Example: fork a process and wait for it |
432 | Example: fork a process and wait for it |
364 | |
433 | |
365 | my $done = AnyEvent->condvar; |
434 | my $done = AnyEvent->condvar; |
366 | |
435 | |
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376 | ); |
445 | ); |
377 | |
446 | |
378 | # do something else, then wait for process exit |
447 | # do something else, then wait for process exit |
379 | $done->recv; |
448 | $done->recv; |
380 | |
449 | |
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450 | =head2 IDLE WATCHERS |
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451 | |
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452 | Sometimes there is a need to do something, but it is not so important |
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453 | to do it instantly, but only when there is nothing better to do. This |
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454 | "nothing better to do" is usually defined to be "no other events need |
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455 | attention by the event loop". |
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456 | |
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457 | Idle watchers ideally get invoked when the event loop has nothing |
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458 | better to do, just before it would block the process to wait for new |
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459 | events. Instead of blocking, the idle watcher is invoked. |
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460 | |
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461 | Most event loops unfortunately do not really support idle watchers (only |
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462 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
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463 | will simply call the callback "from time to time". |
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464 | |
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465 | Example: read lines from STDIN, but only process them when the |
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466 | program is otherwise idle: |
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467 | |
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468 | my @lines; # read data |
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469 | my $idle_w; |
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470 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
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471 | push @lines, scalar <STDIN>; |
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472 | |
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473 | # start an idle watcher, if not already done |
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474 | $idle_w ||= AnyEvent->idle (cb => sub { |
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475 | # handle only one line, when there are lines left |
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476 | if (my $line = shift @lines) { |
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477 | print "handled when idle: $line"; |
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478 | } else { |
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479 | # otherwise disable the idle watcher again |
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480 | undef $idle_w; |
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481 | } |
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482 | }); |
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483 | }); |
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484 | |
381 | =head2 CONDITION VARIABLES |
485 | =head2 CONDITION VARIABLES |
382 | |
486 | |
383 | If you are familiar with some event loops you will know that all of them |
487 | If you are familiar with some event loops you will know that all of them |
384 | require you to run some blocking "loop", "run" or similar function that |
488 | require you to run some blocking "loop", "run" or similar function that |
385 | will actively watch for new events and call your callbacks. |
489 | will actively watch for new events and call your callbacks. |
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518 | |
622 | |
519 | =item $cv->begin ([group callback]) |
623 | =item $cv->begin ([group callback]) |
520 | |
624 | |
521 | =item $cv->end |
625 | =item $cv->end |
522 | |
626 | |
523 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
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524 | |
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525 | These two methods can be used to combine many transactions/events into |
627 | These two methods can be used to combine many transactions/events into |
526 | one. For example, a function that pings many hosts in parallel might want |
628 | one. For example, a function that pings many hosts in parallel might want |
527 | to use a condition variable for the whole process. |
629 | to use a condition variable for the whole process. |
528 | |
630 | |
529 | Every call to C<< ->begin >> will increment a counter, and every call to |
631 | Every call to C<< ->begin >> will increment a counter, and every call to |
530 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
632 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
531 | >>, the (last) callback passed to C<begin> will be executed. That callback |
633 | >>, the (last) callback passed to C<begin> will be executed. That callback |
532 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
634 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
533 | callback was set, C<send> will be called without any arguments. |
635 | callback was set, C<send> will be called without any arguments. |
534 | |
636 | |
535 | Let's clarify this with the ping example: |
637 | You can think of C<< $cv->send >> giving you an OR condition (one call |
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638 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
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639 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
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640 | |
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641 | Let's start with a simple example: you have two I/O watchers (for example, |
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642 | STDOUT and STDERR for a program), and you want to wait for both streams to |
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643 | close before activating a condvar: |
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644 | |
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645 | my $cv = AnyEvent->condvar; |
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646 | |
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647 | $cv->begin; # first watcher |
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648 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
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649 | defined sysread $fh1, my $buf, 4096 |
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650 | or $cv->end; |
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651 | }); |
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652 | |
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653 | $cv->begin; # second watcher |
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654 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
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655 | defined sysread $fh2, my $buf, 4096 |
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656 | or $cv->end; |
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657 | }); |
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658 | |
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659 | $cv->recv; |
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660 | |
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661 | This works because for every event source (EOF on file handle), there is |
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662 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
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663 | sending. |
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664 | |
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665 | The ping example mentioned above is slightly more complicated, as the |
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666 | there are results to be passwd back, and the number of tasks that are |
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667 | begung can potentially be zero: |
536 | |
668 | |
537 | my $cv = AnyEvent->condvar; |
669 | my $cv = AnyEvent->condvar; |
538 | |
670 | |
539 | my %result; |
671 | my %result; |
540 | $cv->begin (sub { $cv->send (\%result) }); |
672 | $cv->begin (sub { $cv->send (\%result) }); |
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560 | loop, which serves two important purposes: first, it sets the callback |
692 | loop, which serves two important purposes: first, it sets the callback |
561 | to be called once the counter reaches C<0>, and second, it ensures that |
693 | to be called once the counter reaches C<0>, and second, it ensures that |
562 | C<send> is called even when C<no> hosts are being pinged (the loop |
694 | C<send> is called even when C<no> hosts are being pinged (the loop |
563 | doesn't execute once). |
695 | doesn't execute once). |
564 | |
696 | |
565 | This is the general pattern when you "fan out" into multiple subrequests: |
697 | This is the general pattern when you "fan out" into multiple (but |
566 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
698 | potentially none) subrequests: use an outer C<begin>/C<end> pair to set |
567 | is called at least once, and then, for each subrequest you start, call |
699 | the callback and ensure C<end> is called at least once, and then, for each |
568 | C<begin> and for each subrequest you finish, call C<end>. |
700 | subrequest you start, call C<begin> and for each subrequest you finish, |
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701 | call C<end>. |
569 | |
702 | |
570 | =back |
703 | =back |
571 | |
704 | |
572 | =head3 METHODS FOR CONSUMERS |
705 | =head3 METHODS FOR CONSUMERS |
573 | |
706 | |
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653 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
786 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
654 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
787 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
655 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
788 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
656 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
789 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
657 | |
790 | |
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791 | # warning, support for IO::Async is only partial, as it is too broken |
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792 | # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async. |
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793 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs). |
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794 | |
658 | There is no support for WxWidgets, as WxWidgets has no support for |
795 | There is no support for WxWidgets, as WxWidgets has no support for |
659 | watching file handles. However, you can use WxWidgets through the |
796 | watching file handles. However, you can use WxWidgets through the |
660 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
797 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
661 | second, which was considered to be too horrible to even consider for |
798 | second, which was considered to be too horrible to even consider for |
662 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
799 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
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818 | =item L<AnyEvent::IGS> |
955 | =item L<AnyEvent::IGS> |
819 | |
956 | |
820 | A non-blocking interface to the Internet Go Server protocol (used by |
957 | A non-blocking interface to the Internet Go Server protocol (used by |
821 | L<App::IGS>). |
958 | L<App::IGS>). |
822 | |
959 | |
823 | =item L<Net::IRC3> |
960 | =item L<AnyEvent::IRC> |
824 | |
961 | |
825 | AnyEvent based IRC client module family. |
962 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
826 | |
963 | |
827 | =item L<Net::XMPP2> |
964 | =item L<Net::XMPP2> |
828 | |
965 | |
829 | AnyEvent based XMPP (Jabber protocol) module family. |
966 | AnyEvent based XMPP (Jabber protocol) module family. |
830 | |
967 | |
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850 | =cut |
987 | =cut |
851 | |
988 | |
852 | package AnyEvent; |
989 | package AnyEvent; |
853 | |
990 | |
854 | no warnings; |
991 | no warnings; |
855 | use strict; |
992 | use strict qw(vars subs); |
856 | |
993 | |
857 | use Carp; |
994 | use Carp; |
858 | |
995 | |
859 | our $VERSION = 4.22; |
996 | our $VERSION = 4.8; |
860 | our $MODEL; |
997 | our $MODEL; |
861 | |
998 | |
862 | our $AUTOLOAD; |
999 | our $AUTOLOAD; |
863 | our @ISA; |
1000 | our @ISA; |
864 | |
1001 | |
865 | our @REGISTRY; |
1002 | our @REGISTRY; |
866 | |
1003 | |
867 | our $WIN32; |
1004 | our $WIN32; |
868 | |
1005 | |
869 | BEGIN { |
1006 | BEGIN { |
870 | my $win32 = ! ! ($^O =~ /mswin32/i); |
1007 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
871 | eval "sub WIN32(){ $win32 }"; |
1008 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
|
|
1009 | |
|
|
1010 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
1011 | if ${^TAINT}; |
872 | } |
1012 | } |
873 | |
1013 | |
874 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
1014 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
875 | |
1015 | |
876 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
1016 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
… | |
… | |
894 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
1034 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
895 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1035 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
896 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1036 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
897 | [Wx:: => AnyEvent::Impl::POE::], |
1037 | [Wx:: => AnyEvent::Impl::POE::], |
898 | [Prima:: => AnyEvent::Impl::POE::], |
1038 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
1039 | # IO::Async is just too broken - we would need workaorunds for its |
|
|
1040 | # byzantine signal and broken child handling, among others. |
|
|
1041 | # IO::Async is rather hard to detect, as it doesn't have any |
|
|
1042 | # obvious default class. |
|
|
1043 | # [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1044 | # [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1045 | # [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
899 | ); |
1046 | ); |
900 | |
1047 | |
901 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
1048 | our %method = map +($_ => 1), |
|
|
1049 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
902 | |
1050 | |
903 | our @post_detect; |
1051 | our @post_detect; |
904 | |
1052 | |
905 | sub post_detect(&) { |
1053 | sub post_detect(&) { |
906 | my ($cb) = @_; |
1054 | my ($cb) = @_; |
… | |
… | |
911 | 1 |
1059 | 1 |
912 | } else { |
1060 | } else { |
913 | push @post_detect, $cb; |
1061 | push @post_detect, $cb; |
914 | |
1062 | |
915 | defined wantarray |
1063 | defined wantarray |
916 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
1064 | ? bless \$cb, "AnyEvent::Util::postdetect" |
917 | : () |
1065 | : () |
918 | } |
1066 | } |
919 | } |
1067 | } |
920 | |
1068 | |
921 | sub AnyEvent::Util::PostDetect::DESTROY { |
1069 | sub AnyEvent::Util::postdetect::DESTROY { |
922 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1070 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
923 | } |
1071 | } |
924 | |
1072 | |
925 | sub detect() { |
1073 | sub detect() { |
926 | unless ($MODEL) { |
1074 | unless ($MODEL) { |
… | |
… | |
963 | last; |
1111 | last; |
964 | } |
1112 | } |
965 | } |
1113 | } |
966 | |
1114 | |
967 | $MODEL |
1115 | $MODEL |
968 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1116 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
969 | } |
1117 | } |
970 | } |
1118 | } |
971 | |
1119 | |
972 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1120 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
973 | |
1121 | |
… | |
… | |
994 | } |
1142 | } |
995 | |
1143 | |
996 | # utility function to dup a filehandle. this is used by many backends |
1144 | # utility function to dup a filehandle. this is used by many backends |
997 | # to support binding more than one watcher per filehandle (they usually |
1145 | # to support binding more than one watcher per filehandle (they usually |
998 | # allow only one watcher per fd, so we dup it to get a different one). |
1146 | # allow only one watcher per fd, so we dup it to get a different one). |
999 | sub _dupfh($$$$) { |
1147 | sub _dupfh($$;$$) { |
1000 | my ($poll, $fh, $r, $w) = @_; |
1148 | my ($poll, $fh, $r, $w) = @_; |
1001 | |
|
|
1002 | require Fcntl; |
|
|
1003 | |
1149 | |
1004 | # cygwin requires the fh mode to be matching, unix doesn't |
1150 | # cygwin requires the fh mode to be matching, unix doesn't |
1005 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1151 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1006 | : $poll eq "w" ? ($w, ">") |
1152 | : $poll eq "w" ? ($w, ">") |
1007 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
1153 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
1008 | |
1154 | |
1009 | open my $fh2, "$mode&" . fileno $fh |
1155 | open my $fh2, "$mode&" . fileno $fh |
1010 | or die "cannot dup() filehandle: $!"; |
1156 | or die "cannot dup() filehandle: $!,"; |
1011 | |
1157 | |
1012 | # we assume CLOEXEC is already set by perl in all important cases |
1158 | # we assume CLOEXEC is already set by perl in all important cases |
1013 | |
1159 | |
1014 | ($fh2, $rw) |
1160 | ($fh2, $rw) |
1015 | } |
1161 | } |
1016 | |
1162 | |
1017 | package AnyEvent::Base; |
1163 | package AnyEvent::Base; |
1018 | |
1164 | |
1019 | # default implementation for now and time |
1165 | # default implementations for many methods |
1020 | |
1166 | |
1021 | use Time::HiRes (); |
1167 | BEGIN { |
|
|
1168 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1169 | *_time = \&Time::HiRes::time; |
|
|
1170 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1171 | } else { |
|
|
1172 | *_time = sub { time }; # epic fail |
|
|
1173 | } |
|
|
1174 | } |
1022 | |
1175 | |
1023 | sub time { Time::HiRes::time } |
1176 | sub time { _time } |
1024 | sub now { Time::HiRes::time } |
1177 | sub now { _time } |
|
|
1178 | sub now_update { } |
1025 | |
1179 | |
1026 | # default implementation for ->condvar |
1180 | # default implementation for ->condvar |
1027 | |
1181 | |
1028 | sub condvar { |
1182 | sub condvar { |
1029 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1183 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
1030 | } |
1184 | } |
1031 | |
1185 | |
1032 | # default implementation for ->signal |
1186 | # default implementation for ->signal |
1033 | |
1187 | |
1034 | our %SIG_CB; |
1188 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1189 | |
|
|
1190 | sub _signal_exec { |
|
|
1191 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1192 | |
|
|
1193 | while (%SIG_EV) { |
|
|
1194 | for (keys %SIG_EV) { |
|
|
1195 | delete $SIG_EV{$_}; |
|
|
1196 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1197 | } |
|
|
1198 | } |
|
|
1199 | } |
1035 | |
1200 | |
1036 | sub signal { |
1201 | sub signal { |
1037 | my (undef, %arg) = @_; |
1202 | my (undef, %arg) = @_; |
1038 | |
1203 | |
|
|
1204 | unless ($SIGPIPE_R) { |
|
|
1205 | require Fcntl; |
|
|
1206 | |
|
|
1207 | if (AnyEvent::WIN32) { |
|
|
1208 | require AnyEvent::Util; |
|
|
1209 | |
|
|
1210 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1211 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1212 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1213 | } else { |
|
|
1214 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1215 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1216 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1217 | |
|
|
1218 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1219 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1220 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1221 | } |
|
|
1222 | |
|
|
1223 | $SIGPIPE_R |
|
|
1224 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1225 | |
|
|
1226 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1227 | } |
|
|
1228 | |
1039 | my $signal = uc $arg{signal} |
1229 | my $signal = uc $arg{signal} |
1040 | or Carp::croak "required option 'signal' is missing"; |
1230 | or Carp::croak "required option 'signal' is missing"; |
1041 | |
1231 | |
1042 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1232 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1043 | $SIG{$signal} ||= sub { |
1233 | $SIG{$signal} ||= sub { |
1044 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1234 | local $!; |
|
|
1235 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1236 | undef $SIG_EV{$signal}; |
1045 | }; |
1237 | }; |
1046 | |
1238 | |
1047 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1239 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
1048 | } |
1240 | } |
1049 | |
1241 | |
1050 | sub AnyEvent::Base::Signal::DESTROY { |
1242 | sub AnyEvent::Base::signal::DESTROY { |
1051 | my ($signal, $cb) = @{$_[0]}; |
1243 | my ($signal, $cb) = @{$_[0]}; |
1052 | |
1244 | |
1053 | delete $SIG_CB{$signal}{$cb}; |
1245 | delete $SIG_CB{$signal}{$cb}; |
1054 | |
1246 | |
|
|
1247 | # delete doesn't work with older perls - they then |
|
|
1248 | # print weird messages, or just unconditionally exit |
|
|
1249 | # instead of getting the default action. |
1055 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1250 | undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1056 | } |
1251 | } |
1057 | |
1252 | |
1058 | # default implementation for ->child |
1253 | # default implementation for ->child |
1059 | |
1254 | |
1060 | our %PID_CB; |
1255 | our %PID_CB; |
1061 | our $CHLD_W; |
1256 | our $CHLD_W; |
1062 | our $CHLD_DELAY_W; |
1257 | our $CHLD_DELAY_W; |
1063 | our $PID_IDLE; |
|
|
1064 | our $WNOHANG; |
1258 | our $WNOHANG; |
1065 | |
1259 | |
1066 | sub _child_wait { |
1260 | sub _sigchld { |
1067 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1261 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1068 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1262 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1069 | (values %{ $PID_CB{0} || {} }); |
1263 | (values %{ $PID_CB{0} || {} }); |
1070 | } |
1264 | } |
1071 | |
|
|
1072 | undef $PID_IDLE; |
|
|
1073 | } |
|
|
1074 | |
|
|
1075 | sub _sigchld { |
|
|
1076 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
1077 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
1078 | undef $CHLD_DELAY_W; |
|
|
1079 | &_child_wait; |
|
|
1080 | }); |
|
|
1081 | } |
1265 | } |
1082 | |
1266 | |
1083 | sub child { |
1267 | sub child { |
1084 | my (undef, %arg) = @_; |
1268 | my (undef, %arg) = @_; |
1085 | |
1269 | |
1086 | defined (my $pid = $arg{pid} + 0) |
1270 | defined (my $pid = $arg{pid} + 0) |
1087 | or Carp::croak "required option 'pid' is missing"; |
1271 | or Carp::croak "required option 'pid' is missing"; |
1088 | |
1272 | |
1089 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1273 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1090 | |
1274 | |
1091 | unless ($WNOHANG) { |
|
|
1092 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1275 | $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1093 | } |
|
|
1094 | |
1276 | |
1095 | unless ($CHLD_W) { |
1277 | unless ($CHLD_W) { |
1096 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1278 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1097 | # child could be a zombie already, so make at least one round |
1279 | # child could be a zombie already, so make at least one round |
1098 | &_sigchld; |
1280 | &_sigchld; |
1099 | } |
1281 | } |
1100 | |
1282 | |
1101 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1283 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
1102 | } |
1284 | } |
1103 | |
1285 | |
1104 | sub AnyEvent::Base::Child::DESTROY { |
1286 | sub AnyEvent::Base::child::DESTROY { |
1105 | my ($pid, $cb) = @{$_[0]}; |
1287 | my ($pid, $cb) = @{$_[0]}; |
1106 | |
1288 | |
1107 | delete $PID_CB{$pid}{$cb}; |
1289 | delete $PID_CB{$pid}{$cb}; |
1108 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1290 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1109 | |
1291 | |
1110 | undef $CHLD_W unless keys %PID_CB; |
1292 | undef $CHLD_W unless keys %PID_CB; |
|
|
1293 | } |
|
|
1294 | |
|
|
1295 | # idle emulation is done by simply using a timer, regardless |
|
|
1296 | # of whether the process is idle or not, and not letting |
|
|
1297 | # the callback use more than 50% of the time. |
|
|
1298 | sub idle { |
|
|
1299 | my (undef, %arg) = @_; |
|
|
1300 | |
|
|
1301 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1302 | |
|
|
1303 | $rcb = sub { |
|
|
1304 | if ($cb) { |
|
|
1305 | $w = _time; |
|
|
1306 | &$cb; |
|
|
1307 | $w = _time - $w; |
|
|
1308 | |
|
|
1309 | # never use more then 50% of the time for the idle watcher, |
|
|
1310 | # within some limits |
|
|
1311 | $w = 0.0001 if $w < 0.0001; |
|
|
1312 | $w = 5 if $w > 5; |
|
|
1313 | |
|
|
1314 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1315 | } else { |
|
|
1316 | # clean up... |
|
|
1317 | undef $w; |
|
|
1318 | undef $rcb; |
|
|
1319 | } |
|
|
1320 | }; |
|
|
1321 | |
|
|
1322 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1323 | |
|
|
1324 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1325 | } |
|
|
1326 | |
|
|
1327 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1328 | undef $${$_[0]}; |
1111 | } |
1329 | } |
1112 | |
1330 | |
1113 | package AnyEvent::CondVar; |
1331 | package AnyEvent::CondVar; |
1114 | |
1332 | |
1115 | our @ISA = AnyEvent::CondVar::Base::; |
1333 | our @ISA = AnyEvent::CondVar::Base::; |
… | |
… | |
1167 | } |
1385 | } |
1168 | |
1386 | |
1169 | # undocumented/compatibility with pre-3.4 |
1387 | # undocumented/compatibility with pre-3.4 |
1170 | *broadcast = \&send; |
1388 | *broadcast = \&send; |
1171 | *wait = \&_wait; |
1389 | *wait = \&_wait; |
|
|
1390 | |
|
|
1391 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1392 | |
|
|
1393 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1394 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1395 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1396 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1397 | development. |
|
|
1398 | |
|
|
1399 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1400 | executing a callback), this is not only highly event-loop specific, but |
|
|
1401 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1402 | program. |
|
|
1403 | |
|
|
1404 | The pure perl event loop simply re-throws the exception (usually |
|
|
1405 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1406 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1407 | so on. |
|
|
1408 | |
|
|
1409 | =head1 ENVIRONMENT VARIABLES |
|
|
1410 | |
|
|
1411 | The following environment variables are used by this module or its |
|
|
1412 | submodules. |
|
|
1413 | |
|
|
1414 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1415 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1416 | enabled. |
|
|
1417 | |
|
|
1418 | =over 4 |
|
|
1419 | |
|
|
1420 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1421 | |
|
|
1422 | By default, AnyEvent will be completely silent except in fatal |
|
|
1423 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1424 | talkative. |
|
|
1425 | |
|
|
1426 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1427 | conditions, such as not being able to load the event model specified by |
|
|
1428 | C<PERL_ANYEVENT_MODEL>. |
|
|
1429 | |
|
|
1430 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1431 | model it chooses. |
|
|
1432 | |
|
|
1433 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1434 | |
|
|
1435 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1436 | argument checking is very costly. Setting this variable to a true value |
|
|
1437 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1438 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1439 | it will croak. |
|
|
1440 | |
|
|
1441 | In other words, enables "strict" mode. |
|
|
1442 | |
|
|
1443 | Unlike C<use strict>, it is definitely recommended to keep it off in |
|
|
1444 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1445 | developing programs can be very useful, however. |
|
|
1446 | |
|
|
1447 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1448 | |
|
|
1449 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1450 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1451 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1452 | and the resulting module name is loaded and if the load was successful, |
|
|
1453 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1454 | auto detection and -probing. |
|
|
1455 | |
|
|
1456 | This functionality might change in future versions. |
|
|
1457 | |
|
|
1458 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1459 | could start your program like this: |
|
|
1460 | |
|
|
1461 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1462 | |
|
|
1463 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1464 | |
|
|
1465 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1466 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1467 | of auto probing). |
|
|
1468 | |
|
|
1469 | Must be set to a comma-separated list of protocols or address families, |
|
|
1470 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1471 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1472 | list. |
|
|
1473 | |
|
|
1474 | This variable can effectively be used for denial-of-service attacks |
|
|
1475 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1476 | small, as the program has to handle conenction and other failures anyways. |
|
|
1477 | |
|
|
1478 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1479 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1480 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1481 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1482 | IPv6, but prefer IPv6 over IPv4. |
|
|
1483 | |
|
|
1484 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1485 | |
|
|
1486 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1487 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1488 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1489 | default. |
|
|
1490 | |
|
|
1491 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1492 | EDNS0 in its DNS requests. |
|
|
1493 | |
|
|
1494 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1495 | |
|
|
1496 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1497 | will create in parallel. |
|
|
1498 | |
|
|
1499 | =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> |
|
|
1500 | |
|
|
1501 | The default value for the C<max_outstanding> parameter for the default DNS |
|
|
1502 | resolver - this is the maximum number of parallel DNS requests that are |
|
|
1503 | sent to the DNS server. |
|
|
1504 | |
|
|
1505 | =item C<PERL_ANYEVENT_RESOLV_CONF> |
|
|
1506 | |
|
|
1507 | The file to use instead of F</etc/resolv.conf> (or OS-specific |
|
|
1508 | configuration) in the default resolver. When set to the empty string, no |
|
|
1509 | default config will be used. |
|
|
1510 | |
|
|
1511 | =item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. |
|
|
1512 | |
|
|
1513 | When neither C<ca_file> nor C<ca_path> was specified during |
|
|
1514 | L<AnyEvent::TLS> context creation, and either of these environment |
|
|
1515 | variables exist, they will be used to specify CA certificate locations |
|
|
1516 | instead of a system-dependent default. |
|
|
1517 | |
|
|
1518 | =back |
1172 | |
1519 | |
1173 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1520 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1174 | |
1521 | |
1175 | This is an advanced topic that you do not normally need to use AnyEvent in |
1522 | This is an advanced topic that you do not normally need to use AnyEvent in |
1176 | a module. This section is only of use to event loop authors who want to |
1523 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1210 | |
1557 | |
1211 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1558 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1212 | condition variables: code blocking while waiting for a condition will |
1559 | condition variables: code blocking while waiting for a condition will |
1213 | C<die>. This still works with most modules/usages, and blocking calls must |
1560 | C<die>. This still works with most modules/usages, and blocking calls must |
1214 | not be done in an interactive application, so it makes sense. |
1561 | not be done in an interactive application, so it makes sense. |
1215 | |
|
|
1216 | =head1 ENVIRONMENT VARIABLES |
|
|
1217 | |
|
|
1218 | The following environment variables are used by this module: |
|
|
1219 | |
|
|
1220 | =over 4 |
|
|
1221 | |
|
|
1222 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1223 | |
|
|
1224 | By default, AnyEvent will be completely silent except in fatal |
|
|
1225 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1226 | talkative. |
|
|
1227 | |
|
|
1228 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1229 | conditions, such as not being able to load the event model specified by |
|
|
1230 | C<PERL_ANYEVENT_MODEL>. |
|
|
1231 | |
|
|
1232 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1233 | model it chooses. |
|
|
1234 | |
|
|
1235 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1236 | |
|
|
1237 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1238 | argument checking is very costly. Setting this variable to a true value |
|
|
1239 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1240 | check the arguments passed to most method calls. If it finds any problems |
|
|
1241 | it will croak. |
|
|
1242 | |
|
|
1243 | In other words, enables "strict" mode. |
|
|
1244 | |
|
|
1245 | Unlike C<use strict> it is definitely recommended ot keep it off in |
|
|
1246 | production. |
|
|
1247 | |
|
|
1248 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1249 | |
|
|
1250 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1251 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1252 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1253 | and the resulting module name is loaded and if the load was successful, |
|
|
1254 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1255 | auto detection and -probing. |
|
|
1256 | |
|
|
1257 | This functionality might change in future versions. |
|
|
1258 | |
|
|
1259 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1260 | could start your program like this: |
|
|
1261 | |
|
|
1262 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1263 | |
|
|
1264 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1265 | |
|
|
1266 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1267 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1268 | of auto probing). |
|
|
1269 | |
|
|
1270 | Must be set to a comma-separated list of protocols or address families, |
|
|
1271 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1272 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1273 | list. |
|
|
1274 | |
|
|
1275 | This variable can effectively be used for denial-of-service attacks |
|
|
1276 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1277 | small, as the program has to handle connection errors already- |
|
|
1278 | |
|
|
1279 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1280 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1281 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1282 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1283 | IPv6, but prefer IPv6 over IPv4. |
|
|
1284 | |
|
|
1285 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1286 | |
|
|
1287 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1288 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1289 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1290 | default. |
|
|
1291 | |
|
|
1292 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1293 | EDNS0 in its DNS requests. |
|
|
1294 | |
|
|
1295 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1296 | |
|
|
1297 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1298 | will create in parallel. |
|
|
1299 | |
|
|
1300 | =back |
|
|
1301 | |
1562 | |
1302 | =head1 EXAMPLE PROGRAM |
1563 | =head1 EXAMPLE PROGRAM |
1303 | |
1564 | |
1304 | The following program uses an I/O watcher to read data from STDIN, a timer |
1565 | The following program uses an I/O watcher to read data from STDIN, a timer |
1305 | to display a message once per second, and a condition variable to quit the |
1566 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1499 | watcher. |
1760 | watcher. |
1500 | |
1761 | |
1501 | =head3 Results |
1762 | =head3 Results |
1502 | |
1763 | |
1503 | name watchers bytes create invoke destroy comment |
1764 | name watchers bytes create invoke destroy comment |
1504 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1765 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1505 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1766 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1506 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1767 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1507 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1768 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1508 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1769 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1509 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1770 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1771 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1772 | IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll |
1510 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1773 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1511 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1774 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1512 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1775 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1513 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1776 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1514 | |
1777 | |
1515 | =head3 Discussion |
1778 | =head3 Discussion |
1516 | |
1779 | |
1517 | The benchmark does I<not> measure scalability of the event loop very |
1780 | The benchmark does I<not> measure scalability of the event loop very |
1518 | well. For example, a select-based event loop (such as the pure perl one) |
1781 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1543 | performance becomes really bad with lots of file descriptors (and few of |
1806 | performance becomes really bad with lots of file descriptors (and few of |
1544 | them active), of course, but this was not subject of this benchmark. |
1807 | them active), of course, but this was not subject of this benchmark. |
1545 | |
1808 | |
1546 | The C<Event> module has a relatively high setup and callback invocation |
1809 | The C<Event> module has a relatively high setup and callback invocation |
1547 | cost, but overall scores in on the third place. |
1810 | cost, but overall scores in on the third place. |
|
|
1811 | |
|
|
1812 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
1813 | when using its pure perl backend. |
1548 | |
1814 | |
1549 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1815 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1550 | faster callback invocation and overall ends up in the same class as |
1816 | faster callback invocation and overall ends up in the same class as |
1551 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1817 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1552 | watchers increases the processing time by more than a factor of four, |
1818 | watchers increases the processing time by more than a factor of four, |
… | |
… | |
1630 | it to another server. This includes deleting the old timeout and creating |
1896 | it to another server. This includes deleting the old timeout and creating |
1631 | a new one that moves the timeout into the future. |
1897 | a new one that moves the timeout into the future. |
1632 | |
1898 | |
1633 | =head3 Results |
1899 | =head3 Results |
1634 | |
1900 | |
1635 | name sockets create request |
1901 | name sockets create request |
1636 | EV 20000 69.01 11.16 |
1902 | EV 20000 69.01 11.16 |
1637 | Perl 20000 73.32 35.87 |
1903 | Perl 20000 73.32 35.87 |
|
|
1904 | IOAsync 20000 157.00 98.14 epoll |
|
|
1905 | IOAsync 20000 159.31 616.06 poll |
1638 | Event 20000 212.62 257.32 |
1906 | Event 20000 212.62 257.32 |
1639 | Glib 20000 651.16 1896.30 |
1907 | Glib 20000 651.16 1896.30 |
1640 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1908 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1641 | |
1909 | |
1642 | =head3 Discussion |
1910 | =head3 Discussion |
1643 | |
1911 | |
1644 | This benchmark I<does> measure scalability and overall performance of the |
1912 | This benchmark I<does> measure scalability and overall performance of the |
1645 | particular event loop. |
1913 | particular event loop. |
… | |
… | |
1647 | EV is again fastest. Since it is using epoll on my system, the setup time |
1915 | EV is again fastest. Since it is using epoll on my system, the setup time |
1648 | is relatively high, though. |
1916 | is relatively high, though. |
1649 | |
1917 | |
1650 | Perl surprisingly comes second. It is much faster than the C-based event |
1918 | Perl surprisingly comes second. It is much faster than the C-based event |
1651 | loops Event and Glib. |
1919 | loops Event and Glib. |
|
|
1920 | |
|
|
1921 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
1922 | good compared to Glib when using its pure perl backend. |
1652 | |
1923 | |
1653 | Event suffers from high setup time as well (look at its code and you will |
1924 | Event suffers from high setup time as well (look at its code and you will |
1654 | understand why). Callback invocation also has a high overhead compared to |
1925 | understand why). Callback invocation also has a high overhead compared to |
1655 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1926 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1656 | uses select or poll in basically all documented configurations. |
1927 | uses select or poll in basically all documented configurations. |
… | |
… | |
1719 | =item * C-based event loops perform very well with small number of |
1990 | =item * C-based event loops perform very well with small number of |
1720 | watchers, as the management overhead dominates. |
1991 | watchers, as the management overhead dominates. |
1721 | |
1992 | |
1722 | =back |
1993 | =back |
1723 | |
1994 | |
|
|
1995 | =head2 THE IO::Lambda BENCHMARK |
|
|
1996 | |
|
|
1997 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
1998 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
1999 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
2000 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
2001 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
2002 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
2003 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
2004 | |
|
|
2005 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
2006 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
2007 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
2008 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
2009 | benchmark nevertheless. |
|
|
2010 | |
|
|
2011 | name runtime |
|
|
2012 | Lambda/select 0.330 sec |
|
|
2013 | + optimized 0.122 sec |
|
|
2014 | Lambda/AnyEvent 0.327 sec |
|
|
2015 | + optimized 0.138 sec |
|
|
2016 | Raw sockets/select 0.077 sec |
|
|
2017 | POE/select, components 0.662 sec |
|
|
2018 | POE/select, raw sockets 0.226 sec |
|
|
2019 | POE/select, optimized 0.404 sec |
|
|
2020 | |
|
|
2021 | AnyEvent/select/nb 0.085 sec |
|
|
2022 | AnyEvent/EV/nb 0.068 sec |
|
|
2023 | +state machine 0.134 sec |
|
|
2024 | |
|
|
2025 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
2026 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
2027 | defeating the purpose of an event-based solution. All of the newly |
|
|
2028 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
2029 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
2030 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
2031 | generally require a lot more bookkeeping and event handling than blocking |
|
|
2032 | connects (which involve a single syscall only). |
|
|
2033 | |
|
|
2034 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
2035 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
2036 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
2037 | non-blocking, further placing it at a disadvantage. |
|
|
2038 | |
|
|
2039 | As you can see, the AnyEvent + EV combination even beats the |
|
|
2040 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
2041 | backend easily beats IO::Lambda and POE. |
|
|
2042 | |
|
|
2043 | And even the 100% non-blocking version written using the high-level (and |
|
|
2044 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
2045 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
2046 | in a non-blocking way. |
|
|
2047 | |
|
|
2048 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2049 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2050 | part of the IO::lambda distribution and were used without any changes. |
|
|
2051 | |
|
|
2052 | |
|
|
2053 | =head1 SIGNALS |
|
|
2054 | |
|
|
2055 | AnyEvent currently installs handlers for these signals: |
|
|
2056 | |
|
|
2057 | =over 4 |
|
|
2058 | |
|
|
2059 | =item SIGCHLD |
|
|
2060 | |
|
|
2061 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2062 | emulation for event loops that do not support them natively. Also, some |
|
|
2063 | event loops install a similar handler. |
|
|
2064 | |
|
|
2065 | If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will |
|
|
2066 | reset it to default, to avoid losing child exit statuses. |
|
|
2067 | |
|
|
2068 | =item SIGPIPE |
|
|
2069 | |
|
|
2070 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2071 | when AnyEvent gets loaded. |
|
|
2072 | |
|
|
2073 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2074 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2075 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2076 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2077 | some random socket. |
|
|
2078 | |
|
|
2079 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2080 | that this way, the handler will be restored to defaults on exec. |
|
|
2081 | |
|
|
2082 | Feel free to install your own handler, or reset it to defaults. |
|
|
2083 | |
|
|
2084 | =back |
|
|
2085 | |
|
|
2086 | =cut |
|
|
2087 | |
|
|
2088 | undef $SIG{CHLD} |
|
|
2089 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2090 | |
|
|
2091 | $SIG{PIPE} = sub { } |
|
|
2092 | unless defined $SIG{PIPE}; |
1724 | |
2093 | |
1725 | =head1 FORK |
2094 | =head1 FORK |
1726 | |
2095 | |
1727 | Most event libraries are not fork-safe. The ones who are usually are |
2096 | Most event libraries are not fork-safe. The ones who are usually are |
1728 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2097 | because they rely on inefficient but fork-safe C<select> or C<poll> |
… | |
… | |
1749 | use AnyEvent; |
2118 | use AnyEvent; |
1750 | |
2119 | |
1751 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2120 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1752 | be used to probe what backend is used and gain other information (which is |
2121 | be used to probe what backend is used and gain other information (which is |
1753 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
2122 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
1754 | $ENV{PERL_ANYEGENT_STRICT}. |
2123 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2124 | |
|
|
2125 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2126 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2127 | enabled. |
1755 | |
2128 | |
1756 | |
2129 | |
1757 | =head1 BUGS |
2130 | =head1 BUGS |
1758 | |
2131 | |
1759 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
2132 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
1760 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
2133 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
1761 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
2134 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
1762 | mamleaks, such as leaking on C<map> and C<grep> but it is usually not as |
2135 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1763 | pronounced). |
2136 | pronounced). |
1764 | |
2137 | |
1765 | |
2138 | |
1766 | =head1 SEE ALSO |
2139 | =head1 SEE ALSO |
1767 | |
2140 | |