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. |
… | |
… | |
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) to watch |
168 | (AnyEvent might or might not keep a reference to this file handle). C<poll> |
182 | for events (AnyEvent might or might not keep a reference to this file |
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183 | 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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308 | In either case, if you care (and in most cases, you don't), then you |
328 | 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 |
329 | can get whatever behaviour you want with any event loop, by taking the |
310 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
330 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
311 | account. |
331 | account. |
312 | |
332 | |
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333 | =item AnyEvent->now_update |
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334 | |
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335 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
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336 | the current time for each loop iteration (see the discussion of L<< |
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337 | AnyEvent->now >>, above). |
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338 | |
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339 | When a callback runs for a long time (or when the process sleeps), then |
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340 | this "current" time will differ substantially from the real time, which |
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341 | might affect timers and time-outs. |
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342 | |
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343 | When this is the case, you can call this method, which will update the |
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344 | event loop's idea of "current time". |
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345 | |
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346 | Note that updating the time I<might> cause some events to be handled. |
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347 | |
313 | =back |
348 | =back |
314 | |
349 | |
315 | =head2 SIGNAL WATCHERS |
350 | =head2 SIGNAL WATCHERS |
316 | |
351 | |
317 | You can watch for signals using a signal watcher, C<signal> is the signal |
352 | You can watch for signals using a signal watcher, C<signal> is the signal |
… | |
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340 | =head2 CHILD PROCESS WATCHERS |
375 | =head2 CHILD PROCESS WATCHERS |
341 | |
376 | |
342 | You can also watch on a child process exit and catch its exit status. |
377 | You can also watch on a child process exit and catch its exit status. |
343 | |
378 | |
344 | The child process is specified by the C<pid> argument (if set to C<0>, it |
379 | 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 |
380 | 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 |
381 | 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 |
382 | any trace events (stopped/continued). |
348 | and exit status (as returned by waitpid), so unlike other watcher types, |
383 | |
349 | you I<can> rely on child watcher callback arguments. |
384 | The callback will be called with the pid and exit status (as returned by |
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385 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
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386 | callback arguments. |
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387 | |
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388 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
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389 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
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390 | random child processes (waiting for specific child processes, e.g. inside |
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391 | C<system>, is just fine). |
350 | |
392 | |
351 | There is a slight catch to child watchers, however: you usually start them |
393 | 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 |
394 | I<after> the child process was created, and this means the process could |
353 | have exited already (and no SIGCHLD will be sent anymore). |
395 | have exited already (and no SIGCHLD will be sent anymore). |
354 | |
396 | |
355 | Not all event models handle this correctly (POE doesn't), but even for |
397 | Not all event models handle this correctly (neither POE nor IO::Async do, |
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398 | 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 |
399 | 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). |
400 | the process exits (i.e. before you fork in the first place). AnyEvent's |
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401 | pure perl event loop handles all cases correctly regardless of when you |
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402 | start the watcher. |
358 | |
403 | |
359 | This means you cannot create a child watcher as the very first thing in an |
404 | 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 |
405 | 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>). |
406 | watcher before you C<fork> the child (alternatively, you can call |
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407 | C<AnyEvent::detect>). |
362 | |
408 | |
363 | Example: fork a process and wait for it |
409 | Example: fork a process and wait for it |
364 | |
410 | |
365 | my $done = AnyEvent->condvar; |
411 | my $done = AnyEvent->condvar; |
366 | |
412 | |
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376 | ); |
422 | ); |
377 | |
423 | |
378 | # do something else, then wait for process exit |
424 | # do something else, then wait for process exit |
379 | $done->recv; |
425 | $done->recv; |
380 | |
426 | |
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427 | =head2 IDLE WATCHERS |
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428 | |
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429 | Sometimes there is a need to do something, but it is not so important |
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430 | to do it instantly, but only when there is nothing better to do. This |
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431 | "nothing better to do" is usually defined to be "no other events need |
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432 | attention by the event loop". |
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433 | |
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434 | Idle watchers ideally get invoked when the event loop has nothing |
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435 | better to do, just before it would block the process to wait for new |
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436 | events. Instead of blocking, the idle watcher is invoked. |
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437 | |
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438 | Most event loops unfortunately do not really support idle watchers (only |
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439 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
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440 | will simply call the callback "from time to time". |
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441 | |
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442 | Example: read lines from STDIN, but only process them when the |
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443 | program is otherwise idle: |
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444 | |
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445 | my @lines; # read data |
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446 | my $idle_w; |
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447 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
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448 | push @lines, scalar <STDIN>; |
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449 | |
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450 | # start an idle watcher, if not already done |
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451 | $idle_w ||= AnyEvent->idle (cb => sub { |
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452 | # handle only one line, when there are lines left |
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453 | if (my $line = shift @lines) { |
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454 | print "handled when idle: $line"; |
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455 | } else { |
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456 | # otherwise disable the idle watcher again |
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457 | undef $idle_w; |
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458 | } |
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459 | }); |
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460 | }); |
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461 | |
381 | =head2 CONDITION VARIABLES |
462 | =head2 CONDITION VARIABLES |
382 | |
463 | |
383 | If you are familiar with some event loops you will know that all of them |
464 | 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 |
465 | require you to run some blocking "loop", "run" or similar function that |
385 | will actively watch for new events and call your callbacks. |
466 | will actively watch for new events and call your callbacks. |
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518 | |
599 | |
519 | =item $cv->begin ([group callback]) |
600 | =item $cv->begin ([group callback]) |
520 | |
601 | |
521 | =item $cv->end |
602 | =item $cv->end |
522 | |
603 | |
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 |
604 | 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 |
605 | one. For example, a function that pings many hosts in parallel might want |
527 | to use a condition variable for the whole process. |
606 | to use a condition variable for the whole process. |
528 | |
607 | |
529 | Every call to C<< ->begin >> will increment a counter, and every call to |
608 | 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 |
609 | 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 |
610 | >>, 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 |
611 | 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. |
612 | callback was set, C<send> will be called without any arguments. |
534 | |
613 | |
535 | Let's clarify this with the ping example: |
614 | You can think of C<< $cv->send >> giving you an OR condition (one call |
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615 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
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616 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
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617 | |
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618 | Let's start with a simple example: you have two I/O watchers (for example, |
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619 | STDOUT and STDERR for a program), and you want to wait for both streams to |
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620 | close before activating a condvar: |
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621 | |
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622 | my $cv = AnyEvent->condvar; |
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623 | |
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624 | $cv->begin; # first watcher |
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625 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
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626 | defined sysread $fh1, my $buf, 4096 |
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627 | or $cv->end; |
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628 | }); |
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629 | |
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630 | $cv->begin; # second watcher |
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631 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
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632 | defined sysread $fh2, my $buf, 4096 |
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633 | or $cv->end; |
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634 | }); |
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635 | |
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636 | $cv->recv; |
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637 | |
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638 | This works because for every event source (EOF on file handle), there is |
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639 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
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640 | sending. |
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641 | |
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642 | The ping example mentioned above is slightly more complicated, as the |
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643 | there are results to be passwd back, and the number of tasks that are |
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644 | begung can potentially be zero: |
536 | |
645 | |
537 | my $cv = AnyEvent->condvar; |
646 | my $cv = AnyEvent->condvar; |
538 | |
647 | |
539 | my %result; |
648 | my %result; |
540 | $cv->begin (sub { $cv->send (\%result) }); |
649 | $cv->begin (sub { $cv->send (\%result) }); |
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560 | loop, which serves two important purposes: first, it sets the callback |
669 | 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 |
670 | 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 |
671 | C<send> is called even when C<no> hosts are being pinged (the loop |
563 | doesn't execute once). |
672 | doesn't execute once). |
564 | |
673 | |
565 | This is the general pattern when you "fan out" into multiple subrequests: |
674 | 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> |
675 | 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 |
676 | 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>. |
677 | subrequest you start, call C<begin> and for each subrequest you finish, |
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678 | call C<end>. |
569 | |
679 | |
570 | =back |
680 | =back |
571 | |
681 | |
572 | =head3 METHODS FOR CONSUMERS |
682 | =head3 METHODS FOR CONSUMERS |
573 | |
683 | |
… | |
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653 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
763 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
654 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
764 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
655 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
765 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
656 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
766 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
657 | |
767 | |
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768 | # warning, support for IO::Async is only partial, as it is too broken |
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769 | # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async. |
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770 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs). |
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771 | |
658 | There is no support for WxWidgets, as WxWidgets has no support for |
772 | There is no support for WxWidgets, as WxWidgets has no support for |
659 | watching file handles. However, you can use WxWidgets through the |
773 | 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 |
774 | 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 |
775 | 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 |
776 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
… | |
… | |
818 | =item L<AnyEvent::IGS> |
932 | =item L<AnyEvent::IGS> |
819 | |
933 | |
820 | A non-blocking interface to the Internet Go Server protocol (used by |
934 | A non-blocking interface to the Internet Go Server protocol (used by |
821 | L<App::IGS>). |
935 | L<App::IGS>). |
822 | |
936 | |
823 | =item L<Net::IRC3> |
937 | =item L<AnyEvent::IRC> |
824 | |
938 | |
825 | AnyEvent based IRC client module family. |
939 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
826 | |
940 | |
827 | =item L<Net::XMPP2> |
941 | =item L<Net::XMPP2> |
828 | |
942 | |
829 | AnyEvent based XMPP (Jabber protocol) module family. |
943 | AnyEvent based XMPP (Jabber protocol) module family. |
830 | |
944 | |
… | |
… | |
850 | =cut |
964 | =cut |
851 | |
965 | |
852 | package AnyEvent; |
966 | package AnyEvent; |
853 | |
967 | |
854 | no warnings; |
968 | no warnings; |
855 | use strict; |
969 | use strict qw(vars subs); |
856 | |
970 | |
857 | use Carp; |
971 | use Carp; |
858 | |
972 | |
859 | our $VERSION = 4.22; |
973 | our $VERSION = 4.8; |
860 | our $MODEL; |
974 | our $MODEL; |
861 | |
975 | |
862 | our $AUTOLOAD; |
976 | our $AUTOLOAD; |
863 | our @ISA; |
977 | our @ISA; |
864 | |
978 | |
865 | our @REGISTRY; |
979 | our @REGISTRY; |
866 | |
980 | |
867 | our $WIN32; |
981 | our $WIN32; |
868 | |
982 | |
869 | BEGIN { |
983 | BEGIN { |
870 | my $win32 = ! ! ($^O =~ /mswin32/i); |
984 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
871 | eval "sub WIN32(){ $win32 }"; |
985 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
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986 | |
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987 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
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988 | if ${^TAINT}; |
872 | } |
989 | } |
873 | |
990 | |
874 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
991 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
875 | |
992 | |
876 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
993 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
… | |
… | |
894 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
1011 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
895 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1012 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
896 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1013 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
897 | [Wx:: => AnyEvent::Impl::POE::], |
1014 | [Wx:: => AnyEvent::Impl::POE::], |
898 | [Prima:: => AnyEvent::Impl::POE::], |
1015 | [Prima:: => AnyEvent::Impl::POE::], |
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1016 | # IO::Async is just too broken - we would need workaorunds for its |
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1017 | # byzantine signal and broken child handling, among others. |
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1018 | # IO::Async is rather hard to detect, as it doesn't have any |
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1019 | # obvious default class. |
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1020 | # [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1021 | # [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1022 | # [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
899 | ); |
1023 | ); |
900 | |
1024 | |
901 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
1025 | our %method = map +($_ => 1), |
|
|
1026 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
902 | |
1027 | |
903 | our @post_detect; |
1028 | our @post_detect; |
904 | |
1029 | |
905 | sub post_detect(&) { |
1030 | sub post_detect(&) { |
906 | my ($cb) = @_; |
1031 | my ($cb) = @_; |
… | |
… | |
911 | 1 |
1036 | 1 |
912 | } else { |
1037 | } else { |
913 | push @post_detect, $cb; |
1038 | push @post_detect, $cb; |
914 | |
1039 | |
915 | defined wantarray |
1040 | defined wantarray |
916 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
1041 | ? bless \$cb, "AnyEvent::Util::postdetect" |
917 | : () |
1042 | : () |
918 | } |
1043 | } |
919 | } |
1044 | } |
920 | |
1045 | |
921 | sub AnyEvent::Util::PostDetect::DESTROY { |
1046 | sub AnyEvent::Util::postdetect::DESTROY { |
922 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1047 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
923 | } |
1048 | } |
924 | |
1049 | |
925 | sub detect() { |
1050 | sub detect() { |
926 | unless ($MODEL) { |
1051 | unless ($MODEL) { |
… | |
… | |
963 | last; |
1088 | last; |
964 | } |
1089 | } |
965 | } |
1090 | } |
966 | |
1091 | |
967 | $MODEL |
1092 | $MODEL |
968 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1093 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
969 | } |
1094 | } |
970 | } |
1095 | } |
971 | |
1096 | |
972 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1097 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
973 | |
1098 | |
… | |
… | |
994 | } |
1119 | } |
995 | |
1120 | |
996 | # utility function to dup a filehandle. this is used by many backends |
1121 | # utility function to dup a filehandle. this is used by many backends |
997 | # to support binding more than one watcher per filehandle (they usually |
1122 | # 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). |
1123 | # allow only one watcher per fd, so we dup it to get a different one). |
999 | sub _dupfh($$$$) { |
1124 | sub _dupfh($$;$$) { |
1000 | my ($poll, $fh, $r, $w) = @_; |
1125 | my ($poll, $fh, $r, $w) = @_; |
1001 | |
|
|
1002 | require Fcntl; |
|
|
1003 | |
1126 | |
1004 | # cygwin requires the fh mode to be matching, unix doesn't |
1127 | # cygwin requires the fh mode to be matching, unix doesn't |
1005 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1128 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
1006 | : $poll eq "w" ? ($w, ">") |
1129 | : $poll eq "w" ? ($w, ">") |
1007 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
1130 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
1008 | |
1131 | |
1009 | open my $fh2, "$mode&" . fileno $fh |
1132 | open my $fh2, "$mode&" . fileno $fh |
1010 | or die "cannot dup() filehandle: $!"; |
1133 | or die "cannot dup() filehandle: $!,"; |
1011 | |
1134 | |
1012 | # we assume CLOEXEC is already set by perl in all important cases |
1135 | # we assume CLOEXEC is already set by perl in all important cases |
1013 | |
1136 | |
1014 | ($fh2, $rw) |
1137 | ($fh2, $rw) |
1015 | } |
1138 | } |
1016 | |
1139 | |
1017 | package AnyEvent::Base; |
1140 | package AnyEvent::Base; |
1018 | |
1141 | |
1019 | # default implementation for now and time |
1142 | # default implementations for many methods |
1020 | |
1143 | |
1021 | use Time::HiRes (); |
1144 | BEGIN { |
|
|
1145 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1146 | *_time = \&Time::HiRes::time; |
|
|
1147 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1148 | } else { |
|
|
1149 | *_time = sub { time }; # epic fail |
|
|
1150 | } |
|
|
1151 | } |
1022 | |
1152 | |
1023 | sub time { Time::HiRes::time } |
1153 | sub time { _time } |
1024 | sub now { Time::HiRes::time } |
1154 | sub now { _time } |
|
|
1155 | sub now_update { } |
1025 | |
1156 | |
1026 | # default implementation for ->condvar |
1157 | # default implementation for ->condvar |
1027 | |
1158 | |
1028 | sub condvar { |
1159 | sub condvar { |
1029 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1160 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
1030 | } |
1161 | } |
1031 | |
1162 | |
1032 | # default implementation for ->signal |
1163 | # default implementation for ->signal |
1033 | |
1164 | |
1034 | our %SIG_CB; |
1165 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1166 | |
|
|
1167 | sub _signal_exec { |
|
|
1168 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1169 | |
|
|
1170 | while (%SIG_EV) { |
|
|
1171 | for (keys %SIG_EV) { |
|
|
1172 | delete $SIG_EV{$_}; |
|
|
1173 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1174 | } |
|
|
1175 | } |
|
|
1176 | } |
1035 | |
1177 | |
1036 | sub signal { |
1178 | sub signal { |
1037 | my (undef, %arg) = @_; |
1179 | my (undef, %arg) = @_; |
1038 | |
1180 | |
|
|
1181 | unless ($SIGPIPE_R) { |
|
|
1182 | require Fcntl; |
|
|
1183 | |
|
|
1184 | if (AnyEvent::WIN32) { |
|
|
1185 | require AnyEvent::Util; |
|
|
1186 | |
|
|
1187 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1188 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1189 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1190 | } else { |
|
|
1191 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1192 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1193 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1194 | |
|
|
1195 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1196 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1197 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1198 | } |
|
|
1199 | |
|
|
1200 | $SIGPIPE_R |
|
|
1201 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1202 | |
|
|
1203 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1204 | } |
|
|
1205 | |
1039 | my $signal = uc $arg{signal} |
1206 | my $signal = uc $arg{signal} |
1040 | or Carp::croak "required option 'signal' is missing"; |
1207 | or Carp::croak "required option 'signal' is missing"; |
1041 | |
1208 | |
1042 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1209 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1043 | $SIG{$signal} ||= sub { |
1210 | $SIG{$signal} ||= sub { |
1044 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1211 | local $!; |
|
|
1212 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1213 | undef $SIG_EV{$signal}; |
1045 | }; |
1214 | }; |
1046 | |
1215 | |
1047 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1216 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
1048 | } |
1217 | } |
1049 | |
1218 | |
1050 | sub AnyEvent::Base::Signal::DESTROY { |
1219 | sub AnyEvent::Base::signal::DESTROY { |
1051 | my ($signal, $cb) = @{$_[0]}; |
1220 | my ($signal, $cb) = @{$_[0]}; |
1052 | |
1221 | |
1053 | delete $SIG_CB{$signal}{$cb}; |
1222 | delete $SIG_CB{$signal}{$cb}; |
1054 | |
1223 | |
|
|
1224 | # delete doesn't work with older perls - they then |
|
|
1225 | # print weird messages, or just unconditionally exit |
|
|
1226 | # instead of getting the default action. |
1055 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1227 | undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1056 | } |
1228 | } |
1057 | |
1229 | |
1058 | # default implementation for ->child |
1230 | # default implementation for ->child |
1059 | |
1231 | |
1060 | our %PID_CB; |
1232 | our %PID_CB; |
1061 | our $CHLD_W; |
1233 | our $CHLD_W; |
1062 | our $CHLD_DELAY_W; |
1234 | our $CHLD_DELAY_W; |
1063 | our $PID_IDLE; |
|
|
1064 | our $WNOHANG; |
1235 | our $WNOHANG; |
1065 | |
1236 | |
1066 | sub _child_wait { |
1237 | sub _sigchld { |
1067 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1238 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1068 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1239 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1069 | (values %{ $PID_CB{0} || {} }); |
1240 | (values %{ $PID_CB{0} || {} }); |
1070 | } |
1241 | } |
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 | } |
1242 | } |
1082 | |
1243 | |
1083 | sub child { |
1244 | sub child { |
1084 | my (undef, %arg) = @_; |
1245 | my (undef, %arg) = @_; |
1085 | |
1246 | |
1086 | defined (my $pid = $arg{pid} + 0) |
1247 | defined (my $pid = $arg{pid} + 0) |
1087 | or Carp::croak "required option 'pid' is missing"; |
1248 | or Carp::croak "required option 'pid' is missing"; |
1088 | |
1249 | |
1089 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1250 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1090 | |
1251 | |
1091 | unless ($WNOHANG) { |
|
|
1092 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1252 | $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1093 | } |
|
|
1094 | |
1253 | |
1095 | unless ($CHLD_W) { |
1254 | unless ($CHLD_W) { |
1096 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1255 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1097 | # child could be a zombie already, so make at least one round |
1256 | # child could be a zombie already, so make at least one round |
1098 | &_sigchld; |
1257 | &_sigchld; |
1099 | } |
1258 | } |
1100 | |
1259 | |
1101 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1260 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
1102 | } |
1261 | } |
1103 | |
1262 | |
1104 | sub AnyEvent::Base::Child::DESTROY { |
1263 | sub AnyEvent::Base::child::DESTROY { |
1105 | my ($pid, $cb) = @{$_[0]}; |
1264 | my ($pid, $cb) = @{$_[0]}; |
1106 | |
1265 | |
1107 | delete $PID_CB{$pid}{$cb}; |
1266 | delete $PID_CB{$pid}{$cb}; |
1108 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1267 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1109 | |
1268 | |
1110 | undef $CHLD_W unless keys %PID_CB; |
1269 | undef $CHLD_W unless keys %PID_CB; |
|
|
1270 | } |
|
|
1271 | |
|
|
1272 | # idle emulation is done by simply using a timer, regardless |
|
|
1273 | # of whether the process is idle or not, and not letting |
|
|
1274 | # the callback use more than 50% of the time. |
|
|
1275 | sub idle { |
|
|
1276 | my (undef, %arg) = @_; |
|
|
1277 | |
|
|
1278 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1279 | |
|
|
1280 | $rcb = sub { |
|
|
1281 | if ($cb) { |
|
|
1282 | $w = _time; |
|
|
1283 | &$cb; |
|
|
1284 | $w = _time - $w; |
|
|
1285 | |
|
|
1286 | # never use more then 50% of the time for the idle watcher, |
|
|
1287 | # within some limits |
|
|
1288 | $w = 0.0001 if $w < 0.0001; |
|
|
1289 | $w = 5 if $w > 5; |
|
|
1290 | |
|
|
1291 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1292 | } else { |
|
|
1293 | # clean up... |
|
|
1294 | undef $w; |
|
|
1295 | undef $rcb; |
|
|
1296 | } |
|
|
1297 | }; |
|
|
1298 | |
|
|
1299 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1300 | |
|
|
1301 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1302 | } |
|
|
1303 | |
|
|
1304 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1305 | undef $${$_[0]}; |
1111 | } |
1306 | } |
1112 | |
1307 | |
1113 | package AnyEvent::CondVar; |
1308 | package AnyEvent::CondVar; |
1114 | |
1309 | |
1115 | our @ISA = AnyEvent::CondVar::Base::; |
1310 | our @ISA = AnyEvent::CondVar::Base::; |
… | |
… | |
1167 | } |
1362 | } |
1168 | |
1363 | |
1169 | # undocumented/compatibility with pre-3.4 |
1364 | # undocumented/compatibility with pre-3.4 |
1170 | *broadcast = \&send; |
1365 | *broadcast = \&send; |
1171 | *wait = \&_wait; |
1366 | *wait = \&_wait; |
|
|
1367 | |
|
|
1368 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1369 | |
|
|
1370 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1371 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1372 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1373 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1374 | development. |
|
|
1375 | |
|
|
1376 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1377 | executing a callback), this is not only highly event-loop specific, but |
|
|
1378 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1379 | program. |
|
|
1380 | |
|
|
1381 | The pure perl event loop simply re-throws the exception (usually |
|
|
1382 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1383 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1384 | so on. |
|
|
1385 | |
|
|
1386 | =head1 ENVIRONMENT VARIABLES |
|
|
1387 | |
|
|
1388 | The following environment variables are used by this module or its |
|
|
1389 | submodules. |
|
|
1390 | |
|
|
1391 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1392 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1393 | enabled. |
|
|
1394 | |
|
|
1395 | =over 4 |
|
|
1396 | |
|
|
1397 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1398 | |
|
|
1399 | By default, AnyEvent will be completely silent except in fatal |
|
|
1400 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1401 | talkative. |
|
|
1402 | |
|
|
1403 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1404 | conditions, such as not being able to load the event model specified by |
|
|
1405 | C<PERL_ANYEVENT_MODEL>. |
|
|
1406 | |
|
|
1407 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1408 | model it chooses. |
|
|
1409 | |
|
|
1410 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1411 | |
|
|
1412 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1413 | argument checking is very costly. Setting this variable to a true value |
|
|
1414 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1415 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1416 | it will croak. |
|
|
1417 | |
|
|
1418 | In other words, enables "strict" mode. |
|
|
1419 | |
|
|
1420 | Unlike C<use strict>, it is definitely recommended to keep it off in |
|
|
1421 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1422 | developing programs can be very useful, however. |
|
|
1423 | |
|
|
1424 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1425 | |
|
|
1426 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1427 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1428 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1429 | and the resulting module name is loaded and if the load was successful, |
|
|
1430 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1431 | auto detection and -probing. |
|
|
1432 | |
|
|
1433 | This functionality might change in future versions. |
|
|
1434 | |
|
|
1435 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1436 | could start your program like this: |
|
|
1437 | |
|
|
1438 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1439 | |
|
|
1440 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1441 | |
|
|
1442 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1443 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1444 | of auto probing). |
|
|
1445 | |
|
|
1446 | Must be set to a comma-separated list of protocols or address families, |
|
|
1447 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1448 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1449 | list. |
|
|
1450 | |
|
|
1451 | This variable can effectively be used for denial-of-service attacks |
|
|
1452 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1453 | small, as the program has to handle conenction and other failures anyways. |
|
|
1454 | |
|
|
1455 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1456 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1457 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1458 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1459 | IPv6, but prefer IPv6 over IPv4. |
|
|
1460 | |
|
|
1461 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1462 | |
|
|
1463 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1464 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1465 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1466 | default. |
|
|
1467 | |
|
|
1468 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1469 | EDNS0 in its DNS requests. |
|
|
1470 | |
|
|
1471 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1472 | |
|
|
1473 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1474 | will create in parallel. |
|
|
1475 | |
|
|
1476 | =back |
1172 | |
1477 | |
1173 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1478 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1174 | |
1479 | |
1175 | This is an advanced topic that you do not normally need to use AnyEvent in |
1480 | 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 |
1481 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1210 | |
1515 | |
1211 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1516 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1212 | condition variables: code blocking while waiting for a condition will |
1517 | condition variables: code blocking while waiting for a condition will |
1213 | C<die>. This still works with most modules/usages, and blocking calls must |
1518 | 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. |
1519 | 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 | |
1520 | |
1302 | =head1 EXAMPLE PROGRAM |
1521 | =head1 EXAMPLE PROGRAM |
1303 | |
1522 | |
1304 | The following program uses an I/O watcher to read data from STDIN, a timer |
1523 | 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 |
1524 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1499 | watcher. |
1718 | watcher. |
1500 | |
1719 | |
1501 | =head3 Results |
1720 | =head3 Results |
1502 | |
1721 | |
1503 | name watchers bytes create invoke destroy comment |
1722 | name watchers bytes create invoke destroy comment |
1504 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1723 | 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 |
1724 | 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 |
1725 | 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 |
1726 | 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 |
1727 | 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 |
1728 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1729 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1730 | 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 |
1731 | 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 |
1732 | 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 |
1733 | 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 |
1734 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1514 | |
1735 | |
1515 | =head3 Discussion |
1736 | =head3 Discussion |
1516 | |
1737 | |
1517 | The benchmark does I<not> measure scalability of the event loop very |
1738 | 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) |
1739 | 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 |
1764 | 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. |
1765 | them active), of course, but this was not subject of this benchmark. |
1545 | |
1766 | |
1546 | The C<Event> module has a relatively high setup and callback invocation |
1767 | The C<Event> module has a relatively high setup and callback invocation |
1547 | cost, but overall scores in on the third place. |
1768 | cost, but overall scores in on the third place. |
|
|
1769 | |
|
|
1770 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
1771 | when using its pure perl backend. |
1548 | |
1772 | |
1549 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1773 | 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 |
1774 | faster callback invocation and overall ends up in the same class as |
1551 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1775 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1552 | watchers increases the processing time by more than a factor of four, |
1776 | 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 |
1854 | it to another server. This includes deleting the old timeout and creating |
1631 | a new one that moves the timeout into the future. |
1855 | a new one that moves the timeout into the future. |
1632 | |
1856 | |
1633 | =head3 Results |
1857 | =head3 Results |
1634 | |
1858 | |
1635 | name sockets create request |
1859 | name sockets create request |
1636 | EV 20000 69.01 11.16 |
1860 | EV 20000 69.01 11.16 |
1637 | Perl 20000 73.32 35.87 |
1861 | Perl 20000 73.32 35.87 |
|
|
1862 | IOAsync 20000 157.00 98.14 epoll |
|
|
1863 | IOAsync 20000 159.31 616.06 poll |
1638 | Event 20000 212.62 257.32 |
1864 | Event 20000 212.62 257.32 |
1639 | Glib 20000 651.16 1896.30 |
1865 | Glib 20000 651.16 1896.30 |
1640 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1866 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1641 | |
1867 | |
1642 | =head3 Discussion |
1868 | =head3 Discussion |
1643 | |
1869 | |
1644 | This benchmark I<does> measure scalability and overall performance of the |
1870 | This benchmark I<does> measure scalability and overall performance of the |
1645 | particular event loop. |
1871 | particular event loop. |
… | |
… | |
1647 | EV is again fastest. Since it is using epoll on my system, the setup time |
1873 | EV is again fastest. Since it is using epoll on my system, the setup time |
1648 | is relatively high, though. |
1874 | is relatively high, though. |
1649 | |
1875 | |
1650 | Perl surprisingly comes second. It is much faster than the C-based event |
1876 | Perl surprisingly comes second. It is much faster than the C-based event |
1651 | loops Event and Glib. |
1877 | loops Event and Glib. |
|
|
1878 | |
|
|
1879 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
1880 | good compared to Glib when using its pure perl backend. |
1652 | |
1881 | |
1653 | Event suffers from high setup time as well (look at its code and you will |
1882 | 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 |
1883 | understand why). Callback invocation also has a high overhead compared to |
1655 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1884 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1656 | uses select or poll in basically all documented configurations. |
1885 | uses select or poll in basically all documented configurations. |
… | |
… | |
1719 | =item * C-based event loops perform very well with small number of |
1948 | =item * C-based event loops perform very well with small number of |
1720 | watchers, as the management overhead dominates. |
1949 | watchers, as the management overhead dominates. |
1721 | |
1950 | |
1722 | =back |
1951 | =back |
1723 | |
1952 | |
|
|
1953 | =head2 THE IO::Lambda BENCHMARK |
|
|
1954 | |
|
|
1955 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
1956 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
1957 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
1958 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
1959 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
1960 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
1961 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
1962 | |
|
|
1963 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
1964 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
1965 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
1966 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
1967 | benchmark nevertheless. |
|
|
1968 | |
|
|
1969 | name runtime |
|
|
1970 | Lambda/select 0.330 sec |
|
|
1971 | + optimized 0.122 sec |
|
|
1972 | Lambda/AnyEvent 0.327 sec |
|
|
1973 | + optimized 0.138 sec |
|
|
1974 | Raw sockets/select 0.077 sec |
|
|
1975 | POE/select, components 0.662 sec |
|
|
1976 | POE/select, raw sockets 0.226 sec |
|
|
1977 | POE/select, optimized 0.404 sec |
|
|
1978 | |
|
|
1979 | AnyEvent/select/nb 0.085 sec |
|
|
1980 | AnyEvent/EV/nb 0.068 sec |
|
|
1981 | +state machine 0.134 sec |
|
|
1982 | |
|
|
1983 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
1984 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
1985 | defeating the purpose of an event-based solution. All of the newly |
|
|
1986 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
1987 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
1988 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
1989 | generally require a lot more bookkeeping and event handling than blocking |
|
|
1990 | connects (which involve a single syscall only). |
|
|
1991 | |
|
|
1992 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
1993 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
1994 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
1995 | non-blocking, further placing it at a disadvantage. |
|
|
1996 | |
|
|
1997 | As you can see, the AnyEvent + EV combination even beats the |
|
|
1998 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
1999 | backend easily beats IO::Lambda and POE. |
|
|
2000 | |
|
|
2001 | And even the 100% non-blocking version written using the high-level (and |
|
|
2002 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
2003 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
2004 | in a non-blocking way. |
|
|
2005 | |
|
|
2006 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2007 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2008 | part of the IO::lambda distribution and were used without any changes. |
|
|
2009 | |
|
|
2010 | |
|
|
2011 | =head1 SIGNALS |
|
|
2012 | |
|
|
2013 | AnyEvent currently installs handlers for these signals: |
|
|
2014 | |
|
|
2015 | =over 4 |
|
|
2016 | |
|
|
2017 | =item SIGCHLD |
|
|
2018 | |
|
|
2019 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2020 | emulation for event loops that do not support them natively. Also, some |
|
|
2021 | event loops install a similar handler. |
|
|
2022 | |
|
|
2023 | If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will |
|
|
2024 | reset it to default, to avoid losing child exit statuses. |
|
|
2025 | |
|
|
2026 | =item SIGPIPE |
|
|
2027 | |
|
|
2028 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2029 | when AnyEvent gets loaded. |
|
|
2030 | |
|
|
2031 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2032 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2033 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2034 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2035 | some random socket. |
|
|
2036 | |
|
|
2037 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2038 | that this way, the handler will be restored to defaults on exec. |
|
|
2039 | |
|
|
2040 | Feel free to install your own handler, or reset it to defaults. |
|
|
2041 | |
|
|
2042 | =back |
|
|
2043 | |
|
|
2044 | =cut |
|
|
2045 | |
|
|
2046 | undef $SIG{CHLD} |
|
|
2047 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2048 | |
|
|
2049 | $SIG{PIPE} = sub { } |
|
|
2050 | unless defined $SIG{PIPE}; |
1724 | |
2051 | |
1725 | =head1 FORK |
2052 | =head1 FORK |
1726 | |
2053 | |
1727 | Most event libraries are not fork-safe. The ones who are usually are |
2054 | 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> |
2055 | because they rely on inefficient but fork-safe C<select> or C<poll> |
… | |
… | |
1749 | use AnyEvent; |
2076 | use AnyEvent; |
1750 | |
2077 | |
1751 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2078 | 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 |
2079 | 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 |
2080 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
1754 | $ENV{PERL_ANYEGENT_STRICT}. |
2081 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2082 | |
|
|
2083 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2084 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2085 | enabled. |
1755 | |
2086 | |
1756 | |
2087 | |
1757 | =head1 BUGS |
2088 | =head1 BUGS |
1758 | |
2089 | |
1759 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
2090 | 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 |
2091 | 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 |
2092 | 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 |
2093 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1763 | pronounced). |
2094 | pronounced). |
1764 | |
2095 | |
1765 | |
2096 | |
1766 | =head1 SEE ALSO |
2097 | =head1 SEE ALSO |
1767 | |
2098 | |