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 { ... }); |
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14 | |
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15 | # one-shot or repeating timers |
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16 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
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17 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
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18 | |
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19 | print AnyEvent->now; # prints current event loop time |
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20 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
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21 | |
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22 | # POSIX signal |
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23 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
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24 | |
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25 | # child process exit |
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26 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
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27 | my ($pid, $status) = @_; |
12 | ... |
28 | ... |
13 | }); |
29 | }); |
14 | |
30 | |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
31 | # called when event loop idle (if applicable) |
16 | ... |
32 | my $w = AnyEvent->idle (cb => sub { ... }); |
17 | }); |
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18 | |
33 | |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
34 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
20 | $w->send; # wake up current and all future recv's |
35 | $w->send; # wake up current and all future recv's |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
36 | $w->recv; # enters "main loop" till $condvar gets ->send |
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37 | # use a condvar in callback mode: |
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38 | $w->cb (sub { $_[0]->recv }); |
22 | |
39 | |
23 | =head1 INTRODUCTION/TUTORIAL |
40 | =head1 INTRODUCTION/TUTORIAL |
24 | |
41 | |
25 | This manpage is mainly a reference manual. If you are interested |
42 | This manpage is mainly a reference manual. If you are interested |
26 | in a tutorial or some gentle introduction, have a look at the |
43 | in a tutorial or some gentle introduction, have a look at the |
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33 | |
50 | |
34 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
51 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
35 | policy> and AnyEvent is I<small and efficient>. |
52 | policy> and AnyEvent is I<small and efficient>. |
36 | |
53 | |
37 | First and foremost, I<AnyEvent is not an event model> itself, it only |
54 | First and foremost, I<AnyEvent is not an event model> itself, it only |
38 | interfaces to whatever event model the main program happens to use in a |
55 | interfaces to whatever event model the main program happens to use, in a |
39 | pragmatic way. For event models and certain classes of immortals alike, |
56 | pragmatic way. For event models and certain classes of immortals alike, |
40 | the statement "there can only be one" is a bitter reality: In general, |
57 | the statement "there can only be one" is a bitter reality: In general, |
41 | only one event loop can be active at the same time in a process. AnyEvent |
58 | only one event loop can be active at the same time in a process. AnyEvent |
42 | helps hiding the differences between those event loops. |
59 | cannot change this, but it can hide the differences between those event |
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60 | loops. |
43 | |
61 | |
44 | The goal of AnyEvent is to offer module authors the ability to do event |
62 | The goal of AnyEvent is to offer module authors the ability to do event |
45 | programming (waiting for I/O or timer events) without subscribing to a |
63 | programming (waiting for I/O or timer events) without subscribing to a |
46 | religion, a way of living, and most importantly: without forcing your |
64 | religion, a way of living, and most importantly: without forcing your |
47 | module users into the same thing by forcing them to use the same event |
65 | module users into the same thing by forcing them to use the same event |
48 | model you use. |
66 | model you use. |
49 | |
67 | |
50 | For modules like POE or IO::Async (which is a total misnomer as it is |
68 | For modules like POE or IO::Async (which is a total misnomer as it is |
51 | actually doing all I/O I<synchronously>...), using them in your module is |
69 | actually doing all I/O I<synchronously>...), using them in your module is |
52 | like joining a cult: After you joined, you are dependent on them and you |
70 | like joining a cult: After you joined, you are dependent on them and you |
53 | cannot use anything else, as it is simply incompatible to everything that |
71 | cannot use anything else, as they are simply incompatible to everything |
54 | isn't itself. What's worse, all the potential users of your module are |
72 | that isn't them. What's worse, all the potential users of your |
55 | I<also> forced to use the same event loop you use. |
73 | module are I<also> forced to use the same event loop you use. |
56 | |
74 | |
57 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
75 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
58 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
76 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
59 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
77 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
60 | your module uses one of those, every user of your module has to use it, |
78 | your module uses one of those, every user of your module has to use it, |
61 | too. But if your module uses AnyEvent, it works transparently with all |
79 | too. But if your module uses AnyEvent, it works transparently with all |
62 | event models it supports (including stuff like POE and IO::Async, as long |
80 | event models it supports (including stuff like IO::Async, as long as those |
63 | as those use one of the supported event loops. It is trivial to add new |
81 | use one of the supported event loops. It is trivial to add new event loops |
64 | event loops to AnyEvent, too, so it is future-proof). |
82 | to AnyEvent, too, so it is future-proof). |
65 | |
83 | |
66 | In addition to being free of having to use I<the one and only true event |
84 | In addition to being free of having to use I<the one and only true event |
67 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
85 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
68 | modules, you get an enormous amount of code and strict rules you have to |
86 | modules, you get an enormous amount of code and strict rules you have to |
69 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
87 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
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127 | These watchers are normal Perl objects with normal Perl lifetime. After |
145 | These watchers are normal Perl objects with normal Perl lifetime. After |
128 | 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 |
129 | 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 |
130 | is in control). |
148 | is in control). |
131 | |
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 | |
132 | 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 |
133 | 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 |
134 | to it). |
158 | to it). |
135 | |
159 | |
136 | 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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152 | =head2 I/O WATCHERS |
176 | =head2 I/O WATCHERS |
153 | |
177 | |
154 | 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 |
155 | with the following mandatory key-value pairs as arguments: |
179 | with the following mandatory key-value pairs as arguments: |
156 | |
180 | |
157 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
181 | C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch |
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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 | |
158 | for events. C<poll> must be a string that is either C<r> or C<w>, |
188 | C<poll> must be a string that is either C<r> or C<w>, which creates a |
159 | which creates a watcher waiting for "r"eadable or "w"ritable events, |
189 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
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190 | |
160 | respectively. C<cb> is the callback to invoke each time the file handle |
191 | C<cb> is the callback to invoke each time the file handle becomes ready. |
161 | becomes ready. |
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162 | |
192 | |
163 | Although the callback might get passed parameters, their value and |
193 | Although the callback might get passed parameters, their value and |
164 | presence is undefined and you cannot rely on them. Portable AnyEvent |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
165 | callbacks cannot use arguments passed to I/O watcher callbacks. |
195 | callbacks cannot use arguments passed to I/O watcher callbacks. |
166 | |
196 | |
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193 | Although the callback might get passed parameters, their value and |
223 | Although the callback might get passed parameters, their value and |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
224 | presence is undefined and you cannot rely on them. Portable AnyEvent |
195 | callbacks cannot use arguments passed to time watcher callbacks. |
225 | callbacks cannot use arguments passed to time watcher callbacks. |
196 | |
226 | |
197 | The callback will normally be invoked once only. If you specify another |
227 | The callback will normally be invoked once only. If you specify another |
198 | parameter, C<interval>, as a positive number, then the callback will be |
228 | parameter, C<interval>, as a strictly positive number (> 0), then the |
199 | invoked regularly at that interval (in fractional seconds) after the first |
229 | callback will be invoked regularly at that interval (in fractional |
200 | invocation. |
230 | seconds) after the first invocation. If C<interval> is specified with a |
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231 | false value, then it is treated as if it were missing. |
201 | |
232 | |
202 | The callback will be rescheduled before invoking the callback, but no |
233 | The callback will be rescheduled before invoking the callback, but no |
203 | attempt is done to avoid timer drift in most backends, so the interval is |
234 | attempt is done to avoid timer drift in most backends, so the interval is |
204 | only approximate. |
235 | only approximate. |
205 | |
236 | |
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297 | 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 |
298 | 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 |
299 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
330 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
300 | account. |
331 | account. |
301 | |
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 | |
302 | =back |
348 | =back |
303 | |
349 | |
304 | =head2 SIGNAL WATCHERS |
350 | =head2 SIGNAL WATCHERS |
305 | |
351 | |
306 | 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 |
307 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
353 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
308 | be invoked whenever a signal occurs. |
354 | callback to be invoked whenever a signal occurs. |
309 | |
355 | |
310 | Although the callback might get passed parameters, their value and |
356 | Although the callback might get passed parameters, their value and |
311 | presence is undefined and you cannot rely on them. Portable AnyEvent |
357 | presence is undefined and you cannot rely on them. Portable AnyEvent |
312 | callbacks cannot use arguments passed to signal watcher callbacks. |
358 | callbacks cannot use arguments passed to signal watcher callbacks. |
313 | |
359 | |
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329 | =head2 CHILD PROCESS WATCHERS |
375 | =head2 CHILD PROCESS WATCHERS |
330 | |
376 | |
331 | 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. |
332 | |
378 | |
333 | 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 |
334 | 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 |
335 | 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 |
336 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
382 | any trace events (stopped/continued). |
337 | and exit status (as returned by waitpid), so unlike other watcher types, |
383 | |
338 | 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). |
339 | |
392 | |
340 | 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 |
341 | 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 |
342 | have exited already (and no SIGCHLD will be sent anymore). |
395 | have exited already (and no SIGCHLD will be sent anymore). |
343 | |
396 | |
344 | 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 |
345 | 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 |
346 | 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. |
347 | |
403 | |
348 | 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 |
349 | 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 |
350 | 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>). |
351 | |
408 | |
352 | Example: fork a process and wait for it |
409 | Example: fork a process and wait for it |
353 | |
410 | |
354 | my $done = AnyEvent->condvar; |
411 | my $done = AnyEvent->condvar; |
355 | |
412 | |
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365 | ); |
422 | ); |
366 | |
423 | |
367 | # do something else, then wait for process exit |
424 | # do something else, then wait for process exit |
368 | $done->recv; |
425 | $done->recv; |
369 | |
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 | |
370 | =head2 CONDITION VARIABLES |
462 | =head2 CONDITION VARIABLES |
371 | |
463 | |
372 | 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 |
373 | 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 |
374 | 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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379 | The instrument to do that is called a "condition variable", so called |
471 | The instrument to do that is called a "condition variable", so called |
380 | because they represent a condition that must become true. |
472 | because they represent a condition that must become true. |
381 | |
473 | |
382 | Condition variables can be created by calling the C<< AnyEvent->condvar |
474 | Condition variables can be created by calling the C<< AnyEvent->condvar |
383 | >> method, usually without arguments. The only argument pair allowed is |
475 | >> method, usually without arguments. The only argument pair allowed is |
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476 | |
384 | C<cb>, which specifies a callback to be called when the condition variable |
477 | C<cb>, which specifies a callback to be called when the condition variable |
385 | becomes true. |
478 | becomes true, with the condition variable as the first argument (but not |
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479 | the results). |
386 | |
480 | |
387 | After creation, the condition variable is "false" until it becomes "true" |
481 | After creation, the condition variable is "false" until it becomes "true" |
388 | by calling the C<send> method (or calling the condition variable as if it |
482 | by calling the C<send> method (or calling the condition variable as if it |
389 | were a callback, read about the caveats in the description for the C<< |
483 | were a callback, read about the caveats in the description for the C<< |
390 | ->send >> method). |
484 | ->send >> method). |
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446 | |
540 | |
447 | my $done = AnyEvent->condvar; |
541 | my $done = AnyEvent->condvar; |
448 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
542 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
449 | $done->recv; |
543 | $done->recv; |
450 | |
544 | |
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545 | Example: Imagine an API that returns a condvar and doesn't support |
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546 | callbacks. This is how you make a synchronous call, for example from |
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547 | the main program: |
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548 | |
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549 | use AnyEvent::CouchDB; |
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550 | |
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551 | ... |
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552 | |
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553 | my @info = $couchdb->info->recv; |
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554 | |
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555 | And this is how you would just ste a callback to be called whenever the |
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556 | results are available: |
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557 | |
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558 | $couchdb->info->cb (sub { |
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559 | my @info = $_[0]->recv; |
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560 | }); |
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561 | |
451 | =head3 METHODS FOR PRODUCERS |
562 | =head3 METHODS FOR PRODUCERS |
452 | |
563 | |
453 | These methods should only be used by the producing side, i.e. the |
564 | These methods should only be used by the producing side, i.e. the |
454 | code/module that eventually sends the signal. Note that it is also |
565 | code/module that eventually sends the signal. Note that it is also |
455 | the producer side which creates the condvar in most cases, but it isn't |
566 | the producer side which creates the condvar in most cases, but it isn't |
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588 | =item $bool = $cv->ready |
699 | =item $bool = $cv->ready |
589 | |
700 | |
590 | Returns true when the condition is "true", i.e. whether C<send> or |
701 | Returns true when the condition is "true", i.e. whether C<send> or |
591 | C<croak> have been called. |
702 | C<croak> have been called. |
592 | |
703 | |
593 | =item $cb = $cv->cb ([new callback]) |
704 | =item $cb = $cv->cb ($cb->($cv)) |
594 | |
705 | |
595 | This is a mutator function that returns the callback set and optionally |
706 | This is a mutator function that returns the callback set and optionally |
596 | replaces it before doing so. |
707 | replaces it before doing so. |
597 | |
708 | |
598 | The callback will be called when the condition becomes "true", i.e. when |
709 | The callback will be called when the condition becomes "true", i.e. when |
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623 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
734 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
624 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
735 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
625 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
736 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
626 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
737 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
627 | |
738 | |
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739 | # warning, support for IO::Async is only partial, as it is too broken |
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740 | # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async. |
|
|
741 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs). |
|
|
742 | |
628 | There is no support for WxWidgets, as WxWidgets has no support for |
743 | There is no support for WxWidgets, as WxWidgets has no support for |
629 | watching file handles. However, you can use WxWidgets through the |
744 | watching file handles. However, you can use WxWidgets through the |
630 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
745 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
631 | second, which was considered to be too horrible to even consider for |
746 | second, which was considered to be too horrible to even consider for |
632 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
747 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
… | |
… | |
788 | =item L<AnyEvent::IGS> |
903 | =item L<AnyEvent::IGS> |
789 | |
904 | |
790 | A non-blocking interface to the Internet Go Server protocol (used by |
905 | A non-blocking interface to the Internet Go Server protocol (used by |
791 | L<App::IGS>). |
906 | L<App::IGS>). |
792 | |
907 | |
793 | =item L<Net::IRC3> |
908 | =item L<AnyEvent::IRC> |
794 | |
909 | |
795 | AnyEvent based IRC client module family. |
910 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
796 | |
911 | |
797 | =item L<Net::XMPP2> |
912 | =item L<Net::XMPP2> |
798 | |
913 | |
799 | AnyEvent based XMPP (Jabber protocol) module family. |
914 | AnyEvent based XMPP (Jabber protocol) module family. |
800 | |
915 | |
… | |
… | |
820 | =cut |
935 | =cut |
821 | |
936 | |
822 | package AnyEvent; |
937 | package AnyEvent; |
823 | |
938 | |
824 | no warnings; |
939 | no warnings; |
825 | use strict; |
940 | use strict qw(vars subs); |
826 | |
941 | |
827 | use Carp; |
942 | use Carp; |
828 | |
943 | |
829 | our $VERSION = 4.2; |
944 | our $VERSION = 4.412; |
830 | our $MODEL; |
945 | our $MODEL; |
831 | |
946 | |
832 | our $AUTOLOAD; |
947 | our $AUTOLOAD; |
833 | our @ISA; |
948 | our @ISA; |
834 | |
949 | |
835 | our @REGISTRY; |
950 | our @REGISTRY; |
836 | |
951 | |
837 | our $WIN32; |
952 | our $WIN32; |
838 | |
953 | |
839 | BEGIN { |
954 | BEGIN { |
840 | my $win32 = ! ! ($^O =~ /mswin32/i); |
955 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
841 | eval "sub WIN32(){ $win32 }"; |
956 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
|
|
957 | |
|
|
958 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
959 | if ${^TAINT}; |
842 | } |
960 | } |
843 | |
961 | |
844 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
962 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
845 | |
963 | |
846 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
964 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
… | |
… | |
864 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
982 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
865 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
983 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
866 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
984 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
867 | [Wx:: => AnyEvent::Impl::POE::], |
985 | [Wx:: => AnyEvent::Impl::POE::], |
868 | [Prima:: => AnyEvent::Impl::POE::], |
986 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
987 | # IO::Async is just too broken - we would need workaorunds for its |
|
|
988 | # byzantine signal and broken child handling, among others. |
|
|
989 | # IO::Async is rather hard to detect, as it doesn't have any |
|
|
990 | # obvious default class. |
|
|
991 | # [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
992 | # [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
993 | # [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
869 | ); |
994 | ); |
870 | |
995 | |
871 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
996 | our %method = map +($_ => 1), |
|
|
997 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
872 | |
998 | |
873 | our @post_detect; |
999 | our @post_detect; |
874 | |
1000 | |
875 | sub post_detect(&) { |
1001 | sub post_detect(&) { |
876 | my ($cb) = @_; |
1002 | my ($cb) = @_; |
… | |
… | |
881 | 1 |
1007 | 1 |
882 | } else { |
1008 | } else { |
883 | push @post_detect, $cb; |
1009 | push @post_detect, $cb; |
884 | |
1010 | |
885 | defined wantarray |
1011 | defined wantarray |
886 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
1012 | ? bless \$cb, "AnyEvent::Util::postdetect" |
887 | : () |
1013 | : () |
888 | } |
1014 | } |
889 | } |
1015 | } |
890 | |
1016 | |
891 | sub AnyEvent::Util::PostDetect::DESTROY { |
1017 | sub AnyEvent::Util::postdetect::DESTROY { |
892 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1018 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
893 | } |
1019 | } |
894 | |
1020 | |
895 | sub detect() { |
1021 | sub detect() { |
896 | unless ($MODEL) { |
1022 | unless ($MODEL) { |
… | |
… | |
933 | last; |
1059 | last; |
934 | } |
1060 | } |
935 | } |
1061 | } |
936 | |
1062 | |
937 | $MODEL |
1063 | $MODEL |
938 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1064 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
939 | } |
1065 | } |
940 | } |
1066 | } |
941 | |
1067 | |
|
|
1068 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
1069 | |
942 | unshift @ISA, $MODEL; |
1070 | unshift @ISA, $MODEL; |
943 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1071 | |
|
|
1072 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
944 | |
1073 | |
945 | (shift @post_detect)->() while @post_detect; |
1074 | (shift @post_detect)->() while @post_detect; |
946 | } |
1075 | } |
947 | |
1076 | |
948 | $MODEL |
1077 | $MODEL |
… | |
… | |
958 | |
1087 | |
959 | my $class = shift; |
1088 | my $class = shift; |
960 | $class->$func (@_); |
1089 | $class->$func (@_); |
961 | } |
1090 | } |
962 | |
1091 | |
|
|
1092 | # utility function to dup a filehandle. this is used by many backends |
|
|
1093 | # to support binding more than one watcher per filehandle (they usually |
|
|
1094 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1095 | sub _dupfh($$;$$) { |
|
|
1096 | my ($poll, $fh, $r, $w) = @_; |
|
|
1097 | |
|
|
1098 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1099 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
|
|
1100 | : $poll eq "w" ? ($w, ">") |
|
|
1101 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
|
|
1102 | |
|
|
1103 | open my $fh2, "$mode&" . fileno $fh |
|
|
1104 | or die "cannot dup() filehandle: $!,"; |
|
|
1105 | |
|
|
1106 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1107 | |
|
|
1108 | ($fh2, $rw) |
|
|
1109 | } |
|
|
1110 | |
963 | package AnyEvent::Base; |
1111 | package AnyEvent::Base; |
964 | |
1112 | |
965 | # default implementation for now and time |
1113 | # default implementations for many methods |
966 | |
1114 | |
967 | use Time::HiRes (); |
1115 | BEGIN { |
|
|
1116 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1117 | *_time = \&Time::HiRes::time; |
|
|
1118 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1119 | } else { |
|
|
1120 | *_time = sub { time }; # epic fail |
|
|
1121 | } |
|
|
1122 | } |
968 | |
1123 | |
969 | sub time { Time::HiRes::time } |
1124 | sub time { _time } |
970 | sub now { Time::HiRes::time } |
1125 | sub now { _time } |
|
|
1126 | sub now_update { } |
971 | |
1127 | |
972 | # default implementation for ->condvar |
1128 | # default implementation for ->condvar |
973 | |
1129 | |
974 | sub condvar { |
1130 | sub condvar { |
975 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1131 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
976 | } |
1132 | } |
977 | |
1133 | |
978 | # default implementation for ->signal |
1134 | # default implementation for ->signal |
979 | |
1135 | |
980 | our %SIG_CB; |
1136 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1137 | |
|
|
1138 | sub _signal_exec { |
|
|
1139 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1140 | |
|
|
1141 | while (%SIG_EV) { |
|
|
1142 | for (keys %SIG_EV) { |
|
|
1143 | delete $SIG_EV{$_}; |
|
|
1144 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1145 | } |
|
|
1146 | } |
|
|
1147 | } |
981 | |
1148 | |
982 | sub signal { |
1149 | sub signal { |
983 | my (undef, %arg) = @_; |
1150 | my (undef, %arg) = @_; |
984 | |
1151 | |
|
|
1152 | unless ($SIGPIPE_R) { |
|
|
1153 | require Fcntl; |
|
|
1154 | |
|
|
1155 | if (AnyEvent::WIN32) { |
|
|
1156 | require AnyEvent::Util; |
|
|
1157 | |
|
|
1158 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1159 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1160 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1161 | } else { |
|
|
1162 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1163 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1164 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1165 | |
|
|
1166 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1167 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1168 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1169 | } |
|
|
1170 | |
|
|
1171 | $SIGPIPE_R |
|
|
1172 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1173 | |
|
|
1174 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1175 | } |
|
|
1176 | |
985 | my $signal = uc $arg{signal} |
1177 | my $signal = uc $arg{signal} |
986 | or Carp::croak "required option 'signal' is missing"; |
1178 | or Carp::croak "required option 'signal' is missing"; |
987 | |
1179 | |
988 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1180 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
989 | $SIG{$signal} ||= sub { |
1181 | $SIG{$signal} ||= sub { |
990 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1182 | local $!; |
|
|
1183 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1184 | undef $SIG_EV{$signal}; |
991 | }; |
1185 | }; |
992 | |
1186 | |
993 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1187 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
994 | } |
1188 | } |
995 | |
1189 | |
996 | sub AnyEvent::Base::Signal::DESTROY { |
1190 | sub AnyEvent::Base::signal::DESTROY { |
997 | my ($signal, $cb) = @{$_[0]}; |
1191 | my ($signal, $cb) = @{$_[0]}; |
998 | |
1192 | |
999 | delete $SIG_CB{$signal}{$cb}; |
1193 | delete $SIG_CB{$signal}{$cb}; |
1000 | |
1194 | |
|
|
1195 | # delete doesn't work with older perls - they then |
|
|
1196 | # print weird messages, or just unconditionally exit |
|
|
1197 | # instead of getting the default action. |
1001 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1198 | undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1002 | } |
1199 | } |
1003 | |
1200 | |
1004 | # default implementation for ->child |
1201 | # default implementation for ->child |
1005 | |
1202 | |
1006 | our %PID_CB; |
1203 | our %PID_CB; |
1007 | our $CHLD_W; |
1204 | our $CHLD_W; |
1008 | our $CHLD_DELAY_W; |
1205 | our $CHLD_DELAY_W; |
1009 | our $PID_IDLE; |
|
|
1010 | our $WNOHANG; |
1206 | our $WNOHANG; |
1011 | |
1207 | |
1012 | sub _child_wait { |
1208 | sub _sigchld { |
1013 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1209 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1014 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1210 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1015 | (values %{ $PID_CB{0} || {} }); |
1211 | (values %{ $PID_CB{0} || {} }); |
1016 | } |
1212 | } |
1017 | |
|
|
1018 | undef $PID_IDLE; |
|
|
1019 | } |
|
|
1020 | |
|
|
1021 | sub _sigchld { |
|
|
1022 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
1023 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
1024 | undef $CHLD_DELAY_W; |
|
|
1025 | &_child_wait; |
|
|
1026 | }); |
|
|
1027 | } |
1213 | } |
1028 | |
1214 | |
1029 | sub child { |
1215 | sub child { |
1030 | my (undef, %arg) = @_; |
1216 | my (undef, %arg) = @_; |
1031 | |
1217 | |
1032 | defined (my $pid = $arg{pid} + 0) |
1218 | defined (my $pid = $arg{pid} + 0) |
1033 | or Carp::croak "required option 'pid' is missing"; |
1219 | or Carp::croak "required option 'pid' is missing"; |
1034 | |
1220 | |
1035 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1221 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1036 | |
1222 | |
1037 | unless ($WNOHANG) { |
|
|
1038 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1223 | $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1039 | } |
|
|
1040 | |
1224 | |
1041 | unless ($CHLD_W) { |
1225 | unless ($CHLD_W) { |
1042 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1226 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1043 | # child could be a zombie already, so make at least one round |
1227 | # child could be a zombie already, so make at least one round |
1044 | &_sigchld; |
1228 | &_sigchld; |
1045 | } |
1229 | } |
1046 | |
1230 | |
1047 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1231 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
1048 | } |
1232 | } |
1049 | |
1233 | |
1050 | sub AnyEvent::Base::Child::DESTROY { |
1234 | sub AnyEvent::Base::child::DESTROY { |
1051 | my ($pid, $cb) = @{$_[0]}; |
1235 | my ($pid, $cb) = @{$_[0]}; |
1052 | |
1236 | |
1053 | delete $PID_CB{$pid}{$cb}; |
1237 | delete $PID_CB{$pid}{$cb}; |
1054 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1238 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1055 | |
1239 | |
1056 | undef $CHLD_W unless keys %PID_CB; |
1240 | undef $CHLD_W unless keys %PID_CB; |
|
|
1241 | } |
|
|
1242 | |
|
|
1243 | # idle emulation is done by simply using a timer, regardless |
|
|
1244 | # of whether the process is idle or not, and not letting |
|
|
1245 | # the callback use more than 50% of the time. |
|
|
1246 | sub idle { |
|
|
1247 | my (undef, %arg) = @_; |
|
|
1248 | |
|
|
1249 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1250 | |
|
|
1251 | $rcb = sub { |
|
|
1252 | if ($cb) { |
|
|
1253 | $w = _time; |
|
|
1254 | &$cb; |
|
|
1255 | $w = _time - $w; |
|
|
1256 | |
|
|
1257 | # never use more then 50% of the time for the idle watcher, |
|
|
1258 | # within some limits |
|
|
1259 | $w = 0.0001 if $w < 0.0001; |
|
|
1260 | $w = 5 if $w > 5; |
|
|
1261 | |
|
|
1262 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1263 | } else { |
|
|
1264 | # clean up... |
|
|
1265 | undef $w; |
|
|
1266 | undef $rcb; |
|
|
1267 | } |
|
|
1268 | }; |
|
|
1269 | |
|
|
1270 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1271 | |
|
|
1272 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1273 | } |
|
|
1274 | |
|
|
1275 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1276 | undef $${$_[0]}; |
1057 | } |
1277 | } |
1058 | |
1278 | |
1059 | package AnyEvent::CondVar; |
1279 | package AnyEvent::CondVar; |
1060 | |
1280 | |
1061 | our @ISA = AnyEvent::CondVar::Base::; |
1281 | our @ISA = AnyEvent::CondVar::Base::; |
… | |
… | |
1113 | } |
1333 | } |
1114 | |
1334 | |
1115 | # undocumented/compatibility with pre-3.4 |
1335 | # undocumented/compatibility with pre-3.4 |
1116 | *broadcast = \&send; |
1336 | *broadcast = \&send; |
1117 | *wait = \&_wait; |
1337 | *wait = \&_wait; |
|
|
1338 | |
|
|
1339 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1340 | |
|
|
1341 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1342 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1343 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1344 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1345 | development. |
|
|
1346 | |
|
|
1347 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1348 | executing a callback), this is not only highly event-loop specific, but |
|
|
1349 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1350 | program. |
|
|
1351 | |
|
|
1352 | The pure perl event loop simply re-throws the exception (usually |
|
|
1353 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1354 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1355 | so on. |
|
|
1356 | |
|
|
1357 | =head1 ENVIRONMENT VARIABLES |
|
|
1358 | |
|
|
1359 | The following environment variables are used by this module or its |
|
|
1360 | submodules. |
|
|
1361 | |
|
|
1362 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1363 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1364 | enabled. |
|
|
1365 | |
|
|
1366 | =over 4 |
|
|
1367 | |
|
|
1368 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1369 | |
|
|
1370 | By default, AnyEvent will be completely silent except in fatal |
|
|
1371 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1372 | talkative. |
|
|
1373 | |
|
|
1374 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1375 | conditions, such as not being able to load the event model specified by |
|
|
1376 | C<PERL_ANYEVENT_MODEL>. |
|
|
1377 | |
|
|
1378 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1379 | model it chooses. |
|
|
1380 | |
|
|
1381 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1382 | |
|
|
1383 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1384 | argument checking is very costly. Setting this variable to a true value |
|
|
1385 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1386 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1387 | it will croak. |
|
|
1388 | |
|
|
1389 | In other words, enables "strict" mode. |
|
|
1390 | |
|
|
1391 | Unlike C<use strict>, it is definitely recommended to keep it off in |
|
|
1392 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1393 | developing programs can be very useful, however. |
|
|
1394 | |
|
|
1395 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1396 | |
|
|
1397 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1398 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1399 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1400 | and the resulting module name is loaded and if the load was successful, |
|
|
1401 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1402 | auto detection and -probing. |
|
|
1403 | |
|
|
1404 | This functionality might change in future versions. |
|
|
1405 | |
|
|
1406 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1407 | could start your program like this: |
|
|
1408 | |
|
|
1409 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1410 | |
|
|
1411 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1412 | |
|
|
1413 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1414 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1415 | of auto probing). |
|
|
1416 | |
|
|
1417 | Must be set to a comma-separated list of protocols or address families, |
|
|
1418 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1419 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1420 | list. |
|
|
1421 | |
|
|
1422 | This variable can effectively be used for denial-of-service attacks |
|
|
1423 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1424 | small, as the program has to handle conenction and other failures anyways. |
|
|
1425 | |
|
|
1426 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1427 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1428 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1429 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1430 | IPv6, but prefer IPv6 over IPv4. |
|
|
1431 | |
|
|
1432 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1433 | |
|
|
1434 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1435 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1436 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1437 | default. |
|
|
1438 | |
|
|
1439 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1440 | EDNS0 in its DNS requests. |
|
|
1441 | |
|
|
1442 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1443 | |
|
|
1444 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1445 | will create in parallel. |
|
|
1446 | |
|
|
1447 | =back |
1118 | |
1448 | |
1119 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1449 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1120 | |
1450 | |
1121 | This is an advanced topic that you do not normally need to use AnyEvent in |
1451 | This is an advanced topic that you do not normally need to use AnyEvent in |
1122 | a module. This section is only of use to event loop authors who want to |
1452 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1156 | |
1486 | |
1157 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1487 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1158 | condition variables: code blocking while waiting for a condition will |
1488 | condition variables: code blocking while waiting for a condition will |
1159 | C<die>. This still works with most modules/usages, and blocking calls must |
1489 | C<die>. This still works with most modules/usages, and blocking calls must |
1160 | not be done in an interactive application, so it makes sense. |
1490 | not be done in an interactive application, so it makes sense. |
1161 | |
|
|
1162 | =head1 ENVIRONMENT VARIABLES |
|
|
1163 | |
|
|
1164 | The following environment variables are used by this module: |
|
|
1165 | |
|
|
1166 | =over 4 |
|
|
1167 | |
|
|
1168 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1169 | |
|
|
1170 | By default, AnyEvent will be completely silent except in fatal |
|
|
1171 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1172 | talkative. |
|
|
1173 | |
|
|
1174 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1175 | conditions, such as not being able to load the event model specified by |
|
|
1176 | C<PERL_ANYEVENT_MODEL>. |
|
|
1177 | |
|
|
1178 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1179 | model it chooses. |
|
|
1180 | |
|
|
1181 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1182 | |
|
|
1183 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1184 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1185 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1186 | and the resulting module name is loaded and if the load was successful, |
|
|
1187 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1188 | auto detection and -probing. |
|
|
1189 | |
|
|
1190 | This functionality might change in future versions. |
|
|
1191 | |
|
|
1192 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1193 | could start your program like this: |
|
|
1194 | |
|
|
1195 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1196 | |
|
|
1197 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1198 | |
|
|
1199 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1200 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1201 | of auto probing). |
|
|
1202 | |
|
|
1203 | Must be set to a comma-separated list of protocols or address families, |
|
|
1204 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1205 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1206 | list. |
|
|
1207 | |
|
|
1208 | This variable can effectively be used for denial-of-service attacks |
|
|
1209 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1210 | small, as the program has to handle connection errors already- |
|
|
1211 | |
|
|
1212 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1213 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1214 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1215 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1216 | IPv6, but prefer IPv6 over IPv4. |
|
|
1217 | |
|
|
1218 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1219 | |
|
|
1220 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1221 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1222 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1223 | default. |
|
|
1224 | |
|
|
1225 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1226 | EDNS0 in its DNS requests. |
|
|
1227 | |
|
|
1228 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1229 | |
|
|
1230 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1231 | will create in parallel. |
|
|
1232 | |
|
|
1233 | =back |
|
|
1234 | |
1491 | |
1235 | =head1 EXAMPLE PROGRAM |
1492 | =head1 EXAMPLE PROGRAM |
1236 | |
1493 | |
1237 | The following program uses an I/O watcher to read data from STDIN, a timer |
1494 | The following program uses an I/O watcher to read data from STDIN, a timer |
1238 | to display a message once per second, and a condition variable to quit the |
1495 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1432 | watcher. |
1689 | watcher. |
1433 | |
1690 | |
1434 | =head3 Results |
1691 | =head3 Results |
1435 | |
1692 | |
1436 | name watchers bytes create invoke destroy comment |
1693 | name watchers bytes create invoke destroy comment |
1437 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1694 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1438 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1695 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1439 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1696 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1440 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1697 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1441 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1698 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1442 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1699 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1700 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1701 | IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll |
1443 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1702 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1444 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1703 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1445 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1704 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1446 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1705 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1447 | |
1706 | |
1448 | =head3 Discussion |
1707 | =head3 Discussion |
1449 | |
1708 | |
1450 | The benchmark does I<not> measure scalability of the event loop very |
1709 | The benchmark does I<not> measure scalability of the event loop very |
1451 | well. For example, a select-based event loop (such as the pure perl one) |
1710 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1476 | performance becomes really bad with lots of file descriptors (and few of |
1735 | performance becomes really bad with lots of file descriptors (and few of |
1477 | them active), of course, but this was not subject of this benchmark. |
1736 | them active), of course, but this was not subject of this benchmark. |
1478 | |
1737 | |
1479 | The C<Event> module has a relatively high setup and callback invocation |
1738 | The C<Event> module has a relatively high setup and callback invocation |
1480 | cost, but overall scores in on the third place. |
1739 | cost, but overall scores in on the third place. |
|
|
1740 | |
|
|
1741 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
1742 | when using its pure perl backend. |
1481 | |
1743 | |
1482 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1744 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1483 | faster callback invocation and overall ends up in the same class as |
1745 | faster callback invocation and overall ends up in the same class as |
1484 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1746 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1485 | watchers increases the processing time by more than a factor of four, |
1747 | watchers increases the processing time by more than a factor of four, |
… | |
… | |
1563 | it to another server. This includes deleting the old timeout and creating |
1825 | it to another server. This includes deleting the old timeout and creating |
1564 | a new one that moves the timeout into the future. |
1826 | a new one that moves the timeout into the future. |
1565 | |
1827 | |
1566 | =head3 Results |
1828 | =head3 Results |
1567 | |
1829 | |
1568 | name sockets create request |
1830 | name sockets create request |
1569 | EV 20000 69.01 11.16 |
1831 | EV 20000 69.01 11.16 |
1570 | Perl 20000 73.32 35.87 |
1832 | Perl 20000 73.32 35.87 |
|
|
1833 | IOAsync 20000 157.00 98.14 epoll |
|
|
1834 | IOAsync 20000 159.31 616.06 poll |
1571 | Event 20000 212.62 257.32 |
1835 | Event 20000 212.62 257.32 |
1572 | Glib 20000 651.16 1896.30 |
1836 | Glib 20000 651.16 1896.30 |
1573 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1837 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1574 | |
1838 | |
1575 | =head3 Discussion |
1839 | =head3 Discussion |
1576 | |
1840 | |
1577 | This benchmark I<does> measure scalability and overall performance of the |
1841 | This benchmark I<does> measure scalability and overall performance of the |
1578 | particular event loop. |
1842 | particular event loop. |
… | |
… | |
1580 | EV is again fastest. Since it is using epoll on my system, the setup time |
1844 | EV is again fastest. Since it is using epoll on my system, the setup time |
1581 | is relatively high, though. |
1845 | is relatively high, though. |
1582 | |
1846 | |
1583 | Perl surprisingly comes second. It is much faster than the C-based event |
1847 | Perl surprisingly comes second. It is much faster than the C-based event |
1584 | loops Event and Glib. |
1848 | loops Event and Glib. |
|
|
1849 | |
|
|
1850 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
1851 | good compared to Glib when using its pure perl backend. |
1585 | |
1852 | |
1586 | Event suffers from high setup time as well (look at its code and you will |
1853 | Event suffers from high setup time as well (look at its code and you will |
1587 | understand why). Callback invocation also has a high overhead compared to |
1854 | understand why). Callback invocation also has a high overhead compared to |
1588 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1855 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1589 | uses select or poll in basically all documented configurations. |
1856 | uses select or poll in basically all documented configurations. |
… | |
… | |
1652 | =item * C-based event loops perform very well with small number of |
1919 | =item * C-based event loops perform very well with small number of |
1653 | watchers, as the management overhead dominates. |
1920 | watchers, as the management overhead dominates. |
1654 | |
1921 | |
1655 | =back |
1922 | =back |
1656 | |
1923 | |
|
|
1924 | =head2 THE IO::Lambda BENCHMARK |
|
|
1925 | |
|
|
1926 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
1927 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
1928 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
1929 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
1930 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
1931 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
1932 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
1933 | |
|
|
1934 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
1935 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
1936 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
1937 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
1938 | benchmark nevertheless. |
|
|
1939 | |
|
|
1940 | name runtime |
|
|
1941 | Lambda/select 0.330 sec |
|
|
1942 | + optimized 0.122 sec |
|
|
1943 | Lambda/AnyEvent 0.327 sec |
|
|
1944 | + optimized 0.138 sec |
|
|
1945 | Raw sockets/select 0.077 sec |
|
|
1946 | POE/select, components 0.662 sec |
|
|
1947 | POE/select, raw sockets 0.226 sec |
|
|
1948 | POE/select, optimized 0.404 sec |
|
|
1949 | |
|
|
1950 | AnyEvent/select/nb 0.085 sec |
|
|
1951 | AnyEvent/EV/nb 0.068 sec |
|
|
1952 | +state machine 0.134 sec |
|
|
1953 | |
|
|
1954 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
1955 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
1956 | defeating the purpose of an event-based solution. All of the newly |
|
|
1957 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
1958 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
1959 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
1960 | generally require a lot more bookkeeping and event handling than blocking |
|
|
1961 | connects (which involve a single syscall only). |
|
|
1962 | |
|
|
1963 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
1964 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
1965 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
1966 | non-blocking, further placing it at a disadvantage. |
|
|
1967 | |
|
|
1968 | As you can see, the AnyEvent + EV combination even beats the |
|
|
1969 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
1970 | backend easily beats IO::Lambda and POE. |
|
|
1971 | |
|
|
1972 | And even the 100% non-blocking version written using the high-level (and |
|
|
1973 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
1974 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
1975 | in a non-blocking way. |
|
|
1976 | |
|
|
1977 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
1978 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
1979 | part of the IO::lambda distribution and were used without any changes. |
|
|
1980 | |
|
|
1981 | |
|
|
1982 | =head1 SIGNALS |
|
|
1983 | |
|
|
1984 | AnyEvent currently installs handlers for these signals: |
|
|
1985 | |
|
|
1986 | =over 4 |
|
|
1987 | |
|
|
1988 | =item SIGCHLD |
|
|
1989 | |
|
|
1990 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
1991 | emulation for event loops that do not support them natively. Also, some |
|
|
1992 | event loops install a similar handler. |
|
|
1993 | |
|
|
1994 | If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will |
|
|
1995 | reset it to default, to avoid losing child exit statuses. |
|
|
1996 | |
|
|
1997 | =item SIGPIPE |
|
|
1998 | |
|
|
1999 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2000 | when AnyEvent gets loaded. |
|
|
2001 | |
|
|
2002 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2003 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2004 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2005 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2006 | some random socket. |
|
|
2007 | |
|
|
2008 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2009 | that this way, the handler will be restored to defaults on exec. |
|
|
2010 | |
|
|
2011 | Feel free to install your own handler, or reset it to defaults. |
|
|
2012 | |
|
|
2013 | =back |
|
|
2014 | |
|
|
2015 | =cut |
|
|
2016 | |
|
|
2017 | undef $SIG{CHLD} |
|
|
2018 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2019 | |
|
|
2020 | $SIG{PIPE} = sub { } |
|
|
2021 | unless defined $SIG{PIPE}; |
1657 | |
2022 | |
1658 | =head1 FORK |
2023 | =head1 FORK |
1659 | |
2024 | |
1660 | Most event libraries are not fork-safe. The ones who are usually are |
2025 | Most event libraries are not fork-safe. The ones who are usually are |
1661 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2026 | because they rely on inefficient but fork-safe C<select> or C<poll> |
… | |
… | |
1681 | |
2046 | |
1682 | use AnyEvent; |
2047 | use AnyEvent; |
1683 | |
2048 | |
1684 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2049 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1685 | be used to probe what backend is used and gain other information (which is |
2050 | be used to probe what backend is used and gain other information (which is |
1686 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
2051 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
2052 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2053 | |
|
|
2054 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2055 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2056 | enabled. |
1687 | |
2057 | |
1688 | |
2058 | |
1689 | =head1 BUGS |
2059 | =head1 BUGS |
1690 | |
2060 | |
1691 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
2061 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
1692 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
2062 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
1693 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
2063 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
1694 | mamleaks, such as leaking on C<map> and C<grep> but it is usually not as |
2064 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1695 | pronounced). |
2065 | pronounced). |
1696 | |
2066 | |
1697 | |
2067 | |
1698 | =head1 SEE ALSO |
2068 | =head1 SEE ALSO |
1699 | |
2069 | |