1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - the DBI of event loop programming |
4 | |
4 | |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, IO::Async, Qt and POE are |
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6 | various supported event loops/environments. |
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 |
27 | L<AnyEvent::Intro> manpage. |
44 | L<AnyEvent::Intro> manpage. |
28 | |
45 | |
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46 | =head1 SUPPORT |
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47 | |
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48 | There is a mailinglist for discussing all things AnyEvent, and an IRC |
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49 | channel, too. |
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50 | |
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51 | See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software |
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52 | Repository>, at L<http://anyevent.schmorp.de>, for more info. |
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53 | |
29 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
54 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
30 | |
55 | |
31 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
56 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
32 | nowadays. So what is different about AnyEvent? |
57 | nowadays. So what is different about AnyEvent? |
33 | |
58 | |
34 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
59 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
35 | policy> and AnyEvent is I<small and efficient>. |
60 | policy> and AnyEvent is I<small and efficient>. |
36 | |
61 | |
37 | First and foremost, I<AnyEvent is not an event model> itself, it only |
62 | 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 |
63 | 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, |
64 | 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, |
65 | 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 |
66 | only one event loop can be active at the same time in a process. AnyEvent |
42 | helps hiding the differences between those event loops. |
67 | cannot change this, but it can hide the differences between those event |
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68 | loops. |
43 | |
69 | |
44 | The goal of AnyEvent is to offer module authors the ability to do event |
70 | 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 |
71 | programming (waiting for I/O or timer events) without subscribing to a |
46 | religion, a way of living, and most importantly: without forcing your |
72 | 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 |
73 | module users into the same thing by forcing them to use the same event |
48 | model you use. |
74 | model you use. |
49 | |
75 | |
50 | For modules like POE or IO::Async (which is a total misnomer as it is |
76 | 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 |
77 | 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 |
78 | 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 |
79 | 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 |
80 | 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. |
81 | module are I<also> forced to use the same event loop you use. |
56 | |
82 | |
57 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
83 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
58 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
84 | 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 |
85 | 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, |
86 | 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 |
87 | 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 |
88 | 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 |
89 | 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). |
90 | to AnyEvent, too, so it is future-proof). |
65 | |
91 | |
66 | In addition to being free of having to use I<the one and only true event |
92 | 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 |
93 | 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 |
94 | 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 |
95 | 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 |
153 | These watchers are normal Perl objects with normal Perl lifetime. After |
128 | creating a watcher it will immediately "watch" for events and invoke the |
154 | 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 |
155 | callback when the event occurs (of course, only when the event model |
130 | is in control). |
156 | is in control). |
131 | |
157 | |
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158 | Note that B<callbacks must not permanently change global variables> |
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159 | potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< |
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160 | callbacks must not C<die> >>. The former is good programming practise in |
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161 | Perl and the latter stems from the fact that exception handling differs |
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162 | widely between event loops. |
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163 | |
132 | To disable the watcher you have to destroy it (e.g. by setting the |
164 | 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 |
165 | variable you store it in to C<undef> or otherwise deleting all references |
134 | to it). |
166 | to it). |
135 | |
167 | |
136 | All watchers are created by calling a method on the C<AnyEvent> class. |
168 | All watchers are created by calling a method on the C<AnyEvent> class. |
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152 | =head2 I/O WATCHERS |
184 | =head2 I/O WATCHERS |
153 | |
185 | |
154 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
186 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
155 | with the following mandatory key-value pairs as arguments: |
187 | with the following mandatory key-value pairs as arguments: |
156 | |
188 | |
157 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
189 | C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch |
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190 | for events (AnyEvent might or might not keep a reference to this file |
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191 | handle). Note that only file handles pointing to things for which |
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192 | non-blocking operation makes sense are allowed. This includes sockets, |
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193 | most character devices, pipes, fifos and so on, but not for example files |
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194 | or block devices. |
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195 | |
158 | for events. C<poll> must be a string that is either C<r> or C<w>, |
196 | 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, |
197 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
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198 | |
160 | respectively. C<cb> is the callback to invoke each time the file handle |
199 | C<cb> is the callback to invoke each time the file handle becomes ready. |
161 | becomes ready. |
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162 | |
200 | |
163 | Although the callback might get passed parameters, their value and |
201 | Although the callback might get passed parameters, their value and |
164 | presence is undefined and you cannot rely on them. Portable AnyEvent |
202 | presence is undefined and you cannot rely on them. Portable AnyEvent |
165 | callbacks cannot use arguments passed to I/O watcher callbacks. |
203 | callbacks cannot use arguments passed to I/O watcher callbacks. |
166 | |
204 | |
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193 | Although the callback might get passed parameters, their value and |
231 | Although the callback might get passed parameters, their value and |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
232 | presence is undefined and you cannot rely on them. Portable AnyEvent |
195 | callbacks cannot use arguments passed to time watcher callbacks. |
233 | callbacks cannot use arguments passed to time watcher callbacks. |
196 | |
234 | |
197 | The callback will normally be invoked once only. If you specify another |
235 | 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 |
236 | parameter, C<interval>, as a strictly positive number (> 0), then the |
199 | invoked regularly at that interval (in fractional seconds) after the first |
237 | callback will be invoked regularly at that interval (in fractional |
200 | invocation. |
238 | seconds) after the first invocation. If C<interval> is specified with a |
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239 | false value, then it is treated as if it were missing. |
201 | |
240 | |
202 | The callback will be rescheduled before invoking the callback, but no |
241 | 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 |
242 | attempt is done to avoid timer drift in most backends, so the interval is |
204 | only approximate. |
243 | only approximate. |
205 | |
244 | |
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297 | In either case, if you care (and in most cases, you don't), then you |
336 | 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 |
337 | can get whatever behaviour you want with any event loop, by taking the |
299 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
338 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
300 | account. |
339 | account. |
301 | |
340 | |
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341 | =item AnyEvent->now_update |
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342 | |
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343 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
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344 | the current time for each loop iteration (see the discussion of L<< |
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345 | AnyEvent->now >>, above). |
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346 | |
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347 | When a callback runs for a long time (or when the process sleeps), then |
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348 | this "current" time will differ substantially from the real time, which |
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349 | might affect timers and time-outs. |
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350 | |
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351 | When this is the case, you can call this method, which will update the |
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352 | event loop's idea of "current time". |
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353 | |
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354 | Note that updating the time I<might> cause some events to be handled. |
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355 | |
302 | =back |
356 | =back |
303 | |
357 | |
304 | =head2 SIGNAL WATCHERS |
358 | =head2 SIGNAL WATCHERS |
305 | |
359 | |
306 | You can watch for signals using a signal watcher, C<signal> is the signal |
360 | 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 |
361 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
308 | be invoked whenever a signal occurs. |
362 | callback to be invoked whenever a signal occurs. |
309 | |
363 | |
310 | Although the callback might get passed parameters, their value and |
364 | Although the callback might get passed parameters, their value and |
311 | presence is undefined and you cannot rely on them. Portable AnyEvent |
365 | presence is undefined and you cannot rely on them. Portable AnyEvent |
312 | callbacks cannot use arguments passed to signal watcher callbacks. |
366 | callbacks cannot use arguments passed to signal watcher callbacks. |
313 | |
367 | |
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315 | invocation, and callback invocation will be synchronous. Synchronous means |
369 | invocation, and callback invocation will be synchronous. Synchronous means |
316 | that it might take a while until the signal gets handled by the process, |
370 | that it might take a while until the signal gets handled by the process, |
317 | but it is guaranteed not to interrupt any other callbacks. |
371 | but it is guaranteed not to interrupt any other callbacks. |
318 | |
372 | |
319 | The main advantage of using these watchers is that you can share a signal |
373 | The main advantage of using these watchers is that you can share a signal |
320 | between multiple watchers. |
374 | between multiple watchers, and AnyEvent will ensure that signals will not |
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375 | interrupt your program at bad times. |
321 | |
376 | |
322 | This watcher might use C<%SIG>, so programs overwriting those signals |
377 | This watcher might use C<%SIG> (depending on the event loop used), |
323 | directly will likely not work correctly. |
378 | so programs overwriting those signals directly will likely not work |
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379 | correctly. |
324 | |
380 | |
325 | Example: exit on SIGINT |
381 | Example: exit on SIGINT |
326 | |
382 | |
327 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
383 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
328 | |
384 | |
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385 | =head3 Signal Races, Delays and Workarounds |
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386 | |
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387 | Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching |
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388 | callbacks to signals in a generic way, which is a pity, as you cannot do |
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389 | race-free signal handling in perl. AnyEvent will try to do it's best, but |
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390 | in some cases, signals will be delayed. The maximum time a signal might |
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391 | be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 |
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392 | seconds). This variable can be changed only before the first signal |
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393 | watcher is created, and should be left alone otherwise. Higher values |
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394 | will cause fewer spurious wake-ups, which is better for power and CPU |
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395 | saving. All these problems can be avoided by installing the optional |
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396 | L<Async::Interrupt> module. This will not work with inherently broken |
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397 | event loops such as L<Event> or L<Event::Lib> (and not with L<POE> |
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398 | currently, as POE does it's own workaround with one-second latency). With |
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399 | those, you just have to suffer the delays. |
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400 | |
329 | =head2 CHILD PROCESS WATCHERS |
401 | =head2 CHILD PROCESS WATCHERS |
330 | |
402 | |
331 | You can also watch on a child process exit and catch its exit status. |
403 | You can also watch on a child process exit and catch its exit status. |
332 | |
404 | |
333 | The child process is specified by the C<pid> argument (if set to C<0>, it |
405 | The child process is specified by the C<pid> argument (one some backends, |
334 | watches for any child process exit). The watcher will trigger as often |
406 | using C<0> watches for any child process exit, on others this will |
335 | as status change for the child are received. This works by installing a |
407 | croak). The watcher will be triggered only when the child process has |
336 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
408 | finished and an exit status is available, not on any trace events |
337 | and exit status (as returned by waitpid), so unlike other watcher types, |
409 | (stopped/continued). |
338 | you I<can> rely on child watcher callback arguments. |
410 | |
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411 | The callback will be called with the pid and exit status (as returned by |
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412 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
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413 | callback arguments. |
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414 | |
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415 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
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416 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
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417 | random child processes (waiting for specific child processes, e.g. inside |
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418 | C<system>, is just fine). |
339 | |
419 | |
340 | There is a slight catch to child watchers, however: you usually start them |
420 | 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 |
421 | I<after> the child process was created, and this means the process could |
342 | have exited already (and no SIGCHLD will be sent anymore). |
422 | have exited already (and no SIGCHLD will be sent anymore). |
343 | |
423 | |
344 | Not all event models handle this correctly (POE doesn't), but even for |
424 | Not all event models handle this correctly (neither POE nor IO::Async do, |
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425 | 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 |
426 | 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). |
427 | the process exits (i.e. before you fork in the first place). AnyEvent's |
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428 | pure perl event loop handles all cases correctly regardless of when you |
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429 | start the watcher. |
347 | |
430 | |
348 | This means you cannot create a child watcher as the very first thing in an |
431 | 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 |
432 | 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>). |
433 | watcher before you C<fork> the child (alternatively, you can call |
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434 | C<AnyEvent::detect>). |
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435 | |
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436 | As most event loops do not support waiting for child events, they will be |
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437 | emulated by AnyEvent in most cases, in which the latency and race problems |
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438 | mentioned in the description of signal watchers apply. |
351 | |
439 | |
352 | Example: fork a process and wait for it |
440 | Example: fork a process and wait for it |
353 | |
441 | |
354 | my $done = AnyEvent->condvar; |
442 | my $done = AnyEvent->condvar; |
355 | |
443 | |
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365 | ); |
453 | ); |
366 | |
454 | |
367 | # do something else, then wait for process exit |
455 | # do something else, then wait for process exit |
368 | $done->recv; |
456 | $done->recv; |
369 | |
457 | |
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458 | =head2 IDLE WATCHERS |
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459 | |
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460 | Sometimes there is a need to do something, but it is not so important |
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461 | to do it instantly, but only when there is nothing better to do. This |
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462 | "nothing better to do" is usually defined to be "no other events need |
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463 | attention by the event loop". |
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464 | |
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465 | Idle watchers ideally get invoked when the event loop has nothing |
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466 | better to do, just before it would block the process to wait for new |
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467 | events. Instead of blocking, the idle watcher is invoked. |
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468 | |
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469 | Most event loops unfortunately do not really support idle watchers (only |
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470 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
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471 | will simply call the callback "from time to time". |
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472 | |
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473 | Example: read lines from STDIN, but only process them when the |
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474 | program is otherwise idle: |
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475 | |
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476 | my @lines; # read data |
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477 | my $idle_w; |
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478 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
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479 | push @lines, scalar <STDIN>; |
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480 | |
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481 | # start an idle watcher, if not already done |
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482 | $idle_w ||= AnyEvent->idle (cb => sub { |
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483 | # handle only one line, when there are lines left |
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484 | if (my $line = shift @lines) { |
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485 | print "handled when idle: $line"; |
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486 | } else { |
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487 | # otherwise disable the idle watcher again |
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488 | undef $idle_w; |
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489 | } |
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490 | }); |
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491 | }); |
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492 | |
370 | =head2 CONDITION VARIABLES |
493 | =head2 CONDITION VARIABLES |
371 | |
494 | |
372 | If you are familiar with some event loops you will know that all of them |
495 | 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 |
496 | require you to run some blocking "loop", "run" or similar function that |
374 | will actively watch for new events and call your callbacks. |
497 | will actively watch for new events and call your callbacks. |
375 | |
498 | |
376 | AnyEvent is different, it expects somebody else to run the event loop and |
499 | AnyEvent is slightly different: it expects somebody else to run the event |
377 | will only block when necessary (usually when told by the user). |
500 | loop and will only block when necessary (usually when told by the user). |
378 | |
501 | |
379 | The instrument to do that is called a "condition variable", so called |
502 | The instrument to do that is called a "condition variable", so called |
380 | because they represent a condition that must become true. |
503 | because they represent a condition that must become true. |
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504 | |
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505 | Now is probably a good time to look at the examples further below. |
381 | |
506 | |
382 | Condition variables can be created by calling the C<< AnyEvent->condvar |
507 | Condition variables can be created by calling the C<< AnyEvent->condvar |
383 | >> method, usually without arguments. The only argument pair allowed is |
508 | >> method, usually without arguments. The only argument pair allowed is |
384 | C<cb>, which specifies a callback to be called when the condition variable |
509 | C<cb>, which specifies a callback to be called when the condition variable |
385 | becomes true. |
510 | becomes true, with the condition variable as the first argument (but not |
|
|
511 | the results). |
386 | |
512 | |
387 | After creation, the condition variable is "false" until it becomes "true" |
513 | 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 |
514 | 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<< |
515 | were a callback, read about the caveats in the description for the C<< |
390 | ->send >> method). |
516 | ->send >> method). |
… | |
… | |
392 | Condition variables are similar to callbacks, except that you can |
518 | Condition variables are similar to callbacks, except that you can |
393 | optionally wait for them. They can also be called merge points - points |
519 | optionally wait for them. They can also be called merge points - points |
394 | in time where multiple outstanding events have been processed. And yet |
520 | in time where multiple outstanding events have been processed. And yet |
395 | another way to call them is transactions - each condition variable can be |
521 | another way to call them is transactions - each condition variable can be |
396 | used to represent a transaction, which finishes at some point and delivers |
522 | used to represent a transaction, which finishes at some point and delivers |
397 | a result. |
523 | a result. And yet some people know them as "futures" - a promise to |
|
|
524 | compute/deliver something that you can wait for. |
398 | |
525 | |
399 | Condition variables are very useful to signal that something has finished, |
526 | Condition variables are very useful to signal that something has finished, |
400 | for example, if you write a module that does asynchronous http requests, |
527 | for example, if you write a module that does asynchronous http requests, |
401 | then a condition variable would be the ideal candidate to signal the |
528 | then a condition variable would be the ideal candidate to signal the |
402 | availability of results. The user can either act when the callback is |
529 | availability of results. The user can either act when the callback is |
… | |
… | |
436 | after => 1, |
563 | after => 1, |
437 | cb => sub { $result_ready->send }, |
564 | cb => sub { $result_ready->send }, |
438 | ); |
565 | ); |
439 | |
566 | |
440 | # this "blocks" (while handling events) till the callback |
567 | # this "blocks" (while handling events) till the callback |
441 | # calls send |
568 | # calls -<send |
442 | $result_ready->recv; |
569 | $result_ready->recv; |
443 | |
570 | |
444 | Example: wait for a timer, but take advantage of the fact that |
571 | Example: wait for a timer, but take advantage of the fact that condition |
445 | condition variables are also code references. |
572 | variables are also callable directly. |
446 | |
573 | |
447 | my $done = AnyEvent->condvar; |
574 | my $done = AnyEvent->condvar; |
448 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
575 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
449 | $done->recv; |
576 | $done->recv; |
|
|
577 | |
|
|
578 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
579 | callbacks. This is how you make a synchronous call, for example from |
|
|
580 | the main program: |
|
|
581 | |
|
|
582 | use AnyEvent::CouchDB; |
|
|
583 | |
|
|
584 | ... |
|
|
585 | |
|
|
586 | my @info = $couchdb->info->recv; |
|
|
587 | |
|
|
588 | And this is how you would just set a callback to be called whenever the |
|
|
589 | results are available: |
|
|
590 | |
|
|
591 | $couchdb->info->cb (sub { |
|
|
592 | my @info = $_[0]->recv; |
|
|
593 | }); |
450 | |
594 | |
451 | =head3 METHODS FOR PRODUCERS |
595 | =head3 METHODS FOR PRODUCERS |
452 | |
596 | |
453 | These methods should only be used by the producing side, i.e. the |
597 | 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 |
598 | code/module that eventually sends the signal. Note that it is also |
… | |
… | |
467 | immediately from within send. |
611 | immediately from within send. |
468 | |
612 | |
469 | Any arguments passed to the C<send> call will be returned by all |
613 | Any arguments passed to the C<send> call will be returned by all |
470 | future C<< ->recv >> calls. |
614 | future C<< ->recv >> calls. |
471 | |
615 | |
472 | Condition variables are overloaded so one can call them directly |
616 | Condition variables are overloaded so one can call them directly (as if |
473 | (as a code reference). Calling them directly is the same as calling |
617 | they were a code reference). Calling them directly is the same as calling |
474 | C<send>. Note, however, that many C-based event loops do not handle |
618 | C<send>. |
475 | overloading, so as tempting as it may be, passing a condition variable |
|
|
476 | instead of a callback does not work. Both the pure perl and EV loops |
|
|
477 | support overloading, however, as well as all functions that use perl to |
|
|
478 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
|
|
479 | example). |
|
|
480 | |
619 | |
481 | =item $cv->croak ($error) |
620 | =item $cv->croak ($error) |
482 | |
621 | |
483 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
622 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
484 | C<Carp::croak> with the given error message/object/scalar. |
623 | C<Carp::croak> with the given error message/object/scalar. |
485 | |
624 | |
486 | This can be used to signal any errors to the condition variable |
625 | This can be used to signal any errors to the condition variable |
487 | user/consumer. |
626 | user/consumer. Doing it this way instead of calling C<croak> directly |
|
|
627 | delays the error detetcion, but has the overwhelmign advantage that it |
|
|
628 | diagnoses the error at the place where the result is expected, and not |
|
|
629 | deep in some event clalback without connection to the actual code causing |
|
|
630 | the problem. |
488 | |
631 | |
489 | =item $cv->begin ([group callback]) |
632 | =item $cv->begin ([group callback]) |
490 | |
633 | |
491 | =item $cv->end |
634 | =item $cv->end |
492 | |
|
|
493 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
|
|
494 | |
635 | |
495 | These two methods can be used to combine many transactions/events into |
636 | These two methods can be used to combine many transactions/events into |
496 | one. For example, a function that pings many hosts in parallel might want |
637 | one. For example, a function that pings many hosts in parallel might want |
497 | to use a condition variable for the whole process. |
638 | to use a condition variable for the whole process. |
498 | |
639 | |
… | |
… | |
500 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
641 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
501 | >>, the (last) callback passed to C<begin> will be executed. That callback |
642 | >>, the (last) callback passed to C<begin> will be executed. That callback |
502 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
643 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
503 | callback was set, C<send> will be called without any arguments. |
644 | callback was set, C<send> will be called without any arguments. |
504 | |
645 | |
505 | Let's clarify this with the ping example: |
646 | You can think of C<< $cv->send >> giving you an OR condition (one call |
|
|
647 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
|
|
648 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
|
|
649 | |
|
|
650 | Let's start with a simple example: you have two I/O watchers (for example, |
|
|
651 | STDOUT and STDERR for a program), and you want to wait for both streams to |
|
|
652 | close before activating a condvar: |
|
|
653 | |
|
|
654 | my $cv = AnyEvent->condvar; |
|
|
655 | |
|
|
656 | $cv->begin; # first watcher |
|
|
657 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
|
|
658 | defined sysread $fh1, my $buf, 4096 |
|
|
659 | or $cv->end; |
|
|
660 | }); |
|
|
661 | |
|
|
662 | $cv->begin; # second watcher |
|
|
663 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
664 | defined sysread $fh2, my $buf, 4096 |
|
|
665 | or $cv->end; |
|
|
666 | }); |
|
|
667 | |
|
|
668 | $cv->recv; |
|
|
669 | |
|
|
670 | This works because for every event source (EOF on file handle), there is |
|
|
671 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
|
|
672 | sending. |
|
|
673 | |
|
|
674 | The ping example mentioned above is slightly more complicated, as the |
|
|
675 | there are results to be passwd back, and the number of tasks that are |
|
|
676 | begung can potentially be zero: |
506 | |
677 | |
507 | my $cv = AnyEvent->condvar; |
678 | my $cv = AnyEvent->condvar; |
508 | |
679 | |
509 | my %result; |
680 | my %result; |
510 | $cv->begin (sub { $cv->send (\%result) }); |
681 | $cv->begin (sub { $cv->send (\%result) }); |
… | |
… | |
530 | loop, which serves two important purposes: first, it sets the callback |
701 | loop, which serves two important purposes: first, it sets the callback |
531 | to be called once the counter reaches C<0>, and second, it ensures that |
702 | to be called once the counter reaches C<0>, and second, it ensures that |
532 | C<send> is called even when C<no> hosts are being pinged (the loop |
703 | C<send> is called even when C<no> hosts are being pinged (the loop |
533 | doesn't execute once). |
704 | doesn't execute once). |
534 | |
705 | |
535 | This is the general pattern when you "fan out" into multiple subrequests: |
706 | This is the general pattern when you "fan out" into multiple (but |
536 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
707 | potentially none) subrequests: use an outer C<begin>/C<end> pair to set |
537 | is called at least once, and then, for each subrequest you start, call |
708 | the callback and ensure C<end> is called at least once, and then, for each |
538 | C<begin> and for each subrequest you finish, call C<end>. |
709 | subrequest you start, call C<begin> and for each subrequest you finish, |
|
|
710 | call C<end>. |
539 | |
711 | |
540 | =back |
712 | =back |
541 | |
713 | |
542 | =head3 METHODS FOR CONSUMERS |
714 | =head3 METHODS FOR CONSUMERS |
543 | |
715 | |
… | |
… | |
559 | function will call C<croak>. |
731 | function will call C<croak>. |
560 | |
732 | |
561 | In list context, all parameters passed to C<send> will be returned, |
733 | In list context, all parameters passed to C<send> will be returned, |
562 | in scalar context only the first one will be returned. |
734 | in scalar context only the first one will be returned. |
563 | |
735 | |
|
|
736 | Note that doing a blocking wait in a callback is not supported by any |
|
|
737 | event loop, that is, recursive invocation of a blocking C<< ->recv |
|
|
738 | >> is not allowed, and the C<recv> call will C<croak> if such a |
|
|
739 | condition is detected. This condition can be slightly loosened by using |
|
|
740 | L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from |
|
|
741 | any thread that doesn't run the event loop itself. |
|
|
742 | |
564 | Not all event models support a blocking wait - some die in that case |
743 | Not all event models support a blocking wait - some die in that case |
565 | (programs might want to do that to stay interactive), so I<if you are |
744 | (programs might want to do that to stay interactive), so I<if you are |
566 | using this from a module, never require a blocking wait>, but let the |
745 | using this from a module, never require a blocking wait>. Instead, let the |
567 | caller decide whether the call will block or not (for example, by coupling |
746 | caller decide whether the call will block or not (for example, by coupling |
568 | condition variables with some kind of request results and supporting |
747 | condition variables with some kind of request results and supporting |
569 | callbacks so the caller knows that getting the result will not block, |
748 | callbacks so the caller knows that getting the result will not block, |
570 | while still supporting blocking waits if the caller so desires). |
749 | while still supporting blocking waits if the caller so desires). |
571 | |
750 | |
572 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
|
|
573 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
|
|
574 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
|
|
575 | can supply. |
|
|
576 | |
|
|
577 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
|
|
578 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
|
|
579 | versions and also integrates coroutines into AnyEvent, making blocking |
|
|
580 | C<< ->recv >> calls perfectly safe as long as they are done from another |
|
|
581 | coroutine (one that doesn't run the event loop). |
|
|
582 | |
|
|
583 | You can ensure that C<< -recv >> never blocks by setting a callback and |
751 | You can ensure that C<< -recv >> never blocks by setting a callback and |
584 | only calling C<< ->recv >> from within that callback (or at a later |
752 | only calling C<< ->recv >> from within that callback (or at a later |
585 | time). This will work even when the event loop does not support blocking |
753 | time). This will work even when the event loop does not support blocking |
586 | waits otherwise. |
754 | waits otherwise. |
587 | |
755 | |
588 | =item $bool = $cv->ready |
756 | =item $bool = $cv->ready |
589 | |
757 | |
590 | Returns true when the condition is "true", i.e. whether C<send> or |
758 | Returns true when the condition is "true", i.e. whether C<send> or |
591 | C<croak> have been called. |
759 | C<croak> have been called. |
592 | |
760 | |
593 | =item $cb = $cv->cb ([new callback]) |
761 | =item $cb = $cv->cb ($cb->($cv)) |
594 | |
762 | |
595 | This is a mutator function that returns the callback set and optionally |
763 | This is a mutator function that returns the callback set and optionally |
596 | replaces it before doing so. |
764 | replaces it before doing so. |
597 | |
765 | |
598 | The callback will be called when the condition becomes "true", i.e. when |
766 | The callback will be called when the condition becomes "true", i.e. when |
… | |
… | |
600 | variable itself. Calling C<recv> inside the callback or at any later time |
768 | variable itself. Calling C<recv> inside the callback or at any later time |
601 | is guaranteed not to block. |
769 | is guaranteed not to block. |
602 | |
770 | |
603 | =back |
771 | =back |
604 | |
772 | |
|
|
773 | =head1 SUPPORTED EVENT LOOPS/BACKENDS |
|
|
774 | |
|
|
775 | The available backend classes are (every class has its own manpage): |
|
|
776 | |
|
|
777 | =over 4 |
|
|
778 | |
|
|
779 | =item Backends that are autoprobed when no other event loop can be found. |
|
|
780 | |
|
|
781 | EV is the preferred backend when no other event loop seems to be in |
|
|
782 | use. If EV is not installed, then AnyEvent will try Event, and, failing |
|
|
783 | that, will fall back to its own pure-perl implementation, which is |
|
|
784 | available everywhere as it comes with AnyEvent itself. |
|
|
785 | |
|
|
786 | AnyEvent::Impl::EV based on EV (interface to libev, best choice). |
|
|
787 | AnyEvent::Impl::Event based on Event, very stable, few glitches. |
|
|
788 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
789 | |
|
|
790 | =item Backends that are transparently being picked up when they are used. |
|
|
791 | |
|
|
792 | These will be used when they are currently loaded when the first watcher |
|
|
793 | is created, in which case it is assumed that the application is using |
|
|
794 | them. This means that AnyEvent will automatically pick the right backend |
|
|
795 | when the main program loads an event module before anything starts to |
|
|
796 | create watchers. Nothing special needs to be done by the main program. |
|
|
797 | |
|
|
798 | AnyEvent::Impl::Glib based on Glib, slow but very stable. |
|
|
799 | AnyEvent::Impl::Tk based on Tk, very broken. |
|
|
800 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
801 | AnyEvent::Impl::POE based on POE, very slow, some limitations. |
|
|
802 | AnyEvent::Impl::Irssi used when running within irssi. |
|
|
803 | |
|
|
804 | =item Backends with special needs. |
|
|
805 | |
|
|
806 | Qt requires the Qt::Application to be instantiated first, but will |
|
|
807 | otherwise be picked up automatically. As long as the main program |
|
|
808 | instantiates the application before any AnyEvent watchers are created, |
|
|
809 | everything should just work. |
|
|
810 | |
|
|
811 | AnyEvent::Impl::Qt based on Qt. |
|
|
812 | |
|
|
813 | Support for IO::Async can only be partial, as it is too broken and |
|
|
814 | architecturally limited to even support the AnyEvent API. It also |
|
|
815 | is the only event loop that needs the loop to be set explicitly, so |
|
|
816 | it can only be used by a main program knowing about AnyEvent. See |
|
|
817 | L<AnyEvent::Impl::Async> for the gory details. |
|
|
818 | |
|
|
819 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed. |
|
|
820 | |
|
|
821 | =item Event loops that are indirectly supported via other backends. |
|
|
822 | |
|
|
823 | Some event loops can be supported via other modules: |
|
|
824 | |
|
|
825 | There is no direct support for WxWidgets (L<Wx>) or L<Prima>. |
|
|
826 | |
|
|
827 | B<WxWidgets> has no support for watching file handles. However, you can |
|
|
828 | use WxWidgets through the POE adaptor, as POE has a Wx backend that simply |
|
|
829 | polls 20 times per second, which was considered to be too horrible to even |
|
|
830 | consider for AnyEvent. |
|
|
831 | |
|
|
832 | B<Prima> is not supported as nobody seems to be using it, but it has a POE |
|
|
833 | backend, so it can be supported through POE. |
|
|
834 | |
|
|
835 | AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to |
|
|
836 | load L<POE> when detecting them, in the hope that POE will pick them up, |
|
|
837 | in which case everything will be automatic. |
|
|
838 | |
|
|
839 | =back |
|
|
840 | |
605 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
841 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
606 | |
842 | |
|
|
843 | These are not normally required to use AnyEvent, but can be useful to |
|
|
844 | write AnyEvent extension modules. |
|
|
845 | |
607 | =over 4 |
846 | =over 4 |
608 | |
847 | |
609 | =item $AnyEvent::MODEL |
848 | =item $AnyEvent::MODEL |
610 | |
849 | |
611 | Contains C<undef> until the first watcher is being created. Then it |
850 | Contains C<undef> until the first watcher is being created, before the |
|
|
851 | backend has been autodetected. |
|
|
852 | |
612 | contains the event model that is being used, which is the name of the |
853 | Afterwards it contains the event model that is being used, which is the |
613 | Perl class implementing the model. This class is usually one of the |
854 | name of the Perl class implementing the model. This class is usually one |
614 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
855 | of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the |
615 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
856 | case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it |
616 | |
857 | will be C<urxvt::anyevent>). |
617 | The known classes so far are: |
|
|
618 | |
|
|
619 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
|
|
620 | AnyEvent::Impl::Event based on Event, second best choice. |
|
|
621 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
622 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
|
|
623 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
|
|
624 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
|
|
625 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
626 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
|
|
627 | |
|
|
628 | There is no support for WxWidgets, as WxWidgets has no support for |
|
|
629 | 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 |
|
|
631 | 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 |
|
|
633 | it's adaptor. |
|
|
634 | |
|
|
635 | AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when |
|
|
636 | autodetecting them. |
|
|
637 | |
858 | |
638 | =item AnyEvent::detect |
859 | =item AnyEvent::detect |
639 | |
860 | |
640 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
861 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
641 | if necessary. You should only call this function right before you would |
862 | if necessary. You should only call this function right before you would |
642 | have created an AnyEvent watcher anyway, that is, as late as possible at |
863 | have created an AnyEvent watcher anyway, that is, as late as possible at |
643 | runtime. |
864 | runtime, and not e.g. while initialising of your module. |
|
|
865 | |
|
|
866 | If you need to do some initialisation before AnyEvent watchers are |
|
|
867 | created, use C<post_detect>. |
644 | |
868 | |
645 | =item $guard = AnyEvent::post_detect { BLOCK } |
869 | =item $guard = AnyEvent::post_detect { BLOCK } |
646 | |
870 | |
647 | Arranges for the code block to be executed as soon as the event model is |
871 | Arranges for the code block to be executed as soon as the event model is |
648 | autodetected (or immediately if this has already happened). |
872 | autodetected (or immediately if this has already happened). |
649 | |
873 | |
|
|
874 | The block will be executed I<after> the actual backend has been detected |
|
|
875 | (C<$AnyEvent::MODEL> is set), but I<before> any watchers have been |
|
|
876 | created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do |
|
|
877 | other initialisations - see the sources of L<AnyEvent::Strict> or |
|
|
878 | L<AnyEvent::AIO> to see how this is used. |
|
|
879 | |
|
|
880 | The most common usage is to create some global watchers, without forcing |
|
|
881 | event module detection too early, for example, L<AnyEvent::AIO> creates |
|
|
882 | and installs the global L<IO::AIO> watcher in a C<post_detect> block to |
|
|
883 | avoid autodetecting the event module at load time. |
|
|
884 | |
650 | If called in scalar or list context, then it creates and returns an object |
885 | If called in scalar or list context, then it creates and returns an object |
651 | that automatically removes the callback again when it is destroyed. See |
886 | that automatically removes the callback again when it is destroyed (or |
|
|
887 | C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for |
652 | L<Coro::BDB> for a case where this is useful. |
888 | a case where this is useful. |
|
|
889 | |
|
|
890 | Example: Create a watcher for the IO::AIO module and store it in |
|
|
891 | C<$WATCHER>. Only do so after the event loop is initialised, though. |
|
|
892 | |
|
|
893 | our WATCHER; |
|
|
894 | |
|
|
895 | my $guard = AnyEvent::post_detect { |
|
|
896 | $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb); |
|
|
897 | }; |
|
|
898 | |
|
|
899 | # the ||= is important in case post_detect immediately runs the block, |
|
|
900 | # as to not clobber the newly-created watcher. assigning both watcher and |
|
|
901 | # post_detect guard to the same variable has the advantage of users being |
|
|
902 | # able to just C<undef $WATCHER> if the watcher causes them grief. |
|
|
903 | |
|
|
904 | $WATCHER ||= $guard; |
653 | |
905 | |
654 | =item @AnyEvent::post_detect |
906 | =item @AnyEvent::post_detect |
655 | |
907 | |
656 | If there are any code references in this array (you can C<push> to it |
908 | If there are any code references in this array (you can C<push> to it |
657 | before or after loading AnyEvent), then they will called directly after |
909 | before or after loading AnyEvent), then they will called directly after |
658 | the event loop has been chosen. |
910 | the event loop has been chosen. |
659 | |
911 | |
660 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
912 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
661 | if it contains a true value then the event loop has already been detected, |
913 | if it is defined then the event loop has already been detected, and the |
662 | and the array will be ignored. |
914 | array will be ignored. |
663 | |
915 | |
664 | Best use C<AnyEvent::post_detect { BLOCK }> instead. |
916 | Best use C<AnyEvent::post_detect { BLOCK }> when your application allows |
|
|
917 | it,as it takes care of these details. |
|
|
918 | |
|
|
919 | This variable is mainly useful for modules that can do something useful |
|
|
920 | when AnyEvent is used and thus want to know when it is initialised, but do |
|
|
921 | not need to even load it by default. This array provides the means to hook |
|
|
922 | into AnyEvent passively, without loading it. |
665 | |
923 | |
666 | =back |
924 | =back |
667 | |
925 | |
668 | =head1 WHAT TO DO IN A MODULE |
926 | =head1 WHAT TO DO IN A MODULE |
669 | |
927 | |
… | |
… | |
724 | |
982 | |
725 | |
983 | |
726 | =head1 OTHER MODULES |
984 | =head1 OTHER MODULES |
727 | |
985 | |
728 | The following is a non-exhaustive list of additional modules that use |
986 | The following is a non-exhaustive list of additional modules that use |
729 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
987 | AnyEvent as a client and can therefore be mixed easily with other AnyEvent |
730 | in the same program. Some of the modules come with AnyEvent, some are |
988 | modules and other event loops in the same program. Some of the modules |
731 | available via CPAN. |
989 | come with AnyEvent, most are available via CPAN. |
732 | |
990 | |
733 | =over 4 |
991 | =over 4 |
734 | |
992 | |
735 | =item L<AnyEvent::Util> |
993 | =item L<AnyEvent::Util> |
736 | |
994 | |
… | |
… | |
745 | |
1003 | |
746 | =item L<AnyEvent::Handle> |
1004 | =item L<AnyEvent::Handle> |
747 | |
1005 | |
748 | Provide read and write buffers, manages watchers for reads and writes, |
1006 | Provide read and write buffers, manages watchers for reads and writes, |
749 | supports raw and formatted I/O, I/O queued and fully transparent and |
1007 | supports raw and formatted I/O, I/O queued and fully transparent and |
750 | non-blocking SSL/TLS. |
1008 | non-blocking SSL/TLS (via L<AnyEvent::TLS>. |
751 | |
1009 | |
752 | =item L<AnyEvent::DNS> |
1010 | =item L<AnyEvent::DNS> |
753 | |
1011 | |
754 | Provides rich asynchronous DNS resolver capabilities. |
1012 | Provides rich asynchronous DNS resolver capabilities. |
755 | |
1013 | |
… | |
… | |
783 | |
1041 | |
784 | =item L<AnyEvent::GPSD> |
1042 | =item L<AnyEvent::GPSD> |
785 | |
1043 | |
786 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
1044 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
787 | |
1045 | |
|
|
1046 | =item L<AnyEvent::IRC> |
|
|
1047 | |
|
|
1048 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
|
|
1049 | |
|
|
1050 | =item L<AnyEvent::XMPP> |
|
|
1051 | |
|
|
1052 | AnyEvent based XMPP (Jabber protocol) module family (replacing the older |
|
|
1053 | Net::XMPP2>. |
|
|
1054 | |
788 | =item L<AnyEvent::IGS> |
1055 | =item L<AnyEvent::IGS> |
789 | |
1056 | |
790 | A non-blocking interface to the Internet Go Server protocol (used by |
1057 | A non-blocking interface to the Internet Go Server protocol (used by |
791 | L<App::IGS>). |
1058 | L<App::IGS>). |
792 | |
1059 | |
793 | =item L<Net::IRC3> |
|
|
794 | |
|
|
795 | AnyEvent based IRC client module family. |
|
|
796 | |
|
|
797 | =item L<Net::XMPP2> |
|
|
798 | |
|
|
799 | AnyEvent based XMPP (Jabber protocol) module family. |
|
|
800 | |
|
|
801 | =item L<Net::FCP> |
1060 | =item L<Net::FCP> |
802 | |
1061 | |
803 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
1062 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
804 | of AnyEvent. |
1063 | of AnyEvent. |
805 | |
1064 | |
… | |
… | |
809 | |
1068 | |
810 | =item L<Coro> |
1069 | =item L<Coro> |
811 | |
1070 | |
812 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
1071 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
813 | |
1072 | |
814 | =item L<IO::Lambda> |
|
|
815 | |
|
|
816 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
|
|
817 | |
|
|
818 | =back |
1073 | =back |
819 | |
1074 | |
820 | =cut |
1075 | =cut |
821 | |
1076 | |
822 | package AnyEvent; |
1077 | package AnyEvent; |
823 | |
1078 | |
|
|
1079 | # basically a tuned-down version of common::sense |
|
|
1080 | sub common_sense { |
824 | no warnings; |
1081 | # no warnings |
825 | use strict; |
1082 | ${^WARNING_BITS} ^= ${^WARNING_BITS}; |
|
|
1083 | # use strict vars subs |
|
|
1084 | $^H |= 0x00000600; |
|
|
1085 | } |
826 | |
1086 | |
|
|
1087 | BEGIN { AnyEvent::common_sense } |
|
|
1088 | |
827 | use Carp; |
1089 | use Carp (); |
828 | |
1090 | |
829 | our $VERSION = 4.2; |
1091 | our $VERSION = 4.87; |
830 | our $MODEL; |
1092 | our $MODEL; |
831 | |
1093 | |
832 | our $AUTOLOAD; |
1094 | our $AUTOLOAD; |
833 | our @ISA; |
1095 | our @ISA; |
834 | |
1096 | |
835 | our @REGISTRY; |
1097 | our @REGISTRY; |
836 | |
1098 | |
837 | our $WIN32; |
1099 | our $WIN32; |
838 | |
1100 | |
|
|
1101 | our $VERBOSE; |
|
|
1102 | |
839 | BEGIN { |
1103 | BEGIN { |
840 | my $win32 = ! ! ($^O =~ /mswin32/i); |
1104 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
841 | eval "sub WIN32(){ $win32 }"; |
1105 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
842 | } |
|
|
843 | |
1106 | |
|
|
1107 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
1108 | if ${^TAINT}; |
|
|
1109 | |
844 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
1110 | $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
|
|
1111 | |
|
|
1112 | } |
|
|
1113 | |
|
|
1114 | our $MAX_SIGNAL_LATENCY = 10; |
845 | |
1115 | |
846 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
1116 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
847 | |
1117 | |
848 | { |
1118 | { |
849 | my $idx; |
1119 | my $idx; |
… | |
… | |
851 | for reverse split /\s*,\s*/, |
1121 | for reverse split /\s*,\s*/, |
852 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
1122 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
853 | } |
1123 | } |
854 | |
1124 | |
855 | my @models = ( |
1125 | my @models = ( |
856 | [EV:: => AnyEvent::Impl::EV::], |
1126 | [EV:: => AnyEvent::Impl::EV:: , 1], |
857 | [Event:: => AnyEvent::Impl::Event::], |
1127 | [Event:: => AnyEvent::Impl::Event::, 1], |
858 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
1128 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1], |
859 | # everything below here will not be autoprobed |
1129 | # everything below here will not (normally) be autoprobed |
860 | # as the pureperl backend should work everywhere |
1130 | # as the pureperl backend should work everywhere |
861 | # and is usually faster |
1131 | # and is usually faster |
|
|
1132 | [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers |
|
|
1133 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
|
|
1134 | [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package |
862 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
1135 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
863 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
|
|
864 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
|
|
865 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1136 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
866 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1137 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
867 | [Wx:: => AnyEvent::Impl::POE::], |
1138 | [Wx:: => AnyEvent::Impl::POE::], |
868 | [Prima:: => AnyEvent::Impl::POE::], |
1139 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
1140 | # IO::Async is just too broken - we would need workarounds for its |
|
|
1141 | # byzantine signal and broken child handling, among others. |
|
|
1142 | # IO::Async is rather hard to detect, as it doesn't have any |
|
|
1143 | # obvious default class. |
|
|
1144 | # [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1145 | # [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1146 | # [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
869 | ); |
1147 | ); |
870 | |
1148 | |
871 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
1149 | our %method = map +($_ => 1), |
|
|
1150 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
872 | |
1151 | |
873 | our @post_detect; |
1152 | our @post_detect; |
874 | |
1153 | |
875 | sub post_detect(&) { |
1154 | sub post_detect(&) { |
876 | my ($cb) = @_; |
1155 | my ($cb) = @_; |
877 | |
1156 | |
878 | if ($MODEL) { |
1157 | if ($MODEL) { |
879 | $cb->(); |
1158 | $cb->(); |
880 | |
1159 | |
881 | 1 |
1160 | undef |
882 | } else { |
1161 | } else { |
883 | push @post_detect, $cb; |
1162 | push @post_detect, $cb; |
884 | |
1163 | |
885 | defined wantarray |
1164 | defined wantarray |
886 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
1165 | ? bless \$cb, "AnyEvent::Util::postdetect" |
887 | : () |
1166 | : () |
888 | } |
1167 | } |
889 | } |
1168 | } |
890 | |
1169 | |
891 | sub AnyEvent::Util::PostDetect::DESTROY { |
1170 | sub AnyEvent::Util::postdetect::DESTROY { |
892 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1171 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
893 | } |
1172 | } |
894 | |
1173 | |
895 | sub detect() { |
1174 | sub detect() { |
896 | unless ($MODEL) { |
1175 | unless ($MODEL) { |
897 | no strict 'refs'; |
|
|
898 | local $SIG{__DIE__}; |
1176 | local $SIG{__DIE__}; |
899 | |
1177 | |
900 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
1178 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
901 | my $model = "AnyEvent::Impl::$1"; |
1179 | my $model = "AnyEvent::Impl::$1"; |
902 | if (eval "require $model") { |
1180 | if (eval "require $model") { |
903 | $MODEL = $model; |
1181 | $MODEL = $model; |
904 | warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; |
1182 | warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; |
905 | } else { |
1183 | } else { |
906 | warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; |
1184 | warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE; |
907 | } |
1185 | } |
908 | } |
1186 | } |
909 | |
1187 | |
910 | # check for already loaded models |
1188 | # check for already loaded models |
911 | unless ($MODEL) { |
1189 | unless ($MODEL) { |
912 | for (@REGISTRY, @models) { |
1190 | for (@REGISTRY, @models) { |
913 | my ($package, $model) = @$_; |
1191 | my ($package, $model) = @$_; |
914 | if (${"$package\::VERSION"} > 0) { |
1192 | if (${"$package\::VERSION"} > 0) { |
915 | if (eval "require $model") { |
1193 | if (eval "require $model") { |
916 | $MODEL = $model; |
1194 | $MODEL = $model; |
917 | warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; |
1195 | warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2; |
918 | last; |
1196 | last; |
919 | } |
1197 | } |
920 | } |
1198 | } |
921 | } |
1199 | } |
922 | |
1200 | |
923 | unless ($MODEL) { |
1201 | unless ($MODEL) { |
924 | # try to load a model |
1202 | # try to autoload a model |
925 | |
|
|
926 | for (@REGISTRY, @models) { |
1203 | for (@REGISTRY, @models) { |
927 | my ($package, $model) = @$_; |
1204 | my ($package, $model, $autoload) = @$_; |
|
|
1205 | if ( |
|
|
1206 | $autoload |
928 | if (eval "require $package" |
1207 | and eval "require $package" |
929 | and ${"$package\::VERSION"} > 0 |
1208 | and ${"$package\::VERSION"} > 0 |
930 | and eval "require $model") { |
1209 | and eval "require $model" |
|
|
1210 | ) { |
931 | $MODEL = $model; |
1211 | $MODEL = $model; |
932 | warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; |
1212 | warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2; |
933 | last; |
1213 | last; |
934 | } |
1214 | } |
935 | } |
1215 | } |
936 | |
1216 | |
937 | $MODEL |
1217 | $MODEL |
938 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1218 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
939 | } |
1219 | } |
940 | } |
1220 | } |
941 | |
1221 | |
|
|
1222 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
1223 | |
942 | unshift @ISA, $MODEL; |
1224 | unshift @ISA, $MODEL; |
943 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1225 | |
|
|
1226 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
944 | |
1227 | |
945 | (shift @post_detect)->() while @post_detect; |
1228 | (shift @post_detect)->() while @post_detect; |
946 | } |
1229 | } |
947 | |
1230 | |
948 | $MODEL |
1231 | $MODEL |
… | |
… | |
950 | |
1233 | |
951 | sub AUTOLOAD { |
1234 | sub AUTOLOAD { |
952 | (my $func = $AUTOLOAD) =~ s/.*://; |
1235 | (my $func = $AUTOLOAD) =~ s/.*://; |
953 | |
1236 | |
954 | $method{$func} |
1237 | $method{$func} |
955 | or croak "$func: not a valid method for AnyEvent objects"; |
1238 | or Carp::croak "$func: not a valid method for AnyEvent objects"; |
956 | |
1239 | |
957 | detect unless $MODEL; |
1240 | detect unless $MODEL; |
958 | |
1241 | |
959 | my $class = shift; |
1242 | my $class = shift; |
960 | $class->$func (@_); |
1243 | $class->$func (@_); |
961 | } |
1244 | } |
962 | |
1245 | |
|
|
1246 | # utility function to dup a filehandle. this is used by many backends |
|
|
1247 | # to support binding more than one watcher per filehandle (they usually |
|
|
1248 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1249 | sub _dupfh($$;$$) { |
|
|
1250 | my ($poll, $fh, $r, $w) = @_; |
|
|
1251 | |
|
|
1252 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1253 | my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&"); |
|
|
1254 | |
|
|
1255 | open my $fh2, $mode, $fh |
|
|
1256 | or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; |
|
|
1257 | |
|
|
1258 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1259 | |
|
|
1260 | ($fh2, $rw) |
|
|
1261 | } |
|
|
1262 | |
963 | package AnyEvent::Base; |
1263 | package AnyEvent::Base; |
964 | |
1264 | |
965 | # default implementation for now and time |
1265 | # default implementations for many methods |
966 | |
1266 | |
967 | use Time::HiRes (); |
1267 | sub _time { |
|
|
1268 | # probe for availability of Time::HiRes |
|
|
1269 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1270 | warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; |
|
|
1271 | *_time = \&Time::HiRes::time; |
|
|
1272 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1273 | } else { |
|
|
1274 | warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; |
|
|
1275 | *_time = sub { time }; # epic fail |
|
|
1276 | } |
968 | |
1277 | |
969 | sub time { Time::HiRes::time } |
1278 | &_time |
970 | sub now { Time::HiRes::time } |
1279 | } |
|
|
1280 | |
|
|
1281 | sub time { _time } |
|
|
1282 | sub now { _time } |
|
|
1283 | sub now_update { } |
971 | |
1284 | |
972 | # default implementation for ->condvar |
1285 | # default implementation for ->condvar |
973 | |
1286 | |
974 | sub condvar { |
1287 | sub condvar { |
975 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1288 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
976 | } |
1289 | } |
977 | |
1290 | |
978 | # default implementation for ->signal |
1291 | # default implementation for ->signal |
979 | |
1292 | |
980 | our %SIG_CB; |
1293 | our $HAVE_ASYNC_INTERRUPT; |
|
|
1294 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1295 | our (%SIG_ASY, %SIG_ASY_W); |
|
|
1296 | our ($SIG_COUNT, $SIG_TW); |
981 | |
1297 | |
|
|
1298 | sub _signal_exec { |
|
|
1299 | $HAVE_ASYNC_INTERRUPT |
|
|
1300 | ? $SIGPIPE_R->drain |
|
|
1301 | : sysread $SIGPIPE_R, my $dummy, 9; |
|
|
1302 | |
|
|
1303 | while (%SIG_EV) { |
|
|
1304 | for (keys %SIG_EV) { |
|
|
1305 | delete $SIG_EV{$_}; |
|
|
1306 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1307 | } |
|
|
1308 | } |
|
|
1309 | } |
|
|
1310 | |
|
|
1311 | # install a dumym wakeupw atcher to reduce signal catching latency |
|
|
1312 | sub _sig_add() { |
|
|
1313 | unless ($SIG_COUNT++) { |
|
|
1314 | # try to align timer on a full-second boundary, if possible |
|
|
1315 | my $NOW = AnyEvent->now; |
|
|
1316 | |
|
|
1317 | $SIG_TW = AnyEvent->timer ( |
|
|
1318 | after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW), |
|
|
1319 | interval => $MAX_SIGNAL_LATENCY, |
|
|
1320 | cb => sub { }, # just for the PERL_ASYNC_CHECK |
|
|
1321 | ); |
|
|
1322 | } |
|
|
1323 | } |
|
|
1324 | |
|
|
1325 | sub _sig_del { |
|
|
1326 | undef $SIG_TW |
|
|
1327 | unless --$SIG_COUNT; |
|
|
1328 | } |
|
|
1329 | |
982 | sub signal { |
1330 | sub _signal { |
983 | my (undef, %arg) = @_; |
1331 | my (undef, %arg) = @_; |
984 | |
1332 | |
985 | my $signal = uc $arg{signal} |
1333 | my $signal = uc $arg{signal} |
986 | or Carp::croak "required option 'signal' is missing"; |
1334 | or Carp::croak "required option 'signal' is missing"; |
987 | |
1335 | |
988 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1336 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
1337 | |
|
|
1338 | if ($HAVE_ASYNC_INTERRUPT) { |
|
|
1339 | # async::interrupt |
|
|
1340 | |
|
|
1341 | $SIG_ASY{$signal} ||= do { |
|
|
1342 | my $asy = new Async::Interrupt |
|
|
1343 | cb => sub { undef $SIG_EV{$signal} }, |
|
|
1344 | signal => $signal, |
|
|
1345 | pipe => [$SIGPIPE_R->filenos], |
|
|
1346 | ; |
|
|
1347 | $asy->pipe_autodrain (0); |
|
|
1348 | |
|
|
1349 | $asy |
|
|
1350 | }; |
|
|
1351 | |
|
|
1352 | } else { |
|
|
1353 | # pure perl |
|
|
1354 | |
989 | $SIG{$signal} ||= sub { |
1355 | $SIG{$signal} ||= sub { |
990 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1356 | local $!; |
|
|
1357 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1358 | undef $SIG_EV{$signal}; |
|
|
1359 | }; |
|
|
1360 | |
|
|
1361 | # can't do signal processing without introducing races in pure perl, |
|
|
1362 | # so limit the signal latency. |
|
|
1363 | _sig_add; |
991 | }; |
1364 | } |
992 | |
1365 | |
993 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1366 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
994 | } |
1367 | } |
995 | |
1368 | |
|
|
1369 | sub signal { |
|
|
1370 | # probe for availability of Async::Interrupt |
|
|
1371 | if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") { |
|
|
1372 | warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8; |
|
|
1373 | |
|
|
1374 | $HAVE_ASYNC_INTERRUPT = 1; |
|
|
1375 | $SIGPIPE_R = new Async::Interrupt::EventPipe; |
|
|
1376 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec); |
|
|
1377 | |
|
|
1378 | } else { |
|
|
1379 | warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; |
|
|
1380 | |
|
|
1381 | require Fcntl; |
|
|
1382 | |
|
|
1383 | if (AnyEvent::WIN32) { |
|
|
1384 | require AnyEvent::Util; |
|
|
1385 | |
|
|
1386 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1387 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1388 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1389 | } else { |
|
|
1390 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1391 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1392 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1393 | |
|
|
1394 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1395 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1396 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1397 | } |
|
|
1398 | |
|
|
1399 | $SIGPIPE_R |
|
|
1400 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1401 | |
|
|
1402 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1403 | } |
|
|
1404 | |
|
|
1405 | *signal = \&_signal; |
|
|
1406 | &signal |
|
|
1407 | } |
|
|
1408 | |
996 | sub AnyEvent::Base::Signal::DESTROY { |
1409 | sub AnyEvent::Base::signal::DESTROY { |
997 | my ($signal, $cb) = @{$_[0]}; |
1410 | my ($signal, $cb) = @{$_[0]}; |
998 | |
1411 | |
|
|
1412 | _sig_del; |
|
|
1413 | |
999 | delete $SIG_CB{$signal}{$cb}; |
1414 | delete $SIG_CB{$signal}{$cb}; |
1000 | |
1415 | |
|
|
1416 | $HAVE_ASYNC_INTERRUPT |
|
|
1417 | ? delete $SIG_ASY{$signal} |
|
|
1418 | : # delete doesn't work with older perls - they then |
|
|
1419 | # print weird messages, or just unconditionally exit |
|
|
1420 | # instead of getting the default action. |
|
|
1421 | undef $SIG{$signal} |
1001 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1422 | unless keys %{ $SIG_CB{$signal} }; |
1002 | } |
1423 | } |
1003 | |
1424 | |
1004 | # default implementation for ->child |
1425 | # default implementation for ->child |
1005 | |
1426 | |
1006 | our %PID_CB; |
1427 | our %PID_CB; |
1007 | our $CHLD_W; |
1428 | our $CHLD_W; |
1008 | our $CHLD_DELAY_W; |
1429 | our $CHLD_DELAY_W; |
1009 | our $PID_IDLE; |
|
|
1010 | our $WNOHANG; |
1430 | our $WNOHANG; |
1011 | |
1431 | |
1012 | sub _child_wait { |
1432 | sub _emit_childstatus($$) { |
1013 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1433 | my (undef, $rpid, $rstatus) = @_; |
|
|
1434 | |
|
|
1435 | $_->($rpid, $rstatus) |
1014 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1436 | for values %{ $PID_CB{$rpid} || {} }, |
1015 | (values %{ $PID_CB{0} || {} }); |
1437 | values %{ $PID_CB{0} || {} }; |
1016 | } |
|
|
1017 | |
|
|
1018 | undef $PID_IDLE; |
|
|
1019 | } |
1438 | } |
1020 | |
1439 | |
1021 | sub _sigchld { |
1440 | sub _sigchld { |
1022 | # make sure we deliver these changes "synchronous" with the event loop. |
1441 | my $pid; |
1023 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
1442 | |
1024 | undef $CHLD_DELAY_W; |
1443 | AnyEvent->_emit_childstatus ($pid, $?) |
1025 | &_child_wait; |
1444 | while ($pid = waitpid -1, $WNOHANG) > 0; |
1026 | }); |
|
|
1027 | } |
1445 | } |
1028 | |
1446 | |
1029 | sub child { |
1447 | sub child { |
1030 | my (undef, %arg) = @_; |
1448 | my (undef, %arg) = @_; |
1031 | |
1449 | |
1032 | defined (my $pid = $arg{pid} + 0) |
1450 | defined (my $pid = $arg{pid} + 0) |
1033 | or Carp::croak "required option 'pid' is missing"; |
1451 | or Carp::croak "required option 'pid' is missing"; |
1034 | |
1452 | |
1035 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1453 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1036 | |
1454 | |
1037 | unless ($WNOHANG) { |
1455 | # WNOHANG is almost cetrainly 1 everywhere |
|
|
1456 | $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ |
|
|
1457 | ? 1 |
1038 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1458 | : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1039 | } |
|
|
1040 | |
1459 | |
1041 | unless ($CHLD_W) { |
1460 | unless ($CHLD_W) { |
1042 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1461 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1043 | # child could be a zombie already, so make at least one round |
1462 | # child could be a zombie already, so make at least one round |
1044 | &_sigchld; |
1463 | &_sigchld; |
1045 | } |
1464 | } |
1046 | |
1465 | |
1047 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1466 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
1048 | } |
1467 | } |
1049 | |
1468 | |
1050 | sub AnyEvent::Base::Child::DESTROY { |
1469 | sub AnyEvent::Base::child::DESTROY { |
1051 | my ($pid, $cb) = @{$_[0]}; |
1470 | my ($pid, $cb) = @{$_[0]}; |
1052 | |
1471 | |
1053 | delete $PID_CB{$pid}{$cb}; |
1472 | delete $PID_CB{$pid}{$cb}; |
1054 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1473 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1055 | |
1474 | |
1056 | undef $CHLD_W unless keys %PID_CB; |
1475 | undef $CHLD_W unless keys %PID_CB; |
1057 | } |
1476 | } |
1058 | |
1477 | |
|
|
1478 | # idle emulation is done by simply using a timer, regardless |
|
|
1479 | # of whether the process is idle or not, and not letting |
|
|
1480 | # the callback use more than 50% of the time. |
|
|
1481 | sub idle { |
|
|
1482 | my (undef, %arg) = @_; |
|
|
1483 | |
|
|
1484 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1485 | |
|
|
1486 | $rcb = sub { |
|
|
1487 | if ($cb) { |
|
|
1488 | $w = _time; |
|
|
1489 | &$cb; |
|
|
1490 | $w = _time - $w; |
|
|
1491 | |
|
|
1492 | # never use more then 50% of the time for the idle watcher, |
|
|
1493 | # within some limits |
|
|
1494 | $w = 0.0001 if $w < 0.0001; |
|
|
1495 | $w = 5 if $w > 5; |
|
|
1496 | |
|
|
1497 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1498 | } else { |
|
|
1499 | # clean up... |
|
|
1500 | undef $w; |
|
|
1501 | undef $rcb; |
|
|
1502 | } |
|
|
1503 | }; |
|
|
1504 | |
|
|
1505 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1506 | |
|
|
1507 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1508 | } |
|
|
1509 | |
|
|
1510 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1511 | undef $${$_[0]}; |
|
|
1512 | } |
|
|
1513 | |
1059 | package AnyEvent::CondVar; |
1514 | package AnyEvent::CondVar; |
1060 | |
1515 | |
1061 | our @ISA = AnyEvent::CondVar::Base::; |
1516 | our @ISA = AnyEvent::CondVar::Base::; |
1062 | |
1517 | |
1063 | package AnyEvent::CondVar::Base; |
1518 | package AnyEvent::CondVar::Base; |
1064 | |
1519 | |
1065 | use overload |
1520 | #use overload |
1066 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
1521 | # '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
1067 | fallback => 1; |
1522 | # fallback => 1; |
|
|
1523 | |
|
|
1524 | # save 300+ kilobytes by dirtily hardcoding overloading |
|
|
1525 | ${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching. |
|
|
1526 | *{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod." |
|
|
1527 | *{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{} |
|
|
1528 | ${'AnyEvent::CondVar::Base::()'} = 1; # fallback |
|
|
1529 | |
|
|
1530 | our $WAITING; |
1068 | |
1531 | |
1069 | sub _send { |
1532 | sub _send { |
1070 | # nop |
1533 | # nop |
1071 | } |
1534 | } |
1072 | |
1535 | |
… | |
… | |
1085 | sub ready { |
1548 | sub ready { |
1086 | $_[0]{_ae_sent} |
1549 | $_[0]{_ae_sent} |
1087 | } |
1550 | } |
1088 | |
1551 | |
1089 | sub _wait { |
1552 | sub _wait { |
|
|
1553 | $WAITING |
|
|
1554 | and !$_[0]{_ae_sent} |
|
|
1555 | and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected"; |
|
|
1556 | |
|
|
1557 | local $WAITING = 1; |
1090 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
1558 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
1091 | } |
1559 | } |
1092 | |
1560 | |
1093 | sub recv { |
1561 | sub recv { |
1094 | $_[0]->_wait; |
1562 | $_[0]->_wait; |
… | |
… | |
1113 | } |
1581 | } |
1114 | |
1582 | |
1115 | # undocumented/compatibility with pre-3.4 |
1583 | # undocumented/compatibility with pre-3.4 |
1116 | *broadcast = \&send; |
1584 | *broadcast = \&send; |
1117 | *wait = \&_wait; |
1585 | *wait = \&_wait; |
|
|
1586 | |
|
|
1587 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1588 | |
|
|
1589 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1590 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1591 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1592 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1593 | development. |
|
|
1594 | |
|
|
1595 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1596 | executing a callback), this is not only highly event-loop specific, but |
|
|
1597 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1598 | program. |
|
|
1599 | |
|
|
1600 | The pure perl event loop simply re-throws the exception (usually |
|
|
1601 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1602 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1603 | so on. |
|
|
1604 | |
|
|
1605 | =head1 ENVIRONMENT VARIABLES |
|
|
1606 | |
|
|
1607 | The following environment variables are used by this module or its |
|
|
1608 | submodules. |
|
|
1609 | |
|
|
1610 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1611 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1612 | enabled. |
|
|
1613 | |
|
|
1614 | =over 4 |
|
|
1615 | |
|
|
1616 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1617 | |
|
|
1618 | By default, AnyEvent will be completely silent except in fatal |
|
|
1619 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1620 | talkative. |
|
|
1621 | |
|
|
1622 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1623 | conditions, such as not being able to load the event model specified by |
|
|
1624 | C<PERL_ANYEVENT_MODEL>. |
|
|
1625 | |
|
|
1626 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1627 | model it chooses. |
|
|
1628 | |
|
|
1629 | When set to C<8> or higher, then AnyEvent will report extra information on |
|
|
1630 | which optional modules it loads and how it implements certain features. |
|
|
1631 | |
|
|
1632 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1633 | |
|
|
1634 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1635 | argument checking is very costly. Setting this variable to a true value |
|
|
1636 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1637 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1638 | it will croak. |
|
|
1639 | |
|
|
1640 | In other words, enables "strict" mode. |
|
|
1641 | |
|
|
1642 | Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> |
|
|
1643 | >>, it is definitely recommended to keep it off in production. Keeping |
|
|
1644 | C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs |
|
|
1645 | can be very useful, however. |
|
|
1646 | |
|
|
1647 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1648 | |
|
|
1649 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1650 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1651 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1652 | and the resulting module name is loaded and if the load was successful, |
|
|
1653 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1654 | auto detection and -probing. |
|
|
1655 | |
|
|
1656 | This functionality might change in future versions. |
|
|
1657 | |
|
|
1658 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1659 | could start your program like this: |
|
|
1660 | |
|
|
1661 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1662 | |
|
|
1663 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1664 | |
|
|
1665 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1666 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1667 | of auto probing). |
|
|
1668 | |
|
|
1669 | Must be set to a comma-separated list of protocols or address families, |
|
|
1670 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1671 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1672 | list. |
|
|
1673 | |
|
|
1674 | This variable can effectively be used for denial-of-service attacks |
|
|
1675 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1676 | small, as the program has to handle conenction and other failures anyways. |
|
|
1677 | |
|
|
1678 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1679 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1680 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1681 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1682 | IPv6, but prefer IPv6 over IPv4. |
|
|
1683 | |
|
|
1684 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1685 | |
|
|
1686 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1687 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1688 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1689 | default. |
|
|
1690 | |
|
|
1691 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1692 | EDNS0 in its DNS requests. |
|
|
1693 | |
|
|
1694 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1695 | |
|
|
1696 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1697 | will create in parallel. |
|
|
1698 | |
|
|
1699 | =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> |
|
|
1700 | |
|
|
1701 | The default value for the C<max_outstanding> parameter for the default DNS |
|
|
1702 | resolver - this is the maximum number of parallel DNS requests that are |
|
|
1703 | sent to the DNS server. |
|
|
1704 | |
|
|
1705 | =item C<PERL_ANYEVENT_RESOLV_CONF> |
|
|
1706 | |
|
|
1707 | The file to use instead of F</etc/resolv.conf> (or OS-specific |
|
|
1708 | configuration) in the default resolver. When set to the empty string, no |
|
|
1709 | default config will be used. |
|
|
1710 | |
|
|
1711 | =item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. |
|
|
1712 | |
|
|
1713 | When neither C<ca_file> nor C<ca_path> was specified during |
|
|
1714 | L<AnyEvent::TLS> context creation, and either of these environment |
|
|
1715 | variables exist, they will be used to specify CA certificate locations |
|
|
1716 | instead of a system-dependent default. |
|
|
1717 | |
|
|
1718 | =item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT> |
|
|
1719 | |
|
|
1720 | When these are set to C<1>, then the respective modules are not |
|
|
1721 | loaded. Mostly good for testing AnyEvent itself. |
|
|
1722 | |
|
|
1723 | =back |
1118 | |
1724 | |
1119 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1725 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1120 | |
1726 | |
1121 | This is an advanced topic that you do not normally need to use AnyEvent in |
1727 | 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 |
1728 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1156 | |
1762 | |
1157 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1763 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1158 | condition variables: code blocking while waiting for a condition will |
1764 | condition variables: code blocking while waiting for a condition will |
1159 | C<die>. This still works with most modules/usages, and blocking calls must |
1765 | 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. |
1766 | 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 | |
1767 | |
1235 | =head1 EXAMPLE PROGRAM |
1768 | =head1 EXAMPLE PROGRAM |
1236 | |
1769 | |
1237 | The following program uses an I/O watcher to read data from STDIN, a timer |
1770 | 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 |
1771 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1432 | watcher. |
1965 | watcher. |
1433 | |
1966 | |
1434 | =head3 Results |
1967 | =head3 Results |
1435 | |
1968 | |
1436 | name watchers bytes create invoke destroy comment |
1969 | name watchers bytes create invoke destroy comment |
1437 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1970 | 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 |
1971 | 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 |
1972 | 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 |
1973 | 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 |
1974 | 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 |
1975 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1976 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1977 | 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 |
1978 | 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 |
1979 | 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 |
1980 | 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 |
1981 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1447 | |
1982 | |
1448 | =head3 Discussion |
1983 | =head3 Discussion |
1449 | |
1984 | |
1450 | The benchmark does I<not> measure scalability of the event loop very |
1985 | 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) |
1986 | 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 |
2011 | 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. |
2012 | them active), of course, but this was not subject of this benchmark. |
1478 | |
2013 | |
1479 | The C<Event> module has a relatively high setup and callback invocation |
2014 | The C<Event> module has a relatively high setup and callback invocation |
1480 | cost, but overall scores in on the third place. |
2015 | cost, but overall scores in on the third place. |
|
|
2016 | |
|
|
2017 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
2018 | when using its pure perl backend. |
1481 | |
2019 | |
1482 | C<Glib>'s memory usage is quite a bit higher, but it features a |
2020 | 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 |
2021 | faster callback invocation and overall ends up in the same class as |
1484 | C<Event>. However, Glib scales extremely badly, doubling the number of |
2022 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1485 | watchers increases the processing time by more than a factor of four, |
2023 | 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 |
2101 | it to another server. This includes deleting the old timeout and creating |
1564 | a new one that moves the timeout into the future. |
2102 | a new one that moves the timeout into the future. |
1565 | |
2103 | |
1566 | =head3 Results |
2104 | =head3 Results |
1567 | |
2105 | |
1568 | name sockets create request |
2106 | name sockets create request |
1569 | EV 20000 69.01 11.16 |
2107 | EV 20000 69.01 11.16 |
1570 | Perl 20000 73.32 35.87 |
2108 | Perl 20000 73.32 35.87 |
|
|
2109 | IOAsync 20000 157.00 98.14 epoll |
|
|
2110 | IOAsync 20000 159.31 616.06 poll |
1571 | Event 20000 212.62 257.32 |
2111 | Event 20000 212.62 257.32 |
1572 | Glib 20000 651.16 1896.30 |
2112 | Glib 20000 651.16 1896.30 |
1573 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
2113 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1574 | |
2114 | |
1575 | =head3 Discussion |
2115 | =head3 Discussion |
1576 | |
2116 | |
1577 | This benchmark I<does> measure scalability and overall performance of the |
2117 | This benchmark I<does> measure scalability and overall performance of the |
1578 | particular event loop. |
2118 | particular event loop. |
… | |
… | |
1580 | EV is again fastest. Since it is using epoll on my system, the setup time |
2120 | EV is again fastest. Since it is using epoll on my system, the setup time |
1581 | is relatively high, though. |
2121 | is relatively high, though. |
1582 | |
2122 | |
1583 | Perl surprisingly comes second. It is much faster than the C-based event |
2123 | Perl surprisingly comes second. It is much faster than the C-based event |
1584 | loops Event and Glib. |
2124 | loops Event and Glib. |
|
|
2125 | |
|
|
2126 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
2127 | good compared to Glib when using its pure perl backend. |
1585 | |
2128 | |
1586 | Event suffers from high setup time as well (look at its code and you will |
2129 | 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 |
2130 | understand why). Callback invocation also has a high overhead compared to |
1588 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
2131 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1589 | uses select or poll in basically all documented configurations. |
2132 | uses select or poll in basically all documented configurations. |
… | |
… | |
1652 | =item * C-based event loops perform very well with small number of |
2195 | =item * C-based event loops perform very well with small number of |
1653 | watchers, as the management overhead dominates. |
2196 | watchers, as the management overhead dominates. |
1654 | |
2197 | |
1655 | =back |
2198 | =back |
1656 | |
2199 | |
|
|
2200 | =head2 THE IO::Lambda BENCHMARK |
|
|
2201 | |
|
|
2202 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
2203 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
2204 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
2205 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
2206 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
2207 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
2208 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
2209 | |
|
|
2210 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
2211 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
2212 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
2213 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
2214 | benchmark nevertheless. |
|
|
2215 | |
|
|
2216 | name runtime |
|
|
2217 | Lambda/select 0.330 sec |
|
|
2218 | + optimized 0.122 sec |
|
|
2219 | Lambda/AnyEvent 0.327 sec |
|
|
2220 | + optimized 0.138 sec |
|
|
2221 | Raw sockets/select 0.077 sec |
|
|
2222 | POE/select, components 0.662 sec |
|
|
2223 | POE/select, raw sockets 0.226 sec |
|
|
2224 | POE/select, optimized 0.404 sec |
|
|
2225 | |
|
|
2226 | AnyEvent/select/nb 0.085 sec |
|
|
2227 | AnyEvent/EV/nb 0.068 sec |
|
|
2228 | +state machine 0.134 sec |
|
|
2229 | |
|
|
2230 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
2231 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
2232 | defeating the purpose of an event-based solution. All of the newly |
|
|
2233 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
2234 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
2235 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
2236 | generally require a lot more bookkeeping and event handling than blocking |
|
|
2237 | connects (which involve a single syscall only). |
|
|
2238 | |
|
|
2239 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
2240 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
2241 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
2242 | non-blocking, further placing it at a disadvantage. |
|
|
2243 | |
|
|
2244 | As you can see, the AnyEvent + EV combination even beats the |
|
|
2245 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
2246 | backend easily beats IO::Lambda and POE. |
|
|
2247 | |
|
|
2248 | And even the 100% non-blocking version written using the high-level (and |
|
|
2249 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
2250 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
2251 | in a non-blocking way. |
|
|
2252 | |
|
|
2253 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2254 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2255 | part of the IO::lambda distribution and were used without any changes. |
|
|
2256 | |
|
|
2257 | |
|
|
2258 | =head1 SIGNALS |
|
|
2259 | |
|
|
2260 | AnyEvent currently installs handlers for these signals: |
|
|
2261 | |
|
|
2262 | =over 4 |
|
|
2263 | |
|
|
2264 | =item SIGCHLD |
|
|
2265 | |
|
|
2266 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2267 | emulation for event loops that do not support them natively. Also, some |
|
|
2268 | event loops install a similar handler. |
|
|
2269 | |
|
|
2270 | Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then |
|
|
2271 | AnyEvent will reset it to default, to avoid losing child exit statuses. |
|
|
2272 | |
|
|
2273 | =item SIGPIPE |
|
|
2274 | |
|
|
2275 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2276 | when AnyEvent gets loaded. |
|
|
2277 | |
|
|
2278 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2279 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2280 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2281 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2282 | some random socket. |
|
|
2283 | |
|
|
2284 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2285 | that this way, the handler will be restored to defaults on exec. |
|
|
2286 | |
|
|
2287 | Feel free to install your own handler, or reset it to defaults. |
|
|
2288 | |
|
|
2289 | =back |
|
|
2290 | |
|
|
2291 | =cut |
|
|
2292 | |
|
|
2293 | undef $SIG{CHLD} |
|
|
2294 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2295 | |
|
|
2296 | $SIG{PIPE} = sub { } |
|
|
2297 | unless defined $SIG{PIPE}; |
|
|
2298 | |
|
|
2299 | =head1 RECOMMENDED/OPTIONAL MODULES |
|
|
2300 | |
|
|
2301 | One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and |
|
|
2302 | it's built-in modules) are required to use it. |
|
|
2303 | |
|
|
2304 | That does not mean that AnyEvent won't take advantage of some additional |
|
|
2305 | modules if they are installed. |
|
|
2306 | |
|
|
2307 | This section epxlains which additional modules will be used, and how they |
|
|
2308 | affect AnyEvent's operetion. |
|
|
2309 | |
|
|
2310 | =over 4 |
|
|
2311 | |
|
|
2312 | =item L<Async::Interrupt> |
|
|
2313 | |
|
|
2314 | This slightly arcane module is used to implement fast signal handling: To |
|
|
2315 | my knowledge, there is no way to do completely race-free and quick |
|
|
2316 | signal handling in pure perl. To ensure that signals still get |
|
|
2317 | delivered, AnyEvent will start an interval timer to wake up perl (and |
|
|
2318 | catch the signals) with some delay (default is 10 seconds, look for |
|
|
2319 | C<$AnyEvent::MAX_SIGNAL_LATENCY>). |
|
|
2320 | |
|
|
2321 | If this module is available, then it will be used to implement signal |
|
|
2322 | catching, which means that signals will not be delayed, and the event loop |
|
|
2323 | will not be interrupted regularly, which is more efficient (And good for |
|
|
2324 | battery life on laptops). |
|
|
2325 | |
|
|
2326 | This affects not just the pure-perl event loop, but also other event loops |
|
|
2327 | that have no signal handling on their own (e.g. Glib, Tk, Qt). |
|
|
2328 | |
|
|
2329 | Some event loops (POE, Event, Event::Lib) offer signal watchers natively, |
|
|
2330 | and either employ their own workarounds (POE) or use AnyEvent's workaround |
|
|
2331 | (using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt> |
|
|
2332 | does nothing for those backends. |
|
|
2333 | |
|
|
2334 | =item L<EV> |
|
|
2335 | |
|
|
2336 | This module isn't really "optional", as it is simply one of the backend |
|
|
2337 | event loops that AnyEvent can use. However, it is simply the best event |
|
|
2338 | loop available in terms of features, speed and stability: It supports |
|
|
2339 | the AnyEvent API optimally, implements all the watcher types in XS, does |
|
|
2340 | automatic timer adjustments even when no monotonic clock is available, |
|
|
2341 | can take avdantage of advanced kernel interfaces such as C<epoll> and |
|
|
2342 | C<kqueue>, and is the fastest backend I<by far>. You can even embed |
|
|
2343 | L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). |
|
|
2344 | |
|
|
2345 | =item L<Guard> |
|
|
2346 | |
|
|
2347 | The guard module, when used, will be used to implement |
|
|
2348 | C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a |
|
|
2349 | lot less memory), but otherwise doesn't affect guard operation much. It is |
|
|
2350 | purely used for performance. |
|
|
2351 | |
|
|
2352 | =item L<JSON> and L<JSON::XS> |
|
|
2353 | |
|
|
2354 | This module is required when you want to read or write JSON data via |
|
|
2355 | L<AnyEvent::Handle>. It is also written in pure-perl, but can take |
|
|
2356 | advantage of the ultra-high-speed L<JSON::XS> module when it is installed. |
|
|
2357 | |
|
|
2358 | In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is |
|
|
2359 | installed. |
|
|
2360 | |
|
|
2361 | =item L<Net::SSLeay> |
|
|
2362 | |
|
|
2363 | Implementing TLS/SSL in Perl is certainly interesting, but not very |
|
|
2364 | worthwhile: If this module is installed, then L<AnyEvent::Handle> (with |
|
|
2365 | the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. |
|
|
2366 | |
|
|
2367 | =item L<Time::HiRes> |
|
|
2368 | |
|
|
2369 | This module is part of perl since release 5.008. It will be used when the |
|
|
2370 | chosen event library does not come with a timing source on it's own. The |
|
|
2371 | pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to |
|
|
2372 | try to use a monotonic clock for timing stability. |
|
|
2373 | |
|
|
2374 | =back |
|
|
2375 | |
1657 | |
2376 | |
1658 | =head1 FORK |
2377 | =head1 FORK |
1659 | |
2378 | |
1660 | Most event libraries are not fork-safe. The ones who are usually are |
2379 | 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> |
2380 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1662 | calls. Only L<EV> is fully fork-aware. |
2381 | calls. Only L<EV> is fully fork-aware. |
1663 | |
2382 | |
1664 | If you have to fork, you must either do so I<before> creating your first |
2383 | If you have to fork, you must either do so I<before> creating your first |
1665 | watcher OR you must not use AnyEvent at all in the child. |
2384 | watcher OR you must not use AnyEvent at all in the child OR you must do |
|
|
2385 | something completely out of the scope of AnyEvent. |
1666 | |
2386 | |
1667 | |
2387 | |
1668 | =head1 SECURITY CONSIDERATIONS |
2388 | =head1 SECURITY CONSIDERATIONS |
1669 | |
2389 | |
1670 | AnyEvent can be forced to load any event model via |
2390 | AnyEvent can be forced to load any event model via |
… | |
… | |
1681 | |
2401 | |
1682 | use AnyEvent; |
2402 | use AnyEvent; |
1683 | |
2403 | |
1684 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2404 | 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 |
2405 | 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). |
2406 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
2407 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2408 | |
|
|
2409 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2410 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2411 | enabled. |
1687 | |
2412 | |
1688 | |
2413 | |
1689 | =head1 BUGS |
2414 | =head1 BUGS |
1690 | |
2415 | |
1691 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
2416 | 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 |
2417 | 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 |
2418 | 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 |
2419 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1695 | pronounced). |
2420 | pronounced). |
1696 | |
2421 | |
1697 | |
2422 | |
1698 | =head1 SEE ALSO |
2423 | =head1 SEE ALSO |
1699 | |
2424 | |
… | |
… | |
1703 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
2428 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1704 | |
2429 | |
1705 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
2430 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1706 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
2431 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1707 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
2432 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1708 | L<AnyEvent::Impl::POE>. |
2433 | L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>. |
1709 | |
2434 | |
1710 | Non-blocking file handles, sockets, TCP clients and |
2435 | Non-blocking file handles, sockets, TCP clients and |
1711 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
2436 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. |
1712 | |
2437 | |
1713 | Asynchronous DNS: L<AnyEvent::DNS>. |
2438 | Asynchronous DNS: L<AnyEvent::DNS>. |
1714 | |
2439 | |
1715 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
2440 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, |
|
|
2441 | L<Coro::Event>, |
1716 | |
2442 | |
1717 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
2443 | Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, |
|
|
2444 | L<AnyEvent::HTTP>. |
1718 | |
2445 | |
1719 | |
2446 | |
1720 | =head1 AUTHOR |
2447 | =head1 AUTHOR |
1721 | |
2448 | |
1722 | Marc Lehmann <schmorp@schmorp.de> |
2449 | Marc Lehmann <schmorp@schmorp.de> |