1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - provide framework for multiple event loops |
4 | |
4 | |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported |
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6 | event loops. |
6 | |
7 | |
7 | =head1 SYNOPSIS |
8 | =head1 SYNOPSIS |
8 | |
9 | |
9 | use AnyEvent; |
10 | use AnyEvent; |
10 | |
11 | |
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12 | # file descriptor readable |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { |
13 | my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); |
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14 | |
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15 | # one-shot or repeating timers |
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16 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
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17 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
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18 | |
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19 | print AnyEvent->now; # prints current event loop time |
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20 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
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21 | |
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22 | # POSIX signal |
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23 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
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24 | |
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25 | # child process exit |
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26 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
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27 | my ($pid, $status) = @_; |
12 | ... |
28 | ... |
13 | }); |
29 | }); |
14 | |
30 | |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
31 | # called when event loop idle (if applicable) |
16 | ... |
32 | my $w = AnyEvent->idle (cb => sub { ... }); |
17 | }); |
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18 | |
33 | |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
34 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
20 | $w->send; # wake up current and all future recv's |
35 | $w->send; # wake up current and all future recv's |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
36 | $w->recv; # enters "main loop" till $condvar gets ->send |
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37 | # use a condvar in callback mode: |
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38 | $w->cb (sub { $_[0]->recv }); |
22 | |
39 | |
23 | =head1 INTRODUCTION/TUTORIAL |
40 | =head1 INTRODUCTION/TUTORIAL |
24 | |
41 | |
25 | This manpage is mainly a reference manual. If you are interested |
42 | This manpage is mainly a reference manual. If you are interested |
26 | in a tutorial or some gentle introduction, have a look at the |
43 | in a tutorial or some gentle introduction, have a look at the |
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33 | |
50 | |
34 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
51 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
35 | policy> and AnyEvent is I<small and efficient>. |
52 | policy> and AnyEvent is I<small and efficient>. |
36 | |
53 | |
37 | First and foremost, I<AnyEvent is not an event model> itself, it only |
54 | First and foremost, I<AnyEvent is not an event model> itself, it only |
38 | interfaces to whatever event model the main program happens to use in a |
55 | interfaces to whatever event model the main program happens to use, in a |
39 | pragmatic way. For event models and certain classes of immortals alike, |
56 | pragmatic way. For event models and certain classes of immortals alike, |
40 | the statement "there can only be one" is a bitter reality: In general, |
57 | the statement "there can only be one" is a bitter reality: In general, |
41 | only one event loop can be active at the same time in a process. AnyEvent |
58 | only one event loop can be active at the same time in a process. AnyEvent |
42 | helps hiding the differences between those event loops. |
59 | cannot change this, but it can hide the differences between those event |
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60 | loops. |
43 | |
61 | |
44 | The goal of AnyEvent is to offer module authors the ability to do event |
62 | The goal of AnyEvent is to offer module authors the ability to do event |
45 | programming (waiting for I/O or timer events) without subscribing to a |
63 | programming (waiting for I/O or timer events) without subscribing to a |
46 | religion, a way of living, and most importantly: without forcing your |
64 | religion, a way of living, and most importantly: without forcing your |
47 | module users into the same thing by forcing them to use the same event |
65 | module users into the same thing by forcing them to use the same event |
48 | model you use. |
66 | model you use. |
49 | |
67 | |
50 | For modules like POE or IO::Async (which is a total misnomer as it is |
68 | For modules like POE or IO::Async (which is a total misnomer as it is |
51 | actually doing all I/O I<synchronously>...), using them in your module is |
69 | actually doing all I/O I<synchronously>...), using them in your module is |
52 | like joining a cult: After you joined, you are dependent on them and you |
70 | like joining a cult: After you joined, you are dependent on them and you |
53 | cannot use anything else, as it is simply incompatible to everything that |
71 | cannot use anything else, as they are simply incompatible to everything |
54 | isn't itself. What's worse, all the potential users of your module are |
72 | that isn't them. What's worse, all the potential users of your |
55 | I<also> forced to use the same event loop you use. |
73 | module are I<also> forced to use the same event loop you use. |
56 | |
74 | |
57 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
75 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
58 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
76 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
59 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
77 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
60 | your module uses one of those, every user of your module has to use it, |
78 | your module uses one of those, every user of your module has to use it, |
61 | too. But if your module uses AnyEvent, it works transparently with all |
79 | too. But if your module uses AnyEvent, it works transparently with all |
62 | event models it supports (including stuff like POE and IO::Async, as long |
80 | event models it supports (including stuff like IO::Async, as long as those |
63 | as those use one of the supported event loops. It is trivial to add new |
81 | use one of the supported event loops. It is trivial to add new event loops |
64 | event loops to AnyEvent, too, so it is future-proof). |
82 | to AnyEvent, too, so it is future-proof). |
65 | |
83 | |
66 | In addition to being free of having to use I<the one and only true event |
84 | In addition to being free of having to use I<the one and only true event |
67 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
85 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
68 | modules, you get an enormous amount of code and strict rules you have to |
86 | modules, you get an enormous amount of code and strict rules you have to |
69 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
87 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
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127 | These watchers are normal Perl objects with normal Perl lifetime. After |
145 | These watchers are normal Perl objects with normal Perl lifetime. After |
128 | creating a watcher it will immediately "watch" for events and invoke the |
146 | creating a watcher it will immediately "watch" for events and invoke the |
129 | callback when the event occurs (of course, only when the event model |
147 | callback when the event occurs (of course, only when the event model |
130 | is in control). |
148 | is in control). |
131 | |
149 | |
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150 | Note that B<callbacks must not permanently change global variables> |
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151 | potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< |
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152 | callbacks must not C<die> >>. The former is good programming practise in |
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153 | Perl and the latter stems from the fact that exception handling differs |
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154 | widely between event loops. |
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155 | |
132 | To disable the watcher you have to destroy it (e.g. by setting the |
156 | To disable the watcher you have to destroy it (e.g. by setting the |
133 | variable you store it in to C<undef> or otherwise deleting all references |
157 | variable you store it in to C<undef> or otherwise deleting all references |
134 | to it). |
158 | to it). |
135 | |
159 | |
136 | All watchers are created by calling a method on the C<AnyEvent> class. |
160 | All watchers are created by calling a method on the C<AnyEvent> class. |
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152 | =head2 I/O WATCHERS |
176 | =head2 I/O WATCHERS |
153 | |
177 | |
154 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
178 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
155 | with the following mandatory key-value pairs as arguments: |
179 | with the following mandatory key-value pairs as arguments: |
156 | |
180 | |
157 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
181 | C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch |
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182 | for events (AnyEvent might or might not keep a reference to this file |
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183 | handle). Note that only file handles pointing to things for which |
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184 | non-blocking operation makes sense are allowed. This includes sockets, |
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185 | most character devices, pipes, fifos and so on, but not for example files |
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186 | or block devices. |
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187 | |
158 | for events. C<poll> must be a string that is either C<r> or C<w>, |
188 | C<poll> must be a string that is either C<r> or C<w>, which creates a |
159 | which creates a watcher waiting for "r"eadable or "w"ritable events, |
189 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
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190 | |
160 | respectively. C<cb> is the callback to invoke each time the file handle |
191 | C<cb> is the callback to invoke each time the file handle becomes ready. |
161 | becomes ready. |
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162 | |
192 | |
163 | Although the callback might get passed parameters, their value and |
193 | Although the callback might get passed parameters, their value and |
164 | presence is undefined and you cannot rely on them. Portable AnyEvent |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
165 | callbacks cannot use arguments passed to I/O watcher callbacks. |
195 | callbacks cannot use arguments passed to I/O watcher callbacks. |
166 | |
196 | |
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193 | Although the callback might get passed parameters, their value and |
223 | Although the callback might get passed parameters, their value and |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
224 | presence is undefined and you cannot rely on them. Portable AnyEvent |
195 | callbacks cannot use arguments passed to time watcher callbacks. |
225 | callbacks cannot use arguments passed to time watcher callbacks. |
196 | |
226 | |
197 | The callback will normally be invoked once only. If you specify another |
227 | The callback will normally be invoked once only. If you specify another |
198 | parameter, C<interval>, as a positive number, then the callback will be |
228 | parameter, C<interval>, as a strictly positive number (> 0), then the |
199 | invoked regularly at that interval (in fractional seconds) after the first |
229 | callback will be invoked regularly at that interval (in fractional |
200 | invocation. |
230 | seconds) after the first invocation. If C<interval> is specified with a |
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231 | false value, then it is treated as if it were missing. |
201 | |
232 | |
202 | The callback will be rescheduled before invoking the callback, but no |
233 | The callback will be rescheduled before invoking the callback, but no |
203 | attempt is done to avoid timer drift in most backends, so the interval is |
234 | attempt is done to avoid timer drift in most backends, so the interval is |
204 | only approximate. |
235 | only approximate. |
205 | |
236 | |
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297 | In either case, if you care (and in most cases, you don't), then you |
328 | In either case, if you care (and in most cases, you don't), then you |
298 | can get whatever behaviour you want with any event loop, by taking the |
329 | can get whatever behaviour you want with any event loop, by taking the |
299 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
330 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
300 | account. |
331 | account. |
301 | |
332 | |
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333 | =item AnyEvent->now_update |
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334 | |
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335 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
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336 | the current time for each loop iteration (see the discussion of L<< |
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337 | AnyEvent->now >>, above). |
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338 | |
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339 | When a callback runs for a long time (or when the process sleeps), then |
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340 | this "current" time will differ substantially from the real time, which |
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341 | might affect timers and time-outs. |
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342 | |
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343 | When this is the case, you can call this method, which will update the |
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344 | event loop's idea of "current time". |
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345 | |
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346 | Note that updating the time I<might> cause some events to be handled. |
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347 | |
302 | =back |
348 | =back |
303 | |
349 | |
304 | =head2 SIGNAL WATCHERS |
350 | =head2 SIGNAL WATCHERS |
305 | |
351 | |
306 | You can watch for signals using a signal watcher, C<signal> is the signal |
352 | You can watch for signals using a signal watcher, C<signal> is the signal |
307 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
353 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
308 | be invoked whenever a signal occurs. |
354 | callback to be invoked whenever a signal occurs. |
309 | |
355 | |
310 | Although the callback might get passed parameters, their value and |
356 | Although the callback might get passed parameters, their value and |
311 | presence is undefined and you cannot rely on them. Portable AnyEvent |
357 | presence is undefined and you cannot rely on them. Portable AnyEvent |
312 | callbacks cannot use arguments passed to signal watcher callbacks. |
358 | callbacks cannot use arguments passed to signal watcher callbacks. |
313 | |
359 | |
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329 | =head2 CHILD PROCESS WATCHERS |
375 | =head2 CHILD PROCESS WATCHERS |
330 | |
376 | |
331 | You can also watch on a child process exit and catch its exit status. |
377 | You can also watch on a child process exit and catch its exit status. |
332 | |
378 | |
333 | The child process is specified by the C<pid> argument (if set to C<0>, it |
379 | The child process is specified by the C<pid> argument (if set to C<0>, it |
334 | watches for any child process exit). The watcher will trigger as often |
380 | watches for any child process exit). The watcher will triggered only when |
335 | as status change for the child are received. This works by installing a |
381 | the child process has finished and an exit status is available, not on |
336 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
382 | any trace events (stopped/continued). |
337 | and exit status (as returned by waitpid), so unlike other watcher types, |
383 | |
338 | you I<can> rely on child watcher callback arguments. |
384 | The callback will be called with the pid and exit status (as returned by |
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385 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
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386 | callback arguments. |
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387 | |
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388 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
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389 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
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390 | random child processes (waiting for specific child processes, e.g. inside |
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391 | C<system>, is just fine). |
339 | |
392 | |
340 | There is a slight catch to child watchers, however: you usually start them |
393 | There is a slight catch to child watchers, however: you usually start them |
341 | I<after> the child process was created, and this means the process could |
394 | I<after> the child process was created, and this means the process could |
342 | have exited already (and no SIGCHLD will be sent anymore). |
395 | have exited already (and no SIGCHLD will be sent anymore). |
343 | |
396 | |
344 | Not all event models handle this correctly (POE doesn't), but even for |
397 | Not all event models handle this correctly (neither POE nor IO::Async do, |
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398 | see their AnyEvent::Impl manpages for details), but even for event models |
345 | event models that I<do> handle this correctly, they usually need to be |
399 | that I<do> handle this correctly, they usually need to be loaded before |
346 | loaded before the process exits (i.e. before you fork in the first place). |
400 | the process exits (i.e. before you fork in the first place). AnyEvent's |
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401 | pure perl event loop handles all cases correctly regardless of when you |
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402 | start the watcher. |
347 | |
403 | |
348 | This means you cannot create a child watcher as the very first thing in an |
404 | This means you cannot create a child watcher as the very first |
349 | AnyEvent program, you I<have> to create at least one watcher before you |
405 | thing in an AnyEvent program, you I<have> to create at least one |
350 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
406 | watcher before you C<fork> the child (alternatively, you can call |
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407 | C<AnyEvent::detect>). |
351 | |
408 | |
352 | Example: fork a process and wait for it |
409 | Example: fork a process and wait for it |
353 | |
410 | |
354 | my $done = AnyEvent->condvar; |
411 | my $done = AnyEvent->condvar; |
355 | |
412 | |
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365 | ); |
422 | ); |
366 | |
423 | |
367 | # do something else, then wait for process exit |
424 | # do something else, then wait for process exit |
368 | $done->recv; |
425 | $done->recv; |
369 | |
426 | |
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427 | =head2 IDLE WATCHERS |
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428 | |
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429 | Sometimes there is a need to do something, but it is not so important |
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430 | to do it instantly, but only when there is nothing better to do. This |
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431 | "nothing better to do" is usually defined to be "no other events need |
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432 | attention by the event loop". |
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433 | |
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434 | Idle watchers ideally get invoked when the event loop has nothing |
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435 | better to do, just before it would block the process to wait for new |
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436 | events. Instead of blocking, the idle watcher is invoked. |
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437 | |
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438 | Most event loops unfortunately do not really support idle watchers (only |
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439 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
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440 | will simply call the callback "from time to time". |
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441 | |
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442 | Example: read lines from STDIN, but only process them when the |
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443 | program is otherwise idle: |
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444 | |
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445 | my @lines; # read data |
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446 | my $idle_w; |
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447 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
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448 | push @lines, scalar <STDIN>; |
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449 | |
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450 | # start an idle watcher, if not already done |
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451 | $idle_w ||= AnyEvent->idle (cb => sub { |
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452 | # handle only one line, when there are lines left |
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453 | if (my $line = shift @lines) { |
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454 | print "handled when idle: $line"; |
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455 | } else { |
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456 | # otherwise disable the idle watcher again |
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457 | undef $idle_w; |
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458 | } |
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459 | }); |
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460 | }); |
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461 | |
370 | =head2 CONDITION VARIABLES |
462 | =head2 CONDITION VARIABLES |
371 | |
463 | |
372 | If you are familiar with some event loops you will know that all of them |
464 | If you are familiar with some event loops you will know that all of them |
373 | require you to run some blocking "loop", "run" or similar function that |
465 | require you to run some blocking "loop", "run" or similar function that |
374 | will actively watch for new events and call your callbacks. |
466 | will actively watch for new events and call your callbacks. |
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379 | The instrument to do that is called a "condition variable", so called |
471 | The instrument to do that is called a "condition variable", so called |
380 | because they represent a condition that must become true. |
472 | because they represent a condition that must become true. |
381 | |
473 | |
382 | Condition variables can be created by calling the C<< AnyEvent->condvar |
474 | Condition variables can be created by calling the C<< AnyEvent->condvar |
383 | >> method, usually without arguments. The only argument pair allowed is |
475 | >> method, usually without arguments. The only argument pair allowed is |
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476 | |
384 | C<cb>, which specifies a callback to be called when the condition variable |
477 | C<cb>, which specifies a callback to be called when the condition variable |
385 | becomes true. |
478 | becomes true, with the condition variable as the first argument (but not |
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479 | the results). |
386 | |
480 | |
387 | After creation, the condition variable is "false" until it becomes "true" |
481 | After creation, the condition variable is "false" until it becomes "true" |
388 | by calling the C<send> method (or calling the condition variable as if it |
482 | by calling the C<send> method (or calling the condition variable as if it |
389 | were a callback, read about the caveats in the description for the C<< |
483 | were a callback, read about the caveats in the description for the C<< |
390 | ->send >> method). |
484 | ->send >> method). |
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446 | |
540 | |
447 | my $done = AnyEvent->condvar; |
541 | my $done = AnyEvent->condvar; |
448 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
542 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
449 | $done->recv; |
543 | $done->recv; |
450 | |
544 | |
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545 | Example: Imagine an API that returns a condvar and doesn't support |
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546 | callbacks. This is how you make a synchronous call, for example from |
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547 | the main program: |
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548 | |
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549 | use AnyEvent::CouchDB; |
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550 | |
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551 | ... |
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552 | |
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553 | my @info = $couchdb->info->recv; |
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554 | |
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555 | And this is how you would just ste a callback to be called whenever the |
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556 | results are available: |
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557 | |
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558 | $couchdb->info->cb (sub { |
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559 | my @info = $_[0]->recv; |
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560 | }); |
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561 | |
451 | =head3 METHODS FOR PRODUCERS |
562 | =head3 METHODS FOR PRODUCERS |
452 | |
563 | |
453 | These methods should only be used by the producing side, i.e. the |
564 | These methods should only be used by the producing side, i.e. the |
454 | code/module that eventually sends the signal. Note that it is also |
565 | code/module that eventually sends the signal. Note that it is also |
455 | the producer side which creates the condvar in most cases, but it isn't |
566 | the producer side which creates the condvar in most cases, but it isn't |
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488 | |
599 | |
489 | =item $cv->begin ([group callback]) |
600 | =item $cv->begin ([group callback]) |
490 | |
601 | |
491 | =item $cv->end |
602 | =item $cv->end |
492 | |
603 | |
493 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
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494 | |
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495 | These two methods can be used to combine many transactions/events into |
604 | These two methods can be used to combine many transactions/events into |
496 | one. For example, a function that pings many hosts in parallel might want |
605 | one. For example, a function that pings many hosts in parallel might want |
497 | to use a condition variable for the whole process. |
606 | to use a condition variable for the whole process. |
498 | |
607 | |
499 | Every call to C<< ->begin >> will increment a counter, and every call to |
608 | Every call to C<< ->begin >> will increment a counter, and every call to |
500 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
609 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
501 | >>, the (last) callback passed to C<begin> will be executed. That callback |
610 | >>, the (last) callback passed to C<begin> will be executed. That callback |
502 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
611 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
503 | callback was set, C<send> will be called without any arguments. |
612 | callback was set, C<send> will be called without any arguments. |
504 | |
613 | |
505 | Let's clarify this with the ping example: |
614 | You can think of C<< $cv->send >> giving you an OR condition (one call |
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|
615 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
|
|
616 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
|
|
617 | |
|
|
618 | Let's start with a simple example: you have two I/O watchers (for example, |
|
|
619 | STDOUT and STDERR for a program), and you want to wait for both streams to |
|
|
620 | close before activating a condvar: |
|
|
621 | |
|
|
622 | my $cv = AnyEvent->condvar; |
|
|
623 | |
|
|
624 | $cv->begin; # first watcher |
|
|
625 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
|
|
626 | defined sysread $fh1, my $buf, 4096 |
|
|
627 | or $cv->end; |
|
|
628 | }); |
|
|
629 | |
|
|
630 | $cv->begin; # second watcher |
|
|
631 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
632 | defined sysread $fh2, my $buf, 4096 |
|
|
633 | or $cv->end; |
|
|
634 | }); |
|
|
635 | |
|
|
636 | $cv->recv; |
|
|
637 | |
|
|
638 | This works because for every event source (EOF on file handle), there is |
|
|
639 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
|
|
640 | sending. |
|
|
641 | |
|
|
642 | The ping example mentioned above is slightly more complicated, as the |
|
|
643 | there are results to be passwd back, and the number of tasks that are |
|
|
644 | begung can potentially be zero: |
506 | |
645 | |
507 | my $cv = AnyEvent->condvar; |
646 | my $cv = AnyEvent->condvar; |
508 | |
647 | |
509 | my %result; |
648 | my %result; |
510 | $cv->begin (sub { $cv->send (\%result) }); |
649 | $cv->begin (sub { $cv->send (\%result) }); |
… | |
… | |
530 | loop, which serves two important purposes: first, it sets the callback |
669 | 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 |
670 | 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 |
671 | C<send> is called even when C<no> hosts are being pinged (the loop |
533 | doesn't execute once). |
672 | doesn't execute once). |
534 | |
673 | |
535 | This is the general pattern when you "fan out" into multiple subrequests: |
674 | This is the general pattern when you "fan out" into multiple (but |
536 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
675 | potentially none) subrequests: use an outer C<begin>/C<end> pair to set |
537 | is called at least once, and then, for each subrequest you start, call |
676 | the callback and ensure C<end> is called at least once, and then, for each |
538 | C<begin> and for each subrequest you finish, call C<end>. |
677 | subrequest you start, call C<begin> and for each subrequest you finish, |
|
|
678 | call C<end>. |
539 | |
679 | |
540 | =back |
680 | =back |
541 | |
681 | |
542 | =head3 METHODS FOR CONSUMERS |
682 | =head3 METHODS FOR CONSUMERS |
543 | |
683 | |
… | |
… | |
588 | =item $bool = $cv->ready |
728 | =item $bool = $cv->ready |
589 | |
729 | |
590 | Returns true when the condition is "true", i.e. whether C<send> or |
730 | Returns true when the condition is "true", i.e. whether C<send> or |
591 | C<croak> have been called. |
731 | C<croak> have been called. |
592 | |
732 | |
593 | =item $cb = $cv->cb ([new callback]) |
733 | =item $cb = $cv->cb ($cb->($cv)) |
594 | |
734 | |
595 | This is a mutator function that returns the callback set and optionally |
735 | This is a mutator function that returns the callback set and optionally |
596 | replaces it before doing so. |
736 | replaces it before doing so. |
597 | |
737 | |
598 | The callback will be called when the condition becomes "true", i.e. when |
738 | The callback will be called when the condition becomes "true", i.e. when |
599 | C<send> or C<croak> are called, with the only argument being the condition |
739 | C<send> or C<croak> are called, with the only argument being the condition |
600 | variable itself. Calling C<recv> inside the callback or at any later time |
740 | variable itself. Calling C<recv> inside the callback or at any later time |
601 | is guaranteed not to block. |
741 | is guaranteed not to block. |
|
|
742 | |
|
|
743 | =back |
|
|
744 | |
|
|
745 | =head1 SUPPORTED EVENT LOOPS/BACKENDS |
|
|
746 | |
|
|
747 | The available backend classes are (every class has its own manpage): |
|
|
748 | |
|
|
749 | =over 4 |
|
|
750 | |
|
|
751 | =item Backends that are autoprobed when no other event loop can be found. |
|
|
752 | |
|
|
753 | EV is the preferred backend when no other event loop seems to be in |
|
|
754 | use. If EV is not installed, then AnyEvent will try Event, and, failing |
|
|
755 | that, will fall back to its own pure-perl implementation, which is |
|
|
756 | available everywhere as it comes with AnyEvent itself. |
|
|
757 | |
|
|
758 | AnyEvent::Impl::EV based on EV (interface to libev, best choice). |
|
|
759 | AnyEvent::Impl::Event based on Event, very stable, few glitches. |
|
|
760 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
761 | |
|
|
762 | =item Backends that are transparently being picked up when they are used. |
|
|
763 | |
|
|
764 | These will be used when they are currently loaded when the first watcher |
|
|
765 | is created, in which case it is assumed that the application is using |
|
|
766 | them. This means that AnyEvent will automatically pick the right backend |
|
|
767 | when the main program loads an event module before anything starts to |
|
|
768 | create watchers. Nothing special needs to be done by the main program. |
|
|
769 | |
|
|
770 | AnyEvent::Impl::Glib based on Glib, slow but very stable. |
|
|
771 | AnyEvent::Impl::Tk based on Tk, very broken. |
|
|
772 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
773 | AnyEvent::Impl::POE based on POE, very slow, some limitations. |
|
|
774 | |
|
|
775 | =item Backends with special needs. |
|
|
776 | |
|
|
777 | Qt requires the Qt::Application to be instantiated first, but will |
|
|
778 | otherwise be picked up automatically. As long as the main program |
|
|
779 | instantiates the application before any AnyEvent watchers are created, |
|
|
780 | everything should just work. |
|
|
781 | |
|
|
782 | AnyEvent::Impl::Qt based on Qt. |
|
|
783 | |
|
|
784 | Support for IO::Async can only be partial, as it is too broken and |
|
|
785 | architecturally limited to even support the AnyEvent API. It also |
|
|
786 | is the only event loop that needs the loop to be set explicitly, so |
|
|
787 | it can only be used by a main program knowing about AnyEvent. See |
|
|
788 | L<AnyEvent::Impl::Async> for the gory details. |
|
|
789 | |
|
|
790 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed. |
|
|
791 | |
|
|
792 | =item Event loops that are indirectly supported via other backends. |
|
|
793 | |
|
|
794 | Some event loops can be supported via other modules: |
|
|
795 | |
|
|
796 | There is no direct support for WxWidgets (L<Wx>) or L<Prima>. |
|
|
797 | |
|
|
798 | B<WxWidgets> has no support for watching file handles. However, you can |
|
|
799 | use WxWidgets through the POE adaptor, as POE has a Wx backend that simply |
|
|
800 | polls 20 times per second, which was considered to be too horrible to even |
|
|
801 | consider for AnyEvent. |
|
|
802 | |
|
|
803 | B<Prima> is not supported as nobody seems to be using it, but it has a POE |
|
|
804 | backend, so it can be supported through POE. |
|
|
805 | |
|
|
806 | AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to |
|
|
807 | load L<POE> when detecting them, in the hope that POE will pick them up, |
|
|
808 | in which case everything will be automatic. |
602 | |
809 | |
603 | =back |
810 | =back |
604 | |
811 | |
605 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
812 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
606 | |
813 | |
… | |
… | |
611 | Contains C<undef> until the first watcher is being created. Then it |
818 | Contains C<undef> until the first watcher is being created. Then it |
612 | contains the event model that is being used, which is the name of the |
819 | contains the event model that is being used, which is the name of the |
613 | Perl class implementing the model. This class is usually one of the |
820 | Perl class implementing the model. This class is usually one of the |
614 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
821 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
615 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
822 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
616 | |
|
|
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 | |
823 | |
638 | =item AnyEvent::detect |
824 | =item AnyEvent::detect |
639 | |
825 | |
640 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
826 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
641 | if necessary. You should only call this function right before you would |
827 | if necessary. You should only call this function right before you would |
… | |
… | |
724 | |
910 | |
725 | |
911 | |
726 | =head1 OTHER MODULES |
912 | =head1 OTHER MODULES |
727 | |
913 | |
728 | The following is a non-exhaustive list of additional modules that use |
914 | The following is a non-exhaustive list of additional modules that use |
729 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
915 | 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 |
916 | modules and other event loops in the same program. Some of the modules |
731 | available via CPAN. |
917 | come with AnyEvent, most are available via CPAN. |
732 | |
918 | |
733 | =over 4 |
919 | =over 4 |
734 | |
920 | |
735 | =item L<AnyEvent::Util> |
921 | =item L<AnyEvent::Util> |
736 | |
922 | |
… | |
… | |
745 | |
931 | |
746 | =item L<AnyEvent::Handle> |
932 | =item L<AnyEvent::Handle> |
747 | |
933 | |
748 | Provide read and write buffers, manages watchers for reads and writes, |
934 | 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 |
935 | supports raw and formatted I/O, I/O queued and fully transparent and |
750 | non-blocking SSL/TLS. |
936 | non-blocking SSL/TLS (via L<AnyEvent::TLS>. |
751 | |
937 | |
752 | =item L<AnyEvent::DNS> |
938 | =item L<AnyEvent::DNS> |
753 | |
939 | |
754 | Provides rich asynchronous DNS resolver capabilities. |
940 | Provides rich asynchronous DNS resolver capabilities. |
755 | |
941 | |
… | |
… | |
783 | |
969 | |
784 | =item L<AnyEvent::GPSD> |
970 | =item L<AnyEvent::GPSD> |
785 | |
971 | |
786 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
972 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
787 | |
973 | |
|
|
974 | =item L<AnyEvent::IRC> |
|
|
975 | |
|
|
976 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
|
|
977 | |
|
|
978 | =item L<AnyEvent::XMPP> |
|
|
979 | |
|
|
980 | AnyEvent based XMPP (Jabber protocol) module family (replacing the older |
|
|
981 | Net::XMPP2>. |
|
|
982 | |
788 | =item L<AnyEvent::IGS> |
983 | =item L<AnyEvent::IGS> |
789 | |
984 | |
790 | A non-blocking interface to the Internet Go Server protocol (used by |
985 | A non-blocking interface to the Internet Go Server protocol (used by |
791 | L<App::IGS>). |
986 | L<App::IGS>). |
792 | |
987 | |
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> |
988 | =item L<Net::FCP> |
802 | |
989 | |
803 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
990 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
804 | of AnyEvent. |
991 | of AnyEvent. |
805 | |
992 | |
… | |
… | |
809 | |
996 | |
810 | =item L<Coro> |
997 | =item L<Coro> |
811 | |
998 | |
812 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
999 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
813 | |
1000 | |
814 | =item L<IO::Lambda> |
|
|
815 | |
|
|
816 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
|
|
817 | |
|
|
818 | =back |
1001 | =back |
819 | |
1002 | |
820 | =cut |
1003 | =cut |
821 | |
1004 | |
822 | package AnyEvent; |
1005 | package AnyEvent; |
823 | |
1006 | |
824 | no warnings; |
1007 | no warnings; |
825 | use strict; |
1008 | use strict qw(vars subs); |
826 | |
1009 | |
827 | use Carp; |
1010 | use Carp; |
828 | |
1011 | |
829 | our $VERSION = 4.2; |
1012 | our $VERSION = 4.801; |
830 | our $MODEL; |
1013 | our $MODEL; |
831 | |
1014 | |
832 | our $AUTOLOAD; |
1015 | our $AUTOLOAD; |
833 | our @ISA; |
1016 | our @ISA; |
834 | |
1017 | |
835 | our @REGISTRY; |
1018 | our @REGISTRY; |
836 | |
1019 | |
837 | our $WIN32; |
1020 | our $WIN32; |
838 | |
1021 | |
839 | BEGIN { |
1022 | BEGIN { |
840 | my $win32 = ! ! ($^O =~ /mswin32/i); |
1023 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
841 | eval "sub WIN32(){ $win32 }"; |
1024 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
|
|
1025 | |
|
|
1026 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
1027 | if ${^TAINT}; |
842 | } |
1028 | } |
843 | |
1029 | |
844 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
1030 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
845 | |
1031 | |
846 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
1032 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
… | |
… | |
857 | [Event:: => AnyEvent::Impl::Event::], |
1043 | [Event:: => AnyEvent::Impl::Event::], |
858 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
1044 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
859 | # everything below here will not be autoprobed |
1045 | # everything below here will not be autoprobed |
860 | # as the pureperl backend should work everywhere |
1046 | # as the pureperl backend should work everywhere |
861 | # and is usually faster |
1047 | # and is usually faster |
862 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
863 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
1048 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
864 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
1049 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
|
|
1050 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
1051 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
865 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1052 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
866 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
|
|
867 | [Wx:: => AnyEvent::Impl::POE::], |
1053 | [Wx:: => AnyEvent::Impl::POE::], |
868 | [Prima:: => AnyEvent::Impl::POE::], |
1054 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
1055 | # IO::Async is just too broken - we would need workarounds for its |
|
|
1056 | # byzantine signal and broken child handling, among others. |
|
|
1057 | # IO::Async is rather hard to detect, as it doesn't have any |
|
|
1058 | # obvious default class. |
|
|
1059 | # [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1060 | # [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1061 | # [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
869 | ); |
1062 | ); |
870 | |
1063 | |
871 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
1064 | our %method = map +($_ => 1), |
|
|
1065 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
872 | |
1066 | |
873 | our @post_detect; |
1067 | our @post_detect; |
874 | |
1068 | |
875 | sub post_detect(&) { |
1069 | sub post_detect(&) { |
876 | my ($cb) = @_; |
1070 | my ($cb) = @_; |
… | |
… | |
881 | 1 |
1075 | 1 |
882 | } else { |
1076 | } else { |
883 | push @post_detect, $cb; |
1077 | push @post_detect, $cb; |
884 | |
1078 | |
885 | defined wantarray |
1079 | defined wantarray |
886 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
1080 | ? bless \$cb, "AnyEvent::Util::postdetect" |
887 | : () |
1081 | : () |
888 | } |
1082 | } |
889 | } |
1083 | } |
890 | |
1084 | |
891 | sub AnyEvent::Util::PostDetect::DESTROY { |
1085 | sub AnyEvent::Util::postdetect::DESTROY { |
892 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1086 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
893 | } |
1087 | } |
894 | |
1088 | |
895 | sub detect() { |
1089 | sub detect() { |
896 | unless ($MODEL) { |
1090 | unless ($MODEL) { |
… | |
… | |
933 | last; |
1127 | last; |
934 | } |
1128 | } |
935 | } |
1129 | } |
936 | |
1130 | |
937 | $MODEL |
1131 | $MODEL |
938 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1132 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
939 | } |
1133 | } |
940 | } |
1134 | } |
941 | |
1135 | |
|
|
1136 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
1137 | |
942 | unshift @ISA, $MODEL; |
1138 | unshift @ISA, $MODEL; |
943 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1139 | |
|
|
1140 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
944 | |
1141 | |
945 | (shift @post_detect)->() while @post_detect; |
1142 | (shift @post_detect)->() while @post_detect; |
946 | } |
1143 | } |
947 | |
1144 | |
948 | $MODEL |
1145 | $MODEL |
… | |
… | |
958 | |
1155 | |
959 | my $class = shift; |
1156 | my $class = shift; |
960 | $class->$func (@_); |
1157 | $class->$func (@_); |
961 | } |
1158 | } |
962 | |
1159 | |
|
|
1160 | # utility function to dup a filehandle. this is used by many backends |
|
|
1161 | # to support binding more than one watcher per filehandle (they usually |
|
|
1162 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1163 | sub _dupfh($$;$$) { |
|
|
1164 | my ($poll, $fh, $r, $w) = @_; |
|
|
1165 | |
|
|
1166 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1167 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">"); |
|
|
1168 | |
|
|
1169 | open my $fh2, "$mode&", $fh |
|
|
1170 | or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; |
|
|
1171 | |
|
|
1172 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1173 | |
|
|
1174 | ($fh2, $rw) |
|
|
1175 | } |
|
|
1176 | |
963 | package AnyEvent::Base; |
1177 | package AnyEvent::Base; |
964 | |
1178 | |
965 | # default implementation for now and time |
1179 | # default implementations for many methods |
966 | |
1180 | |
967 | use Time::HiRes (); |
1181 | BEGIN { |
|
|
1182 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1183 | *_time = \&Time::HiRes::time; |
|
|
1184 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1185 | } else { |
|
|
1186 | *_time = sub { time }; # epic fail |
|
|
1187 | } |
|
|
1188 | } |
968 | |
1189 | |
969 | sub time { Time::HiRes::time } |
1190 | sub time { _time } |
970 | sub now { Time::HiRes::time } |
1191 | sub now { _time } |
|
|
1192 | sub now_update { } |
971 | |
1193 | |
972 | # default implementation for ->condvar |
1194 | # default implementation for ->condvar |
973 | |
1195 | |
974 | sub condvar { |
1196 | sub condvar { |
975 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1197 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
976 | } |
1198 | } |
977 | |
1199 | |
978 | # default implementation for ->signal |
1200 | # default implementation for ->signal |
979 | |
1201 | |
980 | our %SIG_CB; |
1202 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1203 | |
|
|
1204 | sub _signal_exec { |
|
|
1205 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1206 | |
|
|
1207 | while (%SIG_EV) { |
|
|
1208 | for (keys %SIG_EV) { |
|
|
1209 | delete $SIG_EV{$_}; |
|
|
1210 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1211 | } |
|
|
1212 | } |
|
|
1213 | } |
981 | |
1214 | |
982 | sub signal { |
1215 | sub signal { |
983 | my (undef, %arg) = @_; |
1216 | my (undef, %arg) = @_; |
984 | |
1217 | |
|
|
1218 | unless ($SIGPIPE_R) { |
|
|
1219 | require Fcntl; |
|
|
1220 | |
|
|
1221 | if (AnyEvent::WIN32) { |
|
|
1222 | require AnyEvent::Util; |
|
|
1223 | |
|
|
1224 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1225 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1226 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1227 | } else { |
|
|
1228 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1229 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1230 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1231 | |
|
|
1232 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1233 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1234 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1235 | } |
|
|
1236 | |
|
|
1237 | $SIGPIPE_R |
|
|
1238 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1239 | |
|
|
1240 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1241 | } |
|
|
1242 | |
985 | my $signal = uc $arg{signal} |
1243 | my $signal = uc $arg{signal} |
986 | or Carp::croak "required option 'signal' is missing"; |
1244 | or Carp::croak "required option 'signal' is missing"; |
987 | |
1245 | |
988 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1246 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
989 | $SIG{$signal} ||= sub { |
1247 | $SIG{$signal} ||= sub { |
990 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1248 | local $!; |
|
|
1249 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1250 | undef $SIG_EV{$signal}; |
991 | }; |
1251 | }; |
992 | |
1252 | |
993 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1253 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
994 | } |
1254 | } |
995 | |
1255 | |
996 | sub AnyEvent::Base::Signal::DESTROY { |
1256 | sub AnyEvent::Base::signal::DESTROY { |
997 | my ($signal, $cb) = @{$_[0]}; |
1257 | my ($signal, $cb) = @{$_[0]}; |
998 | |
1258 | |
999 | delete $SIG_CB{$signal}{$cb}; |
1259 | delete $SIG_CB{$signal}{$cb}; |
1000 | |
1260 | |
|
|
1261 | # delete doesn't work with older perls - they then |
|
|
1262 | # print weird messages, or just unconditionally exit |
|
|
1263 | # instead of getting the default action. |
1001 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1264 | undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
1002 | } |
1265 | } |
1003 | |
1266 | |
1004 | # default implementation for ->child |
1267 | # default implementation for ->child |
1005 | |
1268 | |
1006 | our %PID_CB; |
1269 | our %PID_CB; |
1007 | our $CHLD_W; |
1270 | our $CHLD_W; |
1008 | our $CHLD_DELAY_W; |
1271 | our $CHLD_DELAY_W; |
1009 | our $PID_IDLE; |
|
|
1010 | our $WNOHANG; |
1272 | our $WNOHANG; |
1011 | |
1273 | |
1012 | sub _child_wait { |
1274 | sub _sigchld { |
1013 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1275 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1014 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1276 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1015 | (values %{ $PID_CB{0} || {} }); |
1277 | (values %{ $PID_CB{0} || {} }); |
1016 | } |
1278 | } |
1017 | |
|
|
1018 | undef $PID_IDLE; |
|
|
1019 | } |
|
|
1020 | |
|
|
1021 | sub _sigchld { |
|
|
1022 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
1023 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
1024 | undef $CHLD_DELAY_W; |
|
|
1025 | &_child_wait; |
|
|
1026 | }); |
|
|
1027 | } |
1279 | } |
1028 | |
1280 | |
1029 | sub child { |
1281 | sub child { |
1030 | my (undef, %arg) = @_; |
1282 | my (undef, %arg) = @_; |
1031 | |
1283 | |
1032 | defined (my $pid = $arg{pid} + 0) |
1284 | defined (my $pid = $arg{pid} + 0) |
1033 | or Carp::croak "required option 'pid' is missing"; |
1285 | or Carp::croak "required option 'pid' is missing"; |
1034 | |
1286 | |
1035 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1287 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1036 | |
1288 | |
1037 | unless ($WNOHANG) { |
|
|
1038 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1289 | $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1039 | } |
|
|
1040 | |
1290 | |
1041 | unless ($CHLD_W) { |
1291 | unless ($CHLD_W) { |
1042 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1292 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1043 | # child could be a zombie already, so make at least one round |
1293 | # child could be a zombie already, so make at least one round |
1044 | &_sigchld; |
1294 | &_sigchld; |
1045 | } |
1295 | } |
1046 | |
1296 | |
1047 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1297 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
1048 | } |
1298 | } |
1049 | |
1299 | |
1050 | sub AnyEvent::Base::Child::DESTROY { |
1300 | sub AnyEvent::Base::child::DESTROY { |
1051 | my ($pid, $cb) = @{$_[0]}; |
1301 | my ($pid, $cb) = @{$_[0]}; |
1052 | |
1302 | |
1053 | delete $PID_CB{$pid}{$cb}; |
1303 | delete $PID_CB{$pid}{$cb}; |
1054 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1304 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1055 | |
1305 | |
1056 | undef $CHLD_W unless keys %PID_CB; |
1306 | undef $CHLD_W unless keys %PID_CB; |
|
|
1307 | } |
|
|
1308 | |
|
|
1309 | # idle emulation is done by simply using a timer, regardless |
|
|
1310 | # of whether the process is idle or not, and not letting |
|
|
1311 | # the callback use more than 50% of the time. |
|
|
1312 | sub idle { |
|
|
1313 | my (undef, %arg) = @_; |
|
|
1314 | |
|
|
1315 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1316 | |
|
|
1317 | $rcb = sub { |
|
|
1318 | if ($cb) { |
|
|
1319 | $w = _time; |
|
|
1320 | &$cb; |
|
|
1321 | $w = _time - $w; |
|
|
1322 | |
|
|
1323 | # never use more then 50% of the time for the idle watcher, |
|
|
1324 | # within some limits |
|
|
1325 | $w = 0.0001 if $w < 0.0001; |
|
|
1326 | $w = 5 if $w > 5; |
|
|
1327 | |
|
|
1328 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1329 | } else { |
|
|
1330 | # clean up... |
|
|
1331 | undef $w; |
|
|
1332 | undef $rcb; |
|
|
1333 | } |
|
|
1334 | }; |
|
|
1335 | |
|
|
1336 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1337 | |
|
|
1338 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1339 | } |
|
|
1340 | |
|
|
1341 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1342 | undef $${$_[0]}; |
1057 | } |
1343 | } |
1058 | |
1344 | |
1059 | package AnyEvent::CondVar; |
1345 | package AnyEvent::CondVar; |
1060 | |
1346 | |
1061 | our @ISA = AnyEvent::CondVar::Base::; |
1347 | our @ISA = AnyEvent::CondVar::Base::; |
… | |
… | |
1113 | } |
1399 | } |
1114 | |
1400 | |
1115 | # undocumented/compatibility with pre-3.4 |
1401 | # undocumented/compatibility with pre-3.4 |
1116 | *broadcast = \&send; |
1402 | *broadcast = \&send; |
1117 | *wait = \&_wait; |
1403 | *wait = \&_wait; |
|
|
1404 | |
|
|
1405 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1406 | |
|
|
1407 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1408 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1409 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1410 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1411 | development. |
|
|
1412 | |
|
|
1413 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1414 | executing a callback), this is not only highly event-loop specific, but |
|
|
1415 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1416 | program. |
|
|
1417 | |
|
|
1418 | The pure perl event loop simply re-throws the exception (usually |
|
|
1419 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1420 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1421 | so on. |
|
|
1422 | |
|
|
1423 | =head1 ENVIRONMENT VARIABLES |
|
|
1424 | |
|
|
1425 | The following environment variables are used by this module or its |
|
|
1426 | submodules. |
|
|
1427 | |
|
|
1428 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1429 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1430 | enabled. |
|
|
1431 | |
|
|
1432 | =over 4 |
|
|
1433 | |
|
|
1434 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1435 | |
|
|
1436 | By default, AnyEvent will be completely silent except in fatal |
|
|
1437 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1438 | talkative. |
|
|
1439 | |
|
|
1440 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1441 | conditions, such as not being able to load the event model specified by |
|
|
1442 | C<PERL_ANYEVENT_MODEL>. |
|
|
1443 | |
|
|
1444 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1445 | model it chooses. |
|
|
1446 | |
|
|
1447 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1448 | |
|
|
1449 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1450 | argument checking is very costly. Setting this variable to a true value |
|
|
1451 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1452 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1453 | it will croak. |
|
|
1454 | |
|
|
1455 | In other words, enables "strict" mode. |
|
|
1456 | |
|
|
1457 | Unlike C<use strict>, it is definitely recommended to keep it off in |
|
|
1458 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1459 | developing programs can be very useful, however. |
|
|
1460 | |
|
|
1461 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1462 | |
|
|
1463 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1464 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1465 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1466 | and the resulting module name is loaded and if the load was successful, |
|
|
1467 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1468 | auto detection and -probing. |
|
|
1469 | |
|
|
1470 | This functionality might change in future versions. |
|
|
1471 | |
|
|
1472 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1473 | could start your program like this: |
|
|
1474 | |
|
|
1475 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1476 | |
|
|
1477 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1478 | |
|
|
1479 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1480 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1481 | of auto probing). |
|
|
1482 | |
|
|
1483 | Must be set to a comma-separated list of protocols or address families, |
|
|
1484 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1485 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1486 | list. |
|
|
1487 | |
|
|
1488 | This variable can effectively be used for denial-of-service attacks |
|
|
1489 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1490 | small, as the program has to handle conenction and other failures anyways. |
|
|
1491 | |
|
|
1492 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1493 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1494 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1495 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1496 | IPv6, but prefer IPv6 over IPv4. |
|
|
1497 | |
|
|
1498 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1499 | |
|
|
1500 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1501 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1502 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1503 | default. |
|
|
1504 | |
|
|
1505 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1506 | EDNS0 in its DNS requests. |
|
|
1507 | |
|
|
1508 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1509 | |
|
|
1510 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1511 | will create in parallel. |
|
|
1512 | |
|
|
1513 | =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> |
|
|
1514 | |
|
|
1515 | The default value for the C<max_outstanding> parameter for the default DNS |
|
|
1516 | resolver - this is the maximum number of parallel DNS requests that are |
|
|
1517 | sent to the DNS server. |
|
|
1518 | |
|
|
1519 | =item C<PERL_ANYEVENT_RESOLV_CONF> |
|
|
1520 | |
|
|
1521 | The file to use instead of F</etc/resolv.conf> (or OS-specific |
|
|
1522 | configuration) in the default resolver. When set to the empty string, no |
|
|
1523 | default config will be used. |
|
|
1524 | |
|
|
1525 | =item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. |
|
|
1526 | |
|
|
1527 | When neither C<ca_file> nor C<ca_path> was specified during |
|
|
1528 | L<AnyEvent::TLS> context creation, and either of these environment |
|
|
1529 | variables exist, they will be used to specify CA certificate locations |
|
|
1530 | instead of a system-dependent default. |
|
|
1531 | |
|
|
1532 | =back |
1118 | |
1533 | |
1119 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1534 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1120 | |
1535 | |
1121 | This is an advanced topic that you do not normally need to use AnyEvent in |
1536 | 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 |
1537 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1156 | |
1571 | |
1157 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1572 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1158 | condition variables: code blocking while waiting for a condition will |
1573 | condition variables: code blocking while waiting for a condition will |
1159 | C<die>. This still works with most modules/usages, and blocking calls must |
1574 | 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. |
1575 | 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 | |
1576 | |
1235 | =head1 EXAMPLE PROGRAM |
1577 | =head1 EXAMPLE PROGRAM |
1236 | |
1578 | |
1237 | The following program uses an I/O watcher to read data from STDIN, a timer |
1579 | 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 |
1580 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1432 | watcher. |
1774 | watcher. |
1433 | |
1775 | |
1434 | =head3 Results |
1776 | =head3 Results |
1435 | |
1777 | |
1436 | name watchers bytes create invoke destroy comment |
1778 | name watchers bytes create invoke destroy comment |
1437 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1779 | 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 |
1780 | 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 |
1781 | 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 |
1782 | 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 |
1783 | 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 |
1784 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1785 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1786 | 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 |
1787 | 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 |
1788 | 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 |
1789 | 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 |
1790 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1447 | |
1791 | |
1448 | =head3 Discussion |
1792 | =head3 Discussion |
1449 | |
1793 | |
1450 | The benchmark does I<not> measure scalability of the event loop very |
1794 | 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) |
1795 | 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 |
1820 | 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. |
1821 | them active), of course, but this was not subject of this benchmark. |
1478 | |
1822 | |
1479 | The C<Event> module has a relatively high setup and callback invocation |
1823 | The C<Event> module has a relatively high setup and callback invocation |
1480 | cost, but overall scores in on the third place. |
1824 | cost, but overall scores in on the third place. |
|
|
1825 | |
|
|
1826 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
1827 | when using its pure perl backend. |
1481 | |
1828 | |
1482 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1829 | 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 |
1830 | faster callback invocation and overall ends up in the same class as |
1484 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1831 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1485 | watchers increases the processing time by more than a factor of four, |
1832 | 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 |
1910 | it to another server. This includes deleting the old timeout and creating |
1564 | a new one that moves the timeout into the future. |
1911 | a new one that moves the timeout into the future. |
1565 | |
1912 | |
1566 | =head3 Results |
1913 | =head3 Results |
1567 | |
1914 | |
1568 | name sockets create request |
1915 | name sockets create request |
1569 | EV 20000 69.01 11.16 |
1916 | EV 20000 69.01 11.16 |
1570 | Perl 20000 73.32 35.87 |
1917 | Perl 20000 73.32 35.87 |
|
|
1918 | IOAsync 20000 157.00 98.14 epoll |
|
|
1919 | IOAsync 20000 159.31 616.06 poll |
1571 | Event 20000 212.62 257.32 |
1920 | Event 20000 212.62 257.32 |
1572 | Glib 20000 651.16 1896.30 |
1921 | Glib 20000 651.16 1896.30 |
1573 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1922 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1574 | |
1923 | |
1575 | =head3 Discussion |
1924 | =head3 Discussion |
1576 | |
1925 | |
1577 | This benchmark I<does> measure scalability and overall performance of the |
1926 | This benchmark I<does> measure scalability and overall performance of the |
1578 | particular event loop. |
1927 | particular event loop. |
… | |
… | |
1580 | EV is again fastest. Since it is using epoll on my system, the setup time |
1929 | EV is again fastest. Since it is using epoll on my system, the setup time |
1581 | is relatively high, though. |
1930 | is relatively high, though. |
1582 | |
1931 | |
1583 | Perl surprisingly comes second. It is much faster than the C-based event |
1932 | Perl surprisingly comes second. It is much faster than the C-based event |
1584 | loops Event and Glib. |
1933 | loops Event and Glib. |
|
|
1934 | |
|
|
1935 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
1936 | good compared to Glib when using its pure perl backend. |
1585 | |
1937 | |
1586 | Event suffers from high setup time as well (look at its code and you will |
1938 | 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 |
1939 | understand why). Callback invocation also has a high overhead compared to |
1588 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1940 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1589 | uses select or poll in basically all documented configurations. |
1941 | uses select or poll in basically all documented configurations. |
… | |
… | |
1652 | =item * C-based event loops perform very well with small number of |
2004 | =item * C-based event loops perform very well with small number of |
1653 | watchers, as the management overhead dominates. |
2005 | watchers, as the management overhead dominates. |
1654 | |
2006 | |
1655 | =back |
2007 | =back |
1656 | |
2008 | |
|
|
2009 | =head2 THE IO::Lambda BENCHMARK |
|
|
2010 | |
|
|
2011 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
2012 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
2013 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
2014 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
2015 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
2016 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
2017 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
2018 | |
|
|
2019 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
2020 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
2021 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
2022 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
2023 | benchmark nevertheless. |
|
|
2024 | |
|
|
2025 | name runtime |
|
|
2026 | Lambda/select 0.330 sec |
|
|
2027 | + optimized 0.122 sec |
|
|
2028 | Lambda/AnyEvent 0.327 sec |
|
|
2029 | + optimized 0.138 sec |
|
|
2030 | Raw sockets/select 0.077 sec |
|
|
2031 | POE/select, components 0.662 sec |
|
|
2032 | POE/select, raw sockets 0.226 sec |
|
|
2033 | POE/select, optimized 0.404 sec |
|
|
2034 | |
|
|
2035 | AnyEvent/select/nb 0.085 sec |
|
|
2036 | AnyEvent/EV/nb 0.068 sec |
|
|
2037 | +state machine 0.134 sec |
|
|
2038 | |
|
|
2039 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
2040 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
2041 | defeating the purpose of an event-based solution. All of the newly |
|
|
2042 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
2043 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
2044 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
2045 | generally require a lot more bookkeeping and event handling than blocking |
|
|
2046 | connects (which involve a single syscall only). |
|
|
2047 | |
|
|
2048 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
2049 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
2050 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
2051 | non-blocking, further placing it at a disadvantage. |
|
|
2052 | |
|
|
2053 | As you can see, the AnyEvent + EV combination even beats the |
|
|
2054 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
2055 | backend easily beats IO::Lambda and POE. |
|
|
2056 | |
|
|
2057 | And even the 100% non-blocking version written using the high-level (and |
|
|
2058 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
2059 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
2060 | in a non-blocking way. |
|
|
2061 | |
|
|
2062 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2063 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2064 | part of the IO::lambda distribution and were used without any changes. |
|
|
2065 | |
|
|
2066 | |
|
|
2067 | =head1 SIGNALS |
|
|
2068 | |
|
|
2069 | AnyEvent currently installs handlers for these signals: |
|
|
2070 | |
|
|
2071 | =over 4 |
|
|
2072 | |
|
|
2073 | =item SIGCHLD |
|
|
2074 | |
|
|
2075 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2076 | emulation for event loops that do not support them natively. Also, some |
|
|
2077 | event loops install a similar handler. |
|
|
2078 | |
|
|
2079 | If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will |
|
|
2080 | reset it to default, to avoid losing child exit statuses. |
|
|
2081 | |
|
|
2082 | =item SIGPIPE |
|
|
2083 | |
|
|
2084 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2085 | when AnyEvent gets loaded. |
|
|
2086 | |
|
|
2087 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2088 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2089 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2090 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2091 | some random socket. |
|
|
2092 | |
|
|
2093 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2094 | that this way, the handler will be restored to defaults on exec. |
|
|
2095 | |
|
|
2096 | Feel free to install your own handler, or reset it to defaults. |
|
|
2097 | |
|
|
2098 | =back |
|
|
2099 | |
|
|
2100 | =cut |
|
|
2101 | |
|
|
2102 | undef $SIG{CHLD} |
|
|
2103 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2104 | |
|
|
2105 | $SIG{PIPE} = sub { } |
|
|
2106 | unless defined $SIG{PIPE}; |
1657 | |
2107 | |
1658 | =head1 FORK |
2108 | =head1 FORK |
1659 | |
2109 | |
1660 | Most event libraries are not fork-safe. The ones who are usually are |
2110 | 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> |
2111 | because they rely on inefficient but fork-safe C<select> or C<poll> |
… | |
… | |
1681 | |
2131 | |
1682 | use AnyEvent; |
2132 | use AnyEvent; |
1683 | |
2133 | |
1684 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2134 | 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 |
2135 | 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). |
2136 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
2137 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2138 | |
|
|
2139 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2140 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2141 | enabled. |
1687 | |
2142 | |
1688 | |
2143 | |
1689 | =head1 BUGS |
2144 | =head1 BUGS |
1690 | |
2145 | |
1691 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
2146 | 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 |
2147 | 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 |
2148 | 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 |
2149 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
1695 | pronounced). |
2150 | pronounced). |
1696 | |
2151 | |
1697 | |
2152 | |
1698 | =head1 SEE ALSO |
2153 | =head1 SEE ALSO |
1699 | |
2154 | |
… | |
… | |
1703 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
2158 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1704 | |
2159 | |
1705 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
2160 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1706 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
2161 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1707 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
2162 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1708 | L<AnyEvent::Impl::POE>. |
2163 | L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>. |
1709 | |
2164 | |
1710 | Non-blocking file handles, sockets, TCP clients and |
2165 | Non-blocking file handles, sockets, TCP clients and |
1711 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
2166 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. |
1712 | |
2167 | |
1713 | Asynchronous DNS: L<AnyEvent::DNS>. |
2168 | Asynchronous DNS: L<AnyEvent::DNS>. |
1714 | |
2169 | |
1715 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
2170 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, |
|
|
2171 | L<Coro::Event>, |
1716 | |
2172 | |
1717 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
2173 | Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, |
|
|
2174 | L<AnyEvent::HTTP>. |
1718 | |
2175 | |
1719 | |
2176 | |
1720 | =head1 AUTHOR |
2177 | =head1 AUTHOR |
1721 | |
2178 | |
1722 | Marc Lehmann <schmorp@schmorp.de> |
2179 | Marc Lehmann <schmorp@schmorp.de> |