… | |
… | |
6 | |
6 | |
7 | =head1 SYNOPSIS |
7 | =head1 SYNOPSIS |
8 | |
8 | |
9 | use AnyEvent; |
9 | use AnyEvent; |
10 | |
10 | |
|
|
11 | # file descriptor readable |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { |
12 | my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); |
|
|
13 | |
|
|
14 | # one-shot or repeating timers |
|
|
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
|
|
16 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
|
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17 | |
|
|
18 | print AnyEvent->now; # prints current event loop time |
|
|
19 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
|
|
20 | |
|
|
21 | # POSIX signal |
|
|
22 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
|
|
23 | |
|
|
24 | # child process exit |
|
|
25 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
|
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26 | my ($pid, $status) = @_; |
12 | ... |
27 | ... |
13 | }); |
28 | }); |
14 | |
29 | |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
30 | # called when event loop idle (if applicable) |
16 | ... |
31 | my $w = AnyEvent->idle (cb => sub { ... }); |
17 | }); |
|
|
18 | |
32 | |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
33 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
20 | $w->send; # wake up current and all future recv's |
34 | $w->send; # wake up current and all future recv's |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
35 | $w->recv; # enters "main loop" till $condvar gets ->send |
|
|
36 | # use a condvar in callback mode: |
|
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37 | $w->cb (sub { $_[0]->recv }); |
22 | |
38 | |
23 | =head1 INTRODUCTION/TUTORIAL |
39 | =head1 INTRODUCTION/TUTORIAL |
24 | |
40 | |
25 | This manpage is mainly a reference manual. If you are interested |
41 | This manpage is mainly a reference manual. If you are interested |
26 | in a tutorial or some gentle introduction, have a look at the |
42 | in a tutorial or some gentle introduction, have a look at the |
… | |
… | |
33 | |
49 | |
34 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
50 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
35 | policy> and AnyEvent is I<small and efficient>. |
51 | policy> and AnyEvent is I<small and efficient>. |
36 | |
52 | |
37 | First and foremost, I<AnyEvent is not an event model> itself, it only |
53 | 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 |
54 | 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, |
55 | 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, |
56 | 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 |
57 | only one event loop can be active at the same time in a process. AnyEvent |
42 | helps hiding the differences between those event loops. |
58 | cannot change this, but it can hide the differences between those event |
|
|
59 | loops. |
43 | |
60 | |
44 | The goal of AnyEvent is to offer module authors the ability to do event |
61 | 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 |
62 | programming (waiting for I/O or timer events) without subscribing to a |
46 | religion, a way of living, and most importantly: without forcing your |
63 | 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 |
64 | module users into the same thing by forcing them to use the same event |
48 | model you use. |
65 | model you use. |
49 | |
66 | |
50 | For modules like POE or IO::Async (which is a total misnomer as it is |
67 | 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 |
68 | 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 |
69 | 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 |
70 | 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 |
71 | 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. |
72 | module are I<also> forced to use the same event loop you use. |
56 | |
73 | |
57 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
74 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
58 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
75 | 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 |
76 | 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, |
77 | 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 |
78 | 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 |
79 | 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 |
80 | 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). |
81 | to AnyEvent, too, so it is future-proof). |
65 | |
82 | |
66 | In addition to being free of having to use I<the one and only true event |
83 | 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 |
84 | 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 |
85 | 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 |
86 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
… | |
… | |
127 | These watchers are normal Perl objects with normal Perl lifetime. After |
144 | These watchers are normal Perl objects with normal Perl lifetime. After |
128 | creating a watcher it will immediately "watch" for events and invoke the |
145 | 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 |
146 | callback when the event occurs (of course, only when the event model |
130 | is in control). |
147 | is in control). |
131 | |
148 | |
|
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149 | Note that B<callbacks must not permanently change global variables> |
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150 | potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< |
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151 | callbacks must not C<die> >>. The former is good programming practise in |
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152 | Perl and the latter stems from the fact that exception handling differs |
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153 | widely between event loops. |
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154 | |
132 | To disable the watcher you have to destroy it (e.g. by setting the |
155 | 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 |
156 | variable you store it in to C<undef> or otherwise deleting all references |
134 | to it). |
157 | to it). |
135 | |
158 | |
136 | All watchers are created by calling a method on the C<AnyEvent> class. |
159 | All watchers are created by calling a method on the C<AnyEvent> class. |
… | |
… | |
138 | Many watchers either are used with "recursion" (repeating timers for |
161 | Many watchers either are used with "recursion" (repeating timers for |
139 | example), or need to refer to their watcher object in other ways. |
162 | example), or need to refer to their watcher object in other ways. |
140 | |
163 | |
141 | An any way to achieve that is this pattern: |
164 | An any way to achieve that is this pattern: |
142 | |
165 | |
143 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
166 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
144 | # you can use $w here, for example to undef it |
167 | # you can use $w here, for example to undef it |
145 | undef $w; |
168 | undef $w; |
146 | }); |
169 | }); |
147 | |
170 | |
148 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
171 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
149 | my variables are only visible after the statement in which they are |
172 | my variables are only visible after the statement in which they are |
150 | declared. |
173 | declared. |
151 | |
174 | |
152 | =head2 I/O WATCHERS |
175 | =head2 I/O WATCHERS |
153 | |
176 | |
154 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
177 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
155 | with the following mandatory key-value pairs as arguments: |
178 | with the following mandatory key-value pairs as arguments: |
156 | |
179 | |
157 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
180 | C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch |
|
|
181 | for events (AnyEvent might or might not keep a reference to this file |
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182 | handle). Note that only file handles pointing to things for which |
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183 | non-blocking operation makes sense are allowed. This includes sockets, |
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184 | most character devices, pipes, fifos and so on, but not for example files |
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185 | or block devices. |
|
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186 | |
158 | for events. C<poll> must be a string that is either C<r> or C<w>, |
187 | 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, |
188 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
|
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189 | |
160 | respectively. C<cb> is the callback to invoke each time the file handle |
190 | C<cb> is the callback to invoke each time the file handle becomes ready. |
161 | becomes ready. |
|
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162 | |
191 | |
163 | Although the callback might get passed parameters, their value and |
192 | Although the callback might get passed parameters, their value and |
164 | presence is undefined and you cannot rely on them. Portable AnyEvent |
193 | presence is undefined and you cannot rely on them. Portable AnyEvent |
165 | callbacks cannot use arguments passed to I/O watcher callbacks. |
194 | callbacks cannot use arguments passed to I/O watcher callbacks. |
166 | |
195 | |
… | |
… | |
170 | |
199 | |
171 | Some event loops issue spurious readyness notifications, so you should |
200 | Some event loops issue spurious readyness notifications, so you should |
172 | always use non-blocking calls when reading/writing from/to your file |
201 | always use non-blocking calls when reading/writing from/to your file |
173 | handles. |
202 | handles. |
174 | |
203 | |
175 | Example: |
|
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176 | |
|
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177 | # wait for readability of STDIN, then read a line and disable the watcher |
204 | Example: wait for readability of STDIN, then read a line and disable the |
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205 | watcher. |
|
|
206 | |
178 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
207 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
179 | chomp (my $input = <STDIN>); |
208 | chomp (my $input = <STDIN>); |
180 | warn "read: $input\n"; |
209 | warn "read: $input\n"; |
181 | undef $w; |
210 | undef $w; |
182 | }); |
211 | }); |
… | |
… | |
192 | |
221 | |
193 | Although the callback might get passed parameters, their value and |
222 | Although the callback might get passed parameters, their value and |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
223 | presence is undefined and you cannot rely on them. Portable AnyEvent |
195 | callbacks cannot use arguments passed to time watcher callbacks. |
224 | callbacks cannot use arguments passed to time watcher callbacks. |
196 | |
225 | |
197 | The timer callback will be invoked at most once: if you want a repeating |
226 | The callback will normally be invoked once only. If you specify another |
198 | timer you have to create a new watcher (this is a limitation by both Tk |
227 | parameter, C<interval>, as a strictly positive number (> 0), then the |
199 | and Glib). |
228 | callback will be invoked regularly at that interval (in fractional |
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229 | seconds) after the first invocation. If C<interval> is specified with a |
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230 | false value, then it is treated as if it were missing. |
200 | |
231 | |
201 | Example: |
232 | The callback will be rescheduled before invoking the callback, but no |
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233 | attempt is done to avoid timer drift in most backends, so the interval is |
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234 | only approximate. |
202 | |
235 | |
203 | # fire an event after 7.7 seconds |
236 | Example: fire an event after 7.7 seconds. |
|
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237 | |
204 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
238 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
205 | warn "timeout\n"; |
239 | warn "timeout\n"; |
206 | }); |
240 | }); |
207 | |
241 | |
208 | # to cancel the timer: |
242 | # to cancel the timer: |
209 | undef $w; |
243 | undef $w; |
210 | |
244 | |
211 | Example 2: |
|
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212 | |
|
|
213 | # fire an event after 0.5 seconds, then roughly every second |
245 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
214 | my $w; |
|
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215 | |
246 | |
216 | my $cb = sub { |
|
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217 | # cancel the old timer while creating a new one |
|
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218 | $w = AnyEvent->timer (after => 1, cb => $cb); |
247 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
|
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248 | warn "timeout\n"; |
219 | }; |
249 | }; |
220 | |
|
|
221 | # start the "loop" by creating the first watcher |
|
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222 | $w = AnyEvent->timer (after => 0.5, cb => $cb); |
|
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223 | |
250 | |
224 | =head3 TIMING ISSUES |
251 | =head3 TIMING ISSUES |
225 | |
252 | |
226 | There are two ways to handle timers: based on real time (relative, "fire |
253 | There are two ways to handle timers: based on real time (relative, "fire |
227 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
254 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
… | |
… | |
300 | In either case, if you care (and in most cases, you don't), then you |
327 | In either case, if you care (and in most cases, you don't), then you |
301 | can get whatever behaviour you want with any event loop, by taking the |
328 | can get whatever behaviour you want with any event loop, by taking the |
302 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
329 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
303 | account. |
330 | account. |
304 | |
331 | |
|
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332 | =item AnyEvent->now_update |
|
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333 | |
|
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334 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
|
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335 | the current time for each loop iteration (see the discussion of L<< |
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336 | AnyEvent->now >>, above). |
|
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337 | |
|
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338 | When a callback runs for a long time (or when the process sleeps), then |
|
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339 | this "current" time will differ substantially from the real time, which |
|
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340 | might affect timers and time-outs. |
|
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341 | |
|
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342 | When this is the case, you can call this method, which will update the |
|
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343 | event loop's idea of "current time". |
|
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344 | |
|
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345 | Note that updating the time I<might> cause some events to be handled. |
|
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346 | |
305 | =back |
347 | =back |
306 | |
348 | |
307 | =head2 SIGNAL WATCHERS |
349 | =head2 SIGNAL WATCHERS |
308 | |
350 | |
309 | You can watch for signals using a signal watcher, C<signal> is the signal |
351 | You can watch for signals using a signal watcher, C<signal> is the signal |
310 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
352 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
311 | be invoked whenever a signal occurs. |
353 | callback to be invoked whenever a signal occurs. |
312 | |
354 | |
313 | Although the callback might get passed parameters, their value and |
355 | Although the callback might get passed parameters, their value and |
314 | presence is undefined and you cannot rely on them. Portable AnyEvent |
356 | presence is undefined and you cannot rely on them. Portable AnyEvent |
315 | callbacks cannot use arguments passed to signal watcher callbacks. |
357 | callbacks cannot use arguments passed to signal watcher callbacks. |
316 | |
358 | |
… | |
… | |
332 | =head2 CHILD PROCESS WATCHERS |
374 | =head2 CHILD PROCESS WATCHERS |
333 | |
375 | |
334 | You can also watch on a child process exit and catch its exit status. |
376 | You can also watch on a child process exit and catch its exit status. |
335 | |
377 | |
336 | The child process is specified by the C<pid> argument (if set to C<0>, it |
378 | The child process is specified by the C<pid> argument (if set to C<0>, it |
337 | watches for any child process exit). The watcher will trigger as often |
379 | watches for any child process exit). The watcher will triggered only when |
338 | as status change for the child are received. This works by installing a |
380 | the child process has finished and an exit status is available, not on |
339 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
381 | any trace events (stopped/continued). |
340 | and exit status (as returned by waitpid), so unlike other watcher types, |
382 | |
341 | you I<can> rely on child watcher callback arguments. |
383 | The callback will be called with the pid and exit status (as returned by |
|
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384 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
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385 | callback arguments. |
|
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386 | |
|
|
387 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
|
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388 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
|
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389 | random child processes (waiting for specific child processes, e.g. inside |
|
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390 | C<system>, is just fine). |
342 | |
391 | |
343 | There is a slight catch to child watchers, however: you usually start them |
392 | There is a slight catch to child watchers, however: you usually start them |
344 | I<after> the child process was created, and this means the process could |
393 | I<after> the child process was created, and this means the process could |
345 | have exited already (and no SIGCHLD will be sent anymore). |
394 | have exited already (and no SIGCHLD will be sent anymore). |
346 | |
395 | |
… | |
… | |
352 | AnyEvent program, you I<have> to create at least one watcher before you |
401 | AnyEvent program, you I<have> to create at least one watcher before you |
353 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
402 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
354 | |
403 | |
355 | Example: fork a process and wait for it |
404 | Example: fork a process and wait for it |
356 | |
405 | |
357 | my $done = AnyEvent->condvar; |
406 | my $done = AnyEvent->condvar; |
358 | |
407 | |
359 | my $pid = fork or exit 5; |
408 | my $pid = fork or exit 5; |
360 | |
409 | |
361 | my $w = AnyEvent->child ( |
410 | my $w = AnyEvent->child ( |
362 | pid => $pid, |
411 | pid => $pid, |
363 | cb => sub { |
412 | cb => sub { |
364 | my ($pid, $status) = @_; |
413 | my ($pid, $status) = @_; |
365 | warn "pid $pid exited with status $status"; |
414 | warn "pid $pid exited with status $status"; |
366 | $done->send; |
415 | $done->send; |
367 | }, |
416 | }, |
368 | ); |
417 | ); |
369 | |
418 | |
370 | # do something else, then wait for process exit |
419 | # do something else, then wait for process exit |
371 | $done->recv; |
420 | $done->recv; |
|
|
421 | |
|
|
422 | =head2 IDLE WATCHERS |
|
|
423 | |
|
|
424 | Sometimes there is a need to do something, but it is not so important |
|
|
425 | to do it instantly, but only when there is nothing better to do. This |
|
|
426 | "nothing better to do" is usually defined to be "no other events need |
|
|
427 | attention by the event loop". |
|
|
428 | |
|
|
429 | Idle watchers ideally get invoked when the event loop has nothing |
|
|
430 | better to do, just before it would block the process to wait for new |
|
|
431 | events. Instead of blocking, the idle watcher is invoked. |
|
|
432 | |
|
|
433 | Most event loops unfortunately do not really support idle watchers (only |
|
|
434 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
|
|
435 | will simply call the callback "from time to time". |
|
|
436 | |
|
|
437 | Example: read lines from STDIN, but only process them when the |
|
|
438 | program is otherwise idle: |
|
|
439 | |
|
|
440 | my @lines; # read data |
|
|
441 | my $idle_w; |
|
|
442 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
|
|
443 | push @lines, scalar <STDIN>; |
|
|
444 | |
|
|
445 | # start an idle watcher, if not already done |
|
|
446 | $idle_w ||= AnyEvent->idle (cb => sub { |
|
|
447 | # handle only one line, when there are lines left |
|
|
448 | if (my $line = shift @lines) { |
|
|
449 | print "handled when idle: $line"; |
|
|
450 | } else { |
|
|
451 | # otherwise disable the idle watcher again |
|
|
452 | undef $idle_w; |
|
|
453 | } |
|
|
454 | }); |
|
|
455 | }); |
372 | |
456 | |
373 | =head2 CONDITION VARIABLES |
457 | =head2 CONDITION VARIABLES |
374 | |
458 | |
375 | If you are familiar with some event loops you will know that all of them |
459 | If you are familiar with some event loops you will know that all of them |
376 | require you to run some blocking "loop", "run" or similar function that |
460 | require you to run some blocking "loop", "run" or similar function that |
… | |
… | |
382 | The instrument to do that is called a "condition variable", so called |
466 | The instrument to do that is called a "condition variable", so called |
383 | because they represent a condition that must become true. |
467 | because they represent a condition that must become true. |
384 | |
468 | |
385 | Condition variables can be created by calling the C<< AnyEvent->condvar |
469 | Condition variables can be created by calling the C<< AnyEvent->condvar |
386 | >> method, usually without arguments. The only argument pair allowed is |
470 | >> method, usually without arguments. The only argument pair allowed is |
|
|
471 | |
387 | C<cb>, which specifies a callback to be called when the condition variable |
472 | C<cb>, which specifies a callback to be called when the condition variable |
388 | becomes true. |
473 | becomes true, with the condition variable as the first argument (but not |
|
|
474 | the results). |
389 | |
475 | |
390 | After creation, the condition variable is "false" until it becomes "true" |
476 | After creation, the condition variable is "false" until it becomes "true" |
391 | by calling the C<send> method (or calling the condition variable as if it |
477 | by calling the C<send> method (or calling the condition variable as if it |
392 | were a callback, read about the caveats in the description for the C<< |
478 | were a callback, read about the caveats in the description for the C<< |
393 | ->send >> method). |
479 | ->send >> method). |
… | |
… | |
449 | |
535 | |
450 | my $done = AnyEvent->condvar; |
536 | my $done = AnyEvent->condvar; |
451 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
537 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
452 | $done->recv; |
538 | $done->recv; |
453 | |
539 | |
|
|
540 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
541 | callbacks. This is how you make a synchronous call, for example from |
|
|
542 | the main program: |
|
|
543 | |
|
|
544 | use AnyEvent::CouchDB; |
|
|
545 | |
|
|
546 | ... |
|
|
547 | |
|
|
548 | my @info = $couchdb->info->recv; |
|
|
549 | |
|
|
550 | And this is how you would just ste a callback to be called whenever the |
|
|
551 | results are available: |
|
|
552 | |
|
|
553 | $couchdb->info->cb (sub { |
|
|
554 | my @info = $_[0]->recv; |
|
|
555 | }); |
|
|
556 | |
454 | =head3 METHODS FOR PRODUCERS |
557 | =head3 METHODS FOR PRODUCERS |
455 | |
558 | |
456 | These methods should only be used by the producing side, i.e. the |
559 | These methods should only be used by the producing side, i.e. the |
457 | code/module that eventually sends the signal. Note that it is also |
560 | code/module that eventually sends the signal. Note that it is also |
458 | the producer side which creates the condvar in most cases, but it isn't |
561 | the producer side which creates the condvar in most cases, but it isn't |
… | |
… | |
591 | =item $bool = $cv->ready |
694 | =item $bool = $cv->ready |
592 | |
695 | |
593 | Returns true when the condition is "true", i.e. whether C<send> or |
696 | Returns true when the condition is "true", i.e. whether C<send> or |
594 | C<croak> have been called. |
697 | C<croak> have been called. |
595 | |
698 | |
596 | =item $cb = $cv->cb ([new callback]) |
699 | =item $cb = $cv->cb ($cb->($cv)) |
597 | |
700 | |
598 | This is a mutator function that returns the callback set and optionally |
701 | This is a mutator function that returns the callback set and optionally |
599 | replaces it before doing so. |
702 | replaces it before doing so. |
600 | |
703 | |
601 | The callback will be called when the condition becomes "true", i.e. when |
704 | The callback will be called when the condition becomes "true", i.e. when |
… | |
… | |
738 | =item L<AnyEvent::Util> |
841 | =item L<AnyEvent::Util> |
739 | |
842 | |
740 | Contains various utility functions that replace often-used but blocking |
843 | Contains various utility functions that replace often-used but blocking |
741 | functions such as C<inet_aton> by event-/callback-based versions. |
844 | functions such as C<inet_aton> by event-/callback-based versions. |
742 | |
845 | |
743 | =item L<AnyEvent::Handle> |
|
|
744 | |
|
|
745 | Provide read and write buffers and manages watchers for reads and writes. |
|
|
746 | |
|
|
747 | =item L<AnyEvent::Socket> |
846 | =item L<AnyEvent::Socket> |
748 | |
847 | |
749 | Provides various utility functions for (internet protocol) sockets, |
848 | Provides various utility functions for (internet protocol) sockets, |
750 | addresses and name resolution. Also functions to create non-blocking tcp |
849 | addresses and name resolution. Also functions to create non-blocking tcp |
751 | connections or tcp servers, with IPv6 and SRV record support and more. |
850 | connections or tcp servers, with IPv6 and SRV record support and more. |
752 | |
851 | |
|
|
852 | =item L<AnyEvent::Handle> |
|
|
853 | |
|
|
854 | Provide read and write buffers, manages watchers for reads and writes, |
|
|
855 | supports raw and formatted I/O, I/O queued and fully transparent and |
|
|
856 | non-blocking SSL/TLS. |
|
|
857 | |
753 | =item L<AnyEvent::DNS> |
858 | =item L<AnyEvent::DNS> |
754 | |
859 | |
755 | Provides rich asynchronous DNS resolver capabilities. |
860 | Provides rich asynchronous DNS resolver capabilities. |
756 | |
861 | |
|
|
862 | =item L<AnyEvent::HTTP> |
|
|
863 | |
|
|
864 | A simple-to-use HTTP library that is capable of making a lot of concurrent |
|
|
865 | HTTP requests. |
|
|
866 | |
757 | =item L<AnyEvent::HTTPD> |
867 | =item L<AnyEvent::HTTPD> |
758 | |
868 | |
759 | Provides a simple web application server framework. |
869 | Provides a simple web application server framework. |
760 | |
870 | |
761 | =item L<AnyEvent::FastPing> |
871 | =item L<AnyEvent::FastPing> |
762 | |
872 | |
763 | The fastest ping in the west. |
873 | The fastest ping in the west. |
764 | |
874 | |
|
|
875 | =item L<AnyEvent::DBI> |
|
|
876 | |
|
|
877 | Executes L<DBI> requests asynchronously in a proxy process. |
|
|
878 | |
|
|
879 | =item L<AnyEvent::AIO> |
|
|
880 | |
|
|
881 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
882 | programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent |
|
|
883 | together. |
|
|
884 | |
|
|
885 | =item L<AnyEvent::BDB> |
|
|
886 | |
|
|
887 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses |
|
|
888 | L<BDB> and AnyEvent together. |
|
|
889 | |
|
|
890 | =item L<AnyEvent::GPSD> |
|
|
891 | |
|
|
892 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
|
|
893 | |
|
|
894 | =item L<AnyEvent::IGS> |
|
|
895 | |
|
|
896 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
897 | L<App::IGS>). |
|
|
898 | |
765 | =item L<Net::IRC3> |
899 | =item L<AnyEvent::IRC> |
766 | |
900 | |
767 | AnyEvent based IRC client module family. |
901 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
768 | |
902 | |
769 | =item L<Net::XMPP2> |
903 | =item L<Net::XMPP2> |
770 | |
904 | |
771 | AnyEvent based XMPP (Jabber protocol) module family. |
905 | AnyEvent based XMPP (Jabber protocol) module family. |
772 | |
906 | |
… | |
… | |
781 | |
915 | |
782 | =item L<Coro> |
916 | =item L<Coro> |
783 | |
917 | |
784 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
918 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
785 | |
919 | |
786 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
787 | |
|
|
788 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
789 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
790 | together. |
|
|
791 | |
|
|
792 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
793 | |
|
|
794 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
795 | IO::AIO and AnyEvent together. |
|
|
796 | |
|
|
797 | =item L<IO::Lambda> |
920 | =item L<IO::Lambda> |
798 | |
921 | |
799 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
922 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
800 | |
923 | |
801 | =back |
924 | =back |
… | |
… | |
803 | =cut |
926 | =cut |
804 | |
927 | |
805 | package AnyEvent; |
928 | package AnyEvent; |
806 | |
929 | |
807 | no warnings; |
930 | no warnings; |
808 | use strict; |
931 | use strict qw(vars subs); |
809 | |
932 | |
810 | use Carp; |
933 | use Carp; |
811 | |
934 | |
812 | our $VERSION = 4.11; |
935 | our $VERSION = 4.41; |
813 | our $MODEL; |
936 | our $MODEL; |
814 | |
937 | |
815 | our $AUTOLOAD; |
938 | our $AUTOLOAD; |
816 | our @ISA; |
939 | our @ISA; |
817 | |
940 | |
… | |
… | |
849 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
972 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
850 | [Wx:: => AnyEvent::Impl::POE::], |
973 | [Wx:: => AnyEvent::Impl::POE::], |
851 | [Prima:: => AnyEvent::Impl::POE::], |
974 | [Prima:: => AnyEvent::Impl::POE::], |
852 | ); |
975 | ); |
853 | |
976 | |
854 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
977 | our %method = map +($_ => 1), |
|
|
978 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
855 | |
979 | |
856 | our @post_detect; |
980 | our @post_detect; |
857 | |
981 | |
858 | sub post_detect(&) { |
982 | sub post_detect(&) { |
859 | my ($cb) = @_; |
983 | my ($cb) = @_; |
… | |
… | |
864 | 1 |
988 | 1 |
865 | } else { |
989 | } else { |
866 | push @post_detect, $cb; |
990 | push @post_detect, $cb; |
867 | |
991 | |
868 | defined wantarray |
992 | defined wantarray |
869 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
993 | ? bless \$cb, "AnyEvent::Util::postdetect" |
870 | : () |
994 | : () |
871 | } |
995 | } |
872 | } |
996 | } |
873 | |
997 | |
874 | sub AnyEvent::Util::PostDetect::DESTROY { |
998 | sub AnyEvent::Util::postdetect::DESTROY { |
875 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
999 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
876 | } |
1000 | } |
877 | |
1001 | |
878 | sub detect() { |
1002 | sub detect() { |
879 | unless ($MODEL) { |
1003 | unless ($MODEL) { |
… | |
… | |
916 | last; |
1040 | last; |
917 | } |
1041 | } |
918 | } |
1042 | } |
919 | |
1043 | |
920 | $MODEL |
1044 | $MODEL |
921 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1045 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
922 | } |
1046 | } |
923 | } |
1047 | } |
924 | |
1048 | |
|
|
1049 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
1050 | |
925 | unshift @ISA, $MODEL; |
1051 | unshift @ISA, $MODEL; |
926 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1052 | |
|
|
1053 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
927 | |
1054 | |
928 | (shift @post_detect)->() while @post_detect; |
1055 | (shift @post_detect)->() while @post_detect; |
929 | } |
1056 | } |
930 | |
1057 | |
931 | $MODEL |
1058 | $MODEL |
… | |
… | |
941 | |
1068 | |
942 | my $class = shift; |
1069 | my $class = shift; |
943 | $class->$func (@_); |
1070 | $class->$func (@_); |
944 | } |
1071 | } |
945 | |
1072 | |
|
|
1073 | # utility function to dup a filehandle. this is used by many backends |
|
|
1074 | # to support binding more than one watcher per filehandle (they usually |
|
|
1075 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1076 | sub _dupfh($$$$) { |
|
|
1077 | my ($poll, $fh, $r, $w) = @_; |
|
|
1078 | |
|
|
1079 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1080 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
|
|
1081 | : $poll eq "w" ? ($w, ">") |
|
|
1082 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
|
|
1083 | |
|
|
1084 | open my $fh2, "$mode&" . fileno $fh |
|
|
1085 | or die "cannot dup() filehandle: $!,"; |
|
|
1086 | |
|
|
1087 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1088 | |
|
|
1089 | ($fh2, $rw) |
|
|
1090 | } |
|
|
1091 | |
946 | package AnyEvent::Base; |
1092 | package AnyEvent::Base; |
947 | |
1093 | |
948 | # default implementation for now and time |
1094 | # default implementations for many methods |
949 | |
1095 | |
950 | use Time::HiRes (); |
1096 | BEGIN { |
|
|
1097 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1098 | *_time = \&Time::HiRes::time; |
|
|
1099 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1100 | } else { |
|
|
1101 | *_time = sub { time }; # epic fail |
|
|
1102 | } |
|
|
1103 | } |
951 | |
1104 | |
952 | sub time { Time::HiRes::time } |
1105 | sub time { _time } |
953 | sub now { Time::HiRes::time } |
1106 | sub now { _time } |
|
|
1107 | sub now_update { } |
954 | |
1108 | |
955 | # default implementation for ->condvar |
1109 | # default implementation for ->condvar |
956 | |
1110 | |
957 | sub condvar { |
1111 | sub condvar { |
958 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1112 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
959 | } |
1113 | } |
960 | |
1114 | |
961 | # default implementation for ->signal |
1115 | # default implementation for ->signal |
962 | |
1116 | |
963 | our %SIG_CB; |
1117 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1118 | |
|
|
1119 | sub _signal_exec { |
|
|
1120 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1121 | |
|
|
1122 | while (%SIG_EV) { |
|
|
1123 | for (keys %SIG_EV) { |
|
|
1124 | delete $SIG_EV{$_}; |
|
|
1125 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1126 | } |
|
|
1127 | } |
|
|
1128 | } |
964 | |
1129 | |
965 | sub signal { |
1130 | sub signal { |
966 | my (undef, %arg) = @_; |
1131 | my (undef, %arg) = @_; |
967 | |
1132 | |
|
|
1133 | unless ($SIGPIPE_R) { |
|
|
1134 | require Fcntl; |
|
|
1135 | |
|
|
1136 | if (AnyEvent::WIN32) { |
|
|
1137 | require AnyEvent::Util; |
|
|
1138 | |
|
|
1139 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1140 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1141 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1142 | } else { |
|
|
1143 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1144 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1145 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1146 | } |
|
|
1147 | |
|
|
1148 | $SIGPIPE_R |
|
|
1149 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1150 | |
|
|
1151 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1152 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1153 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1154 | |
|
|
1155 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1156 | } |
|
|
1157 | |
968 | my $signal = uc $arg{signal} |
1158 | my $signal = uc $arg{signal} |
969 | or Carp::croak "required option 'signal' is missing"; |
1159 | or Carp::croak "required option 'signal' is missing"; |
970 | |
1160 | |
971 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1161 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
972 | $SIG{$signal} ||= sub { |
1162 | $SIG{$signal} ||= sub { |
973 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1163 | local $!; |
|
|
1164 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1165 | undef $SIG_EV{$signal}; |
974 | }; |
1166 | }; |
975 | |
1167 | |
976 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1168 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
977 | } |
1169 | } |
978 | |
1170 | |
979 | sub AnyEvent::Base::Signal::DESTROY { |
1171 | sub AnyEvent::Base::signal::DESTROY { |
980 | my ($signal, $cb) = @{$_[0]}; |
1172 | my ($signal, $cb) = @{$_[0]}; |
981 | |
1173 | |
982 | delete $SIG_CB{$signal}{$cb}; |
1174 | delete $SIG_CB{$signal}{$cb}; |
983 | |
1175 | |
984 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1176 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
… | |
… | |
1025 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1217 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1026 | # child could be a zombie already, so make at least one round |
1218 | # child could be a zombie already, so make at least one round |
1027 | &_sigchld; |
1219 | &_sigchld; |
1028 | } |
1220 | } |
1029 | |
1221 | |
1030 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1222 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
1031 | } |
1223 | } |
1032 | |
1224 | |
1033 | sub AnyEvent::Base::Child::DESTROY { |
1225 | sub AnyEvent::Base::child::DESTROY { |
1034 | my ($pid, $cb) = @{$_[0]}; |
1226 | my ($pid, $cb) = @{$_[0]}; |
1035 | |
1227 | |
1036 | delete $PID_CB{$pid}{$cb}; |
1228 | delete $PID_CB{$pid}{$cb}; |
1037 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1229 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1038 | |
1230 | |
1039 | undef $CHLD_W unless keys %PID_CB; |
1231 | undef $CHLD_W unless keys %PID_CB; |
|
|
1232 | } |
|
|
1233 | |
|
|
1234 | # idle emulation is done by simply using a timer, regardless |
|
|
1235 | # of whether the proces sis idle or not, and not letting |
|
|
1236 | # the callback use more than 50% of the time. |
|
|
1237 | sub idle { |
|
|
1238 | my (undef, %arg) = @_; |
|
|
1239 | |
|
|
1240 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1241 | |
|
|
1242 | $rcb = sub { |
|
|
1243 | if ($cb) { |
|
|
1244 | $w = _time; |
|
|
1245 | &$cb; |
|
|
1246 | $w = _time - $w; |
|
|
1247 | |
|
|
1248 | # never use more then 50% of the time for the idle watcher, |
|
|
1249 | # within some limits |
|
|
1250 | $w = 0.0001 if $w < 0.0001; |
|
|
1251 | $w = 5 if $w > 5; |
|
|
1252 | |
|
|
1253 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1254 | } else { |
|
|
1255 | # clean up... |
|
|
1256 | undef $w; |
|
|
1257 | undef $rcb; |
|
|
1258 | } |
|
|
1259 | }; |
|
|
1260 | |
|
|
1261 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1262 | |
|
|
1263 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1264 | } |
|
|
1265 | |
|
|
1266 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1267 | undef $${$_[0]}; |
1040 | } |
1268 | } |
1041 | |
1269 | |
1042 | package AnyEvent::CondVar; |
1270 | package AnyEvent::CondVar; |
1043 | |
1271 | |
1044 | our @ISA = AnyEvent::CondVar::Base::; |
1272 | our @ISA = AnyEvent::CondVar::Base::; |
… | |
… | |
1096 | } |
1324 | } |
1097 | |
1325 | |
1098 | # undocumented/compatibility with pre-3.4 |
1326 | # undocumented/compatibility with pre-3.4 |
1099 | *broadcast = \&send; |
1327 | *broadcast = \&send; |
1100 | *wait = \&_wait; |
1328 | *wait = \&_wait; |
|
|
1329 | |
|
|
1330 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1331 | |
|
|
1332 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1333 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1334 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1335 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1336 | development. |
|
|
1337 | |
|
|
1338 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1339 | executing a callback), this is not only highly event-loop specific, but |
|
|
1340 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1341 | program. |
|
|
1342 | |
|
|
1343 | The pure perl event loop simply re-throws the exception (usually |
|
|
1344 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1345 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1346 | so on. |
|
|
1347 | |
|
|
1348 | =head1 ENVIRONMENT VARIABLES |
|
|
1349 | |
|
|
1350 | The following environment variables are used by this module or its |
|
|
1351 | submodules: |
|
|
1352 | |
|
|
1353 | =over 4 |
|
|
1354 | |
|
|
1355 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1356 | |
|
|
1357 | By default, AnyEvent will be completely silent except in fatal |
|
|
1358 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1359 | talkative. |
|
|
1360 | |
|
|
1361 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1362 | conditions, such as not being able to load the event model specified by |
|
|
1363 | C<PERL_ANYEVENT_MODEL>. |
|
|
1364 | |
|
|
1365 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1366 | model it chooses. |
|
|
1367 | |
|
|
1368 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1369 | |
|
|
1370 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1371 | argument checking is very costly. Setting this variable to a true value |
|
|
1372 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1373 | check the arguments passed to most method calls. If it finds any problems |
|
|
1374 | it will croak. |
|
|
1375 | |
|
|
1376 | In other words, enables "strict" mode. |
|
|
1377 | |
|
|
1378 | Unlike C<use strict>, it is definitely recommended ot keep it off in |
|
|
1379 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1380 | developing programs can be very useful, however. |
|
|
1381 | |
|
|
1382 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1383 | |
|
|
1384 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1385 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1386 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1387 | and the resulting module name is loaded and if the load was successful, |
|
|
1388 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1389 | auto detection and -probing. |
|
|
1390 | |
|
|
1391 | This functionality might change in future versions. |
|
|
1392 | |
|
|
1393 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1394 | could start your program like this: |
|
|
1395 | |
|
|
1396 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1397 | |
|
|
1398 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1399 | |
|
|
1400 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1401 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1402 | of auto probing). |
|
|
1403 | |
|
|
1404 | Must be set to a comma-separated list of protocols or address families, |
|
|
1405 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1406 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1407 | list. |
|
|
1408 | |
|
|
1409 | This variable can effectively be used for denial-of-service attacks |
|
|
1410 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1411 | small, as the program has to handle conenction and other failures anyways. |
|
|
1412 | |
|
|
1413 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1414 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1415 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1416 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1417 | IPv6, but prefer IPv6 over IPv4. |
|
|
1418 | |
|
|
1419 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1420 | |
|
|
1421 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1422 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1423 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1424 | default. |
|
|
1425 | |
|
|
1426 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1427 | EDNS0 in its DNS requests. |
|
|
1428 | |
|
|
1429 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1430 | |
|
|
1431 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1432 | will create in parallel. |
|
|
1433 | |
|
|
1434 | =back |
1101 | |
1435 | |
1102 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1436 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1103 | |
1437 | |
1104 | This is an advanced topic that you do not normally need to use AnyEvent in |
1438 | This is an advanced topic that you do not normally need to use AnyEvent in |
1105 | a module. This section is only of use to event loop authors who want to |
1439 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1139 | |
1473 | |
1140 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1474 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1141 | condition variables: code blocking while waiting for a condition will |
1475 | condition variables: code blocking while waiting for a condition will |
1142 | C<die>. This still works with most modules/usages, and blocking calls must |
1476 | C<die>. This still works with most modules/usages, and blocking calls must |
1143 | not be done in an interactive application, so it makes sense. |
1477 | not be done in an interactive application, so it makes sense. |
1144 | |
|
|
1145 | =head1 ENVIRONMENT VARIABLES |
|
|
1146 | |
|
|
1147 | The following environment variables are used by this module: |
|
|
1148 | |
|
|
1149 | =over 4 |
|
|
1150 | |
|
|
1151 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1152 | |
|
|
1153 | By default, AnyEvent will be completely silent except in fatal |
|
|
1154 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1155 | talkative. |
|
|
1156 | |
|
|
1157 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1158 | conditions, such as not being able to load the event model specified by |
|
|
1159 | C<PERL_ANYEVENT_MODEL>. |
|
|
1160 | |
|
|
1161 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1162 | model it chooses. |
|
|
1163 | |
|
|
1164 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1165 | |
|
|
1166 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1167 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1168 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1169 | and the resulting module name is loaded and if the load was successful, |
|
|
1170 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1171 | auto detection and -probing. |
|
|
1172 | |
|
|
1173 | This functionality might change in future versions. |
|
|
1174 | |
|
|
1175 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1176 | could start your program like this: |
|
|
1177 | |
|
|
1178 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1179 | |
|
|
1180 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1181 | |
|
|
1182 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1183 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1184 | of auto probing). |
|
|
1185 | |
|
|
1186 | Must be set to a comma-separated list of protocols or address families, |
|
|
1187 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1188 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1189 | list. |
|
|
1190 | |
|
|
1191 | This variable can effectively be used for denial-of-service attacks |
|
|
1192 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1193 | small, as the program has to handle connection errors already- |
|
|
1194 | |
|
|
1195 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1196 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1197 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1198 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1199 | IPv6, but prefer IPv6 over IPv4. |
|
|
1200 | |
|
|
1201 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1202 | |
|
|
1203 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1204 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1205 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1206 | default. |
|
|
1207 | |
|
|
1208 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1209 | EDNS0 in its DNS requests. |
|
|
1210 | |
|
|
1211 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1212 | |
|
|
1213 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1214 | will create in parallel. |
|
|
1215 | |
|
|
1216 | =back |
|
|
1217 | |
1478 | |
1218 | =head1 EXAMPLE PROGRAM |
1479 | =head1 EXAMPLE PROGRAM |
1219 | |
1480 | |
1220 | The following program uses an I/O watcher to read data from STDIN, a timer |
1481 | The following program uses an I/O watcher to read data from STDIN, a timer |
1221 | to display a message once per second, and a condition variable to quit the |
1482 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1415 | watcher. |
1676 | watcher. |
1416 | |
1677 | |
1417 | =head3 Results |
1678 | =head3 Results |
1418 | |
1679 | |
1419 | name watchers bytes create invoke destroy comment |
1680 | name watchers bytes create invoke destroy comment |
1420 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1681 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1421 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1682 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1422 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1683 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1423 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1684 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1424 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1685 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1425 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1686 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
1426 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1687 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1427 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1688 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1428 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1689 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1429 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1690 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1430 | |
1691 | |
1431 | =head3 Discussion |
1692 | =head3 Discussion |
1432 | |
1693 | |
1433 | The benchmark does I<not> measure scalability of the event loop very |
1694 | The benchmark does I<not> measure scalability of the event loop very |
1434 | well. For example, a select-based event loop (such as the pure perl one) |
1695 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1636 | watchers, as the management overhead dominates. |
1897 | watchers, as the management overhead dominates. |
1637 | |
1898 | |
1638 | =back |
1899 | =back |
1639 | |
1900 | |
1640 | |
1901 | |
|
|
1902 | =head1 SIGNALS |
|
|
1903 | |
|
|
1904 | AnyEvent currently installs handlers for these signals: |
|
|
1905 | |
|
|
1906 | =over 4 |
|
|
1907 | |
|
|
1908 | =item SIGCHLD |
|
|
1909 | |
|
|
1910 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
1911 | emulation for event loops that do not support them natively. Also, some |
|
|
1912 | event loops install a similar handler. |
|
|
1913 | |
|
|
1914 | =item SIGPIPE |
|
|
1915 | |
|
|
1916 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
1917 | when AnyEvent gets loaded. |
|
|
1918 | |
|
|
1919 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
1920 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
1921 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
1922 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
1923 | some random socket. |
|
|
1924 | |
|
|
1925 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
1926 | that this way, the handler will be restored to defaults on exec. |
|
|
1927 | |
|
|
1928 | Feel free to install your own handler, or reset it to defaults. |
|
|
1929 | |
|
|
1930 | =back |
|
|
1931 | |
|
|
1932 | =cut |
|
|
1933 | |
|
|
1934 | $SIG{PIPE} = sub { } |
|
|
1935 | unless defined $SIG{PIPE}; |
|
|
1936 | |
|
|
1937 | |
1641 | =head1 FORK |
1938 | =head1 FORK |
1642 | |
1939 | |
1643 | Most event libraries are not fork-safe. The ones who are usually are |
1940 | Most event libraries are not fork-safe. The ones who are usually are |
1644 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1941 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1645 | calls. Only L<EV> is fully fork-aware. |
1942 | calls. Only L<EV> is fully fork-aware. |
… | |
… | |
1658 | specified in the variable. |
1955 | specified in the variable. |
1659 | |
1956 | |
1660 | You can make AnyEvent completely ignore this variable by deleting it |
1957 | You can make AnyEvent completely ignore this variable by deleting it |
1661 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1958 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1662 | |
1959 | |
1663 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1960 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1664 | |
1961 | |
1665 | use AnyEvent; |
1962 | use AnyEvent; |
1666 | |
1963 | |
1667 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1964 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1668 | be used to probe what backend is used and gain other information (which is |
1965 | be used to probe what backend is used and gain other information (which is |
1669 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1966 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
1967 | $ENV{PERL_ANYEGENT_STRICT}. |
|
|
1968 | |
|
|
1969 | |
|
|
1970 | =head1 BUGS |
|
|
1971 | |
|
|
1972 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
|
|
1973 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
|
|
1974 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
|
|
1975 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
|
|
1976 | pronounced). |
1670 | |
1977 | |
1671 | |
1978 | |
1672 | =head1 SEE ALSO |
1979 | =head1 SEE ALSO |
1673 | |
1980 | |
1674 | Utility functions: L<AnyEvent::Util>. |
1981 | Utility functions: L<AnyEvent::Util>. |
… | |
… | |
1691 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
1998 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
1692 | |
1999 | |
1693 | |
2000 | |
1694 | =head1 AUTHOR |
2001 | =head1 AUTHOR |
1695 | |
2002 | |
1696 | Marc Lehmann <schmorp@schmorp.de> |
2003 | Marc Lehmann <schmorp@schmorp.de> |
1697 | http://home.schmorp.de/ |
2004 | http://home.schmorp.de/ |
1698 | |
2005 | |
1699 | =cut |
2006 | =cut |
1700 | |
2007 | |
1701 | 1 |
2008 | 1 |
1702 | |
2009 | |