… | |
… | |
17 | }); |
17 | }); |
18 | |
18 | |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
20 | $w->send; # wake up current and all future recv's |
20 | $w->send; # wake up current and all future recv's |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
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22 | |
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23 | =head1 INTRODUCTION/TUTORIAL |
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24 | |
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25 | This manpage is mainly a reference manual. If you are interested |
|
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26 | in a tutorial or some gentle introduction, have a look at the |
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27 | L<AnyEvent::Intro> manpage. |
22 | |
28 | |
23 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
29 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
24 | |
30 | |
25 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
31 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
26 | nowadays. So what is different about AnyEvent? |
32 | nowadays. So what is different about AnyEvent? |
… | |
… | |
48 | isn't itself. What's worse, all the potential users of your module are |
54 | isn't itself. What's worse, all the potential users of your module are |
49 | I<also> forced to use the same event loop you use. |
55 | I<also> forced to use the same event loop you use. |
50 | |
56 | |
51 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
57 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
52 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
58 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
53 | with the rest: POE + IO::Async? no go. Tk + Event? no go. Again: if |
59 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
54 | your module uses one of those, every user of your module has to use it, |
60 | your module uses one of those, every user of your module has to use it, |
55 | too. But if your module uses AnyEvent, it works transparently with all |
61 | too. But if your module uses AnyEvent, it works transparently with all |
56 | event models it supports (including stuff like POE and IO::Async, as long |
62 | event models it supports (including stuff like POE and IO::Async, as long |
57 | as those use one of the supported event loops. It is trivial to add new |
63 | as those use one of the supported event loops. It is trivial to add new |
58 | event loops to AnyEvent, too, so it is future-proof). |
64 | event loops to AnyEvent, too, so it is future-proof). |
59 | |
65 | |
60 | In addition to being free of having to use I<the one and only true event |
66 | In addition to being free of having to use I<the one and only true event |
61 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
67 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
62 | modules, you get an enourmous amount of code and strict rules you have to |
68 | modules, you get an enormous amount of code and strict rules you have to |
63 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
69 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
64 | offering the functionality that is necessary, in as thin as a wrapper as |
70 | offering the functionality that is necessary, in as thin as a wrapper as |
65 | technically possible. |
71 | technically possible. |
66 | |
72 | |
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73 | Of course, AnyEvent comes with a big (and fully optional!) toolbox |
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74 | of useful functionality, such as an asynchronous DNS resolver, 100% |
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75 | non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms |
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76 | such as Windows) and lots of real-world knowledge and workarounds for |
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77 | platform bugs and differences. |
|
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78 | |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
79 | Now, if you I<do want> lots of policy (this can arguably be somewhat |
68 | useful) and you want to force your users to use the one and only event |
80 | useful) and you want to force your users to use the one and only event |
69 | model, you should I<not> use this module. |
81 | model, you should I<not> use this module. |
70 | |
82 | |
71 | =head1 DESCRIPTION |
83 | =head1 DESCRIPTION |
72 | |
84 | |
… | |
… | |
102 | starts using it, all bets are off. Maybe you should tell their authors to |
114 | starts using it, all bets are off. Maybe you should tell their authors to |
103 | use AnyEvent so their modules work together with others seamlessly... |
115 | use AnyEvent so their modules work together with others seamlessly... |
104 | |
116 | |
105 | The pure-perl implementation of AnyEvent is called |
117 | The pure-perl implementation of AnyEvent is called |
106 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
118 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
107 | explicitly. |
119 | explicitly and enjoy the high availability of that event loop :) |
108 | |
120 | |
109 | =head1 WATCHERS |
121 | =head1 WATCHERS |
110 | |
122 | |
111 | AnyEvent has the central concept of a I<watcher>, which is an object that |
123 | AnyEvent has the central concept of a I<watcher>, which is an object that |
112 | stores relevant data for each kind of event you are waiting for, such as |
124 | stores relevant data for each kind of event you are waiting for, such as |
113 | the callback to call, the filehandle to watch, etc. |
125 | the callback to call, the file handle to watch, etc. |
114 | |
126 | |
115 | These watchers are normal Perl objects with normal Perl lifetime. After |
127 | These watchers are normal Perl objects with normal Perl lifetime. After |
116 | creating a watcher it will immediately "watch" for events and invoke the |
128 | creating a watcher it will immediately "watch" for events and invoke the |
117 | callback when the event occurs (of course, only when the event model |
129 | callback when the event occurs (of course, only when the event model |
118 | is in control). |
130 | is in control). |
… | |
… | |
126 | Many watchers either are used with "recursion" (repeating timers for |
138 | Many watchers either are used with "recursion" (repeating timers for |
127 | example), or need to refer to their watcher object in other ways. |
139 | example), or need to refer to their watcher object in other ways. |
128 | |
140 | |
129 | An any way to achieve that is this pattern: |
141 | An any way to achieve that is this pattern: |
130 | |
142 | |
131 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
143 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
132 | # you can use $w here, for example to undef it |
144 | # you can use $w here, for example to undef it |
133 | undef $w; |
145 | undef $w; |
134 | }); |
146 | }); |
135 | |
147 | |
136 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
148 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
137 | my variables are only visible after the statement in which they are |
149 | my variables are only visible after the statement in which they are |
138 | declared. |
150 | declared. |
139 | |
151 | |
… | |
… | |
158 | |
170 | |
159 | Some event loops issue spurious readyness notifications, so you should |
171 | Some event loops issue spurious readyness notifications, so you should |
160 | always use non-blocking calls when reading/writing from/to your file |
172 | always use non-blocking calls when reading/writing from/to your file |
161 | handles. |
173 | handles. |
162 | |
174 | |
163 | Example: |
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164 | |
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165 | # wait for readability of STDIN, then read a line and disable the watcher |
175 | Example: wait for readability of STDIN, then read a line and disable the |
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176 | watcher. |
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177 | |
166 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
178 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
167 | chomp (my $input = <STDIN>); |
179 | chomp (my $input = <STDIN>); |
168 | warn "read: $input\n"; |
180 | warn "read: $input\n"; |
169 | undef $w; |
181 | undef $w; |
170 | }); |
182 | }); |
… | |
… | |
180 | |
192 | |
181 | Although the callback might get passed parameters, their value and |
193 | Although the callback might get passed parameters, their value and |
182 | presence is undefined and you cannot rely on them. Portable AnyEvent |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
183 | callbacks cannot use arguments passed to time watcher callbacks. |
195 | callbacks cannot use arguments passed to time watcher callbacks. |
184 | |
196 | |
185 | The timer callback will be invoked at most once: if you want a repeating |
197 | The callback will normally be invoked once only. If you specify another |
186 | timer you have to create a new watcher (this is a limitation by both Tk |
198 | parameter, C<interval>, as a positive number, then the callback will be |
187 | and Glib). |
199 | invoked regularly at that interval (in fractional seconds) after the first |
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200 | invocation. |
188 | |
201 | |
189 | Example: |
202 | The callback will be rescheduled before invoking the callback, but no |
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203 | attempt is done to avoid timer drift in most backends, so the interval is |
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204 | only approximate. |
190 | |
205 | |
191 | # fire an event after 7.7 seconds |
206 | Example: fire an event after 7.7 seconds. |
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207 | |
192 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
208 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
193 | warn "timeout\n"; |
209 | warn "timeout\n"; |
194 | }); |
210 | }); |
195 | |
211 | |
196 | # to cancel the timer: |
212 | # to cancel the timer: |
197 | undef $w; |
213 | undef $w; |
198 | |
214 | |
199 | Example 2: |
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200 | |
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201 | # fire an event after 0.5 seconds, then roughly every second |
215 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
202 | my $w; |
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203 | |
216 | |
204 | my $cb = sub { |
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205 | # cancel the old timer while creating a new one |
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206 | $w = AnyEvent->timer (after => 1, cb => $cb); |
217 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
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218 | warn "timeout\n"; |
207 | }; |
219 | }; |
208 | |
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209 | # start the "loop" by creating the first watcher |
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210 | $w = AnyEvent->timer (after => 0.5, cb => $cb); |
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211 | |
220 | |
212 | =head3 TIMING ISSUES |
221 | =head3 TIMING ISSUES |
213 | |
222 | |
214 | There are two ways to handle timers: based on real time (relative, "fire |
223 | There are two ways to handle timers: based on real time (relative, "fire |
215 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
224 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
… | |
… | |
227 | timers. |
236 | timers. |
228 | |
237 | |
229 | AnyEvent always prefers relative timers, if available, matching the |
238 | AnyEvent always prefers relative timers, if available, matching the |
230 | AnyEvent API. |
239 | AnyEvent API. |
231 | |
240 | |
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241 | AnyEvent has two additional methods that return the "current time": |
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242 | |
|
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243 | =over 4 |
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244 | |
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245 | =item AnyEvent->time |
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246 | |
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247 | This returns the "current wallclock time" as a fractional number of |
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248 | seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time> |
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249 | return, and the result is guaranteed to be compatible with those). |
|
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250 | |
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251 | It progresses independently of any event loop processing, i.e. each call |
|
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252 | will check the system clock, which usually gets updated frequently. |
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253 | |
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254 | =item AnyEvent->now |
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255 | |
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256 | This also returns the "current wallclock time", but unlike C<time>, above, |
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257 | this value might change only once per event loop iteration, depending on |
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258 | the event loop (most return the same time as C<time>, above). This is the |
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259 | time that AnyEvent's timers get scheduled against. |
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260 | |
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261 | I<In almost all cases (in all cases if you don't care), this is the |
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262 | function to call when you want to know the current time.> |
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263 | |
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264 | This function is also often faster then C<< AnyEvent->time >>, and |
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265 | thus the preferred method if you want some timestamp (for example, |
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266 | L<AnyEvent::Handle> uses this to update it's activity timeouts). |
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267 | |
|
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268 | The rest of this section is only of relevance if you try to be very exact |
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269 | with your timing, you can skip it without bad conscience. |
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270 | |
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271 | For a practical example of when these times differ, consider L<Event::Lib> |
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272 | and L<EV> and the following set-up: |
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273 | |
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274 | The event loop is running and has just invoked one of your callback at |
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275 | time=500 (assume no other callbacks delay processing). In your callback, |
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276 | you wait a second by executing C<sleep 1> (blocking the process for a |
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277 | second) and then (at time=501) you create a relative timer that fires |
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278 | after three seconds. |
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279 | |
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280 | With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will |
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281 | both return C<501>, because that is the current time, and the timer will |
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282 | be scheduled to fire at time=504 (C<501> + C<3>). |
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283 | |
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284 | With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current |
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285 | time), but C<< AnyEvent->now >> returns C<500>, as that is the time the |
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286 | last event processing phase started. With L<EV>, your timer gets scheduled |
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287 | to run at time=503 (C<500> + C<3>). |
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288 | |
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289 | In one sense, L<Event::Lib> is more exact, as it uses the current time |
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290 | regardless of any delays introduced by event processing. However, most |
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291 | callbacks do not expect large delays in processing, so this causes a |
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292 | higher drift (and a lot more system calls to get the current time). |
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293 | |
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294 | In another sense, L<EV> is more exact, as your timer will be scheduled at |
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295 | the same time, regardless of how long event processing actually took. |
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296 | |
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297 | In either case, if you care (and in most cases, you don't), then you |
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298 | can get whatever behaviour you want with any event loop, by taking the |
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299 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
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300 | account. |
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301 | |
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302 | =back |
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303 | |
232 | =head2 SIGNAL WATCHERS |
304 | =head2 SIGNAL WATCHERS |
233 | |
305 | |
234 | You can watch for signals using a signal watcher, C<signal> is the signal |
306 | You can watch for signals using a signal watcher, C<signal> is the signal |
235 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
307 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
236 | be invoked whenever a signal occurs. |
308 | be invoked whenever a signal occurs. |
237 | |
309 | |
238 | Although the callback might get passed parameters, their value and |
310 | Although the callback might get passed parameters, their value and |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
311 | presence is undefined and you cannot rely on them. Portable AnyEvent |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
312 | callbacks cannot use arguments passed to signal watcher callbacks. |
241 | |
313 | |
242 | Multiple signal occurances can be clumped together into one callback |
314 | Multiple signal occurrences can be clumped together into one callback |
243 | invocation, and callback invocation will be synchronous. synchronous means |
315 | invocation, and callback invocation will be synchronous. Synchronous means |
244 | that it might take a while until the signal gets handled by the process, |
316 | that it might take a while until the signal gets handled by the process, |
245 | but it is guarenteed not to interrupt any other callbacks. |
317 | but it is guaranteed not to interrupt any other callbacks. |
246 | |
318 | |
247 | The main advantage of using these watchers is that you can share a signal |
319 | The main advantage of using these watchers is that you can share a signal |
248 | between multiple watchers. |
320 | between multiple watchers. |
249 | |
321 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
322 | This watcher might use C<%SIG>, so programs overwriting those signals |
… | |
… | |
277 | AnyEvent program, you I<have> to create at least one watcher before you |
349 | AnyEvent program, you I<have> to create at least one watcher before you |
278 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
350 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
279 | |
351 | |
280 | Example: fork a process and wait for it |
352 | Example: fork a process and wait for it |
281 | |
353 | |
282 | my $done = AnyEvent->condvar; |
354 | my $done = AnyEvent->condvar; |
283 | |
355 | |
284 | my $pid = fork or exit 5; |
356 | my $pid = fork or exit 5; |
285 | |
357 | |
286 | my $w = AnyEvent->child ( |
358 | my $w = AnyEvent->child ( |
287 | pid => $pid, |
359 | pid => $pid, |
288 | cb => sub { |
360 | cb => sub { |
289 | my ($pid, $status) = @_; |
361 | my ($pid, $status) = @_; |
290 | warn "pid $pid exited with status $status"; |
362 | warn "pid $pid exited with status $status"; |
291 | $done->send; |
363 | $done->send; |
292 | }, |
364 | }, |
293 | ); |
365 | ); |
294 | |
366 | |
295 | # do something else, then wait for process exit |
367 | # do something else, then wait for process exit |
296 | $done->recv; |
368 | $done->recv; |
297 | |
369 | |
298 | =head2 CONDITION VARIABLES |
370 | =head2 CONDITION VARIABLES |
299 | |
371 | |
300 | If you are familiar with some event loops you will know that all of them |
372 | If you are familiar with some event loops you will know that all of them |
301 | require you to run some blocking "loop", "run" or similar function that |
373 | require you to run some blocking "loop", "run" or similar function that |
… | |
… | |
310 | Condition variables can be created by calling the C<< AnyEvent->condvar |
382 | Condition variables can be created by calling the C<< AnyEvent->condvar |
311 | >> method, usually without arguments. The only argument pair allowed is |
383 | >> method, usually without arguments. The only argument pair allowed is |
312 | C<cb>, which specifies a callback to be called when the condition variable |
384 | C<cb>, which specifies a callback to be called when the condition variable |
313 | becomes true. |
385 | becomes true. |
314 | |
386 | |
315 | After creation, the conditon variable is "false" until it becomes "true" |
387 | After creation, the condition variable is "false" until it becomes "true" |
316 | by calling the C<send> method. |
388 | by calling the C<send> method (or calling the condition variable as if it |
|
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389 | were a callback, read about the caveats in the description for the C<< |
|
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390 | ->send >> method). |
317 | |
391 | |
318 | Condition variables are similar to callbacks, except that you can |
392 | Condition variables are similar to callbacks, except that you can |
319 | optionally wait for them. They can also be called merge points - points |
393 | optionally wait for them. They can also be called merge points - points |
320 | in time where multiple outstandign events have been processed. And yet |
394 | in time where multiple outstanding events have been processed. And yet |
321 | another way to call them is transations - each condition variable can be |
395 | another way to call them is transactions - each condition variable can be |
322 | used to represent a transaction, which finishes at some point and delivers |
396 | used to represent a transaction, which finishes at some point and delivers |
323 | a result. |
397 | a result. |
324 | |
398 | |
325 | Condition variables are very useful to signal that something has finished, |
399 | Condition variables are very useful to signal that something has finished, |
326 | for example, if you write a module that does asynchronous http requests, |
400 | for example, if you write a module that does asynchronous http requests, |
… | |
… | |
332 | you can block your main program until an event occurs - for example, you |
406 | you can block your main program until an event occurs - for example, you |
333 | could C<< ->recv >> in your main program until the user clicks the Quit |
407 | could C<< ->recv >> in your main program until the user clicks the Quit |
334 | button of your app, which would C<< ->send >> the "quit" event. |
408 | button of your app, which would C<< ->send >> the "quit" event. |
335 | |
409 | |
336 | Note that condition variables recurse into the event loop - if you have |
410 | Note that condition variables recurse into the event loop - if you have |
337 | two pieces of code that call C<< ->recv >> in a round-robbin fashion, you |
411 | two pieces of code that call C<< ->recv >> in a round-robin fashion, you |
338 | lose. Therefore, condition variables are good to export to your caller, but |
412 | lose. Therefore, condition variables are good to export to your caller, but |
339 | you should avoid making a blocking wait yourself, at least in callbacks, |
413 | you should avoid making a blocking wait yourself, at least in callbacks, |
340 | as this asks for trouble. |
414 | as this asks for trouble. |
341 | |
415 | |
342 | Condition variables are represented by hash refs in perl, and the keys |
416 | Condition variables are represented by hash refs in perl, and the keys |
… | |
… | |
347 | |
421 | |
348 | There are two "sides" to a condition variable - the "producer side" which |
422 | There are two "sides" to a condition variable - the "producer side" which |
349 | eventually calls C<< -> send >>, and the "consumer side", which waits |
423 | eventually calls C<< -> send >>, and the "consumer side", which waits |
350 | for the send to occur. |
424 | for the send to occur. |
351 | |
425 | |
352 | Example: |
426 | Example: wait for a timer. |
353 | |
427 | |
354 | # wait till the result is ready |
428 | # wait till the result is ready |
355 | my $result_ready = AnyEvent->condvar; |
429 | my $result_ready = AnyEvent->condvar; |
356 | |
430 | |
357 | # do something such as adding a timer |
431 | # do something such as adding a timer |
… | |
… | |
365 | |
439 | |
366 | # this "blocks" (while handling events) till the callback |
440 | # this "blocks" (while handling events) till the callback |
367 | # calls send |
441 | # calls send |
368 | $result_ready->recv; |
442 | $result_ready->recv; |
369 | |
443 | |
|
|
444 | Example: wait for a timer, but take advantage of the fact that |
|
|
445 | condition variables are also code references. |
|
|
446 | |
|
|
447 | my $done = AnyEvent->condvar; |
|
|
448 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
|
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449 | $done->recv; |
|
|
450 | |
370 | =head3 METHODS FOR PRODUCERS |
451 | =head3 METHODS FOR PRODUCERS |
371 | |
452 | |
372 | These methods should only be used by the producing side, i.e. the |
453 | These methods should only be used by the producing side, i.e. the |
373 | code/module that eventually sends the signal. Note that it is also |
454 | code/module that eventually sends the signal. Note that it is also |
374 | the producer side which creates the condvar in most cases, but it isn't |
455 | the producer side which creates the condvar in most cases, but it isn't |
… | |
… | |
385 | If a callback has been set on the condition variable, it is called |
466 | If a callback has been set on the condition variable, it is called |
386 | immediately from within send. |
467 | immediately from within send. |
387 | |
468 | |
388 | Any arguments passed to the C<send> call will be returned by all |
469 | Any arguments passed to the C<send> call will be returned by all |
389 | future C<< ->recv >> calls. |
470 | future C<< ->recv >> calls. |
|
|
471 | |
|
|
472 | Condition variables are overloaded so one can call them directly |
|
|
473 | (as a code reference). Calling them directly is the same as calling |
|
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474 | C<send>. Note, however, that many C-based event loops do not handle |
|
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475 | overloading, so as tempting as it may be, passing a condition variable |
|
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476 | instead of a callback does not work. Both the pure perl and EV loops |
|
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477 | support overloading, however, as well as all functions that use perl to |
|
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478 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
|
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479 | example). |
390 | |
480 | |
391 | =item $cv->croak ($error) |
481 | =item $cv->croak ($error) |
392 | |
482 | |
393 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
483 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
394 | C<Carp::croak> with the given error message/object/scalar. |
484 | C<Carp::croak> with the given error message/object/scalar. |
… | |
… | |
443 | doesn't execute once). |
533 | doesn't execute once). |
444 | |
534 | |
445 | This is the general pattern when you "fan out" into multiple subrequests: |
535 | This is the general pattern when you "fan out" into multiple subrequests: |
446 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
536 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
447 | is called at least once, and then, for each subrequest you start, call |
537 | is called at least once, and then, for each subrequest you start, call |
448 | C<begin> and for eahc subrequest you finish, call C<end>. |
538 | C<begin> and for each subrequest you finish, call C<end>. |
449 | |
539 | |
450 | =back |
540 | =back |
451 | |
541 | |
452 | =head3 METHODS FOR CONSUMERS |
542 | =head3 METHODS FOR CONSUMERS |
453 | |
543 | |
… | |
… | |
475 | (programs might want to do that to stay interactive), so I<if you are |
565 | (programs might want to do that to stay interactive), so I<if you are |
476 | using this from a module, never require a blocking wait>, but let the |
566 | using this from a module, never require a blocking wait>, but let the |
477 | caller decide whether the call will block or not (for example, by coupling |
567 | caller decide whether the call will block or not (for example, by coupling |
478 | condition variables with some kind of request results and supporting |
568 | condition variables with some kind of request results and supporting |
479 | callbacks so the caller knows that getting the result will not block, |
569 | callbacks so the caller knows that getting the result will not block, |
480 | while still suppporting blocking waits if the caller so desires). |
570 | while still supporting blocking waits if the caller so desires). |
481 | |
571 | |
482 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
572 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
483 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
573 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
484 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
574 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
485 | can supply. |
575 | can supply. |
… | |
… | |
504 | |
594 | |
505 | This is a mutator function that returns the callback set and optionally |
595 | This is a mutator function that returns the callback set and optionally |
506 | replaces it before doing so. |
596 | replaces it before doing so. |
507 | |
597 | |
508 | The callback will be called when the condition becomes "true", i.e. when |
598 | The callback will be called when the condition becomes "true", i.e. when |
509 | C<send> or C<croak> are called. Calling C<recv> inside the callback |
599 | C<send> or C<croak> are called, with the only argument being the condition |
510 | or at any later time is guaranteed not to block. |
600 | variable itself. Calling C<recv> inside the callback or at any later time |
|
|
601 | is guaranteed not to block. |
511 | |
602 | |
512 | =back |
603 | =back |
513 | |
604 | |
514 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
605 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
515 | |
606 | |
… | |
… | |
601 | |
692 | |
602 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
693 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
603 | do anything special (it does not need to be event-based) and let AnyEvent |
694 | do anything special (it does not need to be event-based) and let AnyEvent |
604 | decide which implementation to chose if some module relies on it. |
695 | decide which implementation to chose if some module relies on it. |
605 | |
696 | |
606 | If the main program relies on a specific event model. For example, in |
697 | If the main program relies on a specific event model - for example, in |
607 | Gtk2 programs you have to rely on the Glib module. You should load the |
698 | Gtk2 programs you have to rely on the Glib module - you should load the |
608 | event module before loading AnyEvent or any module that uses it: generally |
699 | event module before loading AnyEvent or any module that uses it: generally |
609 | speaking, you should load it as early as possible. The reason is that |
700 | speaking, you should load it as early as possible. The reason is that |
610 | modules might create watchers when they are loaded, and AnyEvent will |
701 | modules might create watchers when they are loaded, and AnyEvent will |
611 | decide on the event model to use as soon as it creates watchers, and it |
702 | decide on the event model to use as soon as it creates watchers, and it |
612 | might chose the wrong one unless you load the correct one yourself. |
703 | might chose the wrong one unless you load the correct one yourself. |
613 | |
704 | |
614 | You can chose to use a rather inefficient pure-perl implementation by |
705 | You can chose to use a pure-perl implementation by loading the |
615 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
706 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
616 | behaviour everywhere, but letting AnyEvent chose is generally better. |
707 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
708 | |
|
|
709 | =head2 MAINLOOP EMULATION |
|
|
710 | |
|
|
711 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
712 | only want to use AnyEvent), you do not want to run a specific event loop. |
|
|
713 | |
|
|
714 | In that case, you can use a condition variable like this: |
|
|
715 | |
|
|
716 | AnyEvent->condvar->recv; |
|
|
717 | |
|
|
718 | This has the effect of entering the event loop and looping forever. |
|
|
719 | |
|
|
720 | Note that usually your program has some exit condition, in which case |
|
|
721 | it is better to use the "traditional" approach of storing a condition |
|
|
722 | variable somewhere, waiting for it, and sending it when the program should |
|
|
723 | exit cleanly. |
|
|
724 | |
617 | |
725 | |
618 | =head1 OTHER MODULES |
726 | =head1 OTHER MODULES |
619 | |
727 | |
620 | The following is a non-exhaustive list of additional modules that use |
728 | The following is a non-exhaustive list of additional modules that use |
621 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
729 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
… | |
… | |
627 | =item L<AnyEvent::Util> |
735 | =item L<AnyEvent::Util> |
628 | |
736 | |
629 | Contains various utility functions that replace often-used but blocking |
737 | Contains various utility functions that replace often-used but blocking |
630 | functions such as C<inet_aton> by event-/callback-based versions. |
738 | functions such as C<inet_aton> by event-/callback-based versions. |
631 | |
739 | |
|
|
740 | =item L<AnyEvent::Socket> |
|
|
741 | |
|
|
742 | Provides various utility functions for (internet protocol) sockets, |
|
|
743 | addresses and name resolution. Also functions to create non-blocking tcp |
|
|
744 | connections or tcp servers, with IPv6 and SRV record support and more. |
|
|
745 | |
632 | =item L<AnyEvent::Handle> |
746 | =item L<AnyEvent::Handle> |
633 | |
747 | |
634 | Provide read and write buffers and manages watchers for reads and writes. |
748 | 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 |
|
|
750 | non-blocking SSL/TLS. |
|
|
751 | |
|
|
752 | =item L<AnyEvent::DNS> |
|
|
753 | |
|
|
754 | Provides rich asynchronous DNS resolver capabilities. |
|
|
755 | |
|
|
756 | =item L<AnyEvent::HTTP> |
|
|
757 | |
|
|
758 | A simple-to-use HTTP library that is capable of making a lot of concurrent |
|
|
759 | HTTP requests. |
635 | |
760 | |
636 | =item L<AnyEvent::HTTPD> |
761 | =item L<AnyEvent::HTTPD> |
637 | |
762 | |
638 | Provides a simple web application server framework. |
763 | Provides a simple web application server framework. |
639 | |
764 | |
640 | =item L<AnyEvent::DNS> |
|
|
641 | |
|
|
642 | Provides asynchronous DNS resolver capabilities, beyond what |
|
|
643 | L<AnyEvent::Util> offers. |
|
|
644 | |
|
|
645 | =item L<AnyEvent::FastPing> |
765 | =item L<AnyEvent::FastPing> |
646 | |
766 | |
647 | The fastest ping in the west. |
767 | The fastest ping in the west. |
|
|
768 | |
|
|
769 | =item L<AnyEvent::DBI> |
|
|
770 | |
|
|
771 | Executes L<DBI> requests asynchronously in a proxy process. |
|
|
772 | |
|
|
773 | =item L<AnyEvent::AIO> |
|
|
774 | |
|
|
775 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
776 | programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent |
|
|
777 | together. |
|
|
778 | |
|
|
779 | =item L<AnyEvent::BDB> |
|
|
780 | |
|
|
781 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses |
|
|
782 | L<BDB> and AnyEvent together. |
|
|
783 | |
|
|
784 | =item L<AnyEvent::GPSD> |
|
|
785 | |
|
|
786 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
|
|
787 | |
|
|
788 | =item L<AnyEvent::IGS> |
|
|
789 | |
|
|
790 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
791 | L<App::IGS>). |
648 | |
792 | |
649 | =item L<Net::IRC3> |
793 | =item L<Net::IRC3> |
650 | |
794 | |
651 | AnyEvent based IRC client module family. |
795 | AnyEvent based IRC client module family. |
652 | |
796 | |
… | |
… | |
665 | |
809 | |
666 | =item L<Coro> |
810 | =item L<Coro> |
667 | |
811 | |
668 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
812 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
669 | |
813 | |
670 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
671 | |
|
|
672 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
673 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
674 | together. |
|
|
675 | |
|
|
676 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
677 | |
|
|
678 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
679 | IO::AIO and AnyEvent together. |
|
|
680 | |
|
|
681 | =item L<IO::Lambda> |
814 | =item L<IO::Lambda> |
682 | |
815 | |
683 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
816 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
684 | |
817 | |
685 | =back |
818 | =back |
… | |
… | |
691 | no warnings; |
824 | no warnings; |
692 | use strict; |
825 | use strict; |
693 | |
826 | |
694 | use Carp; |
827 | use Carp; |
695 | |
828 | |
696 | our $VERSION = '3.4'; |
829 | our $VERSION = 4.2; |
697 | our $MODEL; |
830 | our $MODEL; |
698 | |
831 | |
699 | our $AUTOLOAD; |
832 | our $AUTOLOAD; |
700 | our @ISA; |
833 | our @ISA; |
701 | |
834 | |
|
|
835 | our @REGISTRY; |
|
|
836 | |
|
|
837 | our $WIN32; |
|
|
838 | |
|
|
839 | BEGIN { |
|
|
840 | my $win32 = ! ! ($^O =~ /mswin32/i); |
|
|
841 | eval "sub WIN32(){ $win32 }"; |
|
|
842 | } |
|
|
843 | |
702 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
844 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
703 | |
845 | |
704 | our @REGISTRY; |
846 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
|
|
847 | |
|
|
848 | { |
|
|
849 | my $idx; |
|
|
850 | $PROTOCOL{$_} = ++$idx |
|
|
851 | for reverse split /\s*,\s*/, |
|
|
852 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
|
|
853 | } |
705 | |
854 | |
706 | my @models = ( |
855 | my @models = ( |
707 | [EV:: => AnyEvent::Impl::EV::], |
856 | [EV:: => AnyEvent::Impl::EV::], |
708 | [Event:: => AnyEvent::Impl::Event::], |
857 | [Event:: => AnyEvent::Impl::Event::], |
709 | [Tk:: => AnyEvent::Impl::Tk::], |
|
|
710 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
711 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
712 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
858 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
713 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
859 | # everything below here will not be autoprobed |
714 | [Glib:: => AnyEvent::Impl::Glib::], |
860 | # as the pureperl backend should work everywhere |
|
|
861 | # and is usually faster |
|
|
862 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
863 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
715 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
864 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
716 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
865 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
717 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
866 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
|
|
867 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
868 | [Prima:: => AnyEvent::Impl::POE::], |
718 | ); |
869 | ); |
719 | |
870 | |
720 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
871 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
721 | |
872 | |
722 | our @post_detect; |
873 | our @post_detect; |
723 | |
874 | |
724 | sub post_detect(&) { |
875 | sub post_detect(&) { |
725 | my ($cb) = @_; |
876 | my ($cb) = @_; |
… | |
… | |
730 | 1 |
881 | 1 |
731 | } else { |
882 | } else { |
732 | push @post_detect, $cb; |
883 | push @post_detect, $cb; |
733 | |
884 | |
734 | defined wantarray |
885 | defined wantarray |
735 | ? bless \$cb, "AnyEvent::Util::Guard" |
886 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
736 | : () |
887 | : () |
737 | } |
888 | } |
738 | } |
889 | } |
739 | |
890 | |
740 | sub AnyEvent::Util::Guard::DESTROY { |
891 | sub AnyEvent::Util::PostDetect::DESTROY { |
741 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
892 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
742 | } |
893 | } |
743 | |
894 | |
744 | sub detect() { |
895 | sub detect() { |
745 | unless ($MODEL) { |
896 | unless ($MODEL) { |
746 | no strict 'refs'; |
897 | no strict 'refs'; |
|
|
898 | local $SIG{__DIE__}; |
747 | |
899 | |
748 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
900 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
749 | my $model = "AnyEvent::Impl::$1"; |
901 | my $model = "AnyEvent::Impl::$1"; |
750 | if (eval "require $model") { |
902 | if (eval "require $model") { |
751 | $MODEL = $model; |
903 | $MODEL = $model; |
… | |
… | |
808 | $class->$func (@_); |
960 | $class->$func (@_); |
809 | } |
961 | } |
810 | |
962 | |
811 | package AnyEvent::Base; |
963 | package AnyEvent::Base; |
812 | |
964 | |
|
|
965 | # default implementation for now and time |
|
|
966 | |
|
|
967 | use Time::HiRes (); |
|
|
968 | |
|
|
969 | sub time { Time::HiRes::time } |
|
|
970 | sub now { Time::HiRes::time } |
|
|
971 | |
813 | # default implementation for ->condvar |
972 | # default implementation for ->condvar |
814 | |
973 | |
815 | sub condvar { |
974 | sub condvar { |
816 | bless {}, AnyEvent::CondVar:: |
975 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
817 | } |
976 | } |
818 | |
977 | |
819 | # default implementation for ->signal |
978 | # default implementation for ->signal |
820 | |
979 | |
821 | our %SIG_CB; |
980 | our %SIG_CB; |
… | |
… | |
837 | sub AnyEvent::Base::Signal::DESTROY { |
996 | sub AnyEvent::Base::Signal::DESTROY { |
838 | my ($signal, $cb) = @{$_[0]}; |
997 | my ($signal, $cb) = @{$_[0]}; |
839 | |
998 | |
840 | delete $SIG_CB{$signal}{$cb}; |
999 | delete $SIG_CB{$signal}{$cb}; |
841 | |
1000 | |
842 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1001 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
843 | } |
1002 | } |
844 | |
1003 | |
845 | # default implementation for ->child |
1004 | # default implementation for ->child |
846 | |
1005 | |
847 | our %PID_CB; |
1006 | our %PID_CB; |
… | |
… | |
874 | or Carp::croak "required option 'pid' is missing"; |
1033 | or Carp::croak "required option 'pid' is missing"; |
875 | |
1034 | |
876 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1035 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
877 | |
1036 | |
878 | unless ($WNOHANG) { |
1037 | unless ($WNOHANG) { |
879 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
1038 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
880 | } |
1039 | } |
881 | |
1040 | |
882 | unless ($CHLD_W) { |
1041 | unless ($CHLD_W) { |
883 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1042 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
884 | # child could be a zombie already, so make at least one round |
1043 | # child could be a zombie already, so make at least one round |
… | |
… | |
901 | |
1060 | |
902 | our @ISA = AnyEvent::CondVar::Base::; |
1061 | our @ISA = AnyEvent::CondVar::Base::; |
903 | |
1062 | |
904 | package AnyEvent::CondVar::Base; |
1063 | package AnyEvent::CondVar::Base; |
905 | |
1064 | |
|
|
1065 | use overload |
|
|
1066 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
|
|
1067 | fallback => 1; |
|
|
1068 | |
906 | sub _send { |
1069 | sub _send { |
907 | # nop |
1070 | # nop |
908 | } |
1071 | } |
909 | |
1072 | |
910 | sub send { |
1073 | sub send { |
… | |
… | |
944 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
1107 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
945 | } |
1108 | } |
946 | |
1109 | |
947 | sub end { |
1110 | sub end { |
948 | return if --$_[0]{_ae_counter}; |
1111 | return if --$_[0]{_ae_counter}; |
949 | &{ $_[0]{_ae_end_cb} } if $_[0]{_ae_end_cb}; |
1112 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
950 | } |
1113 | } |
951 | |
1114 | |
952 | # undocumented/compatibility with pre-3.4 |
1115 | # undocumented/compatibility with pre-3.4 |
953 | *broadcast = \&send; |
1116 | *broadcast = \&send; |
954 | *wait = \&_wait; |
1117 | *wait = \&_wait; |
… | |
… | |
1016 | model it chooses. |
1179 | model it chooses. |
1017 | |
1180 | |
1018 | =item C<PERL_ANYEVENT_MODEL> |
1181 | =item C<PERL_ANYEVENT_MODEL> |
1019 | |
1182 | |
1020 | This can be used to specify the event model to be used by AnyEvent, before |
1183 | This can be used to specify the event model to be used by AnyEvent, before |
1021 | autodetection and -probing kicks in. It must be a string consisting |
1184 | auto detection and -probing kicks in. It must be a string consisting |
1022 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
1185 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
1023 | and the resulting module name is loaded and if the load was successful, |
1186 | and the resulting module name is loaded and if the load was successful, |
1024 | used as event model. If it fails to load AnyEvent will proceed with |
1187 | used as event model. If it fails to load AnyEvent will proceed with |
1025 | autodetection and -probing. |
1188 | auto detection and -probing. |
1026 | |
1189 | |
1027 | This functionality might change in future versions. |
1190 | This functionality might change in future versions. |
1028 | |
1191 | |
1029 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
1192 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
1030 | could start your program like this: |
1193 | could start your program like this: |
1031 | |
1194 | |
1032 | PERL_ANYEVENT_MODEL=Perl perl ... |
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. |
1033 | |
1232 | |
1034 | =back |
1233 | =back |
1035 | |
1234 | |
1036 | =head1 EXAMPLE PROGRAM |
1235 | =head1 EXAMPLE PROGRAM |
1037 | |
1236 | |
… | |
… | |
1048 | poll => 'r', |
1247 | poll => 'r', |
1049 | cb => sub { |
1248 | cb => sub { |
1050 | warn "io event <$_[0]>\n"; # will always output <r> |
1249 | warn "io event <$_[0]>\n"; # will always output <r> |
1051 | chomp (my $input = <STDIN>); # read a line |
1250 | chomp (my $input = <STDIN>); # read a line |
1052 | warn "read: $input\n"; # output what has been read |
1251 | warn "read: $input\n"; # output what has been read |
1053 | $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i |
1252 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
1054 | }, |
1253 | }, |
1055 | ); |
1254 | ); |
1056 | |
1255 | |
1057 | my $time_watcher; # can only be used once |
1256 | my $time_watcher; # can only be used once |
1058 | |
1257 | |
… | |
… | |
1063 | }); |
1262 | }); |
1064 | } |
1263 | } |
1065 | |
1264 | |
1066 | new_timer; # create first timer |
1265 | new_timer; # create first timer |
1067 | |
1266 | |
1068 | $cv->wait; # wait until user enters /^q/i |
1267 | $cv->recv; # wait until user enters /^q/i |
1069 | |
1268 | |
1070 | =head1 REAL-WORLD EXAMPLE |
1269 | =head1 REAL-WORLD EXAMPLE |
1071 | |
1270 | |
1072 | Consider the L<Net::FCP> module. It features (among others) the following |
1271 | Consider the L<Net::FCP> module. It features (among others) the following |
1073 | API calls, which are to freenet what HTTP GET requests are to http: |
1272 | API calls, which are to freenet what HTTP GET requests are to http: |
… | |
… | |
1123 | syswrite $txn->{fh}, $txn->{request} |
1322 | syswrite $txn->{fh}, $txn->{request} |
1124 | or die "connection or write error"; |
1323 | or die "connection or write error"; |
1125 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1324 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1126 | |
1325 | |
1127 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1326 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1128 | result and signals any possible waiters that the request ahs finished: |
1327 | result and signals any possible waiters that the request has finished: |
1129 | |
1328 | |
1130 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1329 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1131 | |
1330 | |
1132 | if (end-of-file or data complete) { |
1331 | if (end-of-file or data complete) { |
1133 | $txn->{result} = $txn->{buf}; |
1332 | $txn->{result} = $txn->{buf}; |
1134 | $txn->{finished}->broadcast; |
1333 | $txn->{finished}->send; |
1135 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1334 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1136 | } |
1335 | } |
1137 | |
1336 | |
1138 | The C<result> method, finally, just waits for the finished signal (if the |
1337 | The C<result> method, finally, just waits for the finished signal (if the |
1139 | request was already finished, it doesn't wait, of course, and returns the |
1338 | request was already finished, it doesn't wait, of course, and returns the |
1140 | data: |
1339 | data: |
1141 | |
1340 | |
1142 | $txn->{finished}->wait; |
1341 | $txn->{finished}->recv; |
1143 | return $txn->{result}; |
1342 | return $txn->{result}; |
1144 | |
1343 | |
1145 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1344 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1146 | that occured during request processing. The C<result> method detects |
1345 | that occurred during request processing. The C<result> method detects |
1147 | whether an exception as thrown (it is stored inside the $txn object) |
1346 | whether an exception as thrown (it is stored inside the $txn object) |
1148 | and just throws the exception, which means connection errors and other |
1347 | and just throws the exception, which means connection errors and other |
1149 | problems get reported tot he code that tries to use the result, not in a |
1348 | problems get reported tot he code that tries to use the result, not in a |
1150 | random callback. |
1349 | random callback. |
1151 | |
1350 | |
… | |
… | |
1182 | |
1381 | |
1183 | my $quit = AnyEvent->condvar; |
1382 | my $quit = AnyEvent->condvar; |
1184 | |
1383 | |
1185 | $fcp->txn_client_get ($url)->cb (sub { |
1384 | $fcp->txn_client_get ($url)->cb (sub { |
1186 | ... |
1385 | ... |
1187 | $quit->broadcast; |
1386 | $quit->send; |
1188 | }); |
1387 | }); |
1189 | |
1388 | |
1190 | $quit->wait; |
1389 | $quit->recv; |
1191 | |
1390 | |
1192 | |
1391 | |
1193 | =head1 BENCHMARKS |
1392 | =head1 BENCHMARKS |
1194 | |
1393 | |
1195 | To give you an idea of the performance and overheads that AnyEvent adds |
1394 | To give you an idea of the performance and overheads that AnyEvent adds |
… | |
… | |
1197 | of various event loops I prepared some benchmarks. |
1396 | of various event loops I prepared some benchmarks. |
1198 | |
1397 | |
1199 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1398 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1200 | |
1399 | |
1201 | Here is a benchmark of various supported event models used natively and |
1400 | Here is a benchmark of various supported event models used natively and |
1202 | through anyevent. The benchmark creates a lot of timers (with a zero |
1401 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1203 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1402 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1204 | which it is), lets them fire exactly once and destroys them again. |
1403 | which it is), lets them fire exactly once and destroys them again. |
1205 | |
1404 | |
1206 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1405 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1207 | distribution. |
1406 | distribution. |
… | |
… | |
1224 | all watchers, to avoid adding memory overhead. That means closure creation |
1423 | all watchers, to avoid adding memory overhead. That means closure creation |
1225 | and memory usage is not included in the figures. |
1424 | and memory usage is not included in the figures. |
1226 | |
1425 | |
1227 | I<invoke> is the time, in microseconds, used to invoke a simple |
1426 | I<invoke> is the time, in microseconds, used to invoke a simple |
1228 | callback. The callback simply counts down a Perl variable and after it was |
1427 | callback. The callback simply counts down a Perl variable and after it was |
1229 | invoked "watcher" times, it would C<< ->broadcast >> a condvar once to |
1428 | invoked "watcher" times, it would C<< ->send >> a condvar once to |
1230 | signal the end of this phase. |
1429 | signal the end of this phase. |
1231 | |
1430 | |
1232 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1431 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1233 | watcher. |
1432 | watcher. |
1234 | |
1433 | |
… | |
… | |
1330 | |
1529 | |
1331 | =back |
1530 | =back |
1332 | |
1531 | |
1333 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1532 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1334 | |
1533 | |
1335 | This benchmark atcually benchmarks the event loop itself. It works by |
1534 | This benchmark actually benchmarks the event loop itself. It works by |
1336 | creating a number of "servers": each server consists of a socketpair, a |
1535 | creating a number of "servers": each server consists of a socket pair, a |
1337 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1536 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1338 | watcher waiting for input on one side of the socket. Each time the socket |
1537 | watcher waiting for input on one side of the socket. Each time the socket |
1339 | watcher reads a byte it will write that byte to a random other "server". |
1538 | watcher reads a byte it will write that byte to a random other "server". |
1340 | |
1539 | |
1341 | The effect is that there will be a lot of I/O watchers, only part of which |
1540 | The effect is that there will be a lot of I/O watchers, only part of which |
1342 | are active at any one point (so there is a constant number of active |
1541 | are active at any one point (so there is a constant number of active |
1343 | fds for each loop iterstaion, but which fds these are is random). The |
1542 | fds for each loop iteration, but which fds these are is random). The |
1344 | timeout is reset each time something is read because that reflects how |
1543 | timeout is reset each time something is read because that reflects how |
1345 | most timeouts work (and puts extra pressure on the event loops). |
1544 | most timeouts work (and puts extra pressure on the event loops). |
1346 | |
1545 | |
1347 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 |
1546 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1348 | (1%) are active. This mirrors the activity of large servers with many |
1547 | (1%) are active. This mirrors the activity of large servers with many |
1349 | connections, most of which are idle at any one point in time. |
1548 | connections, most of which are idle at any one point in time. |
1350 | |
1549 | |
1351 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1550 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1352 | distribution. |
1551 | distribution. |
… | |
… | |
1354 | =head3 Explanation of the columns |
1553 | =head3 Explanation of the columns |
1355 | |
1554 | |
1356 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1555 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1357 | each server has a read and write socket end). |
1556 | each server has a read and write socket end). |
1358 | |
1557 | |
1359 | I<create> is the time it takes to create a socketpair (which is |
1558 | I<create> is the time it takes to create a socket pair (which is |
1360 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1559 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1361 | |
1560 | |
1362 | I<request>, the most important value, is the time it takes to handle a |
1561 | I<request>, the most important value, is the time it takes to handle a |
1363 | single "request", that is, reading the token from the pipe and forwarding |
1562 | single "request", that is, reading the token from the pipe and forwarding |
1364 | it to another server. This includes deleting the old timeout and creating |
1563 | it to another server. This includes deleting the old timeout and creating |
… | |
… | |
1437 | speed most when you have lots of watchers, not when you only have a few of |
1636 | speed most when you have lots of watchers, not when you only have a few of |
1438 | them). |
1637 | them). |
1439 | |
1638 | |
1440 | EV is again fastest. |
1639 | EV is again fastest. |
1441 | |
1640 | |
1442 | Perl again comes second. It is noticably faster than the C-based event |
1641 | Perl again comes second. It is noticeably faster than the C-based event |
1443 | loops Event and Glib, although the difference is too small to really |
1642 | loops Event and Glib, although the difference is too small to really |
1444 | matter. |
1643 | matter. |
1445 | |
1644 | |
1446 | POE also performs much better in this case, but is is still far behind the |
1645 | POE also performs much better in this case, but is is still far behind the |
1447 | others. |
1646 | others. |
… | |
… | |
1476 | specified in the variable. |
1675 | specified in the variable. |
1477 | |
1676 | |
1478 | You can make AnyEvent completely ignore this variable by deleting it |
1677 | You can make AnyEvent completely ignore this variable by deleting it |
1479 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1678 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1480 | |
1679 | |
1481 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1680 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1482 | |
1681 | |
1483 | use AnyEvent; |
1682 | use AnyEvent; |
1484 | |
1683 | |
1485 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1684 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1486 | be used to probe what backend is used and gain other information (which is |
1685 | be used to probe what backend is used and gain other information (which is |
1487 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1686 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1488 | |
1687 | |
1489 | |
1688 | |
|
|
1689 | =head1 BUGS |
|
|
1690 | |
|
|
1691 | 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 |
|
|
1693 | 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 |
|
|
1695 | pronounced). |
|
|
1696 | |
|
|
1697 | |
1490 | =head1 SEE ALSO |
1698 | =head1 SEE ALSO |
|
|
1699 | |
|
|
1700 | Utility functions: L<AnyEvent::Util>. |
1491 | |
1701 | |
1492 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1702 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1493 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1703 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1494 | |
1704 | |
1495 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1705 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1496 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1706 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1497 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1707 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1498 | L<AnyEvent::Impl::POE>. |
1708 | L<AnyEvent::Impl::POE>. |
1499 | |
1709 | |
|
|
1710 | Non-blocking file handles, sockets, TCP clients and |
|
|
1711 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
|
|
1712 | |
|
|
1713 | Asynchronous DNS: L<AnyEvent::DNS>. |
|
|
1714 | |
1500 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1715 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1501 | |
1716 | |
1502 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
1717 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
1503 | |
1718 | |
1504 | |
1719 | |
1505 | =head1 AUTHOR |
1720 | =head1 AUTHOR |
1506 | |
1721 | |
1507 | Marc Lehmann <schmorp@schmorp.de> |
1722 | Marc Lehmann <schmorp@schmorp.de> |
1508 | http://home.schmorp.de/ |
1723 | http://home.schmorp.de/ |
1509 | |
1724 | |
1510 | =cut |
1725 | =cut |
1511 | |
1726 | |
1512 | 1 |
1727 | 1 |
1513 | |
1728 | |