1 | => NAME |
1 | NAME |
2 | AnyEvent - provide framework for multiple event loops |
2 | AnyEvent - provide framework for multiple event loops |
3 | |
3 | |
4 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event |
4 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event |
5 | loops |
5 | loops |
6 | |
6 | |
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17 | |
17 | |
18 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
18 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
19 | $w->send; # wake up current and all future recv's |
19 | $w->send; # wake up current and all future recv's |
20 | $w->recv; # enters "main loop" till $condvar gets ->send |
20 | $w->recv; # enters "main loop" till $condvar gets ->send |
21 | |
21 | |
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22 | INTRODUCTION/TUTORIAL |
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23 | This manpage is mainly a reference manual. If you are interested in a |
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24 | tutorial or some gentle introduction, have a look at the AnyEvent::Intro |
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25 | manpage. |
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26 | |
22 | WHY YOU SHOULD USE THIS MODULE (OR NOT) |
27 | WHY YOU SHOULD USE THIS MODULE (OR NOT) |
23 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
28 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
24 | nowadays. So what is different about AnyEvent? |
29 | nowadays. So what is different about AnyEvent? |
25 | |
30 | |
26 | Executive Summary: AnyEvent is *compatible*, AnyEvent is *free of |
31 | Executive Summary: AnyEvent is *compatible*, AnyEvent is *free of |
27 | policy* and AnyEvent is *small and efficient*. |
32 | policy* and AnyEvent is *small and efficient*. |
28 | |
33 | |
29 | First and foremost, *AnyEvent is not an event model* itself, it only |
34 | First and foremost, *AnyEvent is not an event model* itself, it only |
30 | interfaces to whatever event model the main program happens to use in a |
35 | interfaces to whatever event model the main program happens to use, in a |
31 | pragmatic way. For event models and certain classes of immortals alike, |
36 | pragmatic way. For event models and certain classes of immortals alike, |
32 | the statement "there can only be one" is a bitter reality: In general, |
37 | the statement "there can only be one" is a bitter reality: In general, |
33 | only one event loop can be active at the same time in a process. |
38 | only one event loop can be active at the same time in a process. |
34 | AnyEvent helps hiding the differences between those event loops. |
39 | AnyEvent cannot change this, but it can hide the differences between |
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40 | those event loops. |
35 | |
41 | |
36 | The goal of AnyEvent is to offer module authors the ability to do event |
42 | The goal of AnyEvent is to offer module authors the ability to do event |
37 | programming (waiting for I/O or timer events) without subscribing to a |
43 | programming (waiting for I/O or timer events) without subscribing to a |
38 | religion, a way of living, and most importantly: without forcing your |
44 | religion, a way of living, and most importantly: without forcing your |
39 | module users into the same thing by forcing them to use the same event |
45 | module users into the same thing by forcing them to use the same event |
40 | model you use. |
46 | model you use. |
41 | |
47 | |
42 | For modules like POE or IO::Async (which is a total misnomer as it is |
48 | For modules like POE or IO::Async (which is a total misnomer as it is |
43 | actually doing all I/O *synchronously*...), using them in your module is |
49 | actually doing all I/O *synchronously*...), using them in your module is |
44 | like joining a cult: After you joined, you are dependent on them and you |
50 | like joining a cult: After you joined, you are dependent on them and you |
45 | cannot use anything else, as it is simply incompatible to everything |
51 | cannot use anything else, as they are simply incompatible to everything |
46 | that isn't itself. What's worse, all the potential users of your module |
52 | that isn't them. What's worse, all the potential users of your module |
47 | are *also* forced to use the same event loop you use. |
53 | are *also* forced to use the same event loop you use. |
48 | |
54 | |
49 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
55 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
50 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
56 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
51 | with the rest: POE + IO::Async? no go. Tk + Event? no go. Again: if your |
57 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if your |
52 | module uses one of those, every user of your module has to use it, too. |
58 | module uses one of those, every user of your module has to use it, too. |
53 | But if your module uses AnyEvent, it works transparently with all event |
59 | But if your module uses AnyEvent, it works transparently with all event |
54 | models it supports (including stuff like POE and IO::Async, as long as |
60 | models it supports (including stuff like IO::Async, as long as those use |
55 | those use one of the supported event loops. It is trivial to add new |
61 | one of the supported event loops. It is trivial to add new event loops |
56 | event loops to AnyEvent, too, so it is future-proof). |
62 | to AnyEvent, too, so it is future-proof). |
57 | |
63 | |
58 | In addition to being free of having to use *the one and only true event |
64 | In addition to being free of having to use *the one and only true event |
59 | model*, AnyEvent also is free of bloat and policy: with POE or similar |
65 | model*, AnyEvent also is free of bloat and policy: with POE or similar |
60 | modules, you get an enormous amount of code and strict rules you have to |
66 | modules, you get an enormous amount of code and strict rules you have to |
61 | follow. AnyEvent, on the other hand, is lean and up to the point, by |
67 | follow. AnyEvent, on the other hand, is lean and up to the point, by |
62 | only offering the functionality that is necessary, in as thin as a |
68 | only offering the functionality that is necessary, in as thin as a |
63 | wrapper as technically possible. |
69 | wrapper as technically possible. |
64 | |
70 | |
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71 | Of course, AnyEvent comes with a big (and fully optional!) toolbox of |
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72 | useful functionality, such as an asynchronous DNS resolver, 100% |
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73 | non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms |
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74 | such as Windows) and lots of real-world knowledge and workarounds for |
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75 | platform bugs and differences. |
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76 | |
65 | Of course, if you want lots of policy (this can arguably be somewhat |
77 | Now, if you *do want* lots of policy (this can arguably be somewhat |
66 | useful) and you want to force your users to use the one and only event |
78 | useful) and you want to force your users to use the one and only event |
67 | model, you should *not* use this module. |
79 | model, you should *not* use this module. |
68 | |
80 | |
69 | DESCRIPTION |
81 | DESCRIPTION |
70 | AnyEvent provides an identical interface to multiple event loops. This |
82 | AnyEvent provides an identical interface to multiple event loops. This |
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99 | starts using it, all bets are off. Maybe you should tell their authors |
111 | starts using it, all bets are off. Maybe you should tell their authors |
100 | to use AnyEvent so their modules work together with others seamlessly... |
112 | to use AnyEvent so their modules work together with others seamlessly... |
101 | |
113 | |
102 | The pure-perl implementation of AnyEvent is called |
114 | The pure-perl implementation of AnyEvent is called |
103 | "AnyEvent::Impl::Perl". Like other event modules you can load it |
115 | "AnyEvent::Impl::Perl". Like other event modules you can load it |
104 | explicitly. |
116 | explicitly and enjoy the high availability of that event loop :) |
105 | |
117 | |
106 | WATCHERS |
118 | WATCHERS |
107 | AnyEvent has the central concept of a *watcher*, which is an object that |
119 | AnyEvent has the central concept of a *watcher*, which is an object that |
108 | stores relevant data for each kind of event you are waiting for, such as |
120 | stores relevant data for each kind of event you are waiting for, such as |
109 | the callback to call, the file handle to watch, etc. |
121 | the callback to call, the file handle to watch, etc. |
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122 | Many watchers either are used with "recursion" (repeating timers for |
134 | Many watchers either are used with "recursion" (repeating timers for |
123 | example), or need to refer to their watcher object in other ways. |
135 | example), or need to refer to their watcher object in other ways. |
124 | |
136 | |
125 | An any way to achieve that is this pattern: |
137 | An any way to achieve that is this pattern: |
126 | |
138 | |
127 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
139 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
128 | # you can use $w here, for example to undef it |
140 | # you can use $w here, for example to undef it |
129 | undef $w; |
141 | undef $w; |
130 | }); |
142 | }); |
131 | |
143 | |
132 | Note that "my $w; $w =" combination. This is necessary because in Perl, |
144 | Note that "my $w; $w =" combination. This is necessary because in Perl, |
133 | my variables are only visible after the statement in which they are |
145 | my variables are only visible after the statement in which they are |
134 | declared. |
146 | declared. |
135 | |
147 | |
136 | I/O WATCHERS |
148 | I/O WATCHERS |
137 | You can create an I/O watcher by calling the "AnyEvent->io" method with |
149 | You can create an I/O watcher by calling the "AnyEvent->io" method with |
138 | the following mandatory key-value pairs as arguments: |
150 | the following mandatory key-value pairs as arguments: |
139 | |
151 | |
140 | "fh" the Perl *file handle* (*not* file descriptor) to watch for events. |
152 | "fh" the Perl *file handle* (*not* file descriptor) to watch for events |
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153 | (AnyEvent might or might not keep a reference to this file handle). |
141 | "poll" must be a string that is either "r" or "w", which creates a |
154 | "poll" must be a string that is either "r" or "w", which creates a |
142 | watcher waiting for "r"eadable or "w"ritable events, respectively. "cb" |
155 | watcher waiting for "r"eadable or "w"ritable events, respectively. "cb" |
143 | is the callback to invoke each time the file handle becomes ready. |
156 | is the callback to invoke each time the file handle becomes ready. |
144 | |
157 | |
145 | Although the callback might get passed parameters, their value and |
158 | Although the callback might get passed parameters, their value and |
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152 | |
165 | |
153 | Some event loops issue spurious readyness notifications, so you should |
166 | Some event loops issue spurious readyness notifications, so you should |
154 | always use non-blocking calls when reading/writing from/to your file |
167 | always use non-blocking calls when reading/writing from/to your file |
155 | handles. |
168 | handles. |
156 | |
169 | |
157 | Example: |
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158 | |
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159 | # wait for readability of STDIN, then read a line and disable the watcher |
170 | Example: wait for readability of STDIN, then read a line and disable the |
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171 | watcher. |
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172 | |
160 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
173 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
161 | chomp (my $input = <STDIN>); |
174 | chomp (my $input = <STDIN>); |
162 | warn "read: $input\n"; |
175 | warn "read: $input\n"; |
163 | undef $w; |
176 | undef $w; |
164 | }); |
177 | }); |
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173 | |
186 | |
174 | Although the callback might get passed parameters, their value and |
187 | Although the callback might get passed parameters, their value and |
175 | presence is undefined and you cannot rely on them. Portable AnyEvent |
188 | presence is undefined and you cannot rely on them. Portable AnyEvent |
176 | callbacks cannot use arguments passed to time watcher callbacks. |
189 | callbacks cannot use arguments passed to time watcher callbacks. |
177 | |
190 | |
178 | The timer callback will be invoked at most once: if you want a repeating |
191 | The callback will normally be invoked once only. If you specify another |
179 | timer you have to create a new watcher (this is a limitation by both Tk |
192 | parameter, "interval", as a strictly positive number (> 0), then the |
180 | and Glib). |
193 | callback will be invoked regularly at that interval (in fractional |
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194 | seconds) after the first invocation. If "interval" is specified with a |
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195 | false value, then it is treated as if it were missing. |
181 | |
196 | |
182 | Example: |
197 | The callback will be rescheduled before invoking the callback, but no |
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198 | attempt is done to avoid timer drift in most backends, so the interval |
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199 | is only approximate. |
183 | |
200 | |
184 | # fire an event after 7.7 seconds |
201 | Example: fire an event after 7.7 seconds. |
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202 | |
185 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
203 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
186 | warn "timeout\n"; |
204 | warn "timeout\n"; |
187 | }); |
205 | }); |
188 | |
206 | |
189 | # to cancel the timer: |
207 | # to cancel the timer: |
190 | undef $w; |
208 | undef $w; |
191 | |
209 | |
192 | Example 2: |
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193 | |
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194 | # fire an event after 0.5 seconds, then roughly every second |
210 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
195 | my $w; |
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196 | |
211 | |
197 | my $cb = sub { |
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198 | # cancel the old timer while creating a new one |
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199 | $w = AnyEvent->timer (after => 1, cb => $cb); |
212 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
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213 | warn "timeout\n"; |
200 | }; |
214 | }; |
201 | |
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202 | # start the "loop" by creating the first watcher |
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203 | $w = AnyEvent->timer (after => 0.5, cb => $cb); |
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204 | |
215 | |
205 | TIMING ISSUES |
216 | TIMING ISSUES |
206 | There are two ways to handle timers: based on real time (relative, "fire |
217 | There are two ways to handle timers: based on real time (relative, "fire |
207 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
218 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
208 | o'clock"). |
219 | o'clock"). |
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220 | on wallclock time) timers. |
231 | on wallclock time) timers. |
221 | |
232 | |
222 | AnyEvent always prefers relative timers, if available, matching the |
233 | AnyEvent always prefers relative timers, if available, matching the |
223 | AnyEvent API. |
234 | AnyEvent API. |
224 | |
235 | |
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236 | AnyEvent has two additional methods that return the "current time": |
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237 | |
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238 | AnyEvent->time |
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239 | This returns the "current wallclock time" as a fractional number of |
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240 | seconds since the Epoch (the same thing as "time" or |
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241 | "Time::HiRes::time" return, and the result is guaranteed to be |
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242 | compatible with those). |
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243 | |
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244 | It progresses independently of any event loop processing, i.e. each |
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245 | call will check the system clock, which usually gets updated |
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246 | frequently. |
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247 | |
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248 | AnyEvent->now |
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249 | This also returns the "current wallclock time", but unlike "time", |
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250 | above, this value might change only once per event loop iteration, |
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251 | depending on the event loop (most return the same time as "time", |
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252 | above). This is the time that AnyEvent's timers get scheduled |
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253 | against. |
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254 | |
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255 | *In almost all cases (in all cases if you don't care), this is the |
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256 | function to call when you want to know the current time.* |
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257 | |
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258 | This function is also often faster then "AnyEvent->time", and thus |
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259 | the preferred method if you want some timestamp (for example, |
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260 | AnyEvent::Handle uses this to update it's activity timeouts). |
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261 | |
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262 | The rest of this section is only of relevance if you try to be very |
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263 | exact with your timing, you can skip it without bad conscience. |
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264 | |
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265 | For a practical example of when these times differ, consider |
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266 | Event::Lib and EV and the following set-up: |
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267 | |
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268 | The event loop is running and has just invoked one of your callback |
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269 | at time=500 (assume no other callbacks delay processing). In your |
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270 | callback, you wait a second by executing "sleep 1" (blocking the |
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271 | process for a second) and then (at time=501) you create a relative |
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272 | timer that fires after three seconds. |
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273 | |
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274 | With Event::Lib, "AnyEvent->time" and "AnyEvent->now" will both |
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275 | return 501, because that is the current time, and the timer will be |
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276 | scheduled to fire at time=504 (501 + 3). |
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277 | |
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278 | With EV, "AnyEvent->time" returns 501 (as that is the current time), |
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279 | but "AnyEvent->now" returns 500, as that is the time the last event |
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280 | processing phase started. With EV, your timer gets scheduled to run |
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281 | at time=503 (500 + 3). |
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282 | |
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283 | In one sense, Event::Lib is more exact, as it uses the current time |
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284 | regardless of any delays introduced by event processing. However, |
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285 | most callbacks do not expect large delays in processing, so this |
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286 | causes a higher drift (and a lot more system calls to get the |
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287 | current time). |
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288 | |
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289 | In another sense, EV is more exact, as your timer will be scheduled |
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290 | at the same time, regardless of how long event processing actually |
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291 | took. |
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292 | |
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293 | In either case, if you care (and in most cases, you don't), then you |
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294 | can get whatever behaviour you want with any event loop, by taking |
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295 | the difference between "AnyEvent->time" and "AnyEvent->now" into |
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296 | account. |
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297 | |
225 | SIGNAL WATCHERS |
298 | SIGNAL WATCHERS |
226 | You can watch for signals using a signal watcher, "signal" is the signal |
299 | You can watch for signals using a signal watcher, "signal" is the signal |
227 | *name* without any "SIG" prefix, "cb" is the Perl callback to be invoked |
300 | *name* in uppercase and without any "SIG" prefix, "cb" is the Perl |
228 | whenever a signal occurs. |
301 | callback to be invoked whenever a signal occurs. |
229 | |
302 | |
230 | Although the callback might get passed parameters, their value and |
303 | Although the callback might get passed parameters, their value and |
231 | presence is undefined and you cannot rely on them. Portable AnyEvent |
304 | presence is undefined and you cannot rely on them. Portable AnyEvent |
232 | callbacks cannot use arguments passed to signal watcher callbacks. |
305 | callbacks cannot use arguments passed to signal watcher callbacks. |
233 | |
306 | |
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269 | an AnyEvent program, you *have* to create at least one watcher before |
342 | an AnyEvent program, you *have* to create at least one watcher before |
270 | you "fork" the child (alternatively, you can call "AnyEvent::detect"). |
343 | you "fork" the child (alternatively, you can call "AnyEvent::detect"). |
271 | |
344 | |
272 | Example: fork a process and wait for it |
345 | Example: fork a process and wait for it |
273 | |
346 | |
274 | my $done = AnyEvent->condvar; |
347 | my $done = AnyEvent->condvar; |
275 | |
348 | |
276 | my $pid = fork or exit 5; |
349 | my $pid = fork or exit 5; |
277 | |
350 | |
278 | my $w = AnyEvent->child ( |
351 | my $w = AnyEvent->child ( |
279 | pid => $pid, |
352 | pid => $pid, |
280 | cb => sub { |
353 | cb => sub { |
281 | my ($pid, $status) = @_; |
354 | my ($pid, $status) = @_; |
282 | warn "pid $pid exited with status $status"; |
355 | warn "pid $pid exited with status $status"; |
283 | $done->send; |
356 | $done->send; |
284 | }, |
357 | }, |
285 | ); |
358 | ); |
286 | |
359 | |
287 | # do something else, then wait for process exit |
360 | # do something else, then wait for process exit |
288 | $done->recv; |
361 | $done->recv; |
289 | |
362 | |
290 | CONDITION VARIABLES |
363 | CONDITION VARIABLES |
291 | If you are familiar with some event loops you will know that all of them |
364 | If you are familiar with some event loops you will know that all of them |
292 | require you to run some blocking "loop", "run" or similar function that |
365 | require you to run some blocking "loop", "run" or similar function that |
293 | will actively watch for new events and call your callbacks. |
366 | will actively watch for new events and call your callbacks. |
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303 | "cb", which specifies a callback to be called when the condition |
376 | "cb", which specifies a callback to be called when the condition |
304 | variable becomes true. |
377 | variable becomes true. |
305 | |
378 | |
306 | After creation, the condition variable is "false" until it becomes |
379 | After creation, the condition variable is "false" until it becomes |
307 | "true" by calling the "send" method (or calling the condition variable |
380 | "true" by calling the "send" method (or calling the condition variable |
308 | as if it were a callback). |
381 | as if it were a callback, read about the caveats in the description for |
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382 | the "->send" method). |
309 | |
383 | |
310 | Condition variables are similar to callbacks, except that you can |
384 | Condition variables are similar to callbacks, except that you can |
311 | optionally wait for them. They can also be called merge points - points |
385 | optionally wait for them. They can also be called merge points - points |
312 | in time where multiple outstanding events have been processed. And yet |
386 | in time where multiple outstanding events have been processed. And yet |
313 | another way to call them is transactions - each condition variable can |
387 | another way to call them is transactions - each condition variable can |
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383 | Any arguments passed to the "send" call will be returned by all |
457 | Any arguments passed to the "send" call will be returned by all |
384 | future "->recv" calls. |
458 | future "->recv" calls. |
385 | |
459 | |
386 | Condition variables are overloaded so one can call them directly (as |
460 | Condition variables are overloaded so one can call them directly (as |
387 | a code reference). Calling them directly is the same as calling |
461 | a code reference). Calling them directly is the same as calling |
388 | "send". |
462 | "send". Note, however, that many C-based event loops do not handle |
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463 | overloading, so as tempting as it may be, passing a condition |
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464 | variable instead of a callback does not work. Both the pure perl and |
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465 | EV loops support overloading, however, as well as all functions that |
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466 | use perl to invoke a callback (as in AnyEvent::Socket and |
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467 | AnyEvent::DNS for example). |
389 | |
468 | |
390 | $cv->croak ($error) |
469 | $cv->croak ($error) |
391 | Similar to send, but causes all call's to "->recv" to invoke |
470 | Similar to send, but causes all call's to "->recv" to invoke |
392 | "Carp::croak" with the given error message/object/scalar. |
471 | "Carp::croak" with the given error message/object/scalar. |
393 | |
472 | |
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493 | $cb = $cv->cb ([new callback]) |
572 | $cb = $cv->cb ([new callback]) |
494 | This is a mutator function that returns the callback set and |
573 | This is a mutator function that returns the callback set and |
495 | optionally replaces it before doing so. |
574 | optionally replaces it before doing so. |
496 | |
575 | |
497 | The callback will be called when the condition becomes "true", i.e. |
576 | The callback will be called when the condition becomes "true", i.e. |
498 | when "send" or "croak" are called. Calling "recv" inside the |
577 | when "send" or "croak" are called, with the only argument being the |
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578 | condition variable itself. Calling "recv" inside the callback or at |
499 | callback or at any later time is guaranteed not to block. |
579 | any later time is guaranteed not to block. |
500 | |
580 | |
501 | GLOBAL VARIABLES AND FUNCTIONS |
581 | GLOBAL VARIABLES AND FUNCTIONS |
502 | $AnyEvent::MODEL |
582 | $AnyEvent::MODEL |
503 | Contains "undef" until the first watcher is being created. Then it |
583 | Contains "undef" until the first watcher is being created. Then it |
504 | contains the event model that is being used, which is the name of |
584 | contains the event model that is being used, which is the name of |
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578 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
658 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
579 | do anything special (it does not need to be event-based) and let |
659 | do anything special (it does not need to be event-based) and let |
580 | AnyEvent decide which implementation to chose if some module relies on |
660 | AnyEvent decide which implementation to chose if some module relies on |
581 | it. |
661 | it. |
582 | |
662 | |
583 | If the main program relies on a specific event model. For example, in |
663 | If the main program relies on a specific event model - for example, in |
584 | Gtk2 programs you have to rely on the Glib module. You should load the |
664 | Gtk2 programs you have to rely on the Glib module - you should load the |
585 | event module before loading AnyEvent or any module that uses it: |
665 | event module before loading AnyEvent or any module that uses it: |
586 | generally speaking, you should load it as early as possible. The reason |
666 | generally speaking, you should load it as early as possible. The reason |
587 | is that modules might create watchers when they are loaded, and AnyEvent |
667 | is that modules might create watchers when they are loaded, and AnyEvent |
588 | will decide on the event model to use as soon as it creates watchers, |
668 | will decide on the event model to use as soon as it creates watchers, |
589 | and it might chose the wrong one unless you load the correct one |
669 | and it might chose the wrong one unless you load the correct one |
590 | yourself. |
670 | yourself. |
591 | |
671 | |
592 | You can chose to use a rather inefficient pure-perl implementation by |
672 | You can chose to use a pure-perl implementation by loading the |
593 | loading the "AnyEvent::Impl::Perl" module, which gives you similar |
673 | "AnyEvent::Impl::Perl" module, which gives you similar behaviour |
594 | behaviour everywhere, but letting AnyEvent chose is generally better. |
674 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
675 | |
|
|
676 | MAINLOOP EMULATION |
|
|
677 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
678 | only want to use AnyEvent), you do not want to run a specific event |
|
|
679 | loop. |
|
|
680 | |
|
|
681 | In that case, you can use a condition variable like this: |
|
|
682 | |
|
|
683 | AnyEvent->condvar->recv; |
|
|
684 | |
|
|
685 | This has the effect of entering the event loop and looping forever. |
|
|
686 | |
|
|
687 | Note that usually your program has some exit condition, in which case it |
|
|
688 | is better to use the "traditional" approach of storing a condition |
|
|
689 | variable somewhere, waiting for it, and sending it when the program |
|
|
690 | should exit cleanly. |
595 | |
691 | |
596 | OTHER MODULES |
692 | OTHER MODULES |
597 | The following is a non-exhaustive list of additional modules that use |
693 | The following is a non-exhaustive list of additional modules that use |
598 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
694 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
599 | in the same program. Some of the modules come with AnyEvent, some are |
695 | in the same program. Some of the modules come with AnyEvent, some are |
… | |
… | |
602 | AnyEvent::Util |
698 | AnyEvent::Util |
603 | Contains various utility functions that replace often-used but |
699 | Contains various utility functions that replace often-used but |
604 | blocking functions such as "inet_aton" by event-/callback-based |
700 | blocking functions such as "inet_aton" by event-/callback-based |
605 | versions. |
701 | versions. |
606 | |
702 | |
607 | AnyEvent::Handle |
|
|
608 | Provide read and write buffers and manages watchers for reads and |
|
|
609 | writes. |
|
|
610 | |
|
|
611 | AnyEvent::Socket |
703 | AnyEvent::Socket |
612 | Provides various utility functions for (internet protocol) sockets, |
704 | Provides various utility functions for (internet protocol) sockets, |
613 | addresses and name resolution. Also functions to create non-blocking |
705 | addresses and name resolution. Also functions to create non-blocking |
614 | tcp connections or tcp servers, with IPv6 and SRV record support and |
706 | tcp connections or tcp servers, with IPv6 and SRV record support and |
615 | more. |
707 | more. |
616 | |
708 | |
|
|
709 | AnyEvent::Handle |
|
|
710 | Provide read and write buffers, manages watchers for reads and |
|
|
711 | writes, supports raw and formatted I/O, I/O queued and fully |
|
|
712 | transparent and non-blocking SSL/TLS. |
|
|
713 | |
|
|
714 | AnyEvent::DNS |
|
|
715 | Provides rich asynchronous DNS resolver capabilities. |
|
|
716 | |
|
|
717 | AnyEvent::HTTP |
|
|
718 | A simple-to-use HTTP library that is capable of making a lot of |
|
|
719 | concurrent HTTP requests. |
|
|
720 | |
617 | AnyEvent::HTTPD |
721 | AnyEvent::HTTPD |
618 | Provides a simple web application server framework. |
722 | Provides a simple web application server framework. |
619 | |
723 | |
620 | AnyEvent::DNS |
|
|
621 | Provides rich asynchronous DNS resolver capabilities. |
|
|
622 | |
|
|
623 | AnyEvent::FastPing |
724 | AnyEvent::FastPing |
624 | The fastest ping in the west. |
725 | The fastest ping in the west. |
|
|
726 | |
|
|
727 | AnyEvent::DBI |
|
|
728 | Executes DBI requests asynchronously in a proxy process. |
|
|
729 | |
|
|
730 | AnyEvent::AIO |
|
|
731 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
732 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
733 | together. |
|
|
734 | |
|
|
735 | AnyEvent::BDB |
|
|
736 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently |
|
|
737 | fuses BDB and AnyEvent together. |
|
|
738 | |
|
|
739 | AnyEvent::GPSD |
|
|
740 | A non-blocking interface to gpsd, a daemon delivering GPS |
|
|
741 | information. |
|
|
742 | |
|
|
743 | AnyEvent::IGS |
|
|
744 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
745 | App::IGS). |
625 | |
746 | |
626 | Net::IRC3 |
747 | Net::IRC3 |
627 | AnyEvent based IRC client module family. |
748 | AnyEvent based IRC client module family. |
628 | |
749 | |
629 | Net::XMPP2 |
750 | Net::XMPP2 |
… | |
… | |
636 | Event::ExecFlow |
757 | Event::ExecFlow |
637 | High level API for event-based execution flow control. |
758 | High level API for event-based execution flow control. |
638 | |
759 | |
639 | Coro |
760 | Coro |
640 | Has special support for AnyEvent via Coro::AnyEvent. |
761 | Has special support for AnyEvent via Coro::AnyEvent. |
641 | |
|
|
642 | AnyEvent::AIO, IO::AIO |
|
|
643 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
644 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
645 | together. |
|
|
646 | |
|
|
647 | AnyEvent::BDB, BDB |
|
|
648 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently |
|
|
649 | fuses IO::AIO and AnyEvent together. |
|
|
650 | |
762 | |
651 | IO::Lambda |
763 | IO::Lambda |
652 | The lambda approach to I/O - don't ask, look there. Can use |
764 | The lambda approach to I/O - don't ask, look there. Can use |
653 | AnyEvent. |
765 | AnyEvent. |
654 | |
766 | |
… | |
… | |
707 | conditions, such as not being able to load the event model specified |
819 | conditions, such as not being able to load the event model specified |
708 | by "PERL_ANYEVENT_MODEL". |
820 | by "PERL_ANYEVENT_MODEL". |
709 | |
821 | |
710 | When set to 2 or higher, cause AnyEvent to report to STDERR which |
822 | When set to 2 or higher, cause AnyEvent to report to STDERR which |
711 | event model it chooses. |
823 | event model it chooses. |
|
|
824 | |
|
|
825 | "PERL_ANYEVENT_STRICT" |
|
|
826 | AnyEvent does not do much argument checking by default, as thorough |
|
|
827 | argument checking is very costly. Setting this variable to a true |
|
|
828 | value will cause AnyEvent to load "AnyEvent::Strict" and then to |
|
|
829 | thoroughly check the arguments passed to most method calls. If it |
|
|
830 | finds any problems it will croak. |
|
|
831 | |
|
|
832 | In other words, enables "strict" mode. |
|
|
833 | |
|
|
834 | Unlike "use strict" it is definitely recommended ot keep it off in |
|
|
835 | production. |
712 | |
836 | |
713 | "PERL_ANYEVENT_MODEL" |
837 | "PERL_ANYEVENT_MODEL" |
714 | This can be used to specify the event model to be used by AnyEvent, |
838 | This can be used to specify the event model to be used by AnyEvent, |
715 | before auto detection and -probing kicks in. It must be a string |
839 | before auto detection and -probing kicks in. It must be a string |
716 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
840 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
… | |
… | |
721 | This functionality might change in future versions. |
845 | This functionality might change in future versions. |
722 | |
846 | |
723 | For example, to force the pure perl model (AnyEvent::Impl::Perl) you |
847 | For example, to force the pure perl model (AnyEvent::Impl::Perl) you |
724 | could start your program like this: |
848 | could start your program like this: |
725 | |
849 | |
726 | PERL_ANYEVENT_MODEL=Perl perl ... |
850 | PERL_ANYEVENT_MODEL=Perl perl ... |
727 | |
851 | |
728 | "PERL_ANYEVENT_PROTOCOLS" |
852 | "PERL_ANYEVENT_PROTOCOLS" |
729 | Used by both AnyEvent::DNS and AnyEvent::Socket to determine |
853 | Used by both AnyEvent::DNS and AnyEvent::Socket to determine |
730 | preferences for IPv4 or IPv6. The default is unspecified (and might |
854 | preferences for IPv4 or IPv6. The default is unspecified (and might |
731 | change, or be the result of auto probing). |
855 | change, or be the result of auto probing). |
… | |
… | |
753 | but some (broken) firewalls drop such DNS packets, which is why it |
877 | but some (broken) firewalls drop such DNS packets, which is why it |
754 | is off by default. |
878 | is off by default. |
755 | |
879 | |
756 | Setting this variable to 1 will cause AnyEvent::DNS to announce |
880 | Setting this variable to 1 will cause AnyEvent::DNS to announce |
757 | EDNS0 in its DNS requests. |
881 | EDNS0 in its DNS requests. |
|
|
882 | |
|
|
883 | "PERL_ANYEVENT_MAX_FORKS" |
|
|
884 | The maximum number of child processes that |
|
|
885 | "AnyEvent::Util::fork_call" will create in parallel. |
758 | |
886 | |
759 | EXAMPLE PROGRAM |
887 | EXAMPLE PROGRAM |
760 | The following program uses an I/O watcher to read data from STDIN, a |
888 | The following program uses an I/O watcher to read data from STDIN, a |
761 | timer to display a message once per second, and a condition variable to |
889 | timer to display a message once per second, and a condition variable to |
762 | quit the program when the user enters quit: |
890 | quit the program when the user enters quit: |
… | |
… | |
1168 | model than specified in the variable. |
1296 | model than specified in the variable. |
1169 | |
1297 | |
1170 | You can make AnyEvent completely ignore this variable by deleting it |
1298 | You can make AnyEvent completely ignore this variable by deleting it |
1171 | before the first watcher gets created, e.g. with a "BEGIN" block: |
1299 | before the first watcher gets created, e.g. with a "BEGIN" block: |
1172 | |
1300 | |
1173 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1301 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1174 | |
1302 | |
1175 | use AnyEvent; |
1303 | use AnyEvent; |
1176 | |
1304 | |
1177 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1305 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1178 | be used to probe what backend is used and gain other information (which |
1306 | be used to probe what backend is used and gain other information (which |
1179 | is probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1307 | is probably even less useful to an attacker than PERL_ANYEVENT_MODEL), |
|
|
1308 | and $ENV{PERL_ANYEGENT_STRICT}. |
|
|
1309 | |
|
|
1310 | BUGS |
|
|
1311 | Perl 5.8 has numerous memleaks that sometimes hit this module and are |
|
|
1312 | hard to work around. If you suffer from memleaks, first upgrade to Perl |
|
|
1313 | 5.10 and check wether the leaks still show up. (Perl 5.10.0 has other |
|
|
1314 | annoying mamleaks, such as leaking on "map" and "grep" but it is usually |
|
|
1315 | not as pronounced). |
1180 | |
1316 | |
1181 | SEE ALSO |
1317 | SEE ALSO |
1182 | Utility functions: AnyEvent::Util. |
1318 | Utility functions: AnyEvent::Util. |
1183 | |
1319 | |
1184 | Event modules: EV, EV::Glib, Glib::EV, Event, Glib::Event, Glib, Tk, |
1320 | Event modules: EV, EV::Glib, Glib::EV, Event, Glib::Event, Glib, Tk, |
… | |
… | |
1196 | Coroutine support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event, |
1332 | Coroutine support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event, |
1197 | |
1333 | |
1198 | Nontrivial usage examples: Net::FCP, Net::XMPP2, AnyEvent::DNS. |
1334 | Nontrivial usage examples: Net::FCP, Net::XMPP2, AnyEvent::DNS. |
1199 | |
1335 | |
1200 | AUTHOR |
1336 | AUTHOR |
1201 | Marc Lehmann <schmorp@schmorp.de> |
1337 | Marc Lehmann <schmorp@schmorp.de> |
1202 | http://home.schmorp.de/ |
1338 | http://home.schmorp.de/ |
1203 | |
1339 | |