1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - provide framework for multiple event loops |
4 | |
4 | |
5 | EV, Event, Coro::EV, Coro::Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
6 | |
6 | |
7 | =head1 SYNOPSIS |
7 | =head1 SYNOPSIS |
8 | |
8 | |
9 | use AnyEvent; |
9 | use AnyEvent; |
10 | |
10 | |
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15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
16 | ... |
16 | ... |
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 |
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20 | $w->send; # wake up current and all future recv's |
20 | $w->wait; # enters "main loop" till $condvar gets ->broadcast |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
21 | $w->broadcast; # wake up current and all future wait's |
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? |
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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 | |
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78 | The interface itself is vaguely similar, but not identical to the L<Event> |
90 | The interface itself is vaguely similar, but not identical to the L<Event> |
79 | module. |
91 | module. |
80 | |
92 | |
81 | During the first call of any watcher-creation method, the module tries |
93 | During the first call of any watcher-creation method, the module tries |
82 | to detect the currently loaded event loop by probing whether one of the |
94 | to detect the currently loaded event loop by probing whether one of the |
83 | following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>, |
95 | following modules is already loaded: L<EV>, |
84 | L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>, |
96 | L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>, |
85 | L<POE>. The first one found is used. If none are found, the module tries |
97 | L<POE>. The first one found is used. If none are found, the module tries |
86 | to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl |
98 | to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl |
87 | adaptor should always succeed) in the order given. The first one that can |
99 | adaptor should always succeed) in the order given. The first one that can |
88 | be successfully loaded will be used. If, after this, still none could be |
100 | be successfully loaded will be used. If, after this, still none could be |
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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). |
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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 | |
140 | =head2 I/O WATCHERS |
152 | =head2 I/O WATCHERS |
141 | |
153 | |
142 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
154 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
143 | with the following mandatory key-value pairs as arguments: |
155 | with the following mandatory key-value pairs as arguments: |
144 | |
156 | |
145 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
157 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events |
146 | for events. C<poll> must be a string that is either C<r> or C<w>, |
158 | (AnyEvent might or might not keep a reference to this file handle). C<poll> |
147 | which creates a watcher waiting for "r"eadable or "w"ritable events, |
159 | must be a string that is either C<r> or C<w>, which creates a watcher |
148 | respectively. C<cb> is the callback to invoke each time the file handle |
160 | waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the |
149 | becomes ready. |
161 | callback to invoke each time the file handle becomes ready. |
150 | |
162 | |
151 | Although the callback might get passed parameters, their value and |
163 | Although the callback might get passed parameters, their value and |
152 | presence is undefined and you cannot rely on them. Portable AnyEvent |
164 | presence is undefined and you cannot rely on them. Portable AnyEvent |
153 | callbacks cannot use arguments passed to I/O watcher callbacks. |
165 | callbacks cannot use arguments passed to I/O watcher callbacks. |
154 | |
166 | |
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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 | }); |
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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 strictly positive number (> 0), then the |
187 | and Glib). |
199 | callback will be invoked regularly at that interval (in fractional |
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200 | seconds) after the first invocation. If C<interval> is specified with a |
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201 | false value, then it is treated as if it were missing. |
188 | |
202 | |
189 | Example: |
203 | The callback will be rescheduled before invoking the callback, but no |
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204 | attempt is done to avoid timer drift in most backends, so the interval is |
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205 | only approximate. |
190 | |
206 | |
191 | # fire an event after 7.7 seconds |
207 | Example: fire an event after 7.7 seconds. |
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208 | |
192 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
209 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
193 | warn "timeout\n"; |
210 | warn "timeout\n"; |
194 | }); |
211 | }); |
195 | |
212 | |
196 | # to cancel the timer: |
213 | # to cancel the timer: |
197 | undef $w; |
214 | undef $w; |
198 | |
215 | |
199 | Example 2: |
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200 | |
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201 | # fire an event after 0.5 seconds, then roughly every second |
216 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
202 | my $w; |
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203 | |
217 | |
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); |
218 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
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219 | warn "timeout\n"; |
207 | }; |
220 | }; |
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 | |
221 | |
212 | =head3 TIMING ISSUES |
222 | =head3 TIMING ISSUES |
213 | |
223 | |
214 | There are two ways to handle timers: based on real time (relative, "fire |
224 | 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 |
225 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
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227 | timers. |
237 | timers. |
228 | |
238 | |
229 | AnyEvent always prefers relative timers, if available, matching the |
239 | AnyEvent always prefers relative timers, if available, matching the |
230 | AnyEvent API. |
240 | AnyEvent API. |
231 | |
241 | |
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242 | AnyEvent has two additional methods that return the "current time": |
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243 | |
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244 | =over 4 |
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245 | |
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246 | =item AnyEvent->time |
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247 | |
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248 | This returns the "current wallclock time" as a fractional number of |
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249 | seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time> |
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250 | return, and the result is guaranteed to be compatible with those). |
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251 | |
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252 | It progresses independently of any event loop processing, i.e. each call |
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253 | will check the system clock, which usually gets updated frequently. |
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254 | |
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255 | =item AnyEvent->now |
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256 | |
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257 | This also returns the "current wallclock time", but unlike C<time>, above, |
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258 | this value might change only once per event loop iteration, depending on |
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259 | the event loop (most return the same time as C<time>, above). This is the |
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260 | time that AnyEvent's timers get scheduled against. |
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261 | |
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262 | I<In almost all cases (in all cases if you don't care), this is the |
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263 | function to call when you want to know the current time.> |
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264 | |
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265 | This function is also often faster then C<< AnyEvent->time >>, and |
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266 | thus the preferred method if you want some timestamp (for example, |
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267 | L<AnyEvent::Handle> uses this to update it's activity timeouts). |
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268 | |
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269 | The rest of this section is only of relevance if you try to be very exact |
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270 | with your timing, you can skip it without bad conscience. |
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271 | |
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272 | For a practical example of when these times differ, consider L<Event::Lib> |
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273 | and L<EV> and the following set-up: |
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274 | |
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275 | The event loop is running and has just invoked one of your callback at |
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276 | time=500 (assume no other callbacks delay processing). In your callback, |
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277 | you wait a second by executing C<sleep 1> (blocking the process for a |
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278 | second) and then (at time=501) you create a relative timer that fires |
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279 | after three seconds. |
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280 | |
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281 | With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will |
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282 | both return C<501>, because that is the current time, and the timer will |
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283 | be scheduled to fire at time=504 (C<501> + C<3>). |
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284 | |
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285 | With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current |
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286 | time), but C<< AnyEvent->now >> returns C<500>, as that is the time the |
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287 | last event processing phase started. With L<EV>, your timer gets scheduled |
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288 | to run at time=503 (C<500> + C<3>). |
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289 | |
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290 | In one sense, L<Event::Lib> is more exact, as it uses the current time |
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291 | regardless of any delays introduced by event processing. However, most |
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292 | callbacks do not expect large delays in processing, so this causes a |
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293 | higher drift (and a lot more system calls to get the current time). |
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294 | |
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295 | In another sense, L<EV> is more exact, as your timer will be scheduled at |
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296 | the same time, regardless of how long event processing actually took. |
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297 | |
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298 | In either case, if you care (and in most cases, you don't), then you |
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299 | can get whatever behaviour you want with any event loop, by taking the |
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300 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
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301 | account. |
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302 | |
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303 | =back |
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304 | |
232 | =head2 SIGNAL WATCHERS |
305 | =head2 SIGNAL WATCHERS |
233 | |
306 | |
234 | You can watch for signals using a signal watcher, C<signal> is the signal |
307 | 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 |
308 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
236 | be invoked whenever a signal occurs. |
309 | be invoked whenever a signal occurs. |
237 | |
310 | |
238 | Although the callback might get passed parameters, their value and |
311 | Although the callback might get passed parameters, their value and |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
312 | presence is undefined and you cannot rely on them. Portable AnyEvent |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
313 | callbacks cannot use arguments passed to signal watcher callbacks. |
241 | |
314 | |
242 | Multiple signal occurances can be clumped together into one callback |
315 | Multiple signal occurrences can be clumped together into one callback |
243 | invocation, and callback invocation will be synchronous. synchronous means |
316 | invocation, and callback invocation will be synchronous. Synchronous means |
244 | that it might take a while until the signal gets handled by the process, |
317 | 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. |
318 | but it is guaranteed not to interrupt any other callbacks. |
246 | |
319 | |
247 | The main advantage of using these watchers is that you can share a signal |
320 | The main advantage of using these watchers is that you can share a signal |
248 | between multiple watchers. |
321 | between multiple watchers. |
249 | |
322 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
323 | This watcher might use C<%SIG>, so programs overwriting those signals |
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277 | AnyEvent program, you I<have> to create at least one watcher before you |
350 | 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>). |
351 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
279 | |
352 | |
280 | Example: fork a process and wait for it |
353 | Example: fork a process and wait for it |
281 | |
354 | |
282 | my $done = AnyEvent->condvar; |
355 | my $done = AnyEvent->condvar; |
283 | |
356 | |
284 | AnyEvent::detect; # force event module to be initialised |
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285 | |
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286 | my $pid = fork or exit 5; |
357 | my $pid = fork or exit 5; |
287 | |
358 | |
288 | my $w = AnyEvent->child ( |
359 | my $w = AnyEvent->child ( |
289 | pid => $pid, |
360 | pid => $pid, |
290 | cb => sub { |
361 | cb => sub { |
291 | my ($pid, $status) = @_; |
362 | my ($pid, $status) = @_; |
292 | warn "pid $pid exited with status $status"; |
363 | warn "pid $pid exited with status $status"; |
293 | $done->broadcast; |
364 | $done->send; |
294 | }, |
365 | }, |
295 | ); |
366 | ); |
296 | |
367 | |
297 | # do something else, then wait for process exit |
368 | # do something else, then wait for process exit |
298 | $done->wait; |
369 | $done->recv; |
299 | |
370 | |
300 | =head2 CONDITION VARIABLES |
371 | =head2 CONDITION VARIABLES |
301 | |
372 | |
302 | If you are familiar with some event loops you will know that all of them |
373 | If you are familiar with some event loops you will know that all of them |
303 | require you to run some blocking "loop", "run" or similar function that |
374 | require you to run some blocking "loop", "run" or similar function that |
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312 | Condition variables can be created by calling the C<< AnyEvent->condvar |
383 | Condition variables can be created by calling the C<< AnyEvent->condvar |
313 | >> method, usually without arguments. The only argument pair allowed is |
384 | >> method, usually without arguments. The only argument pair allowed is |
314 | C<cb>, which specifies a callback to be called when the condition variable |
385 | C<cb>, which specifies a callback to be called when the condition variable |
315 | becomes true. |
386 | becomes true. |
316 | |
387 | |
317 | After creation, the conditon variable is "false" until it becomes "true" |
388 | After creation, the condition variable is "false" until it becomes "true" |
318 | by calling the C<broadcast> method. |
389 | by calling the C<send> method (or calling the condition variable as if it |
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390 | were a callback, read about the caveats in the description for the C<< |
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391 | ->send >> method). |
319 | |
392 | |
320 | Condition variables are similar to callbacks, except that you can |
393 | Condition variables are similar to callbacks, except that you can |
321 | optionally wait for them. They can also be called merge points - points |
394 | optionally wait for them. They can also be called merge points - points |
322 | in time where multiple outstandign events have been processed. And yet |
395 | in time where multiple outstanding events have been processed. And yet |
323 | another way to call them is transations - each condition variable can be |
396 | another way to call them is transactions - each condition variable can be |
324 | used to represent a transaction, which finishes at some point and delivers |
397 | used to represent a transaction, which finishes at some point and delivers |
325 | a result. |
398 | a result. |
326 | |
399 | |
327 | Condition variables are very useful to signal that something has finished, |
400 | Condition variables are very useful to signal that something has finished, |
328 | for example, if you write a module that does asynchronous http requests, |
401 | for example, if you write a module that does asynchronous http requests, |
329 | then a condition variable would be the ideal candidate to signal the |
402 | then a condition variable would be the ideal candidate to signal the |
330 | availability of results. The user can either act when the callback is |
403 | availability of results. The user can either act when the callback is |
331 | called or can synchronously C<< ->wait >> for the results. |
404 | called or can synchronously C<< ->recv >> for the results. |
332 | |
405 | |
333 | You can also use them to simulate traditional event loops - for example, |
406 | You can also use them to simulate traditional event loops - for example, |
334 | you can block your main program until an event occurs - for example, you |
407 | you can block your main program until an event occurs - for example, you |
335 | could C<< ->wait >> in your main program until the user clicks the Quit |
408 | could C<< ->recv >> in your main program until the user clicks the Quit |
336 | button of your app, which would C<< ->broadcast >> the "quit" event. |
409 | button of your app, which would C<< ->send >> the "quit" event. |
337 | |
410 | |
338 | Note that condition variables recurse into the event loop - if you have |
411 | Note that condition variables recurse into the event loop - if you have |
339 | two pieces of code that call C<< ->wait >> in a round-robbin fashion, you |
412 | two pieces of code that call C<< ->recv >> in a round-robin fashion, you |
340 | lose. Therefore, condition variables are good to export to your caller, but |
413 | lose. Therefore, condition variables are good to export to your caller, but |
341 | you should avoid making a blocking wait yourself, at least in callbacks, |
414 | you should avoid making a blocking wait yourself, at least in callbacks, |
342 | as this asks for trouble. |
415 | as this asks for trouble. |
343 | |
416 | |
344 | Condition variables are represented by hash refs in perl, and the keys |
417 | Condition variables are represented by hash refs in perl, and the keys |
… | |
… | |
346 | easy (it is often useful to build your own transaction class on top of |
419 | easy (it is often useful to build your own transaction class on top of |
347 | AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call |
420 | AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call |
348 | it's C<new> method in your own C<new> method. |
421 | it's C<new> method in your own C<new> method. |
349 | |
422 | |
350 | There are two "sides" to a condition variable - the "producer side" which |
423 | There are two "sides" to a condition variable - the "producer side" which |
351 | eventually calls C<< -> broadcast >>, and the "consumer side", which waits |
424 | eventually calls C<< -> send >>, and the "consumer side", which waits |
352 | for the broadcast to occur. |
425 | for the send to occur. |
353 | |
426 | |
354 | Example: |
427 | Example: wait for a timer. |
355 | |
428 | |
356 | # wait till the result is ready |
429 | # wait till the result is ready |
357 | my $result_ready = AnyEvent->condvar; |
430 | my $result_ready = AnyEvent->condvar; |
358 | |
431 | |
359 | # do something such as adding a timer |
432 | # do something such as adding a timer |
360 | # or socket watcher the calls $result_ready->broadcast |
433 | # or socket watcher the calls $result_ready->send |
361 | # when the "result" is ready. |
434 | # when the "result" is ready. |
362 | # in this case, we simply use a timer: |
435 | # in this case, we simply use a timer: |
363 | my $w = AnyEvent->timer ( |
436 | my $w = AnyEvent->timer ( |
364 | after => 1, |
437 | after => 1, |
365 | cb => sub { $result_ready->broadcast }, |
438 | cb => sub { $result_ready->send }, |
366 | ); |
439 | ); |
367 | |
440 | |
368 | # this "blocks" (while handling events) till the callback |
441 | # this "blocks" (while handling events) till the callback |
369 | # calls broadcast |
442 | # calls send |
370 | $result_ready->wait; |
443 | $result_ready->recv; |
|
|
444 | |
|
|
445 | Example: wait for a timer, but take advantage of the fact that |
|
|
446 | condition variables are also code references. |
|
|
447 | |
|
|
448 | my $done = AnyEvent->condvar; |
|
|
449 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
|
|
450 | $done->recv; |
371 | |
451 | |
372 | =head3 METHODS FOR PRODUCERS |
452 | =head3 METHODS FOR PRODUCERS |
373 | |
453 | |
374 | These methods should only be used by the producing side, i.e. the |
454 | These methods should only be used by the producing side, i.e. the |
375 | code/module that eventually broadcasts the signal. Note that it is also |
455 | code/module that eventually sends the signal. Note that it is also |
376 | the producer side which creates the condvar in most cases, but it isn't |
456 | the producer side which creates the condvar in most cases, but it isn't |
377 | uncommon for the consumer to create it as well. |
457 | uncommon for the consumer to create it as well. |
378 | |
458 | |
379 | =over 4 |
459 | =over 4 |
380 | |
460 | |
381 | =item $cv->broadcast (...) |
461 | =item $cv->send (...) |
382 | |
462 | |
383 | Flag the condition as ready - a running C<< ->wait >> and all further |
463 | Flag the condition as ready - a running C<< ->recv >> and all further |
384 | calls to C<wait> will (eventually) return after this method has been |
464 | calls to C<recv> will (eventually) return after this method has been |
385 | called. If nobody is waiting the broadcast will be remembered. |
465 | called. If nobody is waiting the send will be remembered. |
386 | |
466 | |
387 | If a callback has been set on the condition variable, it is called |
467 | If a callback has been set on the condition variable, it is called |
388 | immediately from within broadcast. |
468 | immediately from within send. |
389 | |
469 | |
390 | Any arguments passed to the C<broadcast> call will be returned by all |
470 | Any arguments passed to the C<send> call will be returned by all |
391 | future C<< ->wait >> calls. |
471 | future C<< ->recv >> calls. |
|
|
472 | |
|
|
473 | Condition variables are overloaded so one can call them directly |
|
|
474 | (as a code reference). Calling them directly is the same as calling |
|
|
475 | C<send>. Note, however, that many C-based event loops do not handle |
|
|
476 | overloading, so as tempting as it may be, passing a condition variable |
|
|
477 | instead of a callback does not work. Both the pure perl and EV loops |
|
|
478 | support overloading, however, as well as all functions that use perl to |
|
|
479 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
|
|
480 | example). |
392 | |
481 | |
393 | =item $cv->croak ($error) |
482 | =item $cv->croak ($error) |
394 | |
483 | |
395 | Similar to broadcast, but causes all call's wait C<< ->wait >> to invoke |
484 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
396 | C<Carp::croak> with the given error message/object/scalar. |
485 | C<Carp::croak> with the given error message/object/scalar. |
397 | |
486 | |
398 | This can be used to signal any errors to the condition variable |
487 | This can be used to signal any errors to the condition variable |
399 | user/consumer. |
488 | user/consumer. |
400 | |
489 | |
401 | =item $cv->begin ([group callback]) |
490 | =item $cv->begin ([group callback]) |
402 | |
491 | |
403 | =item $cv->end |
492 | =item $cv->end |
|
|
493 | |
|
|
494 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
404 | |
495 | |
405 | These two methods can be used to combine many transactions/events into |
496 | These two methods can be used to combine many transactions/events into |
406 | one. For example, a function that pings many hosts in parallel might want |
497 | one. For example, a function that pings many hosts in parallel might want |
407 | to use a condition variable for the whole process. |
498 | to use a condition variable for the whole process. |
408 | |
499 | |
409 | Every call to C<< ->begin >> will increment a counter, and every call to |
500 | Every call to C<< ->begin >> will increment a counter, and every call to |
410 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
501 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
411 | >>, the (last) callback passed to C<begin> will be executed. That callback |
502 | >>, the (last) callback passed to C<begin> will be executed. That callback |
412 | is I<supposed> to call C<< ->broadcast >>, but that is not required. If no |
503 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
413 | callback was set, C<broadcast> will be called without any arguments. |
504 | callback was set, C<send> will be called without any arguments. |
414 | |
505 | |
415 | Let's clarify this with the ping example: |
506 | Let's clarify this with the ping example: |
416 | |
507 | |
417 | my $cv = AnyEvent->condvar; |
508 | my $cv = AnyEvent->condvar; |
418 | |
509 | |
419 | my %result; |
510 | my %result; |
420 | $cv->begin (sub { $cv->broadcast (\%result) }); |
511 | $cv->begin (sub { $cv->send (\%result) }); |
421 | |
512 | |
422 | for my $host (@list_of_hosts) { |
513 | for my $host (@list_of_hosts) { |
423 | $cv->begin; |
514 | $cv->begin; |
424 | ping_host_then_call_callback $host, sub { |
515 | ping_host_then_call_callback $host, sub { |
425 | $result{$host} = ...; |
516 | $result{$host} = ...; |
… | |
… | |
428 | } |
519 | } |
429 | |
520 | |
430 | $cv->end; |
521 | $cv->end; |
431 | |
522 | |
432 | This code fragment supposedly pings a number of hosts and calls |
523 | This code fragment supposedly pings a number of hosts and calls |
433 | C<broadcast> after results for all then have have been gathered - in any |
524 | C<send> after results for all then have have been gathered - in any |
434 | order. To achieve this, the code issues a call to C<begin> when it starts |
525 | order. To achieve this, the code issues a call to C<begin> when it starts |
435 | each ping request and calls C<end> when it has received some result for |
526 | each ping request and calls C<end> when it has received some result for |
436 | it. Since C<begin> and C<end> only maintain a counter, the order in which |
527 | it. Since C<begin> and C<end> only maintain a counter, the order in which |
437 | results arrive is not relevant. |
528 | results arrive is not relevant. |
438 | |
529 | |
439 | There is an additional bracketing call to C<begin> and C<end> outside the |
530 | There is an additional bracketing call to C<begin> and C<end> outside the |
440 | loop, which serves two important purposes: first, it sets the callback |
531 | loop, which serves two important purposes: first, it sets the callback |
441 | to be called once the counter reaches C<0>, and second, it ensures that |
532 | to be called once the counter reaches C<0>, and second, it ensures that |
442 | broadcast is called even when C<no> hosts are being pinged (the loop |
533 | C<send> is called even when C<no> hosts are being pinged (the loop |
443 | doesn't execute once). |
534 | doesn't execute once). |
444 | |
535 | |
445 | This is the general pattern when you "fan out" into multiple subrequests: |
536 | 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> |
537 | 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 |
538 | 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>. |
539 | C<begin> and for each subrequest you finish, call C<end>. |
449 | |
540 | |
450 | =back |
541 | =back |
451 | |
542 | |
452 | =head3 METHODS FOR CONSUMERS |
543 | =head3 METHODS FOR CONSUMERS |
453 | |
544 | |
454 | These methods should only be used by the consuming side, i.e. the |
545 | These methods should only be used by the consuming side, i.e. the |
455 | code awaits the condition. |
546 | code awaits the condition. |
456 | |
547 | |
457 | =item $cv->wait |
548 | =over 4 |
458 | |
549 | |
|
|
550 | =item $cv->recv |
|
|
551 | |
459 | Wait (blocking if necessary) until the C<< ->broadcast >> or C<< ->croak |
552 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
460 | >> methods have been called on c<$cv>, while servicing other watchers |
553 | >> methods have been called on c<$cv>, while servicing other watchers |
461 | normally. |
554 | normally. |
462 | |
555 | |
463 | You can only wait once on a condition - additional calls are valid but |
556 | You can only wait once on a condition - additional calls are valid but |
464 | will return immediately. |
557 | will return immediately. |
465 | |
558 | |
466 | If an error condition has been set by calling C<< ->croak >>, then this |
559 | If an error condition has been set by calling C<< ->croak >>, then this |
467 | function will call C<croak>. |
560 | function will call C<croak>. |
468 | |
561 | |
469 | In list context, all parameters passed to C<broadcast> will be returned, |
562 | In list context, all parameters passed to C<send> will be returned, |
470 | in scalar context only the first one will be returned. |
563 | in scalar context only the first one will be returned. |
471 | |
564 | |
472 | Not all event models support a blocking wait - some die in that case |
565 | Not all event models support a blocking wait - some die in that case |
473 | (programs might want to do that to stay interactive), so I<if you are |
566 | (programs might want to do that to stay interactive), so I<if you are |
474 | using this from a module, never require a blocking wait>, but let the |
567 | using this from a module, never require a blocking wait>, but let the |
475 | caller decide whether the call will block or not (for example, by coupling |
568 | caller decide whether the call will block or not (for example, by coupling |
476 | condition variables with some kind of request results and supporting |
569 | condition variables with some kind of request results and supporting |
477 | callbacks so the caller knows that getting the result will not block, |
570 | callbacks so the caller knows that getting the result will not block, |
478 | while still suppporting blocking waits if the caller so desires). |
571 | while still supporting blocking waits if the caller so desires). |
479 | |
572 | |
480 | Another reason I<never> to C<< ->wait >> in a module is that you cannot |
573 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
481 | sensibly have two C<< ->wait >>'s in parallel, as that would require |
574 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
482 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
575 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
483 | can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and |
576 | can supply. |
484 | L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s |
|
|
485 | from different coroutines, however). |
|
|
486 | |
577 | |
|
|
578 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
|
|
579 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
|
|
580 | versions and also integrates coroutines into AnyEvent, making blocking |
|
|
581 | C<< ->recv >> calls perfectly safe as long as they are done from another |
|
|
582 | coroutine (one that doesn't run the event loop). |
|
|
583 | |
487 | You can ensure that C<< -wait >> never blocks by setting a callback and |
584 | You can ensure that C<< -recv >> never blocks by setting a callback and |
488 | only calling C<< ->wait >> from within that callback (or at a later |
585 | only calling C<< ->recv >> from within that callback (or at a later |
489 | time). This will work even when the event loop does not support blocking |
586 | time). This will work even when the event loop does not support blocking |
490 | waits otherwise. |
587 | waits otherwise. |
|
|
588 | |
|
|
589 | =item $bool = $cv->ready |
|
|
590 | |
|
|
591 | Returns true when the condition is "true", i.e. whether C<send> or |
|
|
592 | C<croak> have been called. |
|
|
593 | |
|
|
594 | =item $cb = $cv->cb ([new callback]) |
|
|
595 | |
|
|
596 | This is a mutator function that returns the callback set and optionally |
|
|
597 | replaces it before doing so. |
|
|
598 | |
|
|
599 | The callback will be called when the condition becomes "true", i.e. when |
|
|
600 | C<send> or C<croak> are called, with the only argument being the condition |
|
|
601 | variable itself. Calling C<recv> inside the callback or at any later time |
|
|
602 | is guaranteed not to block. |
491 | |
603 | |
492 | =back |
604 | =back |
493 | |
605 | |
494 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
606 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
495 | |
607 | |
… | |
… | |
503 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
615 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
504 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
616 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
505 | |
617 | |
506 | The known classes so far are: |
618 | The known classes so far are: |
507 | |
619 | |
508 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
|
|
509 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
|
|
510 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
620 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
511 | AnyEvent::Impl::Event based on Event, second best choice. |
621 | AnyEvent::Impl::Event based on Event, second best choice. |
512 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
622 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
513 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
623 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
514 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
624 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
… | |
… | |
531 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
641 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
532 | if necessary. You should only call this function right before you would |
642 | if necessary. You should only call this function right before you would |
533 | have created an AnyEvent watcher anyway, that is, as late as possible at |
643 | have created an AnyEvent watcher anyway, that is, as late as possible at |
534 | runtime. |
644 | runtime. |
535 | |
645 | |
|
|
646 | =item $guard = AnyEvent::post_detect { BLOCK } |
|
|
647 | |
|
|
648 | Arranges for the code block to be executed as soon as the event model is |
|
|
649 | autodetected (or immediately if this has already happened). |
|
|
650 | |
|
|
651 | If called in scalar or list context, then it creates and returns an object |
|
|
652 | that automatically removes the callback again when it is destroyed. See |
|
|
653 | L<Coro::BDB> for a case where this is useful. |
|
|
654 | |
|
|
655 | =item @AnyEvent::post_detect |
|
|
656 | |
|
|
657 | If there are any code references in this array (you can C<push> to it |
|
|
658 | before or after loading AnyEvent), then they will called directly after |
|
|
659 | the event loop has been chosen. |
|
|
660 | |
|
|
661 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
|
|
662 | if it contains a true value then the event loop has already been detected, |
|
|
663 | and the array will be ignored. |
|
|
664 | |
|
|
665 | Best use C<AnyEvent::post_detect { BLOCK }> instead. |
|
|
666 | |
536 | =back |
667 | =back |
537 | |
668 | |
538 | =head1 WHAT TO DO IN A MODULE |
669 | =head1 WHAT TO DO IN A MODULE |
539 | |
670 | |
540 | As a module author, you should C<use AnyEvent> and call AnyEvent methods |
671 | As a module author, you should C<use AnyEvent> and call AnyEvent methods |
… | |
… | |
543 | Be careful when you create watchers in the module body - AnyEvent will |
674 | Be careful when you create watchers in the module body - AnyEvent will |
544 | decide which event module to use as soon as the first method is called, so |
675 | decide which event module to use as soon as the first method is called, so |
545 | by calling AnyEvent in your module body you force the user of your module |
676 | by calling AnyEvent in your module body you force the user of your module |
546 | to load the event module first. |
677 | to load the event module first. |
547 | |
678 | |
548 | Never call C<< ->wait >> on a condition variable unless you I<know> that |
679 | Never call C<< ->recv >> on a condition variable unless you I<know> that |
549 | the C<< ->broadcast >> method has been called on it already. This is |
680 | the C<< ->send >> method has been called on it already. This is |
550 | because it will stall the whole program, and the whole point of using |
681 | because it will stall the whole program, and the whole point of using |
551 | events is to stay interactive. |
682 | events is to stay interactive. |
552 | |
683 | |
553 | It is fine, however, to call C<< ->wait >> when the user of your module |
684 | It is fine, however, to call C<< ->recv >> when the user of your module |
554 | requests it (i.e. if you create a http request object ad have a method |
685 | requests it (i.e. if you create a http request object ad have a method |
555 | called C<results> that returns the results, it should call C<< ->wait >> |
686 | called C<results> that returns the results, it should call C<< ->recv >> |
556 | freely, as the user of your module knows what she is doing. always). |
687 | freely, as the user of your module knows what she is doing. always). |
557 | |
688 | |
558 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
689 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
559 | |
690 | |
560 | There will always be a single main program - the only place that should |
691 | There will always be a single main program - the only place that should |
… | |
… | |
562 | |
693 | |
563 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
694 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
564 | do anything special (it does not need to be event-based) and let AnyEvent |
695 | do anything special (it does not need to be event-based) and let AnyEvent |
565 | decide which implementation to chose if some module relies on it. |
696 | decide which implementation to chose if some module relies on it. |
566 | |
697 | |
567 | If the main program relies on a specific event model. For example, in |
698 | If the main program relies on a specific event model - for example, in |
568 | Gtk2 programs you have to rely on the Glib module. You should load the |
699 | Gtk2 programs you have to rely on the Glib module - you should load the |
569 | event module before loading AnyEvent or any module that uses it: generally |
700 | event module before loading AnyEvent or any module that uses it: generally |
570 | speaking, you should load it as early as possible. The reason is that |
701 | speaking, you should load it as early as possible. The reason is that |
571 | modules might create watchers when they are loaded, and AnyEvent will |
702 | modules might create watchers when they are loaded, and AnyEvent will |
572 | decide on the event model to use as soon as it creates watchers, and it |
703 | decide on the event model to use as soon as it creates watchers, and it |
573 | might chose the wrong one unless you load the correct one yourself. |
704 | might chose the wrong one unless you load the correct one yourself. |
574 | |
705 | |
575 | You can chose to use a rather inefficient pure-perl implementation by |
706 | You can chose to use a pure-perl implementation by loading the |
576 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
707 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
577 | behaviour everywhere, but letting AnyEvent chose is generally better. |
708 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
709 | |
|
|
710 | =head2 MAINLOOP EMULATION |
|
|
711 | |
|
|
712 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
713 | only want to use AnyEvent), you do not want to run a specific event loop. |
|
|
714 | |
|
|
715 | In that case, you can use a condition variable like this: |
|
|
716 | |
|
|
717 | AnyEvent->condvar->recv; |
|
|
718 | |
|
|
719 | This has the effect of entering the event loop and looping forever. |
|
|
720 | |
|
|
721 | Note that usually your program has some exit condition, in which case |
|
|
722 | it is better to use the "traditional" approach of storing a condition |
|
|
723 | variable somewhere, waiting for it, and sending it when the program should |
|
|
724 | exit cleanly. |
|
|
725 | |
578 | |
726 | |
579 | =head1 OTHER MODULES |
727 | =head1 OTHER MODULES |
580 | |
728 | |
581 | The following is a non-exhaustive list of additional modules that use |
729 | The following is a non-exhaustive list of additional modules that use |
582 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
730 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
… | |
… | |
588 | =item L<AnyEvent::Util> |
736 | =item L<AnyEvent::Util> |
589 | |
737 | |
590 | Contains various utility functions that replace often-used but blocking |
738 | Contains various utility functions that replace often-used but blocking |
591 | functions such as C<inet_aton> by event-/callback-based versions. |
739 | functions such as C<inet_aton> by event-/callback-based versions. |
592 | |
740 | |
|
|
741 | =item L<AnyEvent::Socket> |
|
|
742 | |
|
|
743 | Provides various utility functions for (internet protocol) sockets, |
|
|
744 | addresses and name resolution. Also functions to create non-blocking tcp |
|
|
745 | connections or tcp servers, with IPv6 and SRV record support and more. |
|
|
746 | |
593 | =item L<AnyEvent::Handle> |
747 | =item L<AnyEvent::Handle> |
594 | |
748 | |
595 | Provide read and write buffers and manages watchers for reads and writes. |
749 | Provide read and write buffers, manages watchers for reads and writes, |
|
|
750 | supports raw and formatted I/O, I/O queued and fully transparent and |
|
|
751 | non-blocking SSL/TLS. |
596 | |
752 | |
597 | =item L<AnyEvent::Socket> |
753 | =item L<AnyEvent::DNS> |
598 | |
754 | |
599 | Provides a means to do non-blocking connects, accepts etc. |
755 | Provides rich asynchronous DNS resolver capabilities. |
|
|
756 | |
|
|
757 | =item L<AnyEvent::HTTP> |
|
|
758 | |
|
|
759 | A simple-to-use HTTP library that is capable of making a lot of concurrent |
|
|
760 | HTTP requests. |
600 | |
761 | |
601 | =item L<AnyEvent::HTTPD> |
762 | =item L<AnyEvent::HTTPD> |
602 | |
763 | |
603 | Provides a simple web application server framework. |
764 | Provides a simple web application server framework. |
604 | |
765 | |
605 | =item L<AnyEvent::DNS> |
|
|
606 | |
|
|
607 | Provides asynchronous DNS resolver capabilities, beyond what |
|
|
608 | L<AnyEvent::Util> offers. |
|
|
609 | |
|
|
610 | =item L<AnyEvent::FastPing> |
766 | =item L<AnyEvent::FastPing> |
611 | |
767 | |
612 | The fastest ping in the west. |
768 | The fastest ping in the west. |
|
|
769 | |
|
|
770 | =item L<AnyEvent::DBI> |
|
|
771 | |
|
|
772 | Executes L<DBI> requests asynchronously in a proxy process. |
|
|
773 | |
|
|
774 | =item L<AnyEvent::AIO> |
|
|
775 | |
|
|
776 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
777 | programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent |
|
|
778 | together. |
|
|
779 | |
|
|
780 | =item L<AnyEvent::BDB> |
|
|
781 | |
|
|
782 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses |
|
|
783 | L<BDB> and AnyEvent together. |
|
|
784 | |
|
|
785 | =item L<AnyEvent::GPSD> |
|
|
786 | |
|
|
787 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
|
|
788 | |
|
|
789 | =item L<AnyEvent::IGS> |
|
|
790 | |
|
|
791 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
792 | L<App::IGS>). |
613 | |
793 | |
614 | =item L<Net::IRC3> |
794 | =item L<Net::IRC3> |
615 | |
795 | |
616 | AnyEvent based IRC client module family. |
796 | AnyEvent based IRC client module family. |
617 | |
797 | |
… | |
… | |
628 | |
808 | |
629 | High level API for event-based execution flow control. |
809 | High level API for event-based execution flow control. |
630 | |
810 | |
631 | =item L<Coro> |
811 | =item L<Coro> |
632 | |
812 | |
633 | Has special support for AnyEvent. |
813 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
634 | |
814 | |
635 | =item L<IO::Lambda> |
815 | =item L<IO::Lambda> |
636 | |
816 | |
637 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
817 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
638 | |
|
|
639 | =item L<IO::AIO> |
|
|
640 | |
|
|
641 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
642 | programmer. Can be trivially made to use AnyEvent. |
|
|
643 | |
|
|
644 | =item L<BDB> |
|
|
645 | |
|
|
646 | Truly asynchronous Berkeley DB access. Can be trivially made to use |
|
|
647 | AnyEvent. |
|
|
648 | |
818 | |
649 | =back |
819 | =back |
650 | |
820 | |
651 | =cut |
821 | =cut |
652 | |
822 | |
… | |
… | |
655 | no warnings; |
825 | no warnings; |
656 | use strict; |
826 | use strict; |
657 | |
827 | |
658 | use Carp; |
828 | use Carp; |
659 | |
829 | |
660 | our $VERSION = '3.3'; |
830 | our $VERSION = 4.2; |
661 | our $MODEL; |
831 | our $MODEL; |
662 | |
832 | |
663 | our $AUTOLOAD; |
833 | our $AUTOLOAD; |
664 | our @ISA; |
834 | our @ISA; |
665 | |
835 | |
|
|
836 | our @REGISTRY; |
|
|
837 | |
|
|
838 | our $WIN32; |
|
|
839 | |
|
|
840 | BEGIN { |
|
|
841 | my $win32 = ! ! ($^O =~ /mswin32/i); |
|
|
842 | eval "sub WIN32(){ $win32 }"; |
|
|
843 | } |
|
|
844 | |
666 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
845 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
667 | |
846 | |
668 | our @REGISTRY; |
847 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
|
|
848 | |
|
|
849 | { |
|
|
850 | my $idx; |
|
|
851 | $PROTOCOL{$_} = ++$idx |
|
|
852 | for reverse split /\s*,\s*/, |
|
|
853 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
|
|
854 | } |
669 | |
855 | |
670 | my @models = ( |
856 | my @models = ( |
671 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
|
|
672 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
|
|
673 | [EV:: => AnyEvent::Impl::EV::], |
857 | [EV:: => AnyEvent::Impl::EV::], |
674 | [Event:: => AnyEvent::Impl::Event::], |
858 | [Event:: => AnyEvent::Impl::Event::], |
675 | [Tk:: => AnyEvent::Impl::Tk::], |
|
|
676 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
677 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
678 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
859 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
679 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
860 | # everything below here will not be autoprobed |
680 | [Glib:: => AnyEvent::Impl::Glib::], |
861 | # as the pureperl backend should work everywhere |
|
|
862 | # and is usually faster |
|
|
863 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
864 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
681 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
865 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
682 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
866 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
683 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
867 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
|
|
868 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
869 | [Prima:: => AnyEvent::Impl::POE::], |
684 | ); |
870 | ); |
685 | |
871 | |
686 | our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY); |
872 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
|
|
873 | |
|
|
874 | our @post_detect; |
|
|
875 | |
|
|
876 | sub post_detect(&) { |
|
|
877 | my ($cb) = @_; |
|
|
878 | |
|
|
879 | if ($MODEL) { |
|
|
880 | $cb->(); |
|
|
881 | |
|
|
882 | 1 |
|
|
883 | } else { |
|
|
884 | push @post_detect, $cb; |
|
|
885 | |
|
|
886 | defined wantarray |
|
|
887 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
|
|
888 | : () |
|
|
889 | } |
|
|
890 | } |
|
|
891 | |
|
|
892 | sub AnyEvent::Util::PostDetect::DESTROY { |
|
|
893 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
|
|
894 | } |
687 | |
895 | |
688 | sub detect() { |
896 | sub detect() { |
689 | unless ($MODEL) { |
897 | unless ($MODEL) { |
690 | no strict 'refs'; |
898 | no strict 'refs'; |
|
|
899 | local $SIG{__DIE__}; |
691 | |
900 | |
692 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
901 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
693 | my $model = "AnyEvent::Impl::$1"; |
902 | my $model = "AnyEvent::Impl::$1"; |
694 | if (eval "require $model") { |
903 | if (eval "require $model") { |
695 | $MODEL = $model; |
904 | $MODEL = $model; |
… | |
… | |
725 | last; |
934 | last; |
726 | } |
935 | } |
727 | } |
936 | } |
728 | |
937 | |
729 | $MODEL |
938 | $MODEL |
730 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV (or Coro+EV), Event (or Coro+Event) or Glib."; |
939 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
731 | } |
940 | } |
732 | } |
941 | } |
733 | |
942 | |
734 | unshift @ISA, $MODEL; |
943 | unshift @ISA, $MODEL; |
735 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
944 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
945 | |
|
|
946 | (shift @post_detect)->() while @post_detect; |
736 | } |
947 | } |
737 | |
948 | |
738 | $MODEL |
949 | $MODEL |
739 | } |
950 | } |
740 | |
951 | |
… | |
… | |
750 | $class->$func (@_); |
961 | $class->$func (@_); |
751 | } |
962 | } |
752 | |
963 | |
753 | package AnyEvent::Base; |
964 | package AnyEvent::Base; |
754 | |
965 | |
|
|
966 | # default implementation for now and time |
|
|
967 | |
|
|
968 | use Time::HiRes (); |
|
|
969 | |
|
|
970 | sub time { Time::HiRes::time } |
|
|
971 | sub now { Time::HiRes::time } |
|
|
972 | |
755 | # default implementation for ->condvar, ->wait, ->broadcast |
973 | # default implementation for ->condvar |
756 | |
974 | |
757 | sub condvar { |
975 | sub condvar { |
758 | bless \my $flag, "AnyEvent::Base::CondVar" |
976 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
759 | } |
|
|
760 | |
|
|
761 | sub AnyEvent::Base::CondVar::broadcast { |
|
|
762 | ${$_[0]}++; |
|
|
763 | } |
|
|
764 | |
|
|
765 | sub AnyEvent::Base::CondVar::wait { |
|
|
766 | AnyEvent->one_event while !${$_[0]}; |
|
|
767 | } |
977 | } |
768 | |
978 | |
769 | # default implementation for ->signal |
979 | # default implementation for ->signal |
770 | |
980 | |
771 | our %SIG_CB; |
981 | our %SIG_CB; |
… | |
… | |
787 | sub AnyEvent::Base::Signal::DESTROY { |
997 | sub AnyEvent::Base::Signal::DESTROY { |
788 | my ($signal, $cb) = @{$_[0]}; |
998 | my ($signal, $cb) = @{$_[0]}; |
789 | |
999 | |
790 | delete $SIG_CB{$signal}{$cb}; |
1000 | delete $SIG_CB{$signal}{$cb}; |
791 | |
1001 | |
792 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1002 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
793 | } |
1003 | } |
794 | |
1004 | |
795 | # default implementation for ->child |
1005 | # default implementation for ->child |
796 | |
1006 | |
797 | our %PID_CB; |
1007 | our %PID_CB; |
… | |
… | |
824 | or Carp::croak "required option 'pid' is missing"; |
1034 | or Carp::croak "required option 'pid' is missing"; |
825 | |
1035 | |
826 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1036 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
827 | |
1037 | |
828 | unless ($WNOHANG) { |
1038 | unless ($WNOHANG) { |
829 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
1039 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
830 | } |
1040 | } |
831 | |
1041 | |
832 | unless ($CHLD_W) { |
1042 | unless ($CHLD_W) { |
833 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1043 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
834 | # child could be a zombie already, so make at least one round |
1044 | # child could be a zombie already, so make at least one round |
… | |
… | |
844 | delete $PID_CB{$pid}{$cb}; |
1054 | delete $PID_CB{$pid}{$cb}; |
845 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1055 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
846 | |
1056 | |
847 | undef $CHLD_W unless keys %PID_CB; |
1057 | undef $CHLD_W unless keys %PID_CB; |
848 | } |
1058 | } |
|
|
1059 | |
|
|
1060 | package AnyEvent::CondVar; |
|
|
1061 | |
|
|
1062 | our @ISA = AnyEvent::CondVar::Base::; |
|
|
1063 | |
|
|
1064 | package AnyEvent::CondVar::Base; |
|
|
1065 | |
|
|
1066 | use overload |
|
|
1067 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
|
|
1068 | fallback => 1; |
|
|
1069 | |
|
|
1070 | sub _send { |
|
|
1071 | # nop |
|
|
1072 | } |
|
|
1073 | |
|
|
1074 | sub send { |
|
|
1075 | my $cv = shift; |
|
|
1076 | $cv->{_ae_sent} = [@_]; |
|
|
1077 | (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; |
|
|
1078 | $cv->_send; |
|
|
1079 | } |
|
|
1080 | |
|
|
1081 | sub croak { |
|
|
1082 | $_[0]{_ae_croak} = $_[1]; |
|
|
1083 | $_[0]->send; |
|
|
1084 | } |
|
|
1085 | |
|
|
1086 | sub ready { |
|
|
1087 | $_[0]{_ae_sent} |
|
|
1088 | } |
|
|
1089 | |
|
|
1090 | sub _wait { |
|
|
1091 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
|
|
1092 | } |
|
|
1093 | |
|
|
1094 | sub recv { |
|
|
1095 | $_[0]->_wait; |
|
|
1096 | |
|
|
1097 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
|
|
1098 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
|
|
1099 | } |
|
|
1100 | |
|
|
1101 | sub cb { |
|
|
1102 | $_[0]{_ae_cb} = $_[1] if @_ > 1; |
|
|
1103 | $_[0]{_ae_cb} |
|
|
1104 | } |
|
|
1105 | |
|
|
1106 | sub begin { |
|
|
1107 | ++$_[0]{_ae_counter}; |
|
|
1108 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
|
|
1109 | } |
|
|
1110 | |
|
|
1111 | sub end { |
|
|
1112 | return if --$_[0]{_ae_counter}; |
|
|
1113 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
|
|
1114 | } |
|
|
1115 | |
|
|
1116 | # undocumented/compatibility with pre-3.4 |
|
|
1117 | *broadcast = \&send; |
|
|
1118 | *wait = \&_wait; |
849 | |
1119 | |
850 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1120 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
851 | |
1121 | |
852 | This is an advanced topic that you do not normally need to use AnyEvent in |
1122 | This is an advanced topic that you do not normally need to use AnyEvent in |
853 | a module. This section is only of use to event loop authors who want to |
1123 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
910 | model it chooses. |
1180 | model it chooses. |
911 | |
1181 | |
912 | =item C<PERL_ANYEVENT_MODEL> |
1182 | =item C<PERL_ANYEVENT_MODEL> |
913 | |
1183 | |
914 | This can be used to specify the event model to be used by AnyEvent, before |
1184 | This can be used to specify the event model to be used by AnyEvent, before |
915 | autodetection and -probing kicks in. It must be a string consisting |
1185 | auto detection and -probing kicks in. It must be a string consisting |
916 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
1186 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
917 | and the resulting module name is loaded and if the load was successful, |
1187 | and the resulting module name is loaded and if the load was successful, |
918 | used as event model. If it fails to load AnyEvent will proceed with |
1188 | used as event model. If it fails to load AnyEvent will proceed with |
919 | autodetection and -probing. |
1189 | auto detection and -probing. |
920 | |
1190 | |
921 | This functionality might change in future versions. |
1191 | This functionality might change in future versions. |
922 | |
1192 | |
923 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
1193 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
924 | could start your program like this: |
1194 | could start your program like this: |
925 | |
1195 | |
926 | PERL_ANYEVENT_MODEL=Perl perl ... |
1196 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1197 | |
|
|
1198 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1199 | |
|
|
1200 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1201 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1202 | of auto probing). |
|
|
1203 | |
|
|
1204 | Must be set to a comma-separated list of protocols or address families, |
|
|
1205 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1206 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1207 | list. |
|
|
1208 | |
|
|
1209 | This variable can effectively be used for denial-of-service attacks |
|
|
1210 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1211 | small, as the program has to handle connection errors already- |
|
|
1212 | |
|
|
1213 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1214 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1215 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1216 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1217 | IPv6, but prefer IPv6 over IPv4. |
|
|
1218 | |
|
|
1219 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1220 | |
|
|
1221 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1222 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1223 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1224 | default. |
|
|
1225 | |
|
|
1226 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1227 | EDNS0 in its DNS requests. |
|
|
1228 | |
|
|
1229 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1230 | |
|
|
1231 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1232 | will create in parallel. |
927 | |
1233 | |
928 | =back |
1234 | =back |
929 | |
1235 | |
930 | =head1 EXAMPLE PROGRAM |
1236 | =head1 EXAMPLE PROGRAM |
931 | |
1237 | |
… | |
… | |
942 | poll => 'r', |
1248 | poll => 'r', |
943 | cb => sub { |
1249 | cb => sub { |
944 | warn "io event <$_[0]>\n"; # will always output <r> |
1250 | warn "io event <$_[0]>\n"; # will always output <r> |
945 | chomp (my $input = <STDIN>); # read a line |
1251 | chomp (my $input = <STDIN>); # read a line |
946 | warn "read: $input\n"; # output what has been read |
1252 | warn "read: $input\n"; # output what has been read |
947 | $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i |
1253 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
948 | }, |
1254 | }, |
949 | ); |
1255 | ); |
950 | |
1256 | |
951 | my $time_watcher; # can only be used once |
1257 | my $time_watcher; # can only be used once |
952 | |
1258 | |
… | |
… | |
957 | }); |
1263 | }); |
958 | } |
1264 | } |
959 | |
1265 | |
960 | new_timer; # create first timer |
1266 | new_timer; # create first timer |
961 | |
1267 | |
962 | $cv->wait; # wait until user enters /^q/i |
1268 | $cv->recv; # wait until user enters /^q/i |
963 | |
1269 | |
964 | =head1 REAL-WORLD EXAMPLE |
1270 | =head1 REAL-WORLD EXAMPLE |
965 | |
1271 | |
966 | Consider the L<Net::FCP> module. It features (among others) the following |
1272 | Consider the L<Net::FCP> module. It features (among others) the following |
967 | API calls, which are to freenet what HTTP GET requests are to http: |
1273 | API calls, which are to freenet what HTTP GET requests are to http: |
… | |
… | |
1017 | syswrite $txn->{fh}, $txn->{request} |
1323 | syswrite $txn->{fh}, $txn->{request} |
1018 | or die "connection or write error"; |
1324 | or die "connection or write error"; |
1019 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1325 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1020 | |
1326 | |
1021 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1327 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1022 | result and signals any possible waiters that the request ahs finished: |
1328 | result and signals any possible waiters that the request has finished: |
1023 | |
1329 | |
1024 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1330 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1025 | |
1331 | |
1026 | if (end-of-file or data complete) { |
1332 | if (end-of-file or data complete) { |
1027 | $txn->{result} = $txn->{buf}; |
1333 | $txn->{result} = $txn->{buf}; |
1028 | $txn->{finished}->broadcast; |
1334 | $txn->{finished}->send; |
1029 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1335 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1030 | } |
1336 | } |
1031 | |
1337 | |
1032 | The C<result> method, finally, just waits for the finished signal (if the |
1338 | The C<result> method, finally, just waits for the finished signal (if the |
1033 | request was already finished, it doesn't wait, of course, and returns the |
1339 | request was already finished, it doesn't wait, of course, and returns the |
1034 | data: |
1340 | data: |
1035 | |
1341 | |
1036 | $txn->{finished}->wait; |
1342 | $txn->{finished}->recv; |
1037 | return $txn->{result}; |
1343 | return $txn->{result}; |
1038 | |
1344 | |
1039 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1345 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1040 | that occured during request processing. The C<result> method detects |
1346 | that occurred during request processing. The C<result> method detects |
1041 | whether an exception as thrown (it is stored inside the $txn object) |
1347 | whether an exception as thrown (it is stored inside the $txn object) |
1042 | and just throws the exception, which means connection errors and other |
1348 | and just throws the exception, which means connection errors and other |
1043 | problems get reported tot he code that tries to use the result, not in a |
1349 | problems get reported tot he code that tries to use the result, not in a |
1044 | random callback. |
1350 | random callback. |
1045 | |
1351 | |
… | |
… | |
1076 | |
1382 | |
1077 | my $quit = AnyEvent->condvar; |
1383 | my $quit = AnyEvent->condvar; |
1078 | |
1384 | |
1079 | $fcp->txn_client_get ($url)->cb (sub { |
1385 | $fcp->txn_client_get ($url)->cb (sub { |
1080 | ... |
1386 | ... |
1081 | $quit->broadcast; |
1387 | $quit->send; |
1082 | }); |
1388 | }); |
1083 | |
1389 | |
1084 | $quit->wait; |
1390 | $quit->recv; |
1085 | |
1391 | |
1086 | |
1392 | |
1087 | =head1 BENCHMARKS |
1393 | =head1 BENCHMARKS |
1088 | |
1394 | |
1089 | To give you an idea of the performance and overheads that AnyEvent adds |
1395 | To give you an idea of the performance and overheads that AnyEvent adds |
… | |
… | |
1091 | of various event loops I prepared some benchmarks. |
1397 | of various event loops I prepared some benchmarks. |
1092 | |
1398 | |
1093 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1399 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1094 | |
1400 | |
1095 | Here is a benchmark of various supported event models used natively and |
1401 | Here is a benchmark of various supported event models used natively and |
1096 | through anyevent. The benchmark creates a lot of timers (with a zero |
1402 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1097 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1403 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1098 | which it is), lets them fire exactly once and destroys them again. |
1404 | which it is), lets them fire exactly once and destroys them again. |
1099 | |
1405 | |
1100 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1406 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1101 | distribution. |
1407 | distribution. |
… | |
… | |
1118 | all watchers, to avoid adding memory overhead. That means closure creation |
1424 | all watchers, to avoid adding memory overhead. That means closure creation |
1119 | and memory usage is not included in the figures. |
1425 | and memory usage is not included in the figures. |
1120 | |
1426 | |
1121 | I<invoke> is the time, in microseconds, used to invoke a simple |
1427 | I<invoke> is the time, in microseconds, used to invoke a simple |
1122 | callback. The callback simply counts down a Perl variable and after it was |
1428 | callback. The callback simply counts down a Perl variable and after it was |
1123 | invoked "watcher" times, it would C<< ->broadcast >> a condvar once to |
1429 | invoked "watcher" times, it would C<< ->send >> a condvar once to |
1124 | signal the end of this phase. |
1430 | signal the end of this phase. |
1125 | |
1431 | |
1126 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1432 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1127 | watcher. |
1433 | watcher. |
1128 | |
1434 | |
… | |
… | |
1224 | |
1530 | |
1225 | =back |
1531 | =back |
1226 | |
1532 | |
1227 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1533 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1228 | |
1534 | |
1229 | This benchmark atcually benchmarks the event loop itself. It works by |
1535 | This benchmark actually benchmarks the event loop itself. It works by |
1230 | creating a number of "servers": each server consists of a socketpair, a |
1536 | creating a number of "servers": each server consists of a socket pair, a |
1231 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1537 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1232 | watcher waiting for input on one side of the socket. Each time the socket |
1538 | watcher waiting for input on one side of the socket. Each time the socket |
1233 | watcher reads a byte it will write that byte to a random other "server". |
1539 | watcher reads a byte it will write that byte to a random other "server". |
1234 | |
1540 | |
1235 | The effect is that there will be a lot of I/O watchers, only part of which |
1541 | The effect is that there will be a lot of I/O watchers, only part of which |
1236 | are active at any one point (so there is a constant number of active |
1542 | are active at any one point (so there is a constant number of active |
1237 | fds for each loop iterstaion, but which fds these are is random). The |
1543 | fds for each loop iteration, but which fds these are is random). The |
1238 | timeout is reset each time something is read because that reflects how |
1544 | timeout is reset each time something is read because that reflects how |
1239 | most timeouts work (and puts extra pressure on the event loops). |
1545 | most timeouts work (and puts extra pressure on the event loops). |
1240 | |
1546 | |
1241 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 |
1547 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1242 | (1%) are active. This mirrors the activity of large servers with many |
1548 | (1%) are active. This mirrors the activity of large servers with many |
1243 | connections, most of which are idle at any one point in time. |
1549 | connections, most of which are idle at any one point in time. |
1244 | |
1550 | |
1245 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1551 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1246 | distribution. |
1552 | distribution. |
… | |
… | |
1248 | =head3 Explanation of the columns |
1554 | =head3 Explanation of the columns |
1249 | |
1555 | |
1250 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1556 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1251 | each server has a read and write socket end). |
1557 | each server has a read and write socket end). |
1252 | |
1558 | |
1253 | I<create> is the time it takes to create a socketpair (which is |
1559 | I<create> is the time it takes to create a socket pair (which is |
1254 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1560 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1255 | |
1561 | |
1256 | I<request>, the most important value, is the time it takes to handle a |
1562 | I<request>, the most important value, is the time it takes to handle a |
1257 | single "request", that is, reading the token from the pipe and forwarding |
1563 | single "request", that is, reading the token from the pipe and forwarding |
1258 | it to another server. This includes deleting the old timeout and creating |
1564 | it to another server. This includes deleting the old timeout and creating |
… | |
… | |
1331 | speed most when you have lots of watchers, not when you only have a few of |
1637 | speed most when you have lots of watchers, not when you only have a few of |
1332 | them). |
1638 | them). |
1333 | |
1639 | |
1334 | EV is again fastest. |
1640 | EV is again fastest. |
1335 | |
1641 | |
1336 | Perl again comes second. It is noticably faster than the C-based event |
1642 | Perl again comes second. It is noticeably faster than the C-based event |
1337 | loops Event and Glib, although the difference is too small to really |
1643 | loops Event and Glib, although the difference is too small to really |
1338 | matter. |
1644 | matter. |
1339 | |
1645 | |
1340 | POE also performs much better in this case, but is is still far behind the |
1646 | POE also performs much better in this case, but is is still far behind the |
1341 | others. |
1647 | others. |
… | |
… | |
1370 | specified in the variable. |
1676 | specified in the variable. |
1371 | |
1677 | |
1372 | You can make AnyEvent completely ignore this variable by deleting it |
1678 | You can make AnyEvent completely ignore this variable by deleting it |
1373 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1679 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1374 | |
1680 | |
1375 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1681 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1376 | |
1682 | |
1377 | use AnyEvent; |
1683 | use AnyEvent; |
|
|
1684 | |
|
|
1685 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
|
|
1686 | be used to probe what backend is used and gain other information (which is |
|
|
1687 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
|
|
1688 | |
|
|
1689 | |
|
|
1690 | =head1 BUGS |
|
|
1691 | |
|
|
1692 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
|
|
1693 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
|
|
1694 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
|
|
1695 | mamleaks, such as leaking on C<map> and C<grep> but it is usually not as |
|
|
1696 | pronounced). |
1378 | |
1697 | |
1379 | |
1698 | |
1380 | =head1 SEE ALSO |
1699 | =head1 SEE ALSO |
1381 | |
1700 | |
1382 | Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>, |
1701 | Utility functions: L<AnyEvent::Util>. |
1383 | L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>, |
1702 | |
|
|
1703 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1384 | L<Event::Lib>, L<Qt>, L<POE>. |
1704 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1385 | |
1705 | |
1386 | Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>, |
1706 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1387 | L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>, |
1707 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1388 | L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>, |
1708 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1389 | L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>. |
1709 | L<AnyEvent::Impl::POE>. |
1390 | |
1710 | |
|
|
1711 | Non-blocking file handles, sockets, TCP clients and |
|
|
1712 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
|
|
1713 | |
|
|
1714 | Asynchronous DNS: L<AnyEvent::DNS>. |
|
|
1715 | |
|
|
1716 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
|
|
1717 | |
1391 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
1718 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
1392 | |
1719 | |
1393 | |
1720 | |
1394 | =head1 AUTHOR |
1721 | =head1 AUTHOR |
1395 | |
1722 | |
1396 | Marc Lehmann <schmorp@schmorp.de> |
1723 | Marc Lehmann <schmorp@schmorp.de> |
1397 | http://home.schmorp.de/ |
1724 | http://home.schmorp.de/ |
1398 | |
1725 | |
1399 | =cut |
1726 | =cut |
1400 | |
1727 | |
1401 | 1 |
1728 | 1 |
1402 | |
1729 | |