1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - provide framework for multiple event loops |
4 | |
4 | |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported |
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6 | event loops. |
6 | |
7 | |
7 | =head1 SYNOPSIS |
8 | =head1 SYNOPSIS |
8 | |
9 | |
9 | use AnyEvent; |
10 | use AnyEvent; |
10 | |
11 | |
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12 | # file descriptor readable |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { |
13 | my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); |
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14 | |
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15 | # one-shot or repeating timers |
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16 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
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17 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
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18 | |
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19 | print AnyEvent->now; # prints current event loop time |
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20 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
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21 | |
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22 | # POSIX signal |
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23 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
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24 | |
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25 | # child process exit |
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26 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
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27 | my ($pid, $status) = @_; |
12 | ... |
28 | ... |
13 | }); |
29 | }); |
14 | |
30 | |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
31 | # called when event loop idle (if applicable) |
16 | ... |
32 | my $w = AnyEvent->idle (cb => sub { ... }); |
17 | }); |
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18 | |
33 | |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
34 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
20 | $w->send; # wake up current and all future recv's |
35 | $w->send; # wake up current and all future recv's |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
36 | $w->recv; # enters "main loop" till $condvar gets ->send |
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37 | # use a condvar in callback mode: |
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38 | $w->cb (sub { $_[0]->recv }); |
22 | |
39 | |
23 | =head1 INTRODUCTION/TUTORIAL |
40 | =head1 INTRODUCTION/TUTORIAL |
24 | |
41 | |
25 | This manpage is mainly a reference manual. If you are interested |
42 | This manpage is mainly a reference manual. If you are interested |
26 | in a tutorial or some gentle introduction, have a look at the |
43 | in a tutorial or some gentle introduction, have a look at the |
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33 | |
50 | |
34 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
51 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
35 | policy> and AnyEvent is I<small and efficient>. |
52 | policy> and AnyEvent is I<small and efficient>. |
36 | |
53 | |
37 | First and foremost, I<AnyEvent is not an event model> itself, it only |
54 | First and foremost, I<AnyEvent is not an event model> itself, it only |
38 | interfaces to whatever event model the main program happens to use in a |
55 | interfaces to whatever event model the main program happens to use, in a |
39 | pragmatic way. For event models and certain classes of immortals alike, |
56 | pragmatic way. For event models and certain classes of immortals alike, |
40 | the statement "there can only be one" is a bitter reality: In general, |
57 | the statement "there can only be one" is a bitter reality: In general, |
41 | only one event loop can be active at the same time in a process. AnyEvent |
58 | only one event loop can be active at the same time in a process. AnyEvent |
42 | helps hiding the differences between those event loops. |
59 | cannot change this, but it can hide the differences between those event |
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60 | loops. |
43 | |
61 | |
44 | The goal of AnyEvent is to offer module authors the ability to do event |
62 | The goal of AnyEvent is to offer module authors the ability to do event |
45 | programming (waiting for I/O or timer events) without subscribing to a |
63 | programming (waiting for I/O or timer events) without subscribing to a |
46 | religion, a way of living, and most importantly: without forcing your |
64 | religion, a way of living, and most importantly: without forcing your |
47 | module users into the same thing by forcing them to use the same event |
65 | module users into the same thing by forcing them to use the same event |
48 | model you use. |
66 | model you use. |
49 | |
67 | |
50 | For modules like POE or IO::Async (which is a total misnomer as it is |
68 | For modules like POE or IO::Async (which is a total misnomer as it is |
51 | actually doing all I/O I<synchronously>...), using them in your module is |
69 | actually doing all I/O I<synchronously>...), using them in your module is |
52 | like joining a cult: After you joined, you are dependent on them and you |
70 | like joining a cult: After you joined, you are dependent on them and you |
53 | cannot use anything else, as it is simply incompatible to everything that |
71 | cannot use anything else, as they are simply incompatible to everything |
54 | isn't itself. What's worse, all the potential users of your module are |
72 | that isn't them. What's worse, all the potential users of your |
55 | I<also> forced to use the same event loop you use. |
73 | module are I<also> forced to use the same event loop you use. |
56 | |
74 | |
57 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
75 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
58 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
76 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
59 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
77 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if |
60 | your module uses one of those, every user of your module has to use it, |
78 | your module uses one of those, every user of your module has to use it, |
61 | too. But if your module uses AnyEvent, it works transparently with all |
79 | too. But if your module uses AnyEvent, it works transparently with all |
62 | event models it supports (including stuff like POE and IO::Async, as long |
80 | event models it supports (including stuff like IO::Async, as long as those |
63 | as those use one of the supported event loops. It is trivial to add new |
81 | use one of the supported event loops. It is trivial to add new event loops |
64 | event loops to AnyEvent, too, so it is future-proof). |
82 | to AnyEvent, too, so it is future-proof). |
65 | |
83 | |
66 | In addition to being free of having to use I<the one and only true event |
84 | In addition to being free of having to use I<the one and only true event |
67 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
85 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
68 | modules, you get an enormous amount of code and strict rules you have to |
86 | modules, you get an enormous amount of code and strict rules you have to |
69 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
87 | follow. AnyEvent, on the other hand, is lean and up to the point, by only |
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127 | These watchers are normal Perl objects with normal Perl lifetime. After |
145 | These watchers are normal Perl objects with normal Perl lifetime. After |
128 | creating a watcher it will immediately "watch" for events and invoke the |
146 | creating a watcher it will immediately "watch" for events and invoke the |
129 | callback when the event occurs (of course, only when the event model |
147 | callback when the event occurs (of course, only when the event model |
130 | is in control). |
148 | is in control). |
131 | |
149 | |
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150 | Note that B<callbacks must not permanently change global variables> |
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151 | potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< |
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152 | callbacks must not C<die> >>. The former is good programming practise in |
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153 | Perl and the latter stems from the fact that exception handling differs |
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154 | widely between event loops. |
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155 | |
132 | To disable the watcher you have to destroy it (e.g. by setting the |
156 | To disable the watcher you have to destroy it (e.g. by setting the |
133 | variable you store it in to C<undef> or otherwise deleting all references |
157 | variable you store it in to C<undef> or otherwise deleting all references |
134 | to it). |
158 | to it). |
135 | |
159 | |
136 | All watchers are created by calling a method on the C<AnyEvent> class. |
160 | All watchers are created by calling a method on the C<AnyEvent> class. |
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152 | =head2 I/O WATCHERS |
176 | =head2 I/O WATCHERS |
153 | |
177 | |
154 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
178 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
155 | with the following mandatory key-value pairs as arguments: |
179 | with the following mandatory key-value pairs as arguments: |
156 | |
180 | |
157 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
181 | C<fh> is the Perl I<file handle> (I<not> file descriptor, see below) to |
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182 | watch for events (AnyEvent might or might not keep a reference to this |
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183 | file handle). Note that only file handles pointing to things for which |
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184 | non-blocking operation makes sense are allowed. This includes sockets, |
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185 | most character devices, pipes, fifos and so on, but not for example files |
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186 | or block devices. |
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187 | |
158 | for events. C<poll> must be a string that is either C<r> or C<w>, |
188 | C<poll> must be a string that is either C<r> or C<w>, which creates a |
159 | which creates a watcher waiting for "r"eadable or "w"ritable events, |
189 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
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190 | |
160 | respectively. C<cb> is the callback to invoke each time the file handle |
191 | C<cb> is the callback to invoke each time the file handle becomes ready. |
161 | becomes ready. |
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162 | |
192 | |
163 | Although the callback might get passed parameters, their value and |
193 | Although the callback might get passed parameters, their value and |
164 | presence is undefined and you cannot rely on them. Portable AnyEvent |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
165 | callbacks cannot use arguments passed to I/O watcher callbacks. |
195 | callbacks cannot use arguments passed to I/O watcher callbacks. |
166 | |
196 | |
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170 | |
200 | |
171 | Some event loops issue spurious readyness notifications, so you should |
201 | Some event loops issue spurious readyness notifications, so you should |
172 | always use non-blocking calls when reading/writing from/to your file |
202 | always use non-blocking calls when reading/writing from/to your file |
173 | handles. |
203 | handles. |
174 | |
204 | |
175 | Example: |
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176 | |
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177 | # wait for readability of STDIN, then read a line and disable the watcher |
205 | Example: wait for readability of STDIN, then read a line and disable the |
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206 | watcher. |
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207 | |
178 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
208 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
179 | chomp (my $input = <STDIN>); |
209 | chomp (my $input = <STDIN>); |
180 | warn "read: $input\n"; |
210 | warn "read: $input\n"; |
181 | undef $w; |
211 | undef $w; |
182 | }); |
212 | }); |
183 | |
213 | |
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214 | =head3 GETTING A FILE HANDLE FROM A FILE DESCRIPTOR |
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215 | |
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216 | It is not uncommon to only have a file descriptor, while AnyEvent requires |
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217 | a Perl file handle. |
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218 | |
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219 | There are basically two methods to convert a file descriptor into a file handle. If you own |
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220 | the file descriptor, you can open it with C<&=>, as in: |
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221 | |
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222 | open my $fh, "<&=$fileno" or die "xxx: ยง!"; |
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223 | |
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224 | This will "own" the file descriptor, meaning that when C<$fh> is |
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225 | destroyed, it will automatically close the C<$fileno>. Also, note that |
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226 | the open mode (read, write, read/write) must correspond with how the |
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227 | underlying file descriptor was opened. |
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228 | |
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229 | In many cases, taking over the file descriptor is now what you want, in |
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230 | which case the only alternative is to dup the file descriptor: |
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231 | |
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232 | open my $fh, "<&$fileno" or die "xxx: $!"; |
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233 | |
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234 | This has the advantage of not closing the file descriptor and the |
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235 | disadvantage of making a slow copy. |
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236 | |
184 | =head2 TIME WATCHERS |
237 | =head2 TIME WATCHERS |
185 | |
238 | |
186 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
239 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
187 | method with the following mandatory arguments: |
240 | method with the following mandatory arguments: |
188 | |
241 | |
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192 | |
245 | |
193 | Although the callback might get passed parameters, their value and |
246 | Although the callback might get passed parameters, their value and |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
247 | presence is undefined and you cannot rely on them. Portable AnyEvent |
195 | callbacks cannot use arguments passed to time watcher callbacks. |
248 | callbacks cannot use arguments passed to time watcher callbacks. |
196 | |
249 | |
197 | The timer callback will be invoked at most once: if you want a repeating |
250 | The callback will normally be invoked once only. If you specify another |
198 | timer you have to create a new watcher (this is a limitation by both Tk |
251 | parameter, C<interval>, as a strictly positive number (> 0), then the |
199 | and Glib). |
252 | callback will be invoked regularly at that interval (in fractional |
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253 | seconds) after the first invocation. If C<interval> is specified with a |
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254 | false value, then it is treated as if it were missing. |
200 | |
255 | |
201 | Example: |
256 | The callback will be rescheduled before invoking the callback, but no |
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257 | attempt is done to avoid timer drift in most backends, so the interval is |
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258 | only approximate. |
202 | |
259 | |
203 | # fire an event after 7.7 seconds |
260 | Example: fire an event after 7.7 seconds. |
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261 | |
204 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
262 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
205 | warn "timeout\n"; |
263 | warn "timeout\n"; |
206 | }); |
264 | }); |
207 | |
265 | |
208 | # to cancel the timer: |
266 | # to cancel the timer: |
209 | undef $w; |
267 | undef $w; |
210 | |
268 | |
211 | Example 2: |
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212 | |
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213 | # fire an event after 0.5 seconds, then roughly every second |
269 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
214 | my $w; |
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215 | |
270 | |
216 | my $cb = sub { |
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217 | # cancel the old timer while creating a new one |
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218 | $w = AnyEvent->timer (after => 1, cb => $cb); |
271 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
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272 | warn "timeout\n"; |
219 | }; |
273 | }; |
220 | |
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221 | # start the "loop" by creating the first watcher |
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222 | $w = AnyEvent->timer (after => 0.5, cb => $cb); |
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223 | |
274 | |
224 | =head3 TIMING ISSUES |
275 | =head3 TIMING ISSUES |
225 | |
276 | |
226 | There are two ways to handle timers: based on real time (relative, "fire |
277 | There are two ways to handle timers: based on real time (relative, "fire |
227 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
278 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
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300 | In either case, if you care (and in most cases, you don't), then you |
351 | In either case, if you care (and in most cases, you don't), then you |
301 | can get whatever behaviour you want with any event loop, by taking the |
352 | can get whatever behaviour you want with any event loop, by taking the |
302 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
353 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
303 | account. |
354 | account. |
304 | |
355 | |
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356 | =item AnyEvent->now_update |
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357 | |
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358 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
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359 | the current time for each loop iteration (see the discussion of L<< |
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360 | AnyEvent->now >>, above). |
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361 | |
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362 | When a callback runs for a long time (or when the process sleeps), then |
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363 | this "current" time will differ substantially from the real time, which |
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364 | might affect timers and time-outs. |
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365 | |
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366 | When this is the case, you can call this method, which will update the |
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367 | event loop's idea of "current time". |
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368 | |
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369 | Note that updating the time I<might> cause some events to be handled. |
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370 | |
305 | =back |
371 | =back |
306 | |
372 | |
307 | =head2 SIGNAL WATCHERS |
373 | =head2 SIGNAL WATCHERS |
308 | |
374 | |
309 | You can watch for signals using a signal watcher, C<signal> is the signal |
375 | You can watch for signals using a signal watcher, C<signal> is the signal |
310 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
376 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
311 | be invoked whenever a signal occurs. |
377 | callback to be invoked whenever a signal occurs. |
312 | |
378 | |
313 | Although the callback might get passed parameters, their value and |
379 | Although the callback might get passed parameters, their value and |
314 | presence is undefined and you cannot rely on them. Portable AnyEvent |
380 | presence is undefined and you cannot rely on them. Portable AnyEvent |
315 | callbacks cannot use arguments passed to signal watcher callbacks. |
381 | callbacks cannot use arguments passed to signal watcher callbacks. |
316 | |
382 | |
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332 | =head2 CHILD PROCESS WATCHERS |
398 | =head2 CHILD PROCESS WATCHERS |
333 | |
399 | |
334 | You can also watch on a child process exit and catch its exit status. |
400 | You can also watch on a child process exit and catch its exit status. |
335 | |
401 | |
336 | The child process is specified by the C<pid> argument (if set to C<0>, it |
402 | The child process is specified by the C<pid> argument (if set to C<0>, it |
337 | watches for any child process exit). The watcher will trigger as often |
403 | watches for any child process exit). The watcher will triggered only when |
338 | as status change for the child are received. This works by installing a |
404 | the child process has finished and an exit status is available, not on |
339 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
405 | any trace events (stopped/continued). |
340 | and exit status (as returned by waitpid), so unlike other watcher types, |
406 | |
341 | you I<can> rely on child watcher callback arguments. |
407 | The callback will be called with the pid and exit status (as returned by |
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408 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
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409 | callback arguments. |
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410 | |
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411 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
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412 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
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413 | random child processes (waiting for specific child processes, e.g. inside |
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414 | C<system>, is just fine). |
342 | |
415 | |
343 | There is a slight catch to child watchers, however: you usually start them |
416 | There is a slight catch to child watchers, however: you usually start them |
344 | I<after> the child process was created, and this means the process could |
417 | I<after> the child process was created, and this means the process could |
345 | have exited already (and no SIGCHLD will be sent anymore). |
418 | have exited already (and no SIGCHLD will be sent anymore). |
346 | |
419 | |
347 | Not all event models handle this correctly (POE doesn't), but even for |
420 | Not all event models handle this correctly (neither POE nor IO::Async do, |
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421 | see their AnyEvent::Impl manpages for details), but even for event models |
348 | event models that I<do> handle this correctly, they usually need to be |
422 | that I<do> handle this correctly, they usually need to be loaded before |
349 | loaded before the process exits (i.e. before you fork in the first place). |
423 | the process exits (i.e. before you fork in the first place). AnyEvent's |
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424 | pure perl event loop handles all cases correctly regardless of when you |
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425 | start the watcher. |
350 | |
426 | |
351 | This means you cannot create a child watcher as the very first thing in an |
427 | This means you cannot create a child watcher as the very first |
352 | AnyEvent program, you I<have> to create at least one watcher before you |
428 | thing in an AnyEvent program, you I<have> to create at least one |
353 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
429 | watcher before you C<fork> the child (alternatively, you can call |
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430 | C<AnyEvent::detect>). |
354 | |
431 | |
355 | Example: fork a process and wait for it |
432 | Example: fork a process and wait for it |
356 | |
433 | |
357 | my $done = AnyEvent->condvar; |
434 | my $done = AnyEvent->condvar; |
358 | |
435 | |
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368 | ); |
445 | ); |
369 | |
446 | |
370 | # do something else, then wait for process exit |
447 | # do something else, then wait for process exit |
371 | $done->recv; |
448 | $done->recv; |
372 | |
449 | |
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450 | =head2 IDLE WATCHERS |
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451 | |
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452 | Sometimes there is a need to do something, but it is not so important |
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453 | to do it instantly, but only when there is nothing better to do. This |
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454 | "nothing better to do" is usually defined to be "no other events need |
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455 | attention by the event loop". |
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456 | |
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457 | Idle watchers ideally get invoked when the event loop has nothing |
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458 | better to do, just before it would block the process to wait for new |
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459 | events. Instead of blocking, the idle watcher is invoked. |
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460 | |
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461 | Most event loops unfortunately do not really support idle watchers (only |
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462 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
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463 | will simply call the callback "from time to time". |
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464 | |
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465 | Example: read lines from STDIN, but only process them when the |
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466 | program is otherwise idle: |
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467 | |
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468 | my @lines; # read data |
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469 | my $idle_w; |
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470 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
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471 | push @lines, scalar <STDIN>; |
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472 | |
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473 | # start an idle watcher, if not already done |
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474 | $idle_w ||= AnyEvent->idle (cb => sub { |
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475 | # handle only one line, when there are lines left |
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476 | if (my $line = shift @lines) { |
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477 | print "handled when idle: $line"; |
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478 | } else { |
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479 | # otherwise disable the idle watcher again |
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480 | undef $idle_w; |
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481 | } |
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482 | }); |
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483 | }); |
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484 | |
373 | =head2 CONDITION VARIABLES |
485 | =head2 CONDITION VARIABLES |
374 | |
486 | |
375 | If you are familiar with some event loops you will know that all of them |
487 | If you are familiar with some event loops you will know that all of them |
376 | require you to run some blocking "loop", "run" or similar function that |
488 | require you to run some blocking "loop", "run" or similar function that |
377 | will actively watch for new events and call your callbacks. |
489 | will actively watch for new events and call your callbacks. |
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… | |
382 | The instrument to do that is called a "condition variable", so called |
494 | The instrument to do that is called a "condition variable", so called |
383 | because they represent a condition that must become true. |
495 | because they represent a condition that must become true. |
384 | |
496 | |
385 | Condition variables can be created by calling the C<< AnyEvent->condvar |
497 | Condition variables can be created by calling the C<< AnyEvent->condvar |
386 | >> method, usually without arguments. The only argument pair allowed is |
498 | >> method, usually without arguments. The only argument pair allowed is |
|
|
499 | |
387 | C<cb>, which specifies a callback to be called when the condition variable |
500 | C<cb>, which specifies a callback to be called when the condition variable |
388 | becomes true. |
501 | becomes true, with the condition variable as the first argument (but not |
|
|
502 | the results). |
389 | |
503 | |
390 | After creation, the condition variable is "false" until it becomes "true" |
504 | After creation, the condition variable is "false" until it becomes "true" |
391 | by calling the C<send> method (or calling the condition variable as if it |
505 | by calling the C<send> method (or calling the condition variable as if it |
392 | were a callback, read about the caveats in the description for the C<< |
506 | were a callback, read about the caveats in the description for the C<< |
393 | ->send >> method). |
507 | ->send >> method). |
… | |
… | |
449 | |
563 | |
450 | my $done = AnyEvent->condvar; |
564 | my $done = AnyEvent->condvar; |
451 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
565 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
452 | $done->recv; |
566 | $done->recv; |
453 | |
567 | |
|
|
568 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
569 | callbacks. This is how you make a synchronous call, for example from |
|
|
570 | the main program: |
|
|
571 | |
|
|
572 | use AnyEvent::CouchDB; |
|
|
573 | |
|
|
574 | ... |
|
|
575 | |
|
|
576 | my @info = $couchdb->info->recv; |
|
|
577 | |
|
|
578 | And this is how you would just ste a callback to be called whenever the |
|
|
579 | results are available: |
|
|
580 | |
|
|
581 | $couchdb->info->cb (sub { |
|
|
582 | my @info = $_[0]->recv; |
|
|
583 | }); |
|
|
584 | |
454 | =head3 METHODS FOR PRODUCERS |
585 | =head3 METHODS FOR PRODUCERS |
455 | |
586 | |
456 | These methods should only be used by the producing side, i.e. the |
587 | These methods should only be used by the producing side, i.e. the |
457 | code/module that eventually sends the signal. Note that it is also |
588 | code/module that eventually sends the signal. Note that it is also |
458 | the producer side which creates the condvar in most cases, but it isn't |
589 | the producer side which creates the condvar in most cases, but it isn't |
… | |
… | |
491 | |
622 | |
492 | =item $cv->begin ([group callback]) |
623 | =item $cv->begin ([group callback]) |
493 | |
624 | |
494 | =item $cv->end |
625 | =item $cv->end |
495 | |
626 | |
496 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
|
|
497 | |
|
|
498 | These two methods can be used to combine many transactions/events into |
627 | These two methods can be used to combine many transactions/events into |
499 | one. For example, a function that pings many hosts in parallel might want |
628 | one. For example, a function that pings many hosts in parallel might want |
500 | to use a condition variable for the whole process. |
629 | to use a condition variable for the whole process. |
501 | |
630 | |
502 | Every call to C<< ->begin >> will increment a counter, and every call to |
631 | Every call to C<< ->begin >> will increment a counter, and every call to |
503 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
632 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
504 | >>, the (last) callback passed to C<begin> will be executed. That callback |
633 | >>, the (last) callback passed to C<begin> will be executed. That callback |
505 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
634 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
506 | callback was set, C<send> will be called without any arguments. |
635 | callback was set, C<send> will be called without any arguments. |
507 | |
636 | |
508 | Let's clarify this with the ping example: |
637 | You can think of C<< $cv->send >> giving you an OR condition (one call |
|
|
638 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
|
|
639 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
|
|
640 | |
|
|
641 | Let's start with a simple example: you have two I/O watchers (for example, |
|
|
642 | STDOUT and STDERR for a program), and you want to wait for both streams to |
|
|
643 | close before activating a condvar: |
|
|
644 | |
|
|
645 | my $cv = AnyEvent->condvar; |
|
|
646 | |
|
|
647 | $cv->begin; # first watcher |
|
|
648 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
|
|
649 | defined sysread $fh1, my $buf, 4096 |
|
|
650 | or $cv->end; |
|
|
651 | }); |
|
|
652 | |
|
|
653 | $cv->begin; # second watcher |
|
|
654 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
655 | defined sysread $fh2, my $buf, 4096 |
|
|
656 | or $cv->end; |
|
|
657 | }); |
|
|
658 | |
|
|
659 | $cv->recv; |
|
|
660 | |
|
|
661 | This works because for every event source (EOF on file handle), there is |
|
|
662 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
|
|
663 | sending. |
|
|
664 | |
|
|
665 | The ping example mentioned above is slightly more complicated, as the |
|
|
666 | there are results to be passwd back, and the number of tasks that are |
|
|
667 | begung can potentially be zero: |
509 | |
668 | |
510 | my $cv = AnyEvent->condvar; |
669 | my $cv = AnyEvent->condvar; |
511 | |
670 | |
512 | my %result; |
671 | my %result; |
513 | $cv->begin (sub { $cv->send (\%result) }); |
672 | $cv->begin (sub { $cv->send (\%result) }); |
… | |
… | |
533 | loop, which serves two important purposes: first, it sets the callback |
692 | loop, which serves two important purposes: first, it sets the callback |
534 | to be called once the counter reaches C<0>, and second, it ensures that |
693 | to be called once the counter reaches C<0>, and second, it ensures that |
535 | C<send> is called even when C<no> hosts are being pinged (the loop |
694 | C<send> is called even when C<no> hosts are being pinged (the loop |
536 | doesn't execute once). |
695 | doesn't execute once). |
537 | |
696 | |
538 | This is the general pattern when you "fan out" into multiple subrequests: |
697 | This is the general pattern when you "fan out" into multiple (but |
539 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
698 | potentially none) subrequests: use an outer C<begin>/C<end> pair to set |
540 | is called at least once, and then, for each subrequest you start, call |
699 | the callback and ensure C<end> is called at least once, and then, for each |
541 | C<begin> and for each subrequest you finish, call C<end>. |
700 | subrequest you start, call C<begin> and for each subrequest you finish, |
|
|
701 | call C<end>. |
542 | |
702 | |
543 | =back |
703 | =back |
544 | |
704 | |
545 | =head3 METHODS FOR CONSUMERS |
705 | =head3 METHODS FOR CONSUMERS |
546 | |
706 | |
… | |
… | |
591 | =item $bool = $cv->ready |
751 | =item $bool = $cv->ready |
592 | |
752 | |
593 | Returns true when the condition is "true", i.e. whether C<send> or |
753 | Returns true when the condition is "true", i.e. whether C<send> or |
594 | C<croak> have been called. |
754 | C<croak> have been called. |
595 | |
755 | |
596 | =item $cb = $cv->cb ([new callback]) |
756 | =item $cb = $cv->cb ($cb->($cv)) |
597 | |
757 | |
598 | This is a mutator function that returns the callback set and optionally |
758 | This is a mutator function that returns the callback set and optionally |
599 | replaces it before doing so. |
759 | replaces it before doing so. |
600 | |
760 | |
601 | The callback will be called when the condition becomes "true", i.e. when |
761 | The callback will be called when the condition becomes "true", i.e. when |
… | |
… | |
626 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
786 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
627 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
787 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
628 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
788 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
629 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
789 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
630 | |
790 | |
|
|
791 | # warning, support for IO::Async is only partial, as it is too broken |
|
|
792 | # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async. |
|
|
793 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs). |
|
|
794 | |
631 | There is no support for WxWidgets, as WxWidgets has no support for |
795 | There is no support for WxWidgets, as WxWidgets has no support for |
632 | watching file handles. However, you can use WxWidgets through the |
796 | watching file handles. However, you can use WxWidgets through the |
633 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
797 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
634 | second, which was considered to be too horrible to even consider for |
798 | second, which was considered to be too horrible to even consider for |
635 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
799 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
… | |
… | |
738 | =item L<AnyEvent::Util> |
902 | =item L<AnyEvent::Util> |
739 | |
903 | |
740 | Contains various utility functions that replace often-used but blocking |
904 | Contains various utility functions that replace often-used but blocking |
741 | functions such as C<inet_aton> by event-/callback-based versions. |
905 | functions such as C<inet_aton> by event-/callback-based versions. |
742 | |
906 | |
743 | =item L<AnyEvent::Handle> |
|
|
744 | |
|
|
745 | Provide read and write buffers and manages watchers for reads and writes. |
|
|
746 | |
|
|
747 | =item L<AnyEvent::Socket> |
907 | =item L<AnyEvent::Socket> |
748 | |
908 | |
749 | Provides various utility functions for (internet protocol) sockets, |
909 | Provides various utility functions for (internet protocol) sockets, |
750 | addresses and name resolution. Also functions to create non-blocking tcp |
910 | addresses and name resolution. Also functions to create non-blocking tcp |
751 | connections or tcp servers, with IPv6 and SRV record support and more. |
911 | connections or tcp servers, with IPv6 and SRV record support and more. |
752 | |
912 | |
|
|
913 | =item L<AnyEvent::Handle> |
|
|
914 | |
|
|
915 | Provide read and write buffers, manages watchers for reads and writes, |
|
|
916 | supports raw and formatted I/O, I/O queued and fully transparent and |
|
|
917 | non-blocking SSL/TLS. |
|
|
918 | |
753 | =item L<AnyEvent::DNS> |
919 | =item L<AnyEvent::DNS> |
754 | |
920 | |
755 | Provides rich asynchronous DNS resolver capabilities. |
921 | Provides rich asynchronous DNS resolver capabilities. |
756 | |
922 | |
|
|
923 | =item L<AnyEvent::HTTP> |
|
|
924 | |
|
|
925 | A simple-to-use HTTP library that is capable of making a lot of concurrent |
|
|
926 | HTTP requests. |
|
|
927 | |
757 | =item L<AnyEvent::HTTPD> |
928 | =item L<AnyEvent::HTTPD> |
758 | |
929 | |
759 | Provides a simple web application server framework. |
930 | Provides a simple web application server framework. |
760 | |
931 | |
761 | =item L<AnyEvent::FastPing> |
932 | =item L<AnyEvent::FastPing> |
762 | |
933 | |
763 | The fastest ping in the west. |
934 | The fastest ping in the west. |
764 | |
935 | |
|
|
936 | =item L<AnyEvent::DBI> |
|
|
937 | |
|
|
938 | Executes L<DBI> requests asynchronously in a proxy process. |
|
|
939 | |
|
|
940 | =item L<AnyEvent::AIO> |
|
|
941 | |
|
|
942 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
943 | programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent |
|
|
944 | together. |
|
|
945 | |
|
|
946 | =item L<AnyEvent::BDB> |
|
|
947 | |
|
|
948 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses |
|
|
949 | L<BDB> and AnyEvent together. |
|
|
950 | |
|
|
951 | =item L<AnyEvent::GPSD> |
|
|
952 | |
|
|
953 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
|
|
954 | |
|
|
955 | =item L<AnyEvent::IGS> |
|
|
956 | |
|
|
957 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
958 | L<App::IGS>). |
|
|
959 | |
765 | =item L<Net::IRC3> |
960 | =item L<AnyEvent::IRC> |
766 | |
961 | |
767 | AnyEvent based IRC client module family. |
962 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
768 | |
963 | |
769 | =item L<Net::XMPP2> |
964 | =item L<Net::XMPP2> |
770 | |
965 | |
771 | AnyEvent based XMPP (Jabber protocol) module family. |
966 | AnyEvent based XMPP (Jabber protocol) module family. |
772 | |
967 | |
… | |
… | |
781 | |
976 | |
782 | =item L<Coro> |
977 | =item L<Coro> |
783 | |
978 | |
784 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
979 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
785 | |
980 | |
786 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
787 | |
|
|
788 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
789 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
790 | together. |
|
|
791 | |
|
|
792 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
793 | |
|
|
794 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
795 | IO::AIO and AnyEvent together. |
|
|
796 | |
|
|
797 | =item L<IO::Lambda> |
981 | =item L<IO::Lambda> |
798 | |
982 | |
799 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
983 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
800 | |
984 | |
801 | =back |
985 | =back |
… | |
… | |
803 | =cut |
987 | =cut |
804 | |
988 | |
805 | package AnyEvent; |
989 | package AnyEvent; |
806 | |
990 | |
807 | no warnings; |
991 | no warnings; |
808 | use strict; |
992 | use strict qw(vars subs); |
809 | |
993 | |
810 | use Carp; |
994 | use Carp; |
811 | |
995 | |
812 | our $VERSION = 4.11; |
996 | our $VERSION = 4.8; |
813 | our $MODEL; |
997 | our $MODEL; |
814 | |
998 | |
815 | our $AUTOLOAD; |
999 | our $AUTOLOAD; |
816 | our @ISA; |
1000 | our @ISA; |
817 | |
1001 | |
818 | our @REGISTRY; |
1002 | our @REGISTRY; |
819 | |
1003 | |
820 | our $WIN32; |
1004 | our $WIN32; |
821 | |
1005 | |
822 | BEGIN { |
1006 | BEGIN { |
823 | my $win32 = ! ! ($^O =~ /mswin32/i); |
1007 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
824 | eval "sub WIN32(){ $win32 }"; |
1008 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
|
|
1009 | |
|
|
1010 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
1011 | if ${^TAINT}; |
825 | } |
1012 | } |
826 | |
1013 | |
827 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
1014 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
828 | |
1015 | |
829 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
1016 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
… | |
… | |
847 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
1034 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
848 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1035 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
849 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1036 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
850 | [Wx:: => AnyEvent::Impl::POE::], |
1037 | [Wx:: => AnyEvent::Impl::POE::], |
851 | [Prima:: => AnyEvent::Impl::POE::], |
1038 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
1039 | # IO::Async is just too broken - we would need workaorunds for its |
|
|
1040 | # byzantine signal and broken child handling, among others. |
|
|
1041 | # IO::Async is rather hard to detect, as it doesn't have any |
|
|
1042 | # obvious default class. |
|
|
1043 | # [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1044 | # [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1045 | # [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
852 | ); |
1046 | ); |
853 | |
1047 | |
854 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
1048 | our %method = map +($_ => 1), |
|
|
1049 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
855 | |
1050 | |
856 | our @post_detect; |
1051 | our @post_detect; |
857 | |
1052 | |
858 | sub post_detect(&) { |
1053 | sub post_detect(&) { |
859 | my ($cb) = @_; |
1054 | my ($cb) = @_; |
… | |
… | |
864 | 1 |
1059 | 1 |
865 | } else { |
1060 | } else { |
866 | push @post_detect, $cb; |
1061 | push @post_detect, $cb; |
867 | |
1062 | |
868 | defined wantarray |
1063 | defined wantarray |
869 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
1064 | ? bless \$cb, "AnyEvent::Util::postdetect" |
870 | : () |
1065 | : () |
871 | } |
1066 | } |
872 | } |
1067 | } |
873 | |
1068 | |
874 | sub AnyEvent::Util::PostDetect::DESTROY { |
1069 | sub AnyEvent::Util::postdetect::DESTROY { |
875 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1070 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
876 | } |
1071 | } |
877 | |
1072 | |
878 | sub detect() { |
1073 | sub detect() { |
879 | unless ($MODEL) { |
1074 | unless ($MODEL) { |
… | |
… | |
916 | last; |
1111 | last; |
917 | } |
1112 | } |
918 | } |
1113 | } |
919 | |
1114 | |
920 | $MODEL |
1115 | $MODEL |
921 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1116 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
922 | } |
1117 | } |
923 | } |
1118 | } |
924 | |
1119 | |
|
|
1120 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
1121 | |
925 | unshift @ISA, $MODEL; |
1122 | unshift @ISA, $MODEL; |
926 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1123 | |
|
|
1124 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
927 | |
1125 | |
928 | (shift @post_detect)->() while @post_detect; |
1126 | (shift @post_detect)->() while @post_detect; |
929 | } |
1127 | } |
930 | |
1128 | |
931 | $MODEL |
1129 | $MODEL |
… | |
… | |
941 | |
1139 | |
942 | my $class = shift; |
1140 | my $class = shift; |
943 | $class->$func (@_); |
1141 | $class->$func (@_); |
944 | } |
1142 | } |
945 | |
1143 | |
|
|
1144 | # utility function to dup a filehandle. this is used by many backends |
|
|
1145 | # to support binding more than one watcher per filehandle (they usually |
|
|
1146 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1147 | sub _dupfh($$;$$) { |
|
|
1148 | my ($poll, $fh, $r, $w) = @_; |
|
|
1149 | |
|
|
1150 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1151 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
|
|
1152 | : $poll eq "w" ? ($w, ">") |
|
|
1153 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
|
|
1154 | |
|
|
1155 | open my $fh2, "$mode&" . fileno $fh |
|
|
1156 | or die "cannot dup() filehandle: $!,"; |
|
|
1157 | |
|
|
1158 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1159 | |
|
|
1160 | ($fh2, $rw) |
|
|
1161 | } |
|
|
1162 | |
946 | package AnyEvent::Base; |
1163 | package AnyEvent::Base; |
947 | |
1164 | |
948 | # default implementation for now and time |
1165 | # default implementations for many methods |
949 | |
1166 | |
950 | use Time::HiRes (); |
1167 | BEGIN { |
|
|
1168 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1169 | *_time = \&Time::HiRes::time; |
|
|
1170 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1171 | } else { |
|
|
1172 | *_time = sub { time }; # epic fail |
|
|
1173 | } |
|
|
1174 | } |
951 | |
1175 | |
952 | sub time { Time::HiRes::time } |
1176 | sub time { _time } |
953 | sub now { Time::HiRes::time } |
1177 | sub now { _time } |
|
|
1178 | sub now_update { } |
954 | |
1179 | |
955 | # default implementation for ->condvar |
1180 | # default implementation for ->condvar |
956 | |
1181 | |
957 | sub condvar { |
1182 | sub condvar { |
958 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1183 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
959 | } |
1184 | } |
960 | |
1185 | |
961 | # default implementation for ->signal |
1186 | # default implementation for ->signal |
962 | |
1187 | |
963 | our %SIG_CB; |
1188 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1189 | |
|
|
1190 | sub _signal_exec { |
|
|
1191 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1192 | |
|
|
1193 | while (%SIG_EV) { |
|
|
1194 | for (keys %SIG_EV) { |
|
|
1195 | delete $SIG_EV{$_}; |
|
|
1196 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1197 | } |
|
|
1198 | } |
|
|
1199 | } |
964 | |
1200 | |
965 | sub signal { |
1201 | sub signal { |
966 | my (undef, %arg) = @_; |
1202 | my (undef, %arg) = @_; |
967 | |
1203 | |
|
|
1204 | unless ($SIGPIPE_R) { |
|
|
1205 | require Fcntl; |
|
|
1206 | |
|
|
1207 | if (AnyEvent::WIN32) { |
|
|
1208 | require AnyEvent::Util; |
|
|
1209 | |
|
|
1210 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1211 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1212 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1213 | } else { |
|
|
1214 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1215 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1216 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1217 | |
|
|
1218 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1219 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1220 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1221 | } |
|
|
1222 | |
|
|
1223 | $SIGPIPE_R |
|
|
1224 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1225 | |
|
|
1226 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1227 | } |
|
|
1228 | |
968 | my $signal = uc $arg{signal} |
1229 | my $signal = uc $arg{signal} |
969 | or Carp::croak "required option 'signal' is missing"; |
1230 | or Carp::croak "required option 'signal' is missing"; |
970 | |
1231 | |
971 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1232 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
972 | $SIG{$signal} ||= sub { |
1233 | $SIG{$signal} ||= sub { |
973 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1234 | local $!; |
|
|
1235 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1236 | undef $SIG_EV{$signal}; |
974 | }; |
1237 | }; |
975 | |
1238 | |
976 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1239 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
977 | } |
1240 | } |
978 | |
1241 | |
979 | sub AnyEvent::Base::Signal::DESTROY { |
1242 | sub AnyEvent::Base::signal::DESTROY { |
980 | my ($signal, $cb) = @{$_[0]}; |
1243 | my ($signal, $cb) = @{$_[0]}; |
981 | |
1244 | |
982 | delete $SIG_CB{$signal}{$cb}; |
1245 | delete $SIG_CB{$signal}{$cb}; |
983 | |
1246 | |
|
|
1247 | # delete doesn't work with older perls - they then |
|
|
1248 | # print weird messages, or just unconditionally exit |
|
|
1249 | # instead of getting the default action. |
984 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1250 | undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
985 | } |
1251 | } |
986 | |
1252 | |
987 | # default implementation for ->child |
1253 | # default implementation for ->child |
988 | |
1254 | |
989 | our %PID_CB; |
1255 | our %PID_CB; |
990 | our $CHLD_W; |
1256 | our $CHLD_W; |
991 | our $CHLD_DELAY_W; |
1257 | our $CHLD_DELAY_W; |
992 | our $PID_IDLE; |
|
|
993 | our $WNOHANG; |
1258 | our $WNOHANG; |
994 | |
1259 | |
995 | sub _child_wait { |
1260 | sub _sigchld { |
996 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1261 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
997 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1262 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
998 | (values %{ $PID_CB{0} || {} }); |
1263 | (values %{ $PID_CB{0} || {} }); |
999 | } |
1264 | } |
1000 | |
|
|
1001 | undef $PID_IDLE; |
|
|
1002 | } |
|
|
1003 | |
|
|
1004 | sub _sigchld { |
|
|
1005 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
1006 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
1007 | undef $CHLD_DELAY_W; |
|
|
1008 | &_child_wait; |
|
|
1009 | }); |
|
|
1010 | } |
1265 | } |
1011 | |
1266 | |
1012 | sub child { |
1267 | sub child { |
1013 | my (undef, %arg) = @_; |
1268 | my (undef, %arg) = @_; |
1014 | |
1269 | |
1015 | defined (my $pid = $arg{pid} + 0) |
1270 | defined (my $pid = $arg{pid} + 0) |
1016 | or Carp::croak "required option 'pid' is missing"; |
1271 | or Carp::croak "required option 'pid' is missing"; |
1017 | |
1272 | |
1018 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1273 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1019 | |
1274 | |
1020 | unless ($WNOHANG) { |
|
|
1021 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1275 | $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
1022 | } |
|
|
1023 | |
1276 | |
1024 | unless ($CHLD_W) { |
1277 | unless ($CHLD_W) { |
1025 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1278 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1026 | # child could be a zombie already, so make at least one round |
1279 | # child could be a zombie already, so make at least one round |
1027 | &_sigchld; |
1280 | &_sigchld; |
1028 | } |
1281 | } |
1029 | |
1282 | |
1030 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1283 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
1031 | } |
1284 | } |
1032 | |
1285 | |
1033 | sub AnyEvent::Base::Child::DESTROY { |
1286 | sub AnyEvent::Base::child::DESTROY { |
1034 | my ($pid, $cb) = @{$_[0]}; |
1287 | my ($pid, $cb) = @{$_[0]}; |
1035 | |
1288 | |
1036 | delete $PID_CB{$pid}{$cb}; |
1289 | delete $PID_CB{$pid}{$cb}; |
1037 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1290 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1038 | |
1291 | |
1039 | undef $CHLD_W unless keys %PID_CB; |
1292 | undef $CHLD_W unless keys %PID_CB; |
|
|
1293 | } |
|
|
1294 | |
|
|
1295 | # idle emulation is done by simply using a timer, regardless |
|
|
1296 | # of whether the process is idle or not, and not letting |
|
|
1297 | # the callback use more than 50% of the time. |
|
|
1298 | sub idle { |
|
|
1299 | my (undef, %arg) = @_; |
|
|
1300 | |
|
|
1301 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1302 | |
|
|
1303 | $rcb = sub { |
|
|
1304 | if ($cb) { |
|
|
1305 | $w = _time; |
|
|
1306 | &$cb; |
|
|
1307 | $w = _time - $w; |
|
|
1308 | |
|
|
1309 | # never use more then 50% of the time for the idle watcher, |
|
|
1310 | # within some limits |
|
|
1311 | $w = 0.0001 if $w < 0.0001; |
|
|
1312 | $w = 5 if $w > 5; |
|
|
1313 | |
|
|
1314 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1315 | } else { |
|
|
1316 | # clean up... |
|
|
1317 | undef $w; |
|
|
1318 | undef $rcb; |
|
|
1319 | } |
|
|
1320 | }; |
|
|
1321 | |
|
|
1322 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1323 | |
|
|
1324 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1325 | } |
|
|
1326 | |
|
|
1327 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1328 | undef $${$_[0]}; |
1040 | } |
1329 | } |
1041 | |
1330 | |
1042 | package AnyEvent::CondVar; |
1331 | package AnyEvent::CondVar; |
1043 | |
1332 | |
1044 | our @ISA = AnyEvent::CondVar::Base::; |
1333 | our @ISA = AnyEvent::CondVar::Base::; |
… | |
… | |
1096 | } |
1385 | } |
1097 | |
1386 | |
1098 | # undocumented/compatibility with pre-3.4 |
1387 | # undocumented/compatibility with pre-3.4 |
1099 | *broadcast = \&send; |
1388 | *broadcast = \&send; |
1100 | *wait = \&_wait; |
1389 | *wait = \&_wait; |
|
|
1390 | |
|
|
1391 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1392 | |
|
|
1393 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1394 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1395 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1396 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1397 | development. |
|
|
1398 | |
|
|
1399 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1400 | executing a callback), this is not only highly event-loop specific, but |
|
|
1401 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1402 | program. |
|
|
1403 | |
|
|
1404 | The pure perl event loop simply re-throws the exception (usually |
|
|
1405 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1406 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1407 | so on. |
|
|
1408 | |
|
|
1409 | =head1 ENVIRONMENT VARIABLES |
|
|
1410 | |
|
|
1411 | The following environment variables are used by this module or its |
|
|
1412 | submodules. |
|
|
1413 | |
|
|
1414 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1415 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1416 | enabled. |
|
|
1417 | |
|
|
1418 | =over 4 |
|
|
1419 | |
|
|
1420 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1421 | |
|
|
1422 | By default, AnyEvent will be completely silent except in fatal |
|
|
1423 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1424 | talkative. |
|
|
1425 | |
|
|
1426 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1427 | conditions, such as not being able to load the event model specified by |
|
|
1428 | C<PERL_ANYEVENT_MODEL>. |
|
|
1429 | |
|
|
1430 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1431 | model it chooses. |
|
|
1432 | |
|
|
1433 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1434 | |
|
|
1435 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1436 | argument checking is very costly. Setting this variable to a true value |
|
|
1437 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1438 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1439 | it will croak. |
|
|
1440 | |
|
|
1441 | In other words, enables "strict" mode. |
|
|
1442 | |
|
|
1443 | Unlike C<use strict>, it is definitely recommended to keep it off in |
|
|
1444 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1445 | developing programs can be very useful, however. |
|
|
1446 | |
|
|
1447 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1448 | |
|
|
1449 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1450 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1451 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1452 | and the resulting module name is loaded and if the load was successful, |
|
|
1453 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1454 | auto detection and -probing. |
|
|
1455 | |
|
|
1456 | This functionality might change in future versions. |
|
|
1457 | |
|
|
1458 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1459 | could start your program like this: |
|
|
1460 | |
|
|
1461 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1462 | |
|
|
1463 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1464 | |
|
|
1465 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1466 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1467 | of auto probing). |
|
|
1468 | |
|
|
1469 | Must be set to a comma-separated list of protocols or address families, |
|
|
1470 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1471 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1472 | list. |
|
|
1473 | |
|
|
1474 | This variable can effectively be used for denial-of-service attacks |
|
|
1475 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1476 | small, as the program has to handle conenction and other failures anyways. |
|
|
1477 | |
|
|
1478 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1479 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1480 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1481 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1482 | IPv6, but prefer IPv6 over IPv4. |
|
|
1483 | |
|
|
1484 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1485 | |
|
|
1486 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1487 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1488 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1489 | default. |
|
|
1490 | |
|
|
1491 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1492 | EDNS0 in its DNS requests. |
|
|
1493 | |
|
|
1494 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1495 | |
|
|
1496 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1497 | will create in parallel. |
|
|
1498 | |
|
|
1499 | =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> |
|
|
1500 | |
|
|
1501 | The default value for the C<max_outstanding> parameter for the default DNS |
|
|
1502 | resolver - this is the maximum number of parallel DNS requests that are |
|
|
1503 | sent to the DNS server. |
|
|
1504 | |
|
|
1505 | =item C<PERL_ANYEVENT_RESOLV_CONF> |
|
|
1506 | |
|
|
1507 | The file to use instead of F</etc/resolv.conf> (or OS-specific |
|
|
1508 | configuration) in the default resolver. When set to the empty string, no |
|
|
1509 | default config will be used. |
|
|
1510 | |
|
|
1511 | =item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. |
|
|
1512 | |
|
|
1513 | When neither C<ca_file> nor C<ca_path> was specified during |
|
|
1514 | L<AnyEvent::TLS> context creation, and either of these environment |
|
|
1515 | variables exist, they will be used to specify CA certificate locations |
|
|
1516 | instead of a system-dependent default. |
|
|
1517 | |
|
|
1518 | =back |
1101 | |
1519 | |
1102 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1520 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1103 | |
1521 | |
1104 | This is an advanced topic that you do not normally need to use AnyEvent in |
1522 | This is an advanced topic that you do not normally need to use AnyEvent in |
1105 | a module. This section is only of use to event loop authors who want to |
1523 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1139 | |
1557 | |
1140 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1558 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1141 | condition variables: code blocking while waiting for a condition will |
1559 | condition variables: code blocking while waiting for a condition will |
1142 | C<die>. This still works with most modules/usages, and blocking calls must |
1560 | C<die>. This still works with most modules/usages, and blocking calls must |
1143 | not be done in an interactive application, so it makes sense. |
1561 | not be done in an interactive application, so it makes sense. |
1144 | |
|
|
1145 | =head1 ENVIRONMENT VARIABLES |
|
|
1146 | |
|
|
1147 | The following environment variables are used by this module: |
|
|
1148 | |
|
|
1149 | =over 4 |
|
|
1150 | |
|
|
1151 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1152 | |
|
|
1153 | By default, AnyEvent will be completely silent except in fatal |
|
|
1154 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1155 | talkative. |
|
|
1156 | |
|
|
1157 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1158 | conditions, such as not being able to load the event model specified by |
|
|
1159 | C<PERL_ANYEVENT_MODEL>. |
|
|
1160 | |
|
|
1161 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1162 | model it chooses. |
|
|
1163 | |
|
|
1164 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1165 | |
|
|
1166 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1167 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1168 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1169 | and the resulting module name is loaded and if the load was successful, |
|
|
1170 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1171 | auto detection and -probing. |
|
|
1172 | |
|
|
1173 | This functionality might change in future versions. |
|
|
1174 | |
|
|
1175 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1176 | could start your program like this: |
|
|
1177 | |
|
|
1178 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1179 | |
|
|
1180 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1181 | |
|
|
1182 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1183 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1184 | of auto probing). |
|
|
1185 | |
|
|
1186 | Must be set to a comma-separated list of protocols or address families, |
|
|
1187 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1188 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1189 | list. |
|
|
1190 | |
|
|
1191 | This variable can effectively be used for denial-of-service attacks |
|
|
1192 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1193 | small, as the program has to handle connection errors already- |
|
|
1194 | |
|
|
1195 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1196 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1197 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1198 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1199 | IPv6, but prefer IPv6 over IPv4. |
|
|
1200 | |
|
|
1201 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1202 | |
|
|
1203 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1204 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1205 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1206 | default. |
|
|
1207 | |
|
|
1208 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1209 | EDNS0 in its DNS requests. |
|
|
1210 | |
|
|
1211 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1212 | |
|
|
1213 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1214 | will create in parallel. |
|
|
1215 | |
|
|
1216 | =back |
|
|
1217 | |
1562 | |
1218 | =head1 EXAMPLE PROGRAM |
1563 | =head1 EXAMPLE PROGRAM |
1219 | |
1564 | |
1220 | The following program uses an I/O watcher to read data from STDIN, a timer |
1565 | The following program uses an I/O watcher to read data from STDIN, a timer |
1221 | to display a message once per second, and a condition variable to quit the |
1566 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1415 | watcher. |
1760 | watcher. |
1416 | |
1761 | |
1417 | =head3 Results |
1762 | =head3 Results |
1418 | |
1763 | |
1419 | name watchers bytes create invoke destroy comment |
1764 | name watchers bytes create invoke destroy comment |
1420 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1765 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1421 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1766 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1422 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1767 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1423 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1768 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1424 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1769 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1425 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1770 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1771 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1772 | IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll |
1426 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1773 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1427 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1774 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1428 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1775 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1429 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1776 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1430 | |
1777 | |
1431 | =head3 Discussion |
1778 | =head3 Discussion |
1432 | |
1779 | |
1433 | The benchmark does I<not> measure scalability of the event loop very |
1780 | The benchmark does I<not> measure scalability of the event loop very |
1434 | well. For example, a select-based event loop (such as the pure perl one) |
1781 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1459 | performance becomes really bad with lots of file descriptors (and few of |
1806 | performance becomes really bad with lots of file descriptors (and few of |
1460 | them active), of course, but this was not subject of this benchmark. |
1807 | them active), of course, but this was not subject of this benchmark. |
1461 | |
1808 | |
1462 | The C<Event> module has a relatively high setup and callback invocation |
1809 | The C<Event> module has a relatively high setup and callback invocation |
1463 | cost, but overall scores in on the third place. |
1810 | cost, but overall scores in on the third place. |
|
|
1811 | |
|
|
1812 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
1813 | when using its pure perl backend. |
1464 | |
1814 | |
1465 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1815 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1466 | faster callback invocation and overall ends up in the same class as |
1816 | faster callback invocation and overall ends up in the same class as |
1467 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1817 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1468 | watchers increases the processing time by more than a factor of four, |
1818 | watchers increases the processing time by more than a factor of four, |
… | |
… | |
1546 | it to another server. This includes deleting the old timeout and creating |
1896 | it to another server. This includes deleting the old timeout and creating |
1547 | a new one that moves the timeout into the future. |
1897 | a new one that moves the timeout into the future. |
1548 | |
1898 | |
1549 | =head3 Results |
1899 | =head3 Results |
1550 | |
1900 | |
1551 | name sockets create request |
1901 | name sockets create request |
1552 | EV 20000 69.01 11.16 |
1902 | EV 20000 69.01 11.16 |
1553 | Perl 20000 73.32 35.87 |
1903 | Perl 20000 73.32 35.87 |
|
|
1904 | IOAsync 20000 157.00 98.14 epoll |
|
|
1905 | IOAsync 20000 159.31 616.06 poll |
1554 | Event 20000 212.62 257.32 |
1906 | Event 20000 212.62 257.32 |
1555 | Glib 20000 651.16 1896.30 |
1907 | Glib 20000 651.16 1896.30 |
1556 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1908 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1557 | |
1909 | |
1558 | =head3 Discussion |
1910 | =head3 Discussion |
1559 | |
1911 | |
1560 | This benchmark I<does> measure scalability and overall performance of the |
1912 | This benchmark I<does> measure scalability and overall performance of the |
1561 | particular event loop. |
1913 | particular event loop. |
… | |
… | |
1563 | EV is again fastest. Since it is using epoll on my system, the setup time |
1915 | EV is again fastest. Since it is using epoll on my system, the setup time |
1564 | is relatively high, though. |
1916 | is relatively high, though. |
1565 | |
1917 | |
1566 | Perl surprisingly comes second. It is much faster than the C-based event |
1918 | Perl surprisingly comes second. It is much faster than the C-based event |
1567 | loops Event and Glib. |
1919 | loops Event and Glib. |
|
|
1920 | |
|
|
1921 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
1922 | good compared to Glib when using its pure perl backend. |
1568 | |
1923 | |
1569 | Event suffers from high setup time as well (look at its code and you will |
1924 | Event suffers from high setup time as well (look at its code and you will |
1570 | understand why). Callback invocation also has a high overhead compared to |
1925 | understand why). Callback invocation also has a high overhead compared to |
1571 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1926 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1572 | uses select or poll in basically all documented configurations. |
1927 | uses select or poll in basically all documented configurations. |
… | |
… | |
1635 | =item * C-based event loops perform very well with small number of |
1990 | =item * C-based event loops perform very well with small number of |
1636 | watchers, as the management overhead dominates. |
1991 | watchers, as the management overhead dominates. |
1637 | |
1992 | |
1638 | =back |
1993 | =back |
1639 | |
1994 | |
|
|
1995 | =head2 THE IO::Lambda BENCHMARK |
|
|
1996 | |
|
|
1997 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
1998 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
1999 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
2000 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
2001 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
2002 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
2003 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
2004 | |
|
|
2005 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
2006 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
2007 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
2008 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
2009 | benchmark nevertheless. |
|
|
2010 | |
|
|
2011 | name runtime |
|
|
2012 | Lambda/select 0.330 sec |
|
|
2013 | + optimized 0.122 sec |
|
|
2014 | Lambda/AnyEvent 0.327 sec |
|
|
2015 | + optimized 0.138 sec |
|
|
2016 | Raw sockets/select 0.077 sec |
|
|
2017 | POE/select, components 0.662 sec |
|
|
2018 | POE/select, raw sockets 0.226 sec |
|
|
2019 | POE/select, optimized 0.404 sec |
|
|
2020 | |
|
|
2021 | AnyEvent/select/nb 0.085 sec |
|
|
2022 | AnyEvent/EV/nb 0.068 sec |
|
|
2023 | +state machine 0.134 sec |
|
|
2024 | |
|
|
2025 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
2026 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
2027 | defeating the purpose of an event-based solution. All of the newly |
|
|
2028 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
2029 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
2030 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
2031 | generally require a lot more bookkeeping and event handling than blocking |
|
|
2032 | connects (which involve a single syscall only). |
|
|
2033 | |
|
|
2034 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
2035 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
2036 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
2037 | non-blocking, further placing it at a disadvantage. |
|
|
2038 | |
|
|
2039 | As you can see, the AnyEvent + EV combination even beats the |
|
|
2040 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
2041 | backend easily beats IO::Lambda and POE. |
|
|
2042 | |
|
|
2043 | And even the 100% non-blocking version written using the high-level (and |
|
|
2044 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
2045 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
2046 | in a non-blocking way. |
|
|
2047 | |
|
|
2048 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2049 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2050 | part of the IO::lambda distribution and were used without any changes. |
|
|
2051 | |
|
|
2052 | |
|
|
2053 | =head1 SIGNALS |
|
|
2054 | |
|
|
2055 | AnyEvent currently installs handlers for these signals: |
|
|
2056 | |
|
|
2057 | =over 4 |
|
|
2058 | |
|
|
2059 | =item SIGCHLD |
|
|
2060 | |
|
|
2061 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2062 | emulation for event loops that do not support them natively. Also, some |
|
|
2063 | event loops install a similar handler. |
|
|
2064 | |
|
|
2065 | If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will |
|
|
2066 | reset it to default, to avoid losing child exit statuses. |
|
|
2067 | |
|
|
2068 | =item SIGPIPE |
|
|
2069 | |
|
|
2070 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2071 | when AnyEvent gets loaded. |
|
|
2072 | |
|
|
2073 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2074 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2075 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2076 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2077 | some random socket. |
|
|
2078 | |
|
|
2079 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2080 | that this way, the handler will be restored to defaults on exec. |
|
|
2081 | |
|
|
2082 | Feel free to install your own handler, or reset it to defaults. |
|
|
2083 | |
|
|
2084 | =back |
|
|
2085 | |
|
|
2086 | =cut |
|
|
2087 | |
|
|
2088 | undef $SIG{CHLD} |
|
|
2089 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2090 | |
|
|
2091 | $SIG{PIPE} = sub { } |
|
|
2092 | unless defined $SIG{PIPE}; |
1640 | |
2093 | |
1641 | =head1 FORK |
2094 | =head1 FORK |
1642 | |
2095 | |
1643 | Most event libraries are not fork-safe. The ones who are usually are |
2096 | Most event libraries are not fork-safe. The ones who are usually are |
1644 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2097 | because they rely on inefficient but fork-safe C<select> or C<poll> |
… | |
… | |
1664 | |
2117 | |
1665 | use AnyEvent; |
2118 | use AnyEvent; |
1666 | |
2119 | |
1667 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2120 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1668 | be used to probe what backend is used and gain other information (which is |
2121 | be used to probe what backend is used and gain other information (which is |
1669 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
2122 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
2123 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2124 | |
|
|
2125 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2126 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2127 | enabled. |
|
|
2128 | |
|
|
2129 | |
|
|
2130 | =head1 BUGS |
|
|
2131 | |
|
|
2132 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
|
|
2133 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
|
|
2134 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
|
|
2135 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
|
|
2136 | pronounced). |
1670 | |
2137 | |
1671 | |
2138 | |
1672 | =head1 SEE ALSO |
2139 | =head1 SEE ALSO |
1673 | |
2140 | |
1674 | Utility functions: L<AnyEvent::Util>. |
2141 | Utility functions: L<AnyEvent::Util>. |