… | |
… | |
6 | |
6 | |
7 | =head1 SYNOPSIS |
7 | =head1 SYNOPSIS |
8 | |
8 | |
9 | use AnyEvent; |
9 | use AnyEvent; |
10 | |
10 | |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { ... }); |
12 | ... |
|
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13 | }); |
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14 | |
12 | |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
13 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
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14 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
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15 | |
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16 | print AnyEvent->now; # prints current event loop time |
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17 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
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18 | |
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19 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
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20 | |
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21 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
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22 | my ($pid, $status) = @_; |
16 | ... |
23 | ... |
17 | }); |
24 | }); |
18 | |
25 | |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
26 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
20 | $w->send; # wake up current and all future recv's |
27 | $w->send; # wake up current and all future recv's |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
28 | $w->recv; # enters "main loop" till $condvar gets ->send |
|
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29 | # use a condvar in callback mode: |
|
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30 | $w->cb (sub { $_[0]->recv }); |
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31 | |
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32 | =head1 INTRODUCTION/TUTORIAL |
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33 | |
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34 | This manpage is mainly a reference manual. If you are interested |
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35 | in a tutorial or some gentle introduction, have a look at the |
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36 | L<AnyEvent::Intro> manpage. |
22 | |
37 | |
23 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
38 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
24 | |
39 | |
25 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
40 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
26 | nowadays. So what is different about AnyEvent? |
41 | nowadays. So what is different about AnyEvent? |
27 | |
42 | |
28 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
43 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
29 | policy> and AnyEvent is I<small and efficient>. |
44 | policy> and AnyEvent is I<small and efficient>. |
30 | |
45 | |
31 | First and foremost, I<AnyEvent is not an event model> itself, it only |
46 | First and foremost, I<AnyEvent is not an event model> itself, it only |
32 | interfaces to whatever event model the main program happens to use in a |
47 | interfaces to whatever event model the main program happens to use, in a |
33 | pragmatic way. For event models and certain classes of immortals alike, |
48 | pragmatic way. For event models and certain classes of immortals alike, |
34 | the statement "there can only be one" is a bitter reality: In general, |
49 | the statement "there can only be one" is a bitter reality: In general, |
35 | only one event loop can be active at the same time in a process. AnyEvent |
50 | only one event loop can be active at the same time in a process. AnyEvent |
36 | helps hiding the differences between those event loops. |
51 | cannot change this, but it can hide the differences between those event |
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52 | loops. |
37 | |
53 | |
38 | The goal of AnyEvent is to offer module authors the ability to do event |
54 | The goal of AnyEvent is to offer module authors the ability to do event |
39 | programming (waiting for I/O or timer events) without subscribing to a |
55 | programming (waiting for I/O or timer events) without subscribing to a |
40 | religion, a way of living, and most importantly: without forcing your |
56 | religion, a way of living, and most importantly: without forcing your |
41 | module users into the same thing by forcing them to use the same event |
57 | module users into the same thing by forcing them to use the same event |
42 | model you use. |
58 | model you use. |
43 | |
59 | |
44 | For modules like POE or IO::Async (which is a total misnomer as it is |
60 | For modules like POE or IO::Async (which is a total misnomer as it is |
45 | actually doing all I/O I<synchronously>...), using them in your module is |
61 | actually doing all I/O I<synchronously>...), using them in your module is |
46 | like joining a cult: After you joined, you are dependent on them and you |
62 | like joining a cult: After you joined, you are dependent on them and you |
47 | cannot use anything else, as it is simply incompatible to everything that |
63 | cannot use anything else, as they are simply incompatible to everything |
48 | isn't itself. What's worse, all the potential users of your module are |
64 | that isn't them. What's worse, all the potential users of your |
49 | I<also> forced to use the same event loop you use. |
65 | module are I<also> forced to use the same event loop you use. |
50 | |
66 | |
51 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
67 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
52 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
68 | 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 |
69 | 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, |
70 | 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 |
71 | 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 |
72 | event models it supports (including stuff like IO::Async, as long as those |
57 | as those use one of the supported event loops. It is trivial to add new |
73 | use one of the supported event loops. It is trivial to add new event loops |
58 | event loops to AnyEvent, too, so it is future-proof). |
74 | to AnyEvent, too, so it is future-proof). |
59 | |
75 | |
60 | In addition to being free of having to use I<the one and only true event |
76 | 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 |
77 | 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 |
78 | 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 |
79 | 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 |
80 | offering the functionality that is necessary, in as thin as a wrapper as |
65 | technically possible. |
81 | technically possible. |
66 | |
82 | |
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83 | Of course, AnyEvent comes with a big (and fully optional!) toolbox |
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84 | of useful functionality, such as an asynchronous DNS resolver, 100% |
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85 | non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms |
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86 | such as Windows) and lots of real-world knowledge and workarounds for |
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87 | platform bugs and differences. |
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88 | |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
89 | 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 |
90 | useful) and you want to force your users to use the one and only event |
69 | model, you should I<not> use this module. |
91 | model, you should I<not> use this module. |
70 | |
92 | |
71 | =head1 DESCRIPTION |
93 | =head1 DESCRIPTION |
72 | |
94 | |
… | |
… | |
102 | starts using it, all bets are off. Maybe you should tell their authors to |
124 | 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... |
125 | use AnyEvent so their modules work together with others seamlessly... |
104 | |
126 | |
105 | The pure-perl implementation of AnyEvent is called |
127 | The pure-perl implementation of AnyEvent is called |
106 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
128 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
107 | explicitly. |
129 | explicitly and enjoy the high availability of that event loop :) |
108 | |
130 | |
109 | =head1 WATCHERS |
131 | =head1 WATCHERS |
110 | |
132 | |
111 | AnyEvent has the central concept of a I<watcher>, which is an object that |
133 | 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 |
134 | stores relevant data for each kind of event you are waiting for, such as |
113 | the callback to call, the filehandle to watch, etc. |
135 | the callback to call, the file handle to watch, etc. |
114 | |
136 | |
115 | These watchers are normal Perl objects with normal Perl lifetime. After |
137 | These watchers are normal Perl objects with normal Perl lifetime. After |
116 | creating a watcher it will immediately "watch" for events and invoke the |
138 | 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 |
139 | callback when the event occurs (of course, only when the event model |
118 | is in control). |
140 | is in control). |
119 | |
141 | |
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142 | Note that B<callbacks must not permanently change global variables> |
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143 | potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< |
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144 | callbacks must not C<die> >>. The former is good programming practise in |
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145 | Perl and the latter stems from the fact that exception handling differs |
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146 | widely between event loops. |
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147 | |
120 | To disable the watcher you have to destroy it (e.g. by setting the |
148 | To disable the watcher you have to destroy it (e.g. by setting the |
121 | variable you store it in to C<undef> or otherwise deleting all references |
149 | variable you store it in to C<undef> or otherwise deleting all references |
122 | to it). |
150 | to it). |
123 | |
151 | |
124 | All watchers are created by calling a method on the C<AnyEvent> class. |
152 | All watchers are created by calling a method on the C<AnyEvent> class. |
… | |
… | |
126 | Many watchers either are used with "recursion" (repeating timers for |
154 | Many watchers either are used with "recursion" (repeating timers for |
127 | example), or need to refer to their watcher object in other ways. |
155 | example), or need to refer to their watcher object in other ways. |
128 | |
156 | |
129 | An any way to achieve that is this pattern: |
157 | An any way to achieve that is this pattern: |
130 | |
158 | |
131 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
159 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
132 | # you can use $w here, for example to undef it |
160 | # you can use $w here, for example to undef it |
133 | undef $w; |
161 | undef $w; |
134 | }); |
162 | }); |
135 | |
163 | |
136 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
164 | 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 |
165 | my variables are only visible after the statement in which they are |
138 | declared. |
166 | declared. |
139 | |
167 | |
140 | =head2 I/O WATCHERS |
168 | =head2 I/O WATCHERS |
141 | |
169 | |
142 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
170 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
143 | with the following mandatory key-value pairs as arguments: |
171 | with the following mandatory key-value pairs as arguments: |
144 | |
172 | |
145 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
173 | 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>, |
174 | (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, |
175 | 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 |
176 | waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the |
149 | becomes ready. |
177 | callback to invoke each time the file handle becomes ready. |
150 | |
178 | |
151 | Although the callback might get passed parameters, their value and |
179 | Although the callback might get passed parameters, their value and |
152 | presence is undefined and you cannot rely on them. Portable AnyEvent |
180 | presence is undefined and you cannot rely on them. Portable AnyEvent |
153 | callbacks cannot use arguments passed to I/O watcher callbacks. |
181 | callbacks cannot use arguments passed to I/O watcher callbacks. |
154 | |
182 | |
… | |
… | |
158 | |
186 | |
159 | Some event loops issue spurious readyness notifications, so you should |
187 | Some event loops issue spurious readyness notifications, so you should |
160 | always use non-blocking calls when reading/writing from/to your file |
188 | always use non-blocking calls when reading/writing from/to your file |
161 | handles. |
189 | handles. |
162 | |
190 | |
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 |
191 | Example: wait for readability of STDIN, then read a line and disable the |
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192 | watcher. |
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193 | |
166 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
194 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
167 | chomp (my $input = <STDIN>); |
195 | chomp (my $input = <STDIN>); |
168 | warn "read: $input\n"; |
196 | warn "read: $input\n"; |
169 | undef $w; |
197 | undef $w; |
170 | }); |
198 | }); |
… | |
… | |
180 | |
208 | |
181 | Although the callback might get passed parameters, their value and |
209 | Although the callback might get passed parameters, their value and |
182 | presence is undefined and you cannot rely on them. Portable AnyEvent |
210 | presence is undefined and you cannot rely on them. Portable AnyEvent |
183 | callbacks cannot use arguments passed to time watcher callbacks. |
211 | callbacks cannot use arguments passed to time watcher callbacks. |
184 | |
212 | |
185 | The timer callback will be invoked at most once: if you want a repeating |
213 | 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 |
214 | parameter, C<interval>, as a strictly positive number (> 0), then the |
187 | and Glib). |
215 | callback will be invoked regularly at that interval (in fractional |
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216 | seconds) after the first invocation. If C<interval> is specified with a |
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217 | false value, then it is treated as if it were missing. |
188 | |
218 | |
189 | Example: |
219 | The callback will be rescheduled before invoking the callback, but no |
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220 | attempt is done to avoid timer drift in most backends, so the interval is |
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221 | only approximate. |
190 | |
222 | |
191 | # fire an event after 7.7 seconds |
223 | Example: fire an event after 7.7 seconds. |
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224 | |
192 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
225 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
193 | warn "timeout\n"; |
226 | warn "timeout\n"; |
194 | }); |
227 | }); |
195 | |
228 | |
196 | # to cancel the timer: |
229 | # to cancel the timer: |
197 | undef $w; |
230 | undef $w; |
198 | |
231 | |
199 | Example 2: |
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200 | |
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201 | # fire an event after 0.5 seconds, then roughly every second |
232 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
202 | my $w; |
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203 | |
233 | |
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); |
234 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
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235 | warn "timeout\n"; |
207 | }; |
236 | }; |
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 | |
237 | |
212 | =head3 TIMING ISSUES |
238 | =head3 TIMING ISSUES |
213 | |
239 | |
214 | There are two ways to handle timers: based on real time (relative, "fire |
240 | 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 |
241 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
… | |
… | |
227 | timers. |
253 | timers. |
228 | |
254 | |
229 | AnyEvent always prefers relative timers, if available, matching the |
255 | AnyEvent always prefers relative timers, if available, matching the |
230 | AnyEvent API. |
256 | AnyEvent API. |
231 | |
257 | |
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258 | AnyEvent has two additional methods that return the "current time": |
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259 | |
|
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260 | =over 4 |
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261 | |
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262 | =item AnyEvent->time |
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263 | |
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264 | This returns the "current wallclock time" as a fractional number of |
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265 | seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time> |
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266 | return, and the result is guaranteed to be compatible with those). |
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267 | |
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268 | It progresses independently of any event loop processing, i.e. each call |
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269 | will check the system clock, which usually gets updated frequently. |
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270 | |
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271 | =item AnyEvent->now |
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272 | |
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273 | This also returns the "current wallclock time", but unlike C<time>, above, |
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274 | this value might change only once per event loop iteration, depending on |
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275 | the event loop (most return the same time as C<time>, above). This is the |
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276 | time that AnyEvent's timers get scheduled against. |
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277 | |
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278 | I<In almost all cases (in all cases if you don't care), this is the |
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279 | function to call when you want to know the current time.> |
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280 | |
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281 | This function is also often faster then C<< AnyEvent->time >>, and |
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282 | thus the preferred method if you want some timestamp (for example, |
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283 | L<AnyEvent::Handle> uses this to update it's activity timeouts). |
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284 | |
|
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285 | The rest of this section is only of relevance if you try to be very exact |
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286 | with your timing, you can skip it without bad conscience. |
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287 | |
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288 | For a practical example of when these times differ, consider L<Event::Lib> |
|
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289 | and L<EV> and the following set-up: |
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290 | |
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291 | The event loop is running and has just invoked one of your callback at |
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292 | time=500 (assume no other callbacks delay processing). In your callback, |
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293 | you wait a second by executing C<sleep 1> (blocking the process for a |
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294 | second) and then (at time=501) you create a relative timer that fires |
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295 | after three seconds. |
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296 | |
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297 | With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will |
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298 | both return C<501>, because that is the current time, and the timer will |
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299 | be scheduled to fire at time=504 (C<501> + C<3>). |
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300 | |
|
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301 | With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current |
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302 | time), but C<< AnyEvent->now >> returns C<500>, as that is the time the |
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303 | last event processing phase started. With L<EV>, your timer gets scheduled |
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304 | to run at time=503 (C<500> + C<3>). |
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305 | |
|
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306 | In one sense, L<Event::Lib> is more exact, as it uses the current time |
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307 | regardless of any delays introduced by event processing. However, most |
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308 | callbacks do not expect large delays in processing, so this causes a |
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309 | higher drift (and a lot more system calls to get the current time). |
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310 | |
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311 | In another sense, L<EV> is more exact, as your timer will be scheduled at |
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312 | the same time, regardless of how long event processing actually took. |
|
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313 | |
|
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314 | In either case, if you care (and in most cases, you don't), then you |
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315 | can get whatever behaviour you want with any event loop, by taking the |
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316 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
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317 | account. |
|
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318 | |
|
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319 | =back |
|
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320 | |
232 | =head2 SIGNAL WATCHERS |
321 | =head2 SIGNAL WATCHERS |
233 | |
322 | |
234 | You can watch for signals using a signal watcher, C<signal> is the signal |
323 | 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 |
324 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
236 | be invoked whenever a signal occurs. |
325 | callback to be invoked whenever a signal occurs. |
237 | |
326 | |
238 | Although the callback might get passed parameters, their value and |
327 | Although the callback might get passed parameters, their value and |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
328 | presence is undefined and you cannot rely on them. Portable AnyEvent |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
329 | callbacks cannot use arguments passed to signal watcher callbacks. |
241 | |
330 | |
242 | Multiple signal occurances can be clumped together into one callback |
331 | Multiple signal occurrences can be clumped together into one callback |
243 | invocation, and callback invocation will be synchronous. synchronous means |
332 | invocation, and callback invocation will be synchronous. Synchronous means |
244 | that it might take a while until the signal gets handled by the process, |
333 | 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. |
334 | but it is guaranteed not to interrupt any other callbacks. |
246 | |
335 | |
247 | The main advantage of using these watchers is that you can share a signal |
336 | The main advantage of using these watchers is that you can share a signal |
248 | between multiple watchers. |
337 | between multiple watchers. |
249 | |
338 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
339 | This watcher might use C<%SIG>, so programs overwriting those signals |
… | |
… | |
257 | =head2 CHILD PROCESS WATCHERS |
346 | =head2 CHILD PROCESS WATCHERS |
258 | |
347 | |
259 | You can also watch on a child process exit and catch its exit status. |
348 | You can also watch on a child process exit and catch its exit status. |
260 | |
349 | |
261 | The child process is specified by the C<pid> argument (if set to C<0>, it |
350 | The child process is specified by the C<pid> argument (if set to C<0>, it |
262 | watches for any child process exit). The watcher will trigger as often |
351 | watches for any child process exit). The watcher will triggered only when |
263 | as status change for the child are received. This works by installing a |
352 | the child process has finished and an exit status is available, not on |
264 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
353 | any trace events (stopped/continued). |
265 | and exit status (as returned by waitpid), so unlike other watcher types, |
354 | |
266 | you I<can> rely on child watcher callback arguments. |
355 | The callback will be called with the pid and exit status (as returned by |
|
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356 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
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357 | callback arguments. |
|
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358 | |
|
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359 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
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360 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
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361 | random child processes (waiting for specific child processes, e.g. inside |
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362 | C<system>, is just fine). |
267 | |
363 | |
268 | There is a slight catch to child watchers, however: you usually start them |
364 | There is a slight catch to child watchers, however: you usually start them |
269 | I<after> the child process was created, and this means the process could |
365 | I<after> the child process was created, and this means the process could |
270 | have exited already (and no SIGCHLD will be sent anymore). |
366 | have exited already (and no SIGCHLD will be sent anymore). |
271 | |
367 | |
… | |
… | |
277 | AnyEvent program, you I<have> to create at least one watcher before you |
373 | 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>). |
374 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
279 | |
375 | |
280 | Example: fork a process and wait for it |
376 | Example: fork a process and wait for it |
281 | |
377 | |
282 | my $done = AnyEvent->condvar; |
378 | my $done = AnyEvent->condvar; |
283 | |
379 | |
284 | my $pid = fork or exit 5; |
380 | my $pid = fork or exit 5; |
285 | |
381 | |
286 | my $w = AnyEvent->child ( |
382 | my $w = AnyEvent->child ( |
287 | pid => $pid, |
383 | pid => $pid, |
288 | cb => sub { |
384 | cb => sub { |
289 | my ($pid, $status) = @_; |
385 | my ($pid, $status) = @_; |
290 | warn "pid $pid exited with status $status"; |
386 | warn "pid $pid exited with status $status"; |
291 | $done->send; |
387 | $done->send; |
292 | }, |
388 | }, |
293 | ); |
389 | ); |
294 | |
390 | |
295 | # do something else, then wait for process exit |
391 | # do something else, then wait for process exit |
296 | $done->recv; |
392 | $done->recv; |
297 | |
393 | |
298 | =head2 CONDITION VARIABLES |
394 | =head2 CONDITION VARIABLES |
299 | |
395 | |
300 | If you are familiar with some event loops you will know that all of them |
396 | If you are familiar with some event loops you will know that all of them |
301 | require you to run some blocking "loop", "run" or similar function that |
397 | require you to run some blocking "loop", "run" or similar function that |
… | |
… | |
307 | The instrument to do that is called a "condition variable", so called |
403 | The instrument to do that is called a "condition variable", so called |
308 | because they represent a condition that must become true. |
404 | because they represent a condition that must become true. |
309 | |
405 | |
310 | Condition variables can be created by calling the C<< AnyEvent->condvar |
406 | Condition variables can be created by calling the C<< AnyEvent->condvar |
311 | >> method, usually without arguments. The only argument pair allowed is |
407 | >> method, usually without arguments. The only argument pair allowed is |
|
|
408 | |
312 | C<cb>, which specifies a callback to be called when the condition variable |
409 | C<cb>, which specifies a callback to be called when the condition variable |
313 | becomes true. |
410 | becomes true, with the condition variable as the first argument (but not |
|
|
411 | the results). |
314 | |
412 | |
315 | After creation, the conditon variable is "false" until it becomes "true" |
413 | After creation, the condition variable is "false" until it becomes "true" |
316 | by calling the C<send> method. |
414 | by calling the C<send> method (or calling the condition variable as if it |
|
|
415 | were a callback, read about the caveats in the description for the C<< |
|
|
416 | ->send >> method). |
317 | |
417 | |
318 | Condition variables are similar to callbacks, except that you can |
418 | Condition variables are similar to callbacks, except that you can |
319 | optionally wait for them. They can also be called merge points - points |
419 | optionally wait for them. They can also be called merge points - points |
320 | in time where multiple outstandign events have been processed. And yet |
420 | in time where multiple outstanding events have been processed. And yet |
321 | another way to call them is transations - each condition variable can be |
421 | another way to call them is transactions - each condition variable can be |
322 | used to represent a transaction, which finishes at some point and delivers |
422 | used to represent a transaction, which finishes at some point and delivers |
323 | a result. |
423 | a result. |
324 | |
424 | |
325 | Condition variables are very useful to signal that something has finished, |
425 | Condition variables are very useful to signal that something has finished, |
326 | for example, if you write a module that does asynchronous http requests, |
426 | for example, if you write a module that does asynchronous http requests, |
… | |
… | |
332 | you can block your main program until an event occurs - for example, you |
432 | you can block your main program until an event occurs - for example, you |
333 | could C<< ->recv >> in your main program until the user clicks the Quit |
433 | could C<< ->recv >> in your main program until the user clicks the Quit |
334 | button of your app, which would C<< ->send >> the "quit" event. |
434 | button of your app, which would C<< ->send >> the "quit" event. |
335 | |
435 | |
336 | Note that condition variables recurse into the event loop - if you have |
436 | Note that condition variables recurse into the event loop - if you have |
337 | two pieces of code that call C<< ->recv >> in a round-robbin fashion, you |
437 | two pieces of code that call C<< ->recv >> in a round-robin fashion, you |
338 | lose. Therefore, condition variables are good to export to your caller, but |
438 | lose. Therefore, condition variables are good to export to your caller, but |
339 | you should avoid making a blocking wait yourself, at least in callbacks, |
439 | you should avoid making a blocking wait yourself, at least in callbacks, |
340 | as this asks for trouble. |
440 | as this asks for trouble. |
341 | |
441 | |
342 | Condition variables are represented by hash refs in perl, and the keys |
442 | Condition variables are represented by hash refs in perl, and the keys |
… | |
… | |
347 | |
447 | |
348 | There are two "sides" to a condition variable - the "producer side" which |
448 | There are two "sides" to a condition variable - the "producer side" which |
349 | eventually calls C<< -> send >>, and the "consumer side", which waits |
449 | eventually calls C<< -> send >>, and the "consumer side", which waits |
350 | for the send to occur. |
450 | for the send to occur. |
351 | |
451 | |
352 | Example: |
452 | Example: wait for a timer. |
353 | |
453 | |
354 | # wait till the result is ready |
454 | # wait till the result is ready |
355 | my $result_ready = AnyEvent->condvar; |
455 | my $result_ready = AnyEvent->condvar; |
356 | |
456 | |
357 | # do something such as adding a timer |
457 | # do something such as adding a timer |
… | |
… | |
365 | |
465 | |
366 | # this "blocks" (while handling events) till the callback |
466 | # this "blocks" (while handling events) till the callback |
367 | # calls send |
467 | # calls send |
368 | $result_ready->recv; |
468 | $result_ready->recv; |
369 | |
469 | |
|
|
470 | Example: wait for a timer, but take advantage of the fact that |
|
|
471 | condition variables are also code references. |
|
|
472 | |
|
|
473 | my $done = AnyEvent->condvar; |
|
|
474 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
|
|
475 | $done->recv; |
|
|
476 | |
|
|
477 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
478 | callbacks. This is how you make a synchronous call, for example from |
|
|
479 | the main program: |
|
|
480 | |
|
|
481 | use AnyEvent::CouchDB; |
|
|
482 | |
|
|
483 | ... |
|
|
484 | |
|
|
485 | my @info = $couchdb->info->recv; |
|
|
486 | |
|
|
487 | And this is how you would just ste a callback to be called whenever the |
|
|
488 | results are available: |
|
|
489 | |
|
|
490 | $couchdb->info->cb (sub { |
|
|
491 | my @info = $_[0]->recv; |
|
|
492 | }); |
|
|
493 | |
370 | =head3 METHODS FOR PRODUCERS |
494 | =head3 METHODS FOR PRODUCERS |
371 | |
495 | |
372 | These methods should only be used by the producing side, i.e. the |
496 | These methods should only be used by the producing side, i.e. the |
373 | code/module that eventually sends the signal. Note that it is also |
497 | code/module that eventually sends the signal. Note that it is also |
374 | the producer side which creates the condvar in most cases, but it isn't |
498 | the producer side which creates the condvar in most cases, but it isn't |
… | |
… | |
385 | If a callback has been set on the condition variable, it is called |
509 | If a callback has been set on the condition variable, it is called |
386 | immediately from within send. |
510 | immediately from within send. |
387 | |
511 | |
388 | Any arguments passed to the C<send> call will be returned by all |
512 | Any arguments passed to the C<send> call will be returned by all |
389 | future C<< ->recv >> calls. |
513 | future C<< ->recv >> calls. |
|
|
514 | |
|
|
515 | Condition variables are overloaded so one can call them directly |
|
|
516 | (as a code reference). Calling them directly is the same as calling |
|
|
517 | C<send>. Note, however, that many C-based event loops do not handle |
|
|
518 | overloading, so as tempting as it may be, passing a condition variable |
|
|
519 | instead of a callback does not work. Both the pure perl and EV loops |
|
|
520 | support overloading, however, as well as all functions that use perl to |
|
|
521 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
|
|
522 | example). |
390 | |
523 | |
391 | =item $cv->croak ($error) |
524 | =item $cv->croak ($error) |
392 | |
525 | |
393 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
526 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
394 | C<Carp::croak> with the given error message/object/scalar. |
527 | C<Carp::croak> with the given error message/object/scalar. |
… | |
… | |
443 | doesn't execute once). |
576 | doesn't execute once). |
444 | |
577 | |
445 | This is the general pattern when you "fan out" into multiple subrequests: |
578 | 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> |
579 | 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 |
580 | 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>. |
581 | C<begin> and for each subrequest you finish, call C<end>. |
449 | |
582 | |
450 | =back |
583 | =back |
451 | |
584 | |
452 | =head3 METHODS FOR CONSUMERS |
585 | =head3 METHODS FOR CONSUMERS |
453 | |
586 | |
… | |
… | |
475 | (programs might want to do that to stay interactive), so I<if you are |
608 | (programs might want to do that to stay interactive), so I<if you are |
476 | using this from a module, never require a blocking wait>, but let the |
609 | using this from a module, never require a blocking wait>, but let the |
477 | caller decide whether the call will block or not (for example, by coupling |
610 | caller decide whether the call will block or not (for example, by coupling |
478 | condition variables with some kind of request results and supporting |
611 | condition variables with some kind of request results and supporting |
479 | callbacks so the caller knows that getting the result will not block, |
612 | callbacks so the caller knows that getting the result will not block, |
480 | while still suppporting blocking waits if the caller so desires). |
613 | while still supporting blocking waits if the caller so desires). |
481 | |
614 | |
482 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
615 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
483 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
616 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
484 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
617 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
485 | can supply. |
618 | can supply. |
… | |
… | |
498 | =item $bool = $cv->ready |
631 | =item $bool = $cv->ready |
499 | |
632 | |
500 | Returns true when the condition is "true", i.e. whether C<send> or |
633 | Returns true when the condition is "true", i.e. whether C<send> or |
501 | C<croak> have been called. |
634 | C<croak> have been called. |
502 | |
635 | |
503 | =item $cb = $cv->cb ([new callback]) |
636 | =item $cb = $cv->cb ($cb->($cv)) |
504 | |
637 | |
505 | This is a mutator function that returns the callback set and optionally |
638 | This is a mutator function that returns the callback set and optionally |
506 | replaces it before doing so. |
639 | replaces it before doing so. |
507 | |
640 | |
508 | The callback will be called when the condition becomes "true", i.e. when |
641 | The callback will be called when the condition becomes "true", i.e. when |
509 | C<send> or C<croak> are called. Calling C<recv> inside the callback |
642 | C<send> or C<croak> are called, with the only argument being the condition |
510 | or at any later time is guaranteed not to block. |
643 | variable itself. Calling C<recv> inside the callback or at any later time |
|
|
644 | is guaranteed not to block. |
511 | |
645 | |
512 | =back |
646 | =back |
513 | |
647 | |
514 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
648 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
515 | |
649 | |
… | |
… | |
601 | |
735 | |
602 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
736 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
603 | do anything special (it does not need to be event-based) and let AnyEvent |
737 | do anything special (it does not need to be event-based) and let AnyEvent |
604 | decide which implementation to chose if some module relies on it. |
738 | decide which implementation to chose if some module relies on it. |
605 | |
739 | |
606 | If the main program relies on a specific event model. For example, in |
740 | If the main program relies on a specific event model - for example, in |
607 | Gtk2 programs you have to rely on the Glib module. You should load the |
741 | Gtk2 programs you have to rely on the Glib module - you should load the |
608 | event module before loading AnyEvent or any module that uses it: generally |
742 | event module before loading AnyEvent or any module that uses it: generally |
609 | speaking, you should load it as early as possible. The reason is that |
743 | speaking, you should load it as early as possible. The reason is that |
610 | modules might create watchers when they are loaded, and AnyEvent will |
744 | modules might create watchers when they are loaded, and AnyEvent will |
611 | decide on the event model to use as soon as it creates watchers, and it |
745 | decide on the event model to use as soon as it creates watchers, and it |
612 | might chose the wrong one unless you load the correct one yourself. |
746 | might chose the wrong one unless you load the correct one yourself. |
613 | |
747 | |
614 | You can chose to use a rather inefficient pure-perl implementation by |
748 | You can chose to use a pure-perl implementation by loading the |
615 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
749 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
616 | behaviour everywhere, but letting AnyEvent chose is generally better. |
750 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
751 | |
|
|
752 | =head2 MAINLOOP EMULATION |
|
|
753 | |
|
|
754 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
755 | only want to use AnyEvent), you do not want to run a specific event loop. |
|
|
756 | |
|
|
757 | In that case, you can use a condition variable like this: |
|
|
758 | |
|
|
759 | AnyEvent->condvar->recv; |
|
|
760 | |
|
|
761 | This has the effect of entering the event loop and looping forever. |
|
|
762 | |
|
|
763 | Note that usually your program has some exit condition, in which case |
|
|
764 | it is better to use the "traditional" approach of storing a condition |
|
|
765 | variable somewhere, waiting for it, and sending it when the program should |
|
|
766 | exit cleanly. |
|
|
767 | |
617 | |
768 | |
618 | =head1 OTHER MODULES |
769 | =head1 OTHER MODULES |
619 | |
770 | |
620 | The following is a non-exhaustive list of additional modules that use |
771 | The following is a non-exhaustive list of additional modules that use |
621 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
772 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
… | |
… | |
627 | =item L<AnyEvent::Util> |
778 | =item L<AnyEvent::Util> |
628 | |
779 | |
629 | Contains various utility functions that replace often-used but blocking |
780 | Contains various utility functions that replace often-used but blocking |
630 | functions such as C<inet_aton> by event-/callback-based versions. |
781 | functions such as C<inet_aton> by event-/callback-based versions. |
631 | |
782 | |
|
|
783 | =item L<AnyEvent::Socket> |
|
|
784 | |
|
|
785 | Provides various utility functions for (internet protocol) sockets, |
|
|
786 | addresses and name resolution. Also functions to create non-blocking tcp |
|
|
787 | connections or tcp servers, with IPv6 and SRV record support and more. |
|
|
788 | |
632 | =item L<AnyEvent::Handle> |
789 | =item L<AnyEvent::Handle> |
633 | |
790 | |
634 | Provide read and write buffers and manages watchers for reads and writes. |
791 | Provide read and write buffers, manages watchers for reads and writes, |
|
|
792 | supports raw and formatted I/O, I/O queued and fully transparent and |
|
|
793 | non-blocking SSL/TLS. |
|
|
794 | |
|
|
795 | =item L<AnyEvent::DNS> |
|
|
796 | |
|
|
797 | Provides rich asynchronous DNS resolver capabilities. |
|
|
798 | |
|
|
799 | =item L<AnyEvent::HTTP> |
|
|
800 | |
|
|
801 | A simple-to-use HTTP library that is capable of making a lot of concurrent |
|
|
802 | HTTP requests. |
635 | |
803 | |
636 | =item L<AnyEvent::HTTPD> |
804 | =item L<AnyEvent::HTTPD> |
637 | |
805 | |
638 | Provides a simple web application server framework. |
806 | Provides a simple web application server framework. |
639 | |
807 | |
640 | =item L<AnyEvent::DNS> |
|
|
641 | |
|
|
642 | Provides asynchronous DNS resolver capabilities, beyond what |
|
|
643 | L<AnyEvent::Util> offers. |
|
|
644 | |
|
|
645 | =item L<AnyEvent::FastPing> |
808 | =item L<AnyEvent::FastPing> |
646 | |
809 | |
647 | The fastest ping in the west. |
810 | The fastest ping in the west. |
648 | |
811 | |
|
|
812 | =item L<AnyEvent::DBI> |
|
|
813 | |
|
|
814 | Executes L<DBI> requests asynchronously in a proxy process. |
|
|
815 | |
|
|
816 | =item L<AnyEvent::AIO> |
|
|
817 | |
|
|
818 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
819 | programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent |
|
|
820 | together. |
|
|
821 | |
|
|
822 | =item L<AnyEvent::BDB> |
|
|
823 | |
|
|
824 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses |
|
|
825 | L<BDB> and AnyEvent together. |
|
|
826 | |
|
|
827 | =item L<AnyEvent::GPSD> |
|
|
828 | |
|
|
829 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
|
|
830 | |
|
|
831 | =item L<AnyEvent::IGS> |
|
|
832 | |
|
|
833 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
834 | L<App::IGS>). |
|
|
835 | |
649 | =item L<Net::IRC3> |
836 | =item L<AnyEvent::IRC> |
650 | |
837 | |
651 | AnyEvent based IRC client module family. |
838 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
652 | |
839 | |
653 | =item L<Net::XMPP2> |
840 | =item L<Net::XMPP2> |
654 | |
841 | |
655 | AnyEvent based XMPP (Jabber protocol) module family. |
842 | AnyEvent based XMPP (Jabber protocol) module family. |
656 | |
843 | |
… | |
… | |
665 | |
852 | |
666 | =item L<Coro> |
853 | =item L<Coro> |
667 | |
854 | |
668 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
855 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
669 | |
856 | |
670 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
671 | |
|
|
672 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
673 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
674 | together. |
|
|
675 | |
|
|
676 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
677 | |
|
|
678 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
679 | IO::AIO and AnyEvent together. |
|
|
680 | |
|
|
681 | =item L<IO::Lambda> |
857 | =item L<IO::Lambda> |
682 | |
858 | |
683 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
859 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
684 | |
860 | |
685 | =back |
861 | =back |
… | |
… | |
687 | =cut |
863 | =cut |
688 | |
864 | |
689 | package AnyEvent; |
865 | package AnyEvent; |
690 | |
866 | |
691 | no warnings; |
867 | no warnings; |
692 | use strict; |
868 | use strict qw(vars subs); |
693 | |
869 | |
694 | use Carp; |
870 | use Carp; |
695 | |
871 | |
696 | our $VERSION = '3.4'; |
872 | our $VERSION = 4.341; |
697 | our $MODEL; |
873 | our $MODEL; |
698 | |
874 | |
699 | our $AUTOLOAD; |
875 | our $AUTOLOAD; |
700 | our @ISA; |
876 | our @ISA; |
701 | |
877 | |
|
|
878 | our @REGISTRY; |
|
|
879 | |
|
|
880 | our $WIN32; |
|
|
881 | |
|
|
882 | BEGIN { |
|
|
883 | my $win32 = ! ! ($^O =~ /mswin32/i); |
|
|
884 | eval "sub WIN32(){ $win32 }"; |
|
|
885 | } |
|
|
886 | |
702 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
887 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
703 | |
888 | |
704 | our @REGISTRY; |
889 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
|
|
890 | |
|
|
891 | { |
|
|
892 | my $idx; |
|
|
893 | $PROTOCOL{$_} = ++$idx |
|
|
894 | for reverse split /\s*,\s*/, |
|
|
895 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
|
|
896 | } |
705 | |
897 | |
706 | my @models = ( |
898 | my @models = ( |
707 | [EV:: => AnyEvent::Impl::EV::], |
899 | [EV:: => AnyEvent::Impl::EV::], |
708 | [Event:: => AnyEvent::Impl::Event::], |
900 | [Event:: => AnyEvent::Impl::Event::], |
709 | [Tk:: => AnyEvent::Impl::Tk::], |
|
|
710 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
711 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
712 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
901 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
713 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
902 | # everything below here will not be autoprobed |
714 | [Glib:: => AnyEvent::Impl::Glib::], |
903 | # as the pureperl backend should work everywhere |
|
|
904 | # and is usually faster |
|
|
905 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
906 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
715 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
907 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
716 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
908 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
717 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
909 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
|
|
910 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
911 | [Prima:: => AnyEvent::Impl::POE::], |
718 | ); |
912 | ); |
719 | |
913 | |
720 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
914 | our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY); |
721 | |
915 | |
722 | our @post_detect; |
916 | our @post_detect; |
723 | |
917 | |
724 | sub post_detect(&) { |
918 | sub post_detect(&) { |
725 | my ($cb) = @_; |
919 | my ($cb) = @_; |
… | |
… | |
730 | 1 |
924 | 1 |
731 | } else { |
925 | } else { |
732 | push @post_detect, $cb; |
926 | push @post_detect, $cb; |
733 | |
927 | |
734 | defined wantarray |
928 | defined wantarray |
735 | ? bless \$cb, "AnyEvent::Util::Guard" |
929 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
736 | : () |
930 | : () |
737 | } |
931 | } |
738 | } |
932 | } |
739 | |
933 | |
740 | sub AnyEvent::Util::Guard::DESTROY { |
934 | sub AnyEvent::Util::PostDetect::DESTROY { |
741 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
935 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
742 | } |
936 | } |
743 | |
937 | |
744 | sub detect() { |
938 | sub detect() { |
745 | unless ($MODEL) { |
939 | unless ($MODEL) { |
746 | no strict 'refs'; |
940 | no strict 'refs'; |
|
|
941 | local $SIG{__DIE__}; |
747 | |
942 | |
748 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
943 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
749 | my $model = "AnyEvent::Impl::$1"; |
944 | my $model = "AnyEvent::Impl::$1"; |
750 | if (eval "require $model") { |
945 | if (eval "require $model") { |
751 | $MODEL = $model; |
946 | $MODEL = $model; |
… | |
… | |
785 | $MODEL |
980 | $MODEL |
786 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
981 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
787 | } |
982 | } |
788 | } |
983 | } |
789 | |
984 | |
|
|
985 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
986 | |
790 | unshift @ISA, $MODEL; |
987 | unshift @ISA, $MODEL; |
791 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
988 | |
|
|
989 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
792 | |
990 | |
793 | (shift @post_detect)->() while @post_detect; |
991 | (shift @post_detect)->() while @post_detect; |
794 | } |
992 | } |
795 | |
993 | |
796 | $MODEL |
994 | $MODEL |
… | |
… | |
806 | |
1004 | |
807 | my $class = shift; |
1005 | my $class = shift; |
808 | $class->$func (@_); |
1006 | $class->$func (@_); |
809 | } |
1007 | } |
810 | |
1008 | |
|
|
1009 | # utility function to dup a filehandle. this is used by many backends |
|
|
1010 | # to support binding more than one watcher per filehandle (they usually |
|
|
1011 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1012 | sub _dupfh($$$$) { |
|
|
1013 | my ($poll, $fh, $r, $w) = @_; |
|
|
1014 | |
|
|
1015 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1016 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") |
|
|
1017 | : $poll eq "w" ? ($w, ">") |
|
|
1018 | : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'"; |
|
|
1019 | |
|
|
1020 | open my $fh2, "$mode&" . fileno $fh |
|
|
1021 | or die "cannot dup() filehandle: $!"; |
|
|
1022 | |
|
|
1023 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1024 | |
|
|
1025 | ($fh2, $rw) |
|
|
1026 | } |
|
|
1027 | |
811 | package AnyEvent::Base; |
1028 | package AnyEvent::Base; |
812 | |
1029 | |
|
|
1030 | # default implementation for now and time |
|
|
1031 | |
|
|
1032 | BEGIN { |
|
|
1033 | if (eval "use Time::HiRes (); time (); 1") { |
|
|
1034 | *_time = \&Time::HiRes::time; |
|
|
1035 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1036 | } else { |
|
|
1037 | *_time = sub { time }; # epic fail |
|
|
1038 | } |
|
|
1039 | } |
|
|
1040 | |
|
|
1041 | sub time { _time } |
|
|
1042 | sub now { _time } |
|
|
1043 | |
813 | # default implementation for ->condvar |
1044 | # default implementation for ->condvar |
814 | |
1045 | |
815 | sub condvar { |
1046 | sub condvar { |
816 | bless {}, "AnyEvent::Base::CondVar" |
1047 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
817 | } |
1048 | } |
818 | |
1049 | |
819 | # default implementation for ->signal |
1050 | # default implementation for ->signal |
820 | |
1051 | |
821 | our %SIG_CB; |
1052 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1053 | |
|
|
1054 | sub _signal_exec { |
|
|
1055 | while (%SIG_EV) { |
|
|
1056 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1057 | for (keys %SIG_EV) { |
|
|
1058 | delete $SIG_EV{$_}; |
|
|
1059 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1060 | } |
|
|
1061 | } |
|
|
1062 | } |
822 | |
1063 | |
823 | sub signal { |
1064 | sub signal { |
824 | my (undef, %arg) = @_; |
1065 | my (undef, %arg) = @_; |
825 | |
1066 | |
|
|
1067 | unless ($SIGPIPE_R) { |
|
|
1068 | if (AnyEvent::WIN32) { |
|
|
1069 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1070 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1071 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1072 | } else { |
|
|
1073 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1074 | require Fcntl; |
|
|
1075 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1076 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1077 | } |
|
|
1078 | |
|
|
1079 | $SIGPIPE_R |
|
|
1080 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1081 | |
|
|
1082 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1083 | } |
|
|
1084 | |
826 | my $signal = uc $arg{signal} |
1085 | my $signal = uc $arg{signal} |
827 | or Carp::croak "required option 'signal' is missing"; |
1086 | or Carp::croak "required option 'signal' is missing"; |
828 | |
1087 | |
829 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1088 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
830 | $SIG{$signal} ||= sub { |
1089 | $SIG{$signal} ||= sub { |
831 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1090 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1091 | undef $SIG_EV{$signal}; |
832 | }; |
1092 | }; |
833 | |
1093 | |
834 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1094 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
835 | } |
1095 | } |
836 | |
1096 | |
837 | sub AnyEvent::Base::Signal::DESTROY { |
1097 | sub AnyEvent::Base::Signal::DESTROY { |
838 | my ($signal, $cb) = @{$_[0]}; |
1098 | my ($signal, $cb) = @{$_[0]}; |
839 | |
1099 | |
840 | delete $SIG_CB{$signal}{$cb}; |
1100 | delete $SIG_CB{$signal}{$cb}; |
841 | |
1101 | |
842 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1102 | delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
843 | } |
1103 | } |
844 | |
1104 | |
845 | # default implementation for ->child |
1105 | # default implementation for ->child |
846 | |
1106 | |
847 | our %PID_CB; |
1107 | our %PID_CB; |
… | |
… | |
874 | or Carp::croak "required option 'pid' is missing"; |
1134 | or Carp::croak "required option 'pid' is missing"; |
875 | |
1135 | |
876 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1136 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
877 | |
1137 | |
878 | unless ($WNOHANG) { |
1138 | unless ($WNOHANG) { |
879 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
1139 | $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
880 | } |
1140 | } |
881 | |
1141 | |
882 | unless ($CHLD_W) { |
1142 | unless ($CHLD_W) { |
883 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1143 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
884 | # child could be a zombie already, so make at least one round |
1144 | # child could be a zombie already, so make at least one round |
… | |
… | |
895 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1155 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
896 | |
1156 | |
897 | undef $CHLD_W unless keys %PID_CB; |
1157 | undef $CHLD_W unless keys %PID_CB; |
898 | } |
1158 | } |
899 | |
1159 | |
900 | package AnyEvent::Base::CondVar; |
1160 | package AnyEvent::CondVar; |
901 | |
1161 | |
902 | # wake up the waiter |
1162 | our @ISA = AnyEvent::CondVar::Base::; |
|
|
1163 | |
|
|
1164 | package AnyEvent::CondVar::Base; |
|
|
1165 | |
|
|
1166 | use overload |
|
|
1167 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
|
|
1168 | fallback => 1; |
|
|
1169 | |
903 | sub _send { |
1170 | sub _send { |
904 | &{ delete $_[0]{_ae_cb} } if $_[0]{_ae_cb}; |
1171 | # nop |
905 | } |
1172 | } |
906 | |
1173 | |
907 | sub send { |
1174 | sub send { |
908 | my $cv = shift; |
1175 | my $cv = shift; |
909 | $cv->{_ae_sent} = [@_]; |
1176 | $cv->{_ae_sent} = [@_]; |
|
|
1177 | (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; |
910 | $cv->_send; |
1178 | $cv->_send; |
911 | } |
1179 | } |
912 | |
1180 | |
913 | sub croak { |
1181 | sub croak { |
914 | $_[0]{_ae_croak} = $_[1]; |
1182 | $_[0]{_ae_croak} = $_[1]; |
… | |
… | |
917 | |
1185 | |
918 | sub ready { |
1186 | sub ready { |
919 | $_[0]{_ae_sent} |
1187 | $_[0]{_ae_sent} |
920 | } |
1188 | } |
921 | |
1189 | |
|
|
1190 | sub _wait { |
|
|
1191 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
|
|
1192 | } |
|
|
1193 | |
922 | sub recv { |
1194 | sub recv { |
923 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
1195 | $_[0]->_wait; |
924 | |
1196 | |
925 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
1197 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
926 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
1198 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
927 | } |
1199 | } |
928 | |
1200 | |
… | |
… | |
936 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
1208 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
937 | } |
1209 | } |
938 | |
1210 | |
939 | sub end { |
1211 | sub end { |
940 | return if --$_[0]{_ae_counter}; |
1212 | return if --$_[0]{_ae_counter}; |
941 | &{ $_[0]{_ae_end_cb} } if $_[0]{_ae_end_cb}; |
1213 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
942 | } |
1214 | } |
943 | |
1215 | |
944 | # undocumented/compatibility with pre-3.4 |
1216 | # undocumented/compatibility with pre-3.4 |
945 | *broadcast = \&send; |
1217 | *broadcast = \&send; |
946 | *wait = \&recv; |
1218 | *wait = \&_wait; |
|
|
1219 | |
|
|
1220 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1221 | |
|
|
1222 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1223 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1224 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1225 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1226 | development. |
|
|
1227 | |
|
|
1228 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1229 | executing a callback), this is not only highly event-loop specific, but |
|
|
1230 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1231 | program. |
|
|
1232 | |
|
|
1233 | The pure perl event loop simply re-throws the exception (usually |
|
|
1234 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1235 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1236 | so on. |
|
|
1237 | |
|
|
1238 | =head1 ENVIRONMENT VARIABLES |
|
|
1239 | |
|
|
1240 | The following environment variables are used by this module or its |
|
|
1241 | submodules: |
|
|
1242 | |
|
|
1243 | =over 4 |
|
|
1244 | |
|
|
1245 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1246 | |
|
|
1247 | By default, AnyEvent will be completely silent except in fatal |
|
|
1248 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1249 | talkative. |
|
|
1250 | |
|
|
1251 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1252 | conditions, such as not being able to load the event model specified by |
|
|
1253 | C<PERL_ANYEVENT_MODEL>. |
|
|
1254 | |
|
|
1255 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1256 | model it chooses. |
|
|
1257 | |
|
|
1258 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1259 | |
|
|
1260 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1261 | argument checking is very costly. Setting this variable to a true value |
|
|
1262 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1263 | check the arguments passed to most method calls. If it finds any problems |
|
|
1264 | it will croak. |
|
|
1265 | |
|
|
1266 | In other words, enables "strict" mode. |
|
|
1267 | |
|
|
1268 | Unlike C<use strict>, it is definitely recommended ot keep it off in |
|
|
1269 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1270 | developing programs can be very useful, however. |
|
|
1271 | |
|
|
1272 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1273 | |
|
|
1274 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1275 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1276 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1277 | and the resulting module name is loaded and if the load was successful, |
|
|
1278 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1279 | auto detection and -probing. |
|
|
1280 | |
|
|
1281 | This functionality might change in future versions. |
|
|
1282 | |
|
|
1283 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1284 | could start your program like this: |
|
|
1285 | |
|
|
1286 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1287 | |
|
|
1288 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1289 | |
|
|
1290 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1291 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1292 | of auto probing). |
|
|
1293 | |
|
|
1294 | Must be set to a comma-separated list of protocols or address families, |
|
|
1295 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1296 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1297 | list. |
|
|
1298 | |
|
|
1299 | This variable can effectively be used for denial-of-service attacks |
|
|
1300 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1301 | small, as the program has to handle conenction and other failures anyways. |
|
|
1302 | |
|
|
1303 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1304 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1305 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1306 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1307 | IPv6, but prefer IPv6 over IPv4. |
|
|
1308 | |
|
|
1309 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1310 | |
|
|
1311 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1312 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1313 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1314 | default. |
|
|
1315 | |
|
|
1316 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1317 | EDNS0 in its DNS requests. |
|
|
1318 | |
|
|
1319 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1320 | |
|
|
1321 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1322 | will create in parallel. |
|
|
1323 | |
|
|
1324 | =back |
947 | |
1325 | |
948 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1326 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
949 | |
1327 | |
950 | This is an advanced topic that you do not normally need to use AnyEvent in |
1328 | This is an advanced topic that you do not normally need to use AnyEvent in |
951 | a module. This section is only of use to event loop authors who want to |
1329 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
985 | |
1363 | |
986 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1364 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
987 | condition variables: code blocking while waiting for a condition will |
1365 | condition variables: code blocking while waiting for a condition will |
988 | C<die>. This still works with most modules/usages, and blocking calls must |
1366 | C<die>. This still works with most modules/usages, and blocking calls must |
989 | not be done in an interactive application, so it makes sense. |
1367 | not be done in an interactive application, so it makes sense. |
990 | |
|
|
991 | =head1 ENVIRONMENT VARIABLES |
|
|
992 | |
|
|
993 | The following environment variables are used by this module: |
|
|
994 | |
|
|
995 | =over 4 |
|
|
996 | |
|
|
997 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
998 | |
|
|
999 | By default, AnyEvent will be completely silent except in fatal |
|
|
1000 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1001 | talkative. |
|
|
1002 | |
|
|
1003 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1004 | conditions, such as not being able to load the event model specified by |
|
|
1005 | C<PERL_ANYEVENT_MODEL>. |
|
|
1006 | |
|
|
1007 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1008 | model it chooses. |
|
|
1009 | |
|
|
1010 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1011 | |
|
|
1012 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1013 | autodetection and -probing kicks in. It must be a string consisting |
|
|
1014 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1015 | and the resulting module name is loaded and if the load was successful, |
|
|
1016 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1017 | autodetection and -probing. |
|
|
1018 | |
|
|
1019 | This functionality might change in future versions. |
|
|
1020 | |
|
|
1021 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1022 | could start your program like this: |
|
|
1023 | |
|
|
1024 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1025 | |
|
|
1026 | =back |
|
|
1027 | |
1368 | |
1028 | =head1 EXAMPLE PROGRAM |
1369 | =head1 EXAMPLE PROGRAM |
1029 | |
1370 | |
1030 | The following program uses an I/O watcher to read data from STDIN, a timer |
1371 | The following program uses an I/O watcher to read data from STDIN, a timer |
1031 | to display a message once per second, and a condition variable to quit the |
1372 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1040 | poll => 'r', |
1381 | poll => 'r', |
1041 | cb => sub { |
1382 | cb => sub { |
1042 | warn "io event <$_[0]>\n"; # will always output <r> |
1383 | warn "io event <$_[0]>\n"; # will always output <r> |
1043 | chomp (my $input = <STDIN>); # read a line |
1384 | chomp (my $input = <STDIN>); # read a line |
1044 | warn "read: $input\n"; # output what has been read |
1385 | warn "read: $input\n"; # output what has been read |
1045 | $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i |
1386 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
1046 | }, |
1387 | }, |
1047 | ); |
1388 | ); |
1048 | |
1389 | |
1049 | my $time_watcher; # can only be used once |
1390 | my $time_watcher; # can only be used once |
1050 | |
1391 | |
… | |
… | |
1055 | }); |
1396 | }); |
1056 | } |
1397 | } |
1057 | |
1398 | |
1058 | new_timer; # create first timer |
1399 | new_timer; # create first timer |
1059 | |
1400 | |
1060 | $cv->wait; # wait until user enters /^q/i |
1401 | $cv->recv; # wait until user enters /^q/i |
1061 | |
1402 | |
1062 | =head1 REAL-WORLD EXAMPLE |
1403 | =head1 REAL-WORLD EXAMPLE |
1063 | |
1404 | |
1064 | Consider the L<Net::FCP> module. It features (among others) the following |
1405 | Consider the L<Net::FCP> module. It features (among others) the following |
1065 | API calls, which are to freenet what HTTP GET requests are to http: |
1406 | API calls, which are to freenet what HTTP GET requests are to http: |
… | |
… | |
1115 | syswrite $txn->{fh}, $txn->{request} |
1456 | syswrite $txn->{fh}, $txn->{request} |
1116 | or die "connection or write error"; |
1457 | or die "connection or write error"; |
1117 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1458 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1118 | |
1459 | |
1119 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1460 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1120 | result and signals any possible waiters that the request ahs finished: |
1461 | result and signals any possible waiters that the request has finished: |
1121 | |
1462 | |
1122 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1463 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1123 | |
1464 | |
1124 | if (end-of-file or data complete) { |
1465 | if (end-of-file or data complete) { |
1125 | $txn->{result} = $txn->{buf}; |
1466 | $txn->{result} = $txn->{buf}; |
1126 | $txn->{finished}->broadcast; |
1467 | $txn->{finished}->send; |
1127 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1468 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1128 | } |
1469 | } |
1129 | |
1470 | |
1130 | The C<result> method, finally, just waits for the finished signal (if the |
1471 | The C<result> method, finally, just waits for the finished signal (if the |
1131 | request was already finished, it doesn't wait, of course, and returns the |
1472 | request was already finished, it doesn't wait, of course, and returns the |
1132 | data: |
1473 | data: |
1133 | |
1474 | |
1134 | $txn->{finished}->wait; |
1475 | $txn->{finished}->recv; |
1135 | return $txn->{result}; |
1476 | return $txn->{result}; |
1136 | |
1477 | |
1137 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1478 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1138 | that occured during request processing. The C<result> method detects |
1479 | that occurred during request processing. The C<result> method detects |
1139 | whether an exception as thrown (it is stored inside the $txn object) |
1480 | whether an exception as thrown (it is stored inside the $txn object) |
1140 | and just throws the exception, which means connection errors and other |
1481 | and just throws the exception, which means connection errors and other |
1141 | problems get reported tot he code that tries to use the result, not in a |
1482 | problems get reported tot he code that tries to use the result, not in a |
1142 | random callback. |
1483 | random callback. |
1143 | |
1484 | |
… | |
… | |
1174 | |
1515 | |
1175 | my $quit = AnyEvent->condvar; |
1516 | my $quit = AnyEvent->condvar; |
1176 | |
1517 | |
1177 | $fcp->txn_client_get ($url)->cb (sub { |
1518 | $fcp->txn_client_get ($url)->cb (sub { |
1178 | ... |
1519 | ... |
1179 | $quit->broadcast; |
1520 | $quit->send; |
1180 | }); |
1521 | }); |
1181 | |
1522 | |
1182 | $quit->wait; |
1523 | $quit->recv; |
1183 | |
1524 | |
1184 | |
1525 | |
1185 | =head1 BENCHMARKS |
1526 | =head1 BENCHMARKS |
1186 | |
1527 | |
1187 | To give you an idea of the performance and overheads that AnyEvent adds |
1528 | To give you an idea of the performance and overheads that AnyEvent adds |
… | |
… | |
1189 | of various event loops I prepared some benchmarks. |
1530 | of various event loops I prepared some benchmarks. |
1190 | |
1531 | |
1191 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1532 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1192 | |
1533 | |
1193 | Here is a benchmark of various supported event models used natively and |
1534 | Here is a benchmark of various supported event models used natively and |
1194 | through anyevent. The benchmark creates a lot of timers (with a zero |
1535 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1195 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1536 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1196 | which it is), lets them fire exactly once and destroys them again. |
1537 | which it is), lets them fire exactly once and destroys them again. |
1197 | |
1538 | |
1198 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1539 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1199 | distribution. |
1540 | distribution. |
… | |
… | |
1216 | all watchers, to avoid adding memory overhead. That means closure creation |
1557 | all watchers, to avoid adding memory overhead. That means closure creation |
1217 | and memory usage is not included in the figures. |
1558 | and memory usage is not included in the figures. |
1218 | |
1559 | |
1219 | I<invoke> is the time, in microseconds, used to invoke a simple |
1560 | I<invoke> is the time, in microseconds, used to invoke a simple |
1220 | callback. The callback simply counts down a Perl variable and after it was |
1561 | callback. The callback simply counts down a Perl variable and after it was |
1221 | invoked "watcher" times, it would C<< ->broadcast >> a condvar once to |
1562 | invoked "watcher" times, it would C<< ->send >> a condvar once to |
1222 | signal the end of this phase. |
1563 | signal the end of this phase. |
1223 | |
1564 | |
1224 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1565 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
1225 | watcher. |
1566 | watcher. |
1226 | |
1567 | |
1227 | =head3 Results |
1568 | =head3 Results |
1228 | |
1569 | |
1229 | name watchers bytes create invoke destroy comment |
1570 | name watchers bytes create invoke destroy comment |
1230 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1571 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1231 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1572 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1232 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1573 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1233 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1574 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1234 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1575 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1235 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1576 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
1236 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1577 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1237 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1578 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1238 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1579 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1239 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1580 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1240 | |
1581 | |
1241 | =head3 Discussion |
1582 | =head3 Discussion |
1242 | |
1583 | |
1243 | The benchmark does I<not> measure scalability of the event loop very |
1584 | The benchmark does I<not> measure scalability of the event loop very |
1244 | well. For example, a select-based event loop (such as the pure perl one) |
1585 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1322 | |
1663 | |
1323 | =back |
1664 | =back |
1324 | |
1665 | |
1325 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1666 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1326 | |
1667 | |
1327 | This benchmark atcually benchmarks the event loop itself. It works by |
1668 | This benchmark actually benchmarks the event loop itself. It works by |
1328 | creating a number of "servers": each server consists of a socketpair, a |
1669 | creating a number of "servers": each server consists of a socket pair, a |
1329 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1670 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1330 | watcher waiting for input on one side of the socket. Each time the socket |
1671 | watcher waiting for input on one side of the socket. Each time the socket |
1331 | watcher reads a byte it will write that byte to a random other "server". |
1672 | watcher reads a byte it will write that byte to a random other "server". |
1332 | |
1673 | |
1333 | The effect is that there will be a lot of I/O watchers, only part of which |
1674 | The effect is that there will be a lot of I/O watchers, only part of which |
1334 | are active at any one point (so there is a constant number of active |
1675 | are active at any one point (so there is a constant number of active |
1335 | fds for each loop iterstaion, but which fds these are is random). The |
1676 | fds for each loop iteration, but which fds these are is random). The |
1336 | timeout is reset each time something is read because that reflects how |
1677 | timeout is reset each time something is read because that reflects how |
1337 | most timeouts work (and puts extra pressure on the event loops). |
1678 | most timeouts work (and puts extra pressure on the event loops). |
1338 | |
1679 | |
1339 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 |
1680 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1340 | (1%) are active. This mirrors the activity of large servers with many |
1681 | (1%) are active. This mirrors the activity of large servers with many |
1341 | connections, most of which are idle at any one point in time. |
1682 | connections, most of which are idle at any one point in time. |
1342 | |
1683 | |
1343 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1684 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1344 | distribution. |
1685 | distribution. |
… | |
… | |
1346 | =head3 Explanation of the columns |
1687 | =head3 Explanation of the columns |
1347 | |
1688 | |
1348 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1689 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1349 | each server has a read and write socket end). |
1690 | each server has a read and write socket end). |
1350 | |
1691 | |
1351 | I<create> is the time it takes to create a socketpair (which is |
1692 | I<create> is the time it takes to create a socket pair (which is |
1352 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1693 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1353 | |
1694 | |
1354 | I<request>, the most important value, is the time it takes to handle a |
1695 | I<request>, the most important value, is the time it takes to handle a |
1355 | single "request", that is, reading the token from the pipe and forwarding |
1696 | single "request", that is, reading the token from the pipe and forwarding |
1356 | it to another server. This includes deleting the old timeout and creating |
1697 | it to another server. This includes deleting the old timeout and creating |
… | |
… | |
1429 | speed most when you have lots of watchers, not when you only have a few of |
1770 | speed most when you have lots of watchers, not when you only have a few of |
1430 | them). |
1771 | them). |
1431 | |
1772 | |
1432 | EV is again fastest. |
1773 | EV is again fastest. |
1433 | |
1774 | |
1434 | Perl again comes second. It is noticably faster than the C-based event |
1775 | Perl again comes second. It is noticeably faster than the C-based event |
1435 | loops Event and Glib, although the difference is too small to really |
1776 | loops Event and Glib, although the difference is too small to really |
1436 | matter. |
1777 | matter. |
1437 | |
1778 | |
1438 | POE also performs much better in this case, but is is still far behind the |
1779 | POE also performs much better in this case, but is is still far behind the |
1439 | others. |
1780 | others. |
… | |
… | |
1444 | |
1785 | |
1445 | =item * C-based event loops perform very well with small number of |
1786 | =item * C-based event loops perform very well with small number of |
1446 | watchers, as the management overhead dominates. |
1787 | watchers, as the management overhead dominates. |
1447 | |
1788 | |
1448 | =back |
1789 | =back |
|
|
1790 | |
|
|
1791 | |
|
|
1792 | =head1 SIGNALS |
|
|
1793 | |
|
|
1794 | AnyEvent currently installs handlers for these signals: |
|
|
1795 | |
|
|
1796 | =over 4 |
|
|
1797 | |
|
|
1798 | =item SIGCHLD |
|
|
1799 | |
|
|
1800 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
1801 | emulation for event loops that do not support them natively. Also, some |
|
|
1802 | event loops install a similar handler. |
|
|
1803 | |
|
|
1804 | =item SIGPIPE |
|
|
1805 | |
|
|
1806 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
1807 | when AnyEvent gets loaded. |
|
|
1808 | |
|
|
1809 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
1810 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
1811 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
1812 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
1813 | some random socket. |
|
|
1814 | |
|
|
1815 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
1816 | that this way, the handler will be restored to defaults on exec. |
|
|
1817 | |
|
|
1818 | Feel free to install your own handler, or reset it to defaults. |
|
|
1819 | |
|
|
1820 | =back |
|
|
1821 | |
|
|
1822 | =cut |
|
|
1823 | |
|
|
1824 | $SIG{PIPE} = sub { } |
|
|
1825 | unless defined $SIG{PIPE}; |
1449 | |
1826 | |
1450 | |
1827 | |
1451 | =head1 FORK |
1828 | =head1 FORK |
1452 | |
1829 | |
1453 | Most event libraries are not fork-safe. The ones who are usually are |
1830 | Most event libraries are not fork-safe. The ones who are usually are |
… | |
… | |
1468 | specified in the variable. |
1845 | specified in the variable. |
1469 | |
1846 | |
1470 | You can make AnyEvent completely ignore this variable by deleting it |
1847 | You can make AnyEvent completely ignore this variable by deleting it |
1471 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1848 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1472 | |
1849 | |
1473 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1850 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1474 | |
1851 | |
1475 | use AnyEvent; |
1852 | use AnyEvent; |
1476 | |
1853 | |
1477 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1854 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1478 | be used to probe what backend is used and gain other information (which is |
1855 | be used to probe what backend is used and gain other information (which is |
1479 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1856 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
1857 | $ENV{PERL_ANYEGENT_STRICT}. |
|
|
1858 | |
|
|
1859 | |
|
|
1860 | =head1 BUGS |
|
|
1861 | |
|
|
1862 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
|
|
1863 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
|
|
1864 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
|
|
1865 | mamleaks, such as leaking on C<map> and C<grep> but it is usually not as |
|
|
1866 | pronounced). |
1480 | |
1867 | |
1481 | |
1868 | |
1482 | =head1 SEE ALSO |
1869 | =head1 SEE ALSO |
|
|
1870 | |
|
|
1871 | Utility functions: L<AnyEvent::Util>. |
1483 | |
1872 | |
1484 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1873 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1485 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1874 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1486 | |
1875 | |
1487 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1876 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1488 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1877 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1489 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1878 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1490 | L<AnyEvent::Impl::POE>. |
1879 | L<AnyEvent::Impl::POE>. |
1491 | |
1880 | |
|
|
1881 | Non-blocking file handles, sockets, TCP clients and |
|
|
1882 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
|
|
1883 | |
|
|
1884 | Asynchronous DNS: L<AnyEvent::DNS>. |
|
|
1885 | |
1492 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1886 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
1493 | |
1887 | |
1494 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
1888 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
1495 | |
1889 | |
1496 | |
1890 | |
1497 | =head1 AUTHOR |
1891 | =head1 AUTHOR |
1498 | |
1892 | |
1499 | Marc Lehmann <schmorp@schmorp.de> |
1893 | Marc Lehmann <schmorp@schmorp.de> |
1500 | http://home.schmorp.de/ |
1894 | http://home.schmorp.de/ |
1501 | |
1895 | |
1502 | =cut |
1896 | =cut |
1503 | |
1897 | |
1504 | 1 |
1898 | 1 |
1505 | |
1899 | |