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 }); |
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39 | |
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40 | =head1 INTRODUCTION/TUTORIAL |
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41 | |
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42 | This manpage is mainly a reference manual. If you are interested |
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43 | in a tutorial or some gentle introduction, have a look at the |
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44 | L<AnyEvent::Intro> manpage. |
22 | |
45 | |
23 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
46 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
24 | |
47 | |
25 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
48 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
26 | nowadays. So what is different about AnyEvent? |
49 | nowadays. So what is different about AnyEvent? |
27 | |
50 | |
28 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
51 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
29 | policy> and AnyEvent is I<small and efficient>. |
52 | policy> and AnyEvent is I<small and efficient>. |
30 | |
53 | |
31 | 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 |
32 | 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 |
33 | pragmatic way. For event models and certain classes of immortals alike, |
56 | 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, |
57 | 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 |
58 | only one event loop can be active at the same time in a process. AnyEvent |
36 | 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. |
37 | |
61 | |
38 | 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 |
39 | 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 |
40 | religion, a way of living, and most importantly: without forcing your |
64 | 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 |
65 | module users into the same thing by forcing them to use the same event |
42 | model you use. |
66 | model you use. |
43 | |
67 | |
44 | 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 |
45 | 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 |
46 | 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 |
47 | cannot use anything else, as it is simply incompatible to everything that |
71 | 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 |
72 | 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. |
73 | module are I<also> forced to use the same event loop you use. |
50 | |
74 | |
51 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
75 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
52 | 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 |
53 | 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 |
54 | 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, |
55 | 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 |
56 | 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 |
57 | 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 |
58 | event loops to AnyEvent, too, so it is future-proof). |
82 | to AnyEvent, too, so it is future-proof). |
59 | |
83 | |
60 | 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 |
61 | 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 |
62 | modules, you get an enourmous amount of code and strict rules you have to |
86 | 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 |
87 | 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 |
88 | offering the functionality that is necessary, in as thin as a wrapper as |
65 | technically possible. |
89 | technically possible. |
66 | |
90 | |
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91 | Of course, AnyEvent comes with a big (and fully optional!) toolbox |
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92 | of useful functionality, such as an asynchronous DNS resolver, 100% |
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93 | non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms |
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94 | such as Windows) and lots of real-world knowledge and workarounds for |
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95 | platform bugs and differences. |
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96 | |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
97 | 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 |
98 | useful) and you want to force your users to use the one and only event |
69 | model, you should I<not> use this module. |
99 | model, you should I<not> use this module. |
70 | |
100 | |
71 | =head1 DESCRIPTION |
101 | =head1 DESCRIPTION |
72 | |
102 | |
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102 | starts using it, all bets are off. Maybe you should tell their authors to |
132 | 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... |
133 | use AnyEvent so their modules work together with others seamlessly... |
104 | |
134 | |
105 | The pure-perl implementation of AnyEvent is called |
135 | The pure-perl implementation of AnyEvent is called |
106 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
136 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
107 | explicitly. |
137 | explicitly and enjoy the high availability of that event loop :) |
108 | |
138 | |
109 | =head1 WATCHERS |
139 | =head1 WATCHERS |
110 | |
140 | |
111 | AnyEvent has the central concept of a I<watcher>, which is an object that |
141 | 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 |
142 | stores relevant data for each kind of event you are waiting for, such as |
113 | the callback to call, the filehandle to watch, etc. |
143 | the callback to call, the file handle to watch, etc. |
114 | |
144 | |
115 | These watchers are normal Perl objects with normal Perl lifetime. After |
145 | These watchers are normal Perl objects with normal Perl lifetime. After |
116 | 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 |
117 | 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 |
118 | is in control). |
148 | is in control). |
119 | |
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 | |
120 | 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 |
121 | 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 |
122 | to it). |
158 | to it). |
123 | |
159 | |
124 | 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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126 | Many watchers either are used with "recursion" (repeating timers for |
162 | Many watchers either are used with "recursion" (repeating timers for |
127 | example), or need to refer to their watcher object in other ways. |
163 | example), or need to refer to their watcher object in other ways. |
128 | |
164 | |
129 | An any way to achieve that is this pattern: |
165 | An any way to achieve that is this pattern: |
130 | |
166 | |
131 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
167 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
132 | # you can use $w here, for example to undef it |
168 | # you can use $w here, for example to undef it |
133 | undef $w; |
169 | undef $w; |
134 | }); |
170 | }); |
135 | |
171 | |
136 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
172 | 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 |
173 | my variables are only visible after the statement in which they are |
138 | declared. |
174 | declared. |
139 | |
175 | |
140 | =head2 I/O WATCHERS |
176 | =head2 I/O WATCHERS |
141 | |
177 | |
142 | 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 |
143 | with the following mandatory key-value pairs as arguments: |
179 | with the following mandatory key-value pairs as arguments: |
144 | |
180 | |
145 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
181 | C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch |
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182 | for events (AnyEvent might or might not keep a reference to this file |
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183 | 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 | |
146 | 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 |
147 | 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 | |
148 | 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. |
149 | becomes ready. |
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150 | |
192 | |
151 | Although the callback might get passed parameters, their value and |
193 | Although the callback might get passed parameters, their value and |
152 | presence is undefined and you cannot rely on them. Portable AnyEvent |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
153 | callbacks cannot use arguments passed to I/O watcher callbacks. |
195 | callbacks cannot use arguments passed to I/O watcher callbacks. |
154 | |
196 | |
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158 | |
200 | |
159 | Some event loops issue spurious readyness notifications, so you should |
201 | Some event loops issue spurious readyness notifications, so you should |
160 | 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 |
161 | handles. |
203 | handles. |
162 | |
204 | |
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 |
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 | |
166 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
208 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
167 | chomp (my $input = <STDIN>); |
209 | chomp (my $input = <STDIN>); |
168 | warn "read: $input\n"; |
210 | warn "read: $input\n"; |
169 | undef $w; |
211 | undef $w; |
170 | }); |
212 | }); |
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180 | |
222 | |
181 | Although the callback might get passed parameters, their value and |
223 | Although the callback might get passed parameters, their value and |
182 | presence is undefined and you cannot rely on them. Portable AnyEvent |
224 | presence is undefined and you cannot rely on them. Portable AnyEvent |
183 | callbacks cannot use arguments passed to time watcher callbacks. |
225 | callbacks cannot use arguments passed to time watcher callbacks. |
184 | |
226 | |
185 | The timer callback will be invoked at most once: if you want a repeating |
227 | 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 |
228 | parameter, C<interval>, as a strictly positive number (> 0), then the |
187 | and Glib). |
229 | callback will be invoked regularly at that interval (in fractional |
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230 | seconds) after the first invocation. If C<interval> is specified with a |
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231 | false value, then it is treated as if it were missing. |
188 | |
232 | |
189 | Example: |
233 | The callback will be rescheduled before invoking the callback, but no |
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234 | attempt is done to avoid timer drift in most backends, so the interval is |
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235 | only approximate. |
190 | |
236 | |
191 | # fire an event after 7.7 seconds |
237 | Example: fire an event after 7.7 seconds. |
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238 | |
192 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
239 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
193 | warn "timeout\n"; |
240 | warn "timeout\n"; |
194 | }); |
241 | }); |
195 | |
242 | |
196 | # to cancel the timer: |
243 | # to cancel the timer: |
197 | undef $w; |
244 | undef $w; |
198 | |
245 | |
199 | Example 2: |
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200 | |
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201 | # fire an event after 0.5 seconds, then roughly every second |
246 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
202 | my $w; |
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203 | |
247 | |
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); |
248 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
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249 | warn "timeout\n"; |
207 | }; |
250 | }; |
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 | |
251 | |
212 | =head3 TIMING ISSUES |
252 | =head3 TIMING ISSUES |
213 | |
253 | |
214 | There are two ways to handle timers: based on real time (relative, "fire |
254 | 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 |
255 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
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227 | timers. |
267 | timers. |
228 | |
268 | |
229 | AnyEvent always prefers relative timers, if available, matching the |
269 | AnyEvent always prefers relative timers, if available, matching the |
230 | AnyEvent API. |
270 | AnyEvent API. |
231 | |
271 | |
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272 | AnyEvent has two additional methods that return the "current time": |
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273 | |
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274 | =over 4 |
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275 | |
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276 | =item AnyEvent->time |
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277 | |
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278 | This returns the "current wallclock time" as a fractional number of |
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279 | seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time> |
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280 | return, and the result is guaranteed to be compatible with those). |
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281 | |
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282 | It progresses independently of any event loop processing, i.e. each call |
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283 | will check the system clock, which usually gets updated frequently. |
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284 | |
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285 | =item AnyEvent->now |
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286 | |
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287 | This also returns the "current wallclock time", but unlike C<time>, above, |
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288 | this value might change only once per event loop iteration, depending on |
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289 | the event loop (most return the same time as C<time>, above). This is the |
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290 | time that AnyEvent's timers get scheduled against. |
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291 | |
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292 | I<In almost all cases (in all cases if you don't care), this is the |
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293 | function to call when you want to know the current time.> |
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294 | |
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295 | This function is also often faster then C<< AnyEvent->time >>, and |
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296 | thus the preferred method if you want some timestamp (for example, |
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297 | L<AnyEvent::Handle> uses this to update it's activity timeouts). |
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298 | |
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299 | The rest of this section is only of relevance if you try to be very exact |
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300 | with your timing, you can skip it without bad conscience. |
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301 | |
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302 | For a practical example of when these times differ, consider L<Event::Lib> |
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303 | and L<EV> and the following set-up: |
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304 | |
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305 | The event loop is running and has just invoked one of your callback at |
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306 | time=500 (assume no other callbacks delay processing). In your callback, |
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307 | you wait a second by executing C<sleep 1> (blocking the process for a |
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308 | second) and then (at time=501) you create a relative timer that fires |
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309 | after three seconds. |
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310 | |
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311 | With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will |
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312 | both return C<501>, because that is the current time, and the timer will |
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313 | be scheduled to fire at time=504 (C<501> + C<3>). |
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314 | |
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315 | With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current |
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316 | time), but C<< AnyEvent->now >> returns C<500>, as that is the time the |
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317 | last event processing phase started. With L<EV>, your timer gets scheduled |
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318 | to run at time=503 (C<500> + C<3>). |
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319 | |
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320 | In one sense, L<Event::Lib> is more exact, as it uses the current time |
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321 | regardless of any delays introduced by event processing. However, most |
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322 | callbacks do not expect large delays in processing, so this causes a |
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323 | higher drift (and a lot more system calls to get the current time). |
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324 | |
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325 | In another sense, L<EV> is more exact, as your timer will be scheduled at |
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326 | the same time, regardless of how long event processing actually took. |
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327 | |
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328 | In either case, if you care (and in most cases, you don't), then you |
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329 | can get whatever behaviour you want with any event loop, by taking the |
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330 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
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331 | account. |
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332 | |
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333 | =item AnyEvent->now_update |
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334 | |
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335 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
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336 | the current time for each loop iteration (see the discussion of L<< |
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337 | AnyEvent->now >>, above). |
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338 | |
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339 | When a callback runs for a long time (or when the process sleeps), then |
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340 | this "current" time will differ substantially from the real time, which |
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341 | might affect timers and time-outs. |
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342 | |
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343 | When this is the case, you can call this method, which will update the |
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344 | event loop's idea of "current time". |
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345 | |
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346 | Note that updating the time I<might> cause some events to be handled. |
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347 | |
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348 | =back |
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349 | |
232 | =head2 SIGNAL WATCHERS |
350 | =head2 SIGNAL WATCHERS |
233 | |
351 | |
234 | You can watch for signals using a signal watcher, C<signal> is the signal |
352 | 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 |
353 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
236 | be invoked whenever a signal occurs. |
354 | callback to be invoked whenever a signal occurs. |
237 | |
355 | |
238 | Although the callback might get passed parameters, their value and |
356 | Although the callback might get passed parameters, their value and |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
357 | presence is undefined and you cannot rely on them. Portable AnyEvent |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
358 | callbacks cannot use arguments passed to signal watcher callbacks. |
241 | |
359 | |
242 | Multiple signal occurances can be clumped together into one callback |
360 | Multiple signal occurrences can be clumped together into one callback |
243 | invocation, and callback invocation will be synchronous. synchronous means |
361 | invocation, and callback invocation will be synchronous. Synchronous means |
244 | that it might take a while until the signal gets handled by the process, |
362 | 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. |
363 | but it is guaranteed not to interrupt any other callbacks. |
246 | |
364 | |
247 | The main advantage of using these watchers is that you can share a signal |
365 | The main advantage of using these watchers is that you can share a signal |
248 | between multiple watchers. |
366 | between multiple watchers, and AnyEvent will ensure that signals will not |
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367 | interrupt your program at bad times. |
249 | |
368 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
369 | This watcher might use C<%SIG> (depending on the event loop used), |
251 | directly will likely not work correctly. |
370 | so programs overwriting those signals directly will likely not work |
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371 | correctly. |
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372 | |
|
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373 | Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not |
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374 | support attaching callbacks to signals, which is a pity, as you cannot do |
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375 | race-free signal handling in perl. AnyEvent will try to do it's best, but |
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376 | in some cases, signals will be delayed. The maximum time a signal might |
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377 | be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 |
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378 | seconds). This variable can be changed only before the first signal |
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379 | watcher is created, and should be left alone otherwise. Higher values |
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380 | will cause fewer spurious wake-ups, which is better for power and CPU |
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381 | saving. All these problems can be avoided by installing the optional |
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382 | L<Async::Interrupt> module. |
252 | |
383 | |
253 | Example: exit on SIGINT |
384 | Example: exit on SIGINT |
254 | |
385 | |
255 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
386 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
256 | |
387 | |
257 | =head2 CHILD PROCESS WATCHERS |
388 | =head2 CHILD PROCESS WATCHERS |
258 | |
389 | |
259 | You can also watch on a child process exit and catch its exit status. |
390 | You can also watch on a child process exit and catch its exit status. |
260 | |
391 | |
261 | The child process is specified by the C<pid> argument (if set to C<0>, it |
392 | 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 |
393 | 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 |
394 | 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 |
395 | any trace events (stopped/continued). |
265 | and exit status (as returned by waitpid), so unlike other watcher types, |
396 | |
266 | you I<can> rely on child watcher callback arguments. |
397 | The callback will be called with the pid and exit status (as returned by |
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398 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
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399 | callback arguments. |
|
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400 | |
|
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401 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
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402 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
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403 | random child processes (waiting for specific child processes, e.g. inside |
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404 | C<system>, is just fine). |
267 | |
405 | |
268 | There is a slight catch to child watchers, however: you usually start them |
406 | 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 |
407 | I<after> the child process was created, and this means the process could |
270 | have exited already (and no SIGCHLD will be sent anymore). |
408 | have exited already (and no SIGCHLD will be sent anymore). |
271 | |
409 | |
272 | Not all event models handle this correctly (POE doesn't), but even for |
410 | Not all event models handle this correctly (neither POE nor IO::Async do, |
|
|
411 | see their AnyEvent::Impl manpages for details), but even for event models |
273 | event models that I<do> handle this correctly, they usually need to be |
412 | that I<do> handle this correctly, they usually need to be loaded before |
274 | loaded before the process exits (i.e. before you fork in the first place). |
413 | the process exits (i.e. before you fork in the first place). AnyEvent's |
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414 | pure perl event loop handles all cases correctly regardless of when you |
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415 | start the watcher. |
275 | |
416 | |
276 | This means you cannot create a child watcher as the very first thing in an |
417 | This means you cannot create a child watcher as the very first |
277 | AnyEvent program, you I<have> to create at least one watcher before you |
418 | thing in an AnyEvent program, you I<have> to create at least one |
278 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
419 | watcher before you C<fork> the child (alternatively, you can call |
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420 | C<AnyEvent::detect>). |
|
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421 | |
|
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422 | As most event loops do not support waiting for child events, they will be |
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423 | emulated by AnyEvent in most cases, in which the latency and race problems |
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424 | mentioned in the description of signal watchers apply. |
279 | |
425 | |
280 | Example: fork a process and wait for it |
426 | Example: fork a process and wait for it |
281 | |
427 | |
282 | my $done = AnyEvent->condvar; |
428 | my $done = AnyEvent->condvar; |
283 | |
429 | |
284 | my $pid = fork or exit 5; |
430 | my $pid = fork or exit 5; |
285 | |
431 | |
286 | my $w = AnyEvent->child ( |
432 | my $w = AnyEvent->child ( |
287 | pid => $pid, |
433 | pid => $pid, |
288 | cb => sub { |
434 | cb => sub { |
289 | my ($pid, $status) = @_; |
435 | my ($pid, $status) = @_; |
290 | warn "pid $pid exited with status $status"; |
436 | warn "pid $pid exited with status $status"; |
291 | $done->send; |
437 | $done->send; |
292 | }, |
438 | }, |
293 | ); |
439 | ); |
294 | |
440 | |
295 | # do something else, then wait for process exit |
441 | # do something else, then wait for process exit |
296 | $done->recv; |
442 | $done->recv; |
|
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443 | |
|
|
444 | =head2 IDLE WATCHERS |
|
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445 | |
|
|
446 | Sometimes there is a need to do something, but it is not so important |
|
|
447 | to do it instantly, but only when there is nothing better to do. This |
|
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448 | "nothing better to do" is usually defined to be "no other events need |
|
|
449 | attention by the event loop". |
|
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450 | |
|
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451 | Idle watchers ideally get invoked when the event loop has nothing |
|
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452 | better to do, just before it would block the process to wait for new |
|
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453 | events. Instead of blocking, the idle watcher is invoked. |
|
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454 | |
|
|
455 | Most event loops unfortunately do not really support idle watchers (only |
|
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456 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
|
|
457 | will simply call the callback "from time to time". |
|
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458 | |
|
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459 | Example: read lines from STDIN, but only process them when the |
|
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460 | program is otherwise idle: |
|
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461 | |
|
|
462 | my @lines; # read data |
|
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463 | my $idle_w; |
|
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464 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
|
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465 | push @lines, scalar <STDIN>; |
|
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466 | |
|
|
467 | # start an idle watcher, if not already done |
|
|
468 | $idle_w ||= AnyEvent->idle (cb => sub { |
|
|
469 | # handle only one line, when there are lines left |
|
|
470 | if (my $line = shift @lines) { |
|
|
471 | print "handled when idle: $line"; |
|
|
472 | } else { |
|
|
473 | # otherwise disable the idle watcher again |
|
|
474 | undef $idle_w; |
|
|
475 | } |
|
|
476 | }); |
|
|
477 | }); |
297 | |
478 | |
298 | =head2 CONDITION VARIABLES |
479 | =head2 CONDITION VARIABLES |
299 | |
480 | |
300 | If you are familiar with some event loops you will know that all of them |
481 | 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 |
482 | require you to run some blocking "loop", "run" or similar function that |
302 | will actively watch for new events and call your callbacks. |
483 | will actively watch for new events and call your callbacks. |
303 | |
484 | |
304 | AnyEvent is different, it expects somebody else to run the event loop and |
485 | AnyEvent is slightly different: it expects somebody else to run the event |
305 | will only block when necessary (usually when told by the user). |
486 | loop and will only block when necessary (usually when told by the user). |
306 | |
487 | |
307 | The instrument to do that is called a "condition variable", so called |
488 | The instrument to do that is called a "condition variable", so called |
308 | because they represent a condition that must become true. |
489 | because they represent a condition that must become true. |
|
|
490 | |
|
|
491 | Now is probably a good time to look at the examples further below. |
309 | |
492 | |
310 | Condition variables can be created by calling the C<< AnyEvent->condvar |
493 | Condition variables can be created by calling the C<< AnyEvent->condvar |
311 | >> method, usually without arguments. The only argument pair allowed is |
494 | >> method, usually without arguments. The only argument pair allowed is |
312 | C<cb>, which specifies a callback to be called when the condition variable |
495 | C<cb>, which specifies a callback to be called when the condition variable |
313 | becomes true. |
496 | becomes true, with the condition variable as the first argument (but not |
|
|
497 | the results). |
314 | |
498 | |
315 | After creation, the conditon variable is "false" until it becomes "true" |
499 | After creation, the condition variable is "false" until it becomes "true" |
316 | by calling the C<send> method. |
500 | by calling the C<send> method (or calling the condition variable as if it |
|
|
501 | were a callback, read about the caveats in the description for the C<< |
|
|
502 | ->send >> method). |
317 | |
503 | |
318 | Condition variables are similar to callbacks, except that you can |
504 | Condition variables are similar to callbacks, except that you can |
319 | optionally wait for them. They can also be called merge points - points |
505 | optionally wait for them. They can also be called merge points - points |
320 | in time where multiple outstandign events have been processed. And yet |
506 | in time where multiple outstanding events have been processed. And yet |
321 | another way to call them is transations - each condition variable can be |
507 | 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 |
508 | used to represent a transaction, which finishes at some point and delivers |
323 | a result. |
509 | a result. |
324 | |
510 | |
325 | Condition variables are very useful to signal that something has finished, |
511 | Condition variables are very useful to signal that something has finished, |
326 | for example, if you write a module that does asynchronous http requests, |
512 | 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 |
518 | 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 |
519 | 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. |
520 | button of your app, which would C<< ->send >> the "quit" event. |
335 | |
521 | |
336 | Note that condition variables recurse into the event loop - if you have |
522 | 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 |
523 | 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 |
524 | 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, |
525 | you should avoid making a blocking wait yourself, at least in callbacks, |
340 | as this asks for trouble. |
526 | as this asks for trouble. |
341 | |
527 | |
342 | Condition variables are represented by hash refs in perl, and the keys |
528 | Condition variables are represented by hash refs in perl, and the keys |
… | |
… | |
347 | |
533 | |
348 | There are two "sides" to a condition variable - the "producer side" which |
534 | There are two "sides" to a condition variable - the "producer side" which |
349 | eventually calls C<< -> send >>, and the "consumer side", which waits |
535 | eventually calls C<< -> send >>, and the "consumer side", which waits |
350 | for the send to occur. |
536 | for the send to occur. |
351 | |
537 | |
352 | Example: |
538 | Example: wait for a timer. |
353 | |
539 | |
354 | # wait till the result is ready |
540 | # wait till the result is ready |
355 | my $result_ready = AnyEvent->condvar; |
541 | my $result_ready = AnyEvent->condvar; |
356 | |
542 | |
357 | # do something such as adding a timer |
543 | # do something such as adding a timer |
… | |
… | |
362 | after => 1, |
548 | after => 1, |
363 | cb => sub { $result_ready->send }, |
549 | cb => sub { $result_ready->send }, |
364 | ); |
550 | ); |
365 | |
551 | |
366 | # this "blocks" (while handling events) till the callback |
552 | # this "blocks" (while handling events) till the callback |
367 | # calls send |
553 | # calls -<send |
368 | $result_ready->recv; |
554 | $result_ready->recv; |
|
|
555 | |
|
|
556 | Example: wait for a timer, but take advantage of the fact that condition |
|
|
557 | variables are also callable directly. |
|
|
558 | |
|
|
559 | my $done = AnyEvent->condvar; |
|
|
560 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
|
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561 | $done->recv; |
|
|
562 | |
|
|
563 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
564 | callbacks. This is how you make a synchronous call, for example from |
|
|
565 | the main program: |
|
|
566 | |
|
|
567 | use AnyEvent::CouchDB; |
|
|
568 | |
|
|
569 | ... |
|
|
570 | |
|
|
571 | my @info = $couchdb->info->recv; |
|
|
572 | |
|
|
573 | And this is how you would just set a callback to be called whenever the |
|
|
574 | results are available: |
|
|
575 | |
|
|
576 | $couchdb->info->cb (sub { |
|
|
577 | my @info = $_[0]->recv; |
|
|
578 | }); |
369 | |
579 | |
370 | =head3 METHODS FOR PRODUCERS |
580 | =head3 METHODS FOR PRODUCERS |
371 | |
581 | |
372 | These methods should only be used by the producing side, i.e. the |
582 | 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 |
583 | code/module that eventually sends the signal. Note that it is also |
… | |
… | |
386 | immediately from within send. |
596 | immediately from within send. |
387 | |
597 | |
388 | Any arguments passed to the C<send> call will be returned by all |
598 | Any arguments passed to the C<send> call will be returned by all |
389 | future C<< ->recv >> calls. |
599 | future C<< ->recv >> calls. |
390 | |
600 | |
|
|
601 | Condition variables are overloaded so one can call them directly (as if |
|
|
602 | they were a code reference). Calling them directly is the same as calling |
|
|
603 | C<send>. |
|
|
604 | |
391 | =item $cv->croak ($error) |
605 | =item $cv->croak ($error) |
392 | |
606 | |
393 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
607 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
394 | C<Carp::croak> with the given error message/object/scalar. |
608 | C<Carp::croak> with the given error message/object/scalar. |
395 | |
609 | |
396 | This can be used to signal any errors to the condition variable |
610 | This can be used to signal any errors to the condition variable |
397 | user/consumer. |
611 | user/consumer. Doing it this way instead of calling C<croak> directly |
|
|
612 | delays the error detetcion, but has the overwhelmign advantage that it |
|
|
613 | diagnoses the error at the place where the result is expected, and not |
|
|
614 | deep in some event clalback without connection to the actual code causing |
|
|
615 | the problem. |
398 | |
616 | |
399 | =item $cv->begin ([group callback]) |
617 | =item $cv->begin ([group callback]) |
400 | |
618 | |
401 | =item $cv->end |
619 | =item $cv->end |
402 | |
|
|
403 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
|
|
404 | |
620 | |
405 | These two methods can be used to combine many transactions/events into |
621 | These two methods can be used to combine many transactions/events into |
406 | one. For example, a function that pings many hosts in parallel might want |
622 | one. For example, a function that pings many hosts in parallel might want |
407 | to use a condition variable for the whole process. |
623 | to use a condition variable for the whole process. |
408 | |
624 | |
… | |
… | |
410 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
626 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
411 | >>, the (last) callback passed to C<begin> will be executed. That callback |
627 | >>, the (last) callback passed to C<begin> will be executed. That callback |
412 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
628 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
413 | callback was set, C<send> will be called without any arguments. |
629 | callback was set, C<send> will be called without any arguments. |
414 | |
630 | |
415 | Let's clarify this with the ping example: |
631 | You can think of C<< $cv->send >> giving you an OR condition (one call |
|
|
632 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
|
|
633 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
|
|
634 | |
|
|
635 | Let's start with a simple example: you have two I/O watchers (for example, |
|
|
636 | STDOUT and STDERR for a program), and you want to wait for both streams to |
|
|
637 | close before activating a condvar: |
|
|
638 | |
|
|
639 | my $cv = AnyEvent->condvar; |
|
|
640 | |
|
|
641 | $cv->begin; # first watcher |
|
|
642 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
|
|
643 | defined sysread $fh1, my $buf, 4096 |
|
|
644 | or $cv->end; |
|
|
645 | }); |
|
|
646 | |
|
|
647 | $cv->begin; # second watcher |
|
|
648 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
649 | defined sysread $fh2, my $buf, 4096 |
|
|
650 | or $cv->end; |
|
|
651 | }); |
|
|
652 | |
|
|
653 | $cv->recv; |
|
|
654 | |
|
|
655 | This works because for every event source (EOF on file handle), there is |
|
|
656 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
|
|
657 | sending. |
|
|
658 | |
|
|
659 | The ping example mentioned above is slightly more complicated, as the |
|
|
660 | there are results to be passwd back, and the number of tasks that are |
|
|
661 | begung can potentially be zero: |
416 | |
662 | |
417 | my $cv = AnyEvent->condvar; |
663 | my $cv = AnyEvent->condvar; |
418 | |
664 | |
419 | my %result; |
665 | my %result; |
420 | $cv->begin (sub { $cv->send (\%result) }); |
666 | $cv->begin (sub { $cv->send (\%result) }); |
… | |
… | |
440 | loop, which serves two important purposes: first, it sets the callback |
686 | loop, which serves two important purposes: first, it sets the callback |
441 | to be called once the counter reaches C<0>, and second, it ensures that |
687 | to be called once the counter reaches C<0>, and second, it ensures that |
442 | C<send> is called even when C<no> hosts are being pinged (the loop |
688 | C<send> is called even when C<no> hosts are being pinged (the loop |
443 | doesn't execute once). |
689 | doesn't execute once). |
444 | |
690 | |
445 | This is the general pattern when you "fan out" into multiple subrequests: |
691 | This is the general pattern when you "fan out" into multiple (but |
446 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
692 | potentially none) subrequests: use an outer C<begin>/C<end> pair to set |
447 | is called at least once, and then, for each subrequest you start, call |
693 | the callback and ensure C<end> is called at least once, and then, for each |
448 | C<begin> and for eahc subrequest you finish, call C<end>. |
694 | subrequest you start, call C<begin> and for each subrequest you finish, |
|
|
695 | call C<end>. |
449 | |
696 | |
450 | =back |
697 | =back |
451 | |
698 | |
452 | =head3 METHODS FOR CONSUMERS |
699 | =head3 METHODS FOR CONSUMERS |
453 | |
700 | |
… | |
… | |
469 | function will call C<croak>. |
716 | function will call C<croak>. |
470 | |
717 | |
471 | In list context, all parameters passed to C<send> will be returned, |
718 | In list context, all parameters passed to C<send> will be returned, |
472 | in scalar context only the first one will be returned. |
719 | in scalar context only the first one will be returned. |
473 | |
720 | |
|
|
721 | Note that doing a blocking wait in a callback is not supported by any |
|
|
722 | event loop, that is, recursive invocation of a blocking C<< ->recv |
|
|
723 | >> is not allowed, and the C<recv> call will C<croak> if such a |
|
|
724 | condition is detected. This condition can be slightly loosened by using |
|
|
725 | L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from |
|
|
726 | any thread that doesn't run the event loop itself. |
|
|
727 | |
474 | Not all event models support a blocking wait - some die in that case |
728 | Not all event models support a blocking wait - some die in that case |
475 | (programs might want to do that to stay interactive), so I<if you are |
729 | (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 |
730 | using this from a module, never require a blocking wait>. Instead, let the |
477 | caller decide whether the call will block or not (for example, by coupling |
731 | caller decide whether the call will block or not (for example, by coupling |
478 | condition variables with some kind of request results and supporting |
732 | condition variables with some kind of request results and supporting |
479 | callbacks so the caller knows that getting the result will not block, |
733 | callbacks so the caller knows that getting the result will not block, |
480 | while still suppporting blocking waits if the caller so desires). |
734 | while still supporting blocking waits if the caller so desires). |
481 | |
|
|
482 | 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 |
|
|
484 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
|
|
485 | can supply. |
|
|
486 | |
|
|
487 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
|
|
488 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
|
|
489 | versions and also integrates coroutines into AnyEvent, making blocking |
|
|
490 | C<< ->recv >> calls perfectly safe as long as they are done from another |
|
|
491 | coroutine (one that doesn't run the event loop). |
|
|
492 | |
735 | |
493 | You can ensure that C<< -recv >> never blocks by setting a callback and |
736 | You can ensure that C<< -recv >> never blocks by setting a callback and |
494 | only calling C<< ->recv >> from within that callback (or at a later |
737 | only calling C<< ->recv >> from within that callback (or at a later |
495 | time). This will work even when the event loop does not support blocking |
738 | time). This will work even when the event loop does not support blocking |
496 | waits otherwise. |
739 | waits otherwise. |
… | |
… | |
498 | =item $bool = $cv->ready |
741 | =item $bool = $cv->ready |
499 | |
742 | |
500 | Returns true when the condition is "true", i.e. whether C<send> or |
743 | Returns true when the condition is "true", i.e. whether C<send> or |
501 | C<croak> have been called. |
744 | C<croak> have been called. |
502 | |
745 | |
503 | =item $cb = $cv->cb ([new callback]) |
746 | =item $cb = $cv->cb ($cb->($cv)) |
504 | |
747 | |
505 | This is a mutator function that returns the callback set and optionally |
748 | This is a mutator function that returns the callback set and optionally |
506 | replaces it before doing so. |
749 | replaces it before doing so. |
507 | |
750 | |
508 | The callback will be called when the condition becomes "true", i.e. when |
751 | 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 |
752 | 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. |
753 | variable itself. Calling C<recv> inside the callback or at any later time |
|
|
754 | is guaranteed not to block. |
511 | |
755 | |
512 | =back |
756 | =back |
513 | |
757 | |
|
|
758 | =head1 SUPPORTED EVENT LOOPS/BACKENDS |
|
|
759 | |
|
|
760 | The available backend classes are (every class has its own manpage): |
|
|
761 | |
|
|
762 | =over 4 |
|
|
763 | |
|
|
764 | =item Backends that are autoprobed when no other event loop can be found. |
|
|
765 | |
|
|
766 | EV is the preferred backend when no other event loop seems to be in |
|
|
767 | use. If EV is not installed, then AnyEvent will try Event, and, failing |
|
|
768 | that, will fall back to its own pure-perl implementation, which is |
|
|
769 | available everywhere as it comes with AnyEvent itself. |
|
|
770 | |
|
|
771 | AnyEvent::Impl::EV based on EV (interface to libev, best choice). |
|
|
772 | AnyEvent::Impl::Event based on Event, very stable, few glitches. |
|
|
773 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
774 | |
|
|
775 | =item Backends that are transparently being picked up when they are used. |
|
|
776 | |
|
|
777 | These will be used when they are currently loaded when the first watcher |
|
|
778 | is created, in which case it is assumed that the application is using |
|
|
779 | them. This means that AnyEvent will automatically pick the right backend |
|
|
780 | when the main program loads an event module before anything starts to |
|
|
781 | create watchers. Nothing special needs to be done by the main program. |
|
|
782 | |
|
|
783 | AnyEvent::Impl::Glib based on Glib, slow but very stable. |
|
|
784 | AnyEvent::Impl::Tk based on Tk, very broken. |
|
|
785 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
786 | AnyEvent::Impl::POE based on POE, very slow, some limitations. |
|
|
787 | |
|
|
788 | =item Backends with special needs. |
|
|
789 | |
|
|
790 | Qt requires the Qt::Application to be instantiated first, but will |
|
|
791 | otherwise be picked up automatically. As long as the main program |
|
|
792 | instantiates the application before any AnyEvent watchers are created, |
|
|
793 | everything should just work. |
|
|
794 | |
|
|
795 | AnyEvent::Impl::Qt based on Qt. |
|
|
796 | |
|
|
797 | Support for IO::Async can only be partial, as it is too broken and |
|
|
798 | architecturally limited to even support the AnyEvent API. It also |
|
|
799 | is the only event loop that needs the loop to be set explicitly, so |
|
|
800 | it can only be used by a main program knowing about AnyEvent. See |
|
|
801 | L<AnyEvent::Impl::Async> for the gory details. |
|
|
802 | |
|
|
803 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed. |
|
|
804 | |
|
|
805 | =item Event loops that are indirectly supported via other backends. |
|
|
806 | |
|
|
807 | Some event loops can be supported via other modules: |
|
|
808 | |
|
|
809 | There is no direct support for WxWidgets (L<Wx>) or L<Prima>. |
|
|
810 | |
|
|
811 | B<WxWidgets> has no support for watching file handles. However, you can |
|
|
812 | use WxWidgets through the POE adaptor, as POE has a Wx backend that simply |
|
|
813 | polls 20 times per second, which was considered to be too horrible to even |
|
|
814 | consider for AnyEvent. |
|
|
815 | |
|
|
816 | B<Prima> is not supported as nobody seems to be using it, but it has a POE |
|
|
817 | backend, so it can be supported through POE. |
|
|
818 | |
|
|
819 | AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to |
|
|
820 | load L<POE> when detecting them, in the hope that POE will pick them up, |
|
|
821 | in which case everything will be automatic. |
|
|
822 | |
|
|
823 | =back |
|
|
824 | |
514 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
825 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
515 | |
826 | |
|
|
827 | These are not normally required to use AnyEvent, but can be useful to |
|
|
828 | write AnyEvent extension modules. |
|
|
829 | |
516 | =over 4 |
830 | =over 4 |
517 | |
831 | |
518 | =item $AnyEvent::MODEL |
832 | =item $AnyEvent::MODEL |
519 | |
833 | |
520 | Contains C<undef> until the first watcher is being created. Then it |
834 | Contains C<undef> until the first watcher is being created, before the |
|
|
835 | backend has been autodetected. |
|
|
836 | |
521 | contains the event model that is being used, which is the name of the |
837 | Afterwards it contains the event model that is being used, which is the |
522 | Perl class implementing the model. This class is usually one of the |
838 | name of the Perl class implementing the model. This class is usually one |
523 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
839 | of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the |
524 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
840 | case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it |
525 | |
841 | will be C<urxvt::anyevent>). |
526 | The known classes so far are: |
|
|
527 | |
|
|
528 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
|
|
529 | AnyEvent::Impl::Event based on Event, second best choice. |
|
|
530 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
531 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
|
|
532 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
|
|
533 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
|
|
534 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
535 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
|
|
536 | |
|
|
537 | There is no support for WxWidgets, as WxWidgets has no support for |
|
|
538 | watching file handles. However, you can use WxWidgets through the |
|
|
539 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
|
|
540 | second, which was considered to be too horrible to even consider for |
|
|
541 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
|
|
542 | it's adaptor. |
|
|
543 | |
|
|
544 | AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when |
|
|
545 | autodetecting them. |
|
|
546 | |
842 | |
547 | =item AnyEvent::detect |
843 | =item AnyEvent::detect |
548 | |
844 | |
549 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
845 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
550 | if necessary. You should only call this function right before you would |
846 | if necessary. You should only call this function right before you would |
551 | have created an AnyEvent watcher anyway, that is, as late as possible at |
847 | have created an AnyEvent watcher anyway, that is, as late as possible at |
552 | runtime. |
848 | runtime, and not e.g. while initialising of your module. |
|
|
849 | |
|
|
850 | If you need to do some initialisation before AnyEvent watchers are |
|
|
851 | created, use C<post_detect>. |
553 | |
852 | |
554 | =item $guard = AnyEvent::post_detect { BLOCK } |
853 | =item $guard = AnyEvent::post_detect { BLOCK } |
555 | |
854 | |
556 | Arranges for the code block to be executed as soon as the event model is |
855 | Arranges for the code block to be executed as soon as the event model is |
557 | autodetected (or immediately if this has already happened). |
856 | autodetected (or immediately if this has already happened). |
|
|
857 | |
|
|
858 | The block will be executed I<after> the actual backend has been detected |
|
|
859 | (C<$AnyEvent::MODEL> is set), but I<before> any watchers have been |
|
|
860 | created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do |
|
|
861 | other initialisations - see the sources of L<AnyEvent::Strict> or |
|
|
862 | L<AnyEvent::AIO> to see how this is used. |
|
|
863 | |
|
|
864 | The most common usage is to create some global watchers, without forcing |
|
|
865 | event module detection too early, for example, L<AnyEvent::AIO> creates |
|
|
866 | and installs the global L<IO::AIO> watcher in a C<post_detect> block to |
|
|
867 | avoid autodetecting the event module at load time. |
558 | |
868 | |
559 | If called in scalar or list context, then it creates and returns an object |
869 | If called in scalar or list context, then it creates and returns an object |
560 | that automatically removes the callback again when it is destroyed. See |
870 | that automatically removes the callback again when it is destroyed. See |
561 | L<Coro::BDB> for a case where this is useful. |
871 | L<Coro::BDB> for a case where this is useful. |
562 | |
872 | |
… | |
… | |
565 | If there are any code references in this array (you can C<push> to it |
875 | If there are any code references in this array (you can C<push> to it |
566 | before or after loading AnyEvent), then they will called directly after |
876 | before or after loading AnyEvent), then they will called directly after |
567 | the event loop has been chosen. |
877 | the event loop has been chosen. |
568 | |
878 | |
569 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
879 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
570 | if it contains a true value then the event loop has already been detected, |
880 | if it is defined then the event loop has already been detected, and the |
571 | and the array will be ignored. |
881 | array will be ignored. |
572 | |
882 | |
573 | Best use C<AnyEvent::post_detect { BLOCK }> instead. |
883 | Best use C<AnyEvent::post_detect { BLOCK }> when your application allows |
|
|
884 | it,as it takes care of these details. |
|
|
885 | |
|
|
886 | This variable is mainly useful for modules that can do something useful |
|
|
887 | when AnyEvent is used and thus want to know when it is initialised, but do |
|
|
888 | not need to even load it by default. This array provides the means to hook |
|
|
889 | into AnyEvent passively, without loading it. |
574 | |
890 | |
575 | =back |
891 | =back |
576 | |
892 | |
577 | =head1 WHAT TO DO IN A MODULE |
893 | =head1 WHAT TO DO IN A MODULE |
578 | |
894 | |
… | |
… | |
601 | |
917 | |
602 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
918 | 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 |
919 | 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. |
920 | decide which implementation to chose if some module relies on it. |
605 | |
921 | |
606 | If the main program relies on a specific event model. For example, in |
922 | 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 |
923 | 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 |
924 | 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 |
925 | 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 |
926 | 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 |
927 | 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. |
928 | might chose the wrong one unless you load the correct one yourself. |
613 | |
929 | |
614 | You can chose to use a rather inefficient pure-perl implementation by |
930 | You can chose to use a pure-perl implementation by loading the |
615 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
931 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
616 | behaviour everywhere, but letting AnyEvent chose is generally better. |
932 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
933 | |
|
|
934 | =head2 MAINLOOP EMULATION |
|
|
935 | |
|
|
936 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
937 | only want to use AnyEvent), you do not want to run a specific event loop. |
|
|
938 | |
|
|
939 | In that case, you can use a condition variable like this: |
|
|
940 | |
|
|
941 | AnyEvent->condvar->recv; |
|
|
942 | |
|
|
943 | This has the effect of entering the event loop and looping forever. |
|
|
944 | |
|
|
945 | Note that usually your program has some exit condition, in which case |
|
|
946 | it is better to use the "traditional" approach of storing a condition |
|
|
947 | variable somewhere, waiting for it, and sending it when the program should |
|
|
948 | exit cleanly. |
|
|
949 | |
617 | |
950 | |
618 | =head1 OTHER MODULES |
951 | =head1 OTHER MODULES |
619 | |
952 | |
620 | The following is a non-exhaustive list of additional modules that use |
953 | The following is a non-exhaustive list of additional modules that use |
621 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
954 | AnyEvent as a client and can therefore be mixed easily with other AnyEvent |
622 | in the same program. Some of the modules come with AnyEvent, some are |
955 | modules and other event loops in the same program. Some of the modules |
623 | available via CPAN. |
956 | come with AnyEvent, most are available via CPAN. |
624 | |
957 | |
625 | =over 4 |
958 | =over 4 |
626 | |
959 | |
627 | =item L<AnyEvent::Util> |
960 | =item L<AnyEvent::Util> |
628 | |
961 | |
629 | Contains various utility functions that replace often-used but blocking |
962 | Contains various utility functions that replace often-used but blocking |
630 | functions such as C<inet_aton> by event-/callback-based versions. |
963 | functions such as C<inet_aton> by event-/callback-based versions. |
631 | |
964 | |
|
|
965 | =item L<AnyEvent::Socket> |
|
|
966 | |
|
|
967 | Provides various utility functions for (internet protocol) sockets, |
|
|
968 | addresses and name resolution. Also functions to create non-blocking tcp |
|
|
969 | connections or tcp servers, with IPv6 and SRV record support and more. |
|
|
970 | |
632 | =item L<AnyEvent::Handle> |
971 | =item L<AnyEvent::Handle> |
633 | |
972 | |
634 | Provide read and write buffers and manages watchers for reads and writes. |
973 | Provide read and write buffers, manages watchers for reads and writes, |
|
|
974 | supports raw and formatted I/O, I/O queued and fully transparent and |
|
|
975 | non-blocking SSL/TLS (via L<AnyEvent::TLS>. |
|
|
976 | |
|
|
977 | =item L<AnyEvent::DNS> |
|
|
978 | |
|
|
979 | Provides rich asynchronous DNS resolver capabilities. |
|
|
980 | |
|
|
981 | =item L<AnyEvent::HTTP> |
|
|
982 | |
|
|
983 | A simple-to-use HTTP library that is capable of making a lot of concurrent |
|
|
984 | HTTP requests. |
635 | |
985 | |
636 | =item L<AnyEvent::HTTPD> |
986 | =item L<AnyEvent::HTTPD> |
637 | |
987 | |
638 | Provides a simple web application server framework. |
988 | Provides a simple web application server framework. |
639 | |
989 | |
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> |
990 | =item L<AnyEvent::FastPing> |
646 | |
991 | |
647 | The fastest ping in the west. |
992 | The fastest ping in the west. |
648 | |
993 | |
|
|
994 | =item L<AnyEvent::DBI> |
|
|
995 | |
|
|
996 | Executes L<DBI> requests asynchronously in a proxy process. |
|
|
997 | |
|
|
998 | =item L<AnyEvent::AIO> |
|
|
999 | |
|
|
1000 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
1001 | programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent |
|
|
1002 | together. |
|
|
1003 | |
|
|
1004 | =item L<AnyEvent::BDB> |
|
|
1005 | |
|
|
1006 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses |
|
|
1007 | L<BDB> and AnyEvent together. |
|
|
1008 | |
|
|
1009 | =item L<AnyEvent::GPSD> |
|
|
1010 | |
|
|
1011 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
|
|
1012 | |
649 | =item L<Net::IRC3> |
1013 | =item L<AnyEvent::IRC> |
650 | |
1014 | |
651 | AnyEvent based IRC client module family. |
1015 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
652 | |
1016 | |
653 | =item L<Net::XMPP2> |
1017 | =item L<AnyEvent::XMPP> |
654 | |
1018 | |
655 | AnyEvent based XMPP (Jabber protocol) module family. |
1019 | AnyEvent based XMPP (Jabber protocol) module family (replacing the older |
|
|
1020 | Net::XMPP2>. |
|
|
1021 | |
|
|
1022 | =item L<AnyEvent::IGS> |
|
|
1023 | |
|
|
1024 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
1025 | L<App::IGS>). |
656 | |
1026 | |
657 | =item L<Net::FCP> |
1027 | =item L<Net::FCP> |
658 | |
1028 | |
659 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
1029 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
660 | of AnyEvent. |
1030 | of AnyEvent. |
… | |
… | |
665 | |
1035 | |
666 | =item L<Coro> |
1036 | =item L<Coro> |
667 | |
1037 | |
668 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
1038 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
669 | |
1039 | |
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> |
|
|
682 | |
|
|
683 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
|
|
684 | |
|
|
685 | =back |
1040 | =back |
686 | |
1041 | |
687 | =cut |
1042 | =cut |
688 | |
1043 | |
689 | package AnyEvent; |
1044 | package AnyEvent; |
690 | |
1045 | |
|
|
1046 | # basically a tuned-down version of common::sense |
|
|
1047 | sub common_sense { |
691 | no warnings; |
1048 | # no warnings |
692 | use strict; |
1049 | ${^WARNING_BITS} ^= ${^WARNING_BITS}; |
|
|
1050 | # use strict vars subs |
|
|
1051 | $^H |= 0x00000600; |
|
|
1052 | } |
693 | |
1053 | |
|
|
1054 | BEGIN { AnyEvent::common_sense } |
|
|
1055 | |
694 | use Carp; |
1056 | use Carp (); |
695 | |
1057 | |
696 | our $VERSION = '3.51'; |
1058 | our $VERSION = 4.85; |
697 | our $MODEL; |
1059 | our $MODEL; |
698 | |
1060 | |
699 | our $AUTOLOAD; |
1061 | our $AUTOLOAD; |
700 | our @ISA; |
1062 | our @ISA; |
701 | |
1063 | |
702 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
|
|
703 | |
|
|
704 | our @REGISTRY; |
1064 | our @REGISTRY; |
|
|
1065 | |
|
|
1066 | our $WIN32; |
|
|
1067 | |
|
|
1068 | our $VERBOSE; |
|
|
1069 | |
|
|
1070 | BEGIN { |
|
|
1071 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
|
|
1072 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
|
|
1073 | |
|
|
1074 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
1075 | if ${^TAINT}; |
|
|
1076 | |
|
|
1077 | $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
|
|
1078 | |
|
|
1079 | } |
|
|
1080 | |
|
|
1081 | our $MAX_SIGNAL_LATENCY = 10; |
|
|
1082 | |
|
|
1083 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
|
|
1084 | |
|
|
1085 | { |
|
|
1086 | my $idx; |
|
|
1087 | $PROTOCOL{$_} = ++$idx |
|
|
1088 | for reverse split /\s*,\s*/, |
|
|
1089 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
|
|
1090 | } |
705 | |
1091 | |
706 | my @models = ( |
1092 | my @models = ( |
707 | [EV:: => AnyEvent::Impl::EV::], |
1093 | [EV:: => AnyEvent::Impl::EV::], |
708 | [Event:: => AnyEvent::Impl::Event::], |
1094 | [Event:: => AnyEvent::Impl::Event::], |
|
|
1095 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
|
|
1096 | # everything below here will not be autoprobed |
|
|
1097 | # as the pureperl backend should work everywhere |
|
|
1098 | # and is usually faster |
|
|
1099 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
|
|
1100 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
709 | [Tk:: => AnyEvent::Impl::Tk::], |
1101 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
1102 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
|
|
1103 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
710 | [Wx:: => AnyEvent::Impl::POE::], |
1104 | [Wx:: => AnyEvent::Impl::POE::], |
711 | [Prima:: => AnyEvent::Impl::POE::], |
1105 | [Prima:: => AnyEvent::Impl::POE::], |
712 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
1106 | # IO::Async is just too broken - we would need workarounds for its |
713 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
1107 | # byzantine signal and broken child handling, among others. |
714 | [Glib:: => AnyEvent::Impl::Glib::], |
1108 | # IO::Async is rather hard to detect, as it doesn't have any |
715 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
1109 | # obvious default class. |
716 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1110 | # [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
717 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1111 | # [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1112 | # [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
718 | ); |
1113 | ); |
719 | |
1114 | |
720 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
1115 | our %method = map +($_ => 1), |
|
|
1116 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
721 | |
1117 | |
722 | our @post_detect; |
1118 | our @post_detect; |
723 | |
1119 | |
724 | sub post_detect(&) { |
1120 | sub post_detect(&) { |
725 | my ($cb) = @_; |
1121 | my ($cb) = @_; |
… | |
… | |
730 | 1 |
1126 | 1 |
731 | } else { |
1127 | } else { |
732 | push @post_detect, $cb; |
1128 | push @post_detect, $cb; |
733 | |
1129 | |
734 | defined wantarray |
1130 | defined wantarray |
735 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
1131 | ? bless \$cb, "AnyEvent::Util::postdetect" |
736 | : () |
1132 | : () |
737 | } |
1133 | } |
738 | } |
1134 | } |
739 | |
1135 | |
740 | sub AnyEvent::Util::PostDetect::DESTROY { |
1136 | sub AnyEvent::Util::postdetect::DESTROY { |
741 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1137 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
742 | } |
1138 | } |
743 | |
1139 | |
744 | sub detect() { |
1140 | sub detect() { |
745 | unless ($MODEL) { |
1141 | unless ($MODEL) { |
746 | no strict 'refs'; |
1142 | local $SIG{__DIE__}; |
747 | |
1143 | |
748 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
1144 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
749 | my $model = "AnyEvent::Impl::$1"; |
1145 | my $model = "AnyEvent::Impl::$1"; |
750 | if (eval "require $model") { |
1146 | if (eval "require $model") { |
751 | $MODEL = $model; |
1147 | $MODEL = $model; |
752 | warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; |
1148 | warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; |
753 | } else { |
1149 | } else { |
754 | warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; |
1150 | warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE; |
755 | } |
1151 | } |
756 | } |
1152 | } |
757 | |
1153 | |
758 | # check for already loaded models |
1154 | # check for already loaded models |
759 | unless ($MODEL) { |
1155 | unless ($MODEL) { |
760 | for (@REGISTRY, @models) { |
1156 | for (@REGISTRY, @models) { |
761 | my ($package, $model) = @$_; |
1157 | my ($package, $model) = @$_; |
762 | if (${"$package\::VERSION"} > 0) { |
1158 | if (${"$package\::VERSION"} > 0) { |
763 | if (eval "require $model") { |
1159 | if (eval "require $model") { |
764 | $MODEL = $model; |
1160 | $MODEL = $model; |
765 | warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; |
1161 | warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2; |
766 | last; |
1162 | last; |
767 | } |
1163 | } |
768 | } |
1164 | } |
769 | } |
1165 | } |
770 | |
1166 | |
… | |
… | |
775 | my ($package, $model) = @$_; |
1171 | my ($package, $model) = @$_; |
776 | if (eval "require $package" |
1172 | if (eval "require $package" |
777 | and ${"$package\::VERSION"} > 0 |
1173 | and ${"$package\::VERSION"} > 0 |
778 | and eval "require $model") { |
1174 | and eval "require $model") { |
779 | $MODEL = $model; |
1175 | $MODEL = $model; |
780 | warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; |
1176 | warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2; |
781 | last; |
1177 | last; |
782 | } |
1178 | } |
783 | } |
1179 | } |
784 | |
1180 | |
785 | $MODEL |
1181 | $MODEL |
786 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1182 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
787 | } |
1183 | } |
788 | } |
1184 | } |
789 | |
1185 | |
|
|
1186 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
1187 | |
790 | unshift @ISA, $MODEL; |
1188 | unshift @ISA, $MODEL; |
791 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1189 | |
|
|
1190 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
792 | |
1191 | |
793 | (shift @post_detect)->() while @post_detect; |
1192 | (shift @post_detect)->() while @post_detect; |
794 | } |
1193 | } |
795 | |
1194 | |
796 | $MODEL |
1195 | $MODEL |
… | |
… | |
798 | |
1197 | |
799 | sub AUTOLOAD { |
1198 | sub AUTOLOAD { |
800 | (my $func = $AUTOLOAD) =~ s/.*://; |
1199 | (my $func = $AUTOLOAD) =~ s/.*://; |
801 | |
1200 | |
802 | $method{$func} |
1201 | $method{$func} |
803 | or croak "$func: not a valid method for AnyEvent objects"; |
1202 | or Carp::croak "$func: not a valid method for AnyEvent objects"; |
804 | |
1203 | |
805 | detect unless $MODEL; |
1204 | detect unless $MODEL; |
806 | |
1205 | |
807 | my $class = shift; |
1206 | my $class = shift; |
808 | $class->$func (@_); |
1207 | $class->$func (@_); |
809 | } |
1208 | } |
810 | |
1209 | |
|
|
1210 | # utility function to dup a filehandle. this is used by many backends |
|
|
1211 | # to support binding more than one watcher per filehandle (they usually |
|
|
1212 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1213 | sub _dupfh($$;$$) { |
|
|
1214 | my ($poll, $fh, $r, $w) = @_; |
|
|
1215 | |
|
|
1216 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1217 | my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&"); |
|
|
1218 | |
|
|
1219 | open my $fh2, $mode, $fh |
|
|
1220 | or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; |
|
|
1221 | |
|
|
1222 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1223 | |
|
|
1224 | ($fh2, $rw) |
|
|
1225 | } |
|
|
1226 | |
811 | package AnyEvent::Base; |
1227 | package AnyEvent::Base; |
812 | |
1228 | |
|
|
1229 | # default implementations for many methods |
|
|
1230 | |
|
|
1231 | sub _time { |
|
|
1232 | # probe for availability of Time::HiRes |
|
|
1233 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1234 | warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; |
|
|
1235 | *_time = \&Time::HiRes::time; |
|
|
1236 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1237 | } else { |
|
|
1238 | warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; |
|
|
1239 | *_time = sub { time }; # epic fail |
|
|
1240 | } |
|
|
1241 | |
|
|
1242 | &_time |
|
|
1243 | } |
|
|
1244 | |
|
|
1245 | sub time { _time } |
|
|
1246 | sub now { _time } |
|
|
1247 | sub now_update { } |
|
|
1248 | |
813 | # default implementation for ->condvar |
1249 | # default implementation for ->condvar |
814 | |
1250 | |
815 | sub condvar { |
1251 | sub condvar { |
816 | bless {}, AnyEvent::CondVar:: |
1252 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
817 | } |
1253 | } |
818 | |
1254 | |
819 | # default implementation for ->signal |
1255 | # default implementation for ->signal |
820 | |
1256 | |
821 | our %SIG_CB; |
1257 | our $HAVE_ASYNC_INTERRUPT; |
|
|
1258 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1259 | our (%SIG_ASY, %SIG_ASY_W); |
|
|
1260 | our ($SIG_COUNT, $SIG_TW); |
822 | |
1261 | |
|
|
1262 | sub _signal_exec { |
|
|
1263 | $HAVE_ASYNC_INTERRUPT |
|
|
1264 | ? $SIGPIPE_R->drain |
|
|
1265 | : sysread $SIGPIPE_R, my $dummy, 9; |
|
|
1266 | |
|
|
1267 | while (%SIG_EV) { |
|
|
1268 | for (keys %SIG_EV) { |
|
|
1269 | delete $SIG_EV{$_}; |
|
|
1270 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1271 | } |
|
|
1272 | } |
|
|
1273 | } |
|
|
1274 | |
|
|
1275 | # install a dumym wakeupw atcher to reduce signal catching latency |
|
|
1276 | sub _sig_add() { |
|
|
1277 | unless ($SIG_COUNT++) { |
|
|
1278 | # try to align timer on a full-second boundary, if possible |
|
|
1279 | my $NOW = AnyEvent->now; |
|
|
1280 | |
|
|
1281 | $SIG_TW = AnyEvent->timer ( |
|
|
1282 | after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW), |
|
|
1283 | interval => $MAX_SIGNAL_LATENCY, |
|
|
1284 | cb => sub { }, # just for the PERL_ASYNC_CHECK |
|
|
1285 | ); |
|
|
1286 | } |
|
|
1287 | } |
|
|
1288 | |
|
|
1289 | sub _sig_del { |
|
|
1290 | undef $SIG_TW |
|
|
1291 | unless --$SIG_COUNT; |
|
|
1292 | } |
|
|
1293 | |
823 | sub signal { |
1294 | sub _signal { |
824 | my (undef, %arg) = @_; |
1295 | my (undef, %arg) = @_; |
825 | |
1296 | |
826 | my $signal = uc $arg{signal} |
1297 | my $signal = uc $arg{signal} |
827 | or Carp::croak "required option 'signal' is missing"; |
1298 | or Carp::croak "required option 'signal' is missing"; |
828 | |
1299 | |
829 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1300 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
1301 | |
|
|
1302 | if ($HAVE_ASYNC_INTERRUPT) { |
|
|
1303 | # async::interrupt |
|
|
1304 | |
|
|
1305 | $SIG_ASY{$signal} ||= do { |
|
|
1306 | my $asy = new Async::Interrupt |
|
|
1307 | cb => sub { undef $SIG_EV{$signal} }, |
|
|
1308 | signal => $signal, |
|
|
1309 | pipe => [$SIGPIPE_R->filenos], |
|
|
1310 | ; |
|
|
1311 | $asy->pipe_autodrain (0); |
|
|
1312 | |
|
|
1313 | $asy |
|
|
1314 | }; |
|
|
1315 | |
|
|
1316 | } else { |
|
|
1317 | # pure perl |
|
|
1318 | |
830 | $SIG{$signal} ||= sub { |
1319 | $SIG{$signal} ||= sub { |
831 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1320 | local $!; |
|
|
1321 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1322 | undef $SIG_EV{$signal}; |
|
|
1323 | }; |
|
|
1324 | |
|
|
1325 | # can't do signal processing without introducing races in pure perl, |
|
|
1326 | # so limit the signal latency. |
|
|
1327 | _sig_add; |
832 | }; |
1328 | } |
833 | |
1329 | |
834 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1330 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
835 | } |
1331 | } |
836 | |
1332 | |
|
|
1333 | sub signal { |
|
|
1334 | # probe for availability of Async::Interrupt |
|
|
1335 | if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") { |
|
|
1336 | warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8; |
|
|
1337 | |
|
|
1338 | $HAVE_ASYNC_INTERRUPT = 1; |
|
|
1339 | $SIGPIPE_R = new Async::Interrupt::EventPipe; |
|
|
1340 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec); |
|
|
1341 | |
|
|
1342 | } else { |
|
|
1343 | warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; |
|
|
1344 | |
|
|
1345 | require Fcntl; |
|
|
1346 | |
|
|
1347 | if (AnyEvent::WIN32) { |
|
|
1348 | require AnyEvent::Util; |
|
|
1349 | |
|
|
1350 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1351 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1352 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1353 | } else { |
|
|
1354 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1355 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1356 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1357 | |
|
|
1358 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1359 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1360 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1361 | } |
|
|
1362 | |
|
|
1363 | $SIGPIPE_R |
|
|
1364 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1365 | |
|
|
1366 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1367 | } |
|
|
1368 | |
|
|
1369 | *signal = \&_signal; |
|
|
1370 | &signal |
|
|
1371 | } |
|
|
1372 | |
837 | sub AnyEvent::Base::Signal::DESTROY { |
1373 | sub AnyEvent::Base::signal::DESTROY { |
838 | my ($signal, $cb) = @{$_[0]}; |
1374 | my ($signal, $cb) = @{$_[0]}; |
839 | |
1375 | |
|
|
1376 | _sig_del; |
|
|
1377 | |
840 | delete $SIG_CB{$signal}{$cb}; |
1378 | delete $SIG_CB{$signal}{$cb}; |
841 | |
1379 | |
842 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1380 | $HAVE_ASYNC_INTERRUPT |
|
|
1381 | ? delete $SIG_ASY{$signal} |
|
|
1382 | : # delete doesn't work with older perls - they then |
|
|
1383 | # print weird messages, or just unconditionally exit |
|
|
1384 | # instead of getting the default action. |
|
|
1385 | undef $SIG{$signal} |
|
|
1386 | unless keys %{ $SIG_CB{$signal} }; |
843 | } |
1387 | } |
844 | |
1388 | |
845 | # default implementation for ->child |
1389 | # default implementation for ->child |
846 | |
1390 | |
847 | our %PID_CB; |
1391 | our %PID_CB; |
848 | our $CHLD_W; |
1392 | our $CHLD_W; |
849 | our $CHLD_DELAY_W; |
1393 | our $CHLD_DELAY_W; |
850 | our $PID_IDLE; |
|
|
851 | our $WNOHANG; |
1394 | our $WNOHANG; |
852 | |
1395 | |
853 | sub _child_wait { |
1396 | sub _sigchld { |
854 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1397 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
|
|
1398 | $_->($pid, $?) |
855 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1399 | for values %{ $PID_CB{$pid} || {} }, |
856 | (values %{ $PID_CB{0} || {} }); |
1400 | values %{ $PID_CB{0} || {} }; |
857 | } |
1401 | } |
858 | |
|
|
859 | undef $PID_IDLE; |
|
|
860 | } |
|
|
861 | |
|
|
862 | sub _sigchld { |
|
|
863 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
864 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
865 | undef $CHLD_DELAY_W; |
|
|
866 | &_child_wait; |
|
|
867 | }); |
|
|
868 | } |
1402 | } |
869 | |
1403 | |
870 | sub child { |
1404 | sub child { |
871 | my (undef, %arg) = @_; |
1405 | my (undef, %arg) = @_; |
872 | |
1406 | |
873 | defined (my $pid = $arg{pid} + 0) |
1407 | defined (my $pid = $arg{pid} + 0) |
874 | or Carp::croak "required option 'pid' is missing"; |
1408 | or Carp::croak "required option 'pid' is missing"; |
875 | |
1409 | |
876 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1410 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
877 | |
1411 | |
878 | unless ($WNOHANG) { |
1412 | # WNOHANG is almost cetrainly 1 everywhere |
879 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
1413 | $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ |
880 | } |
1414 | ? 1 |
|
|
1415 | : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
881 | |
1416 | |
882 | unless ($CHLD_W) { |
1417 | unless ($CHLD_W) { |
883 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1418 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
884 | # child could be a zombie already, so make at least one round |
1419 | # child could be a zombie already, so make at least one round |
885 | &_sigchld; |
1420 | &_sigchld; |
886 | } |
1421 | } |
887 | |
1422 | |
888 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1423 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
889 | } |
1424 | } |
890 | |
1425 | |
891 | sub AnyEvent::Base::Child::DESTROY { |
1426 | sub AnyEvent::Base::child::DESTROY { |
892 | my ($pid, $cb) = @{$_[0]}; |
1427 | my ($pid, $cb) = @{$_[0]}; |
893 | |
1428 | |
894 | delete $PID_CB{$pid}{$cb}; |
1429 | delete $PID_CB{$pid}{$cb}; |
895 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1430 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
896 | |
1431 | |
897 | undef $CHLD_W unless keys %PID_CB; |
1432 | undef $CHLD_W unless keys %PID_CB; |
898 | } |
1433 | } |
899 | |
1434 | |
|
|
1435 | # idle emulation is done by simply using a timer, regardless |
|
|
1436 | # of whether the process is idle or not, and not letting |
|
|
1437 | # the callback use more than 50% of the time. |
|
|
1438 | sub idle { |
|
|
1439 | my (undef, %arg) = @_; |
|
|
1440 | |
|
|
1441 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1442 | |
|
|
1443 | $rcb = sub { |
|
|
1444 | if ($cb) { |
|
|
1445 | $w = _time; |
|
|
1446 | &$cb; |
|
|
1447 | $w = _time - $w; |
|
|
1448 | |
|
|
1449 | # never use more then 50% of the time for the idle watcher, |
|
|
1450 | # within some limits |
|
|
1451 | $w = 0.0001 if $w < 0.0001; |
|
|
1452 | $w = 5 if $w > 5; |
|
|
1453 | |
|
|
1454 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1455 | } else { |
|
|
1456 | # clean up... |
|
|
1457 | undef $w; |
|
|
1458 | undef $rcb; |
|
|
1459 | } |
|
|
1460 | }; |
|
|
1461 | |
|
|
1462 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1463 | |
|
|
1464 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1465 | } |
|
|
1466 | |
|
|
1467 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1468 | undef $${$_[0]}; |
|
|
1469 | } |
|
|
1470 | |
900 | package AnyEvent::CondVar; |
1471 | package AnyEvent::CondVar; |
901 | |
1472 | |
902 | our @ISA = AnyEvent::CondVar::Base::; |
1473 | our @ISA = AnyEvent::CondVar::Base::; |
903 | |
1474 | |
904 | package AnyEvent::CondVar::Base; |
1475 | package AnyEvent::CondVar::Base; |
|
|
1476 | |
|
|
1477 | #use overload |
|
|
1478 | # '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
|
|
1479 | # fallback => 1; |
|
|
1480 | |
|
|
1481 | # save 300+ kilobytes by dirtily hardcoding overloading |
|
|
1482 | ${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching. |
|
|
1483 | *{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod." |
|
|
1484 | *{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{} |
|
|
1485 | ${'AnyEvent::CondVar::Base::()'} = 1; # fallback |
|
|
1486 | |
|
|
1487 | our $WAITING; |
905 | |
1488 | |
906 | sub _send { |
1489 | sub _send { |
907 | # nop |
1490 | # nop |
908 | } |
1491 | } |
909 | |
1492 | |
… | |
… | |
922 | sub ready { |
1505 | sub ready { |
923 | $_[0]{_ae_sent} |
1506 | $_[0]{_ae_sent} |
924 | } |
1507 | } |
925 | |
1508 | |
926 | sub _wait { |
1509 | sub _wait { |
|
|
1510 | $WAITING |
|
|
1511 | and !$_[0]{_ae_sent} |
|
|
1512 | and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected"; |
|
|
1513 | |
|
|
1514 | local $WAITING = 1; |
927 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
1515 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
928 | } |
1516 | } |
929 | |
1517 | |
930 | sub recv { |
1518 | sub recv { |
931 | $_[0]->_wait; |
1519 | $_[0]->_wait; |
… | |
… | |
944 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
1532 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
945 | } |
1533 | } |
946 | |
1534 | |
947 | sub end { |
1535 | sub end { |
948 | return if --$_[0]{_ae_counter}; |
1536 | return if --$_[0]{_ae_counter}; |
949 | &{ $_[0]{_ae_end_cb} } if $_[0]{_ae_end_cb}; |
1537 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
950 | } |
1538 | } |
951 | |
1539 | |
952 | # undocumented/compatibility with pre-3.4 |
1540 | # undocumented/compatibility with pre-3.4 |
953 | *broadcast = \&send; |
1541 | *broadcast = \&send; |
954 | *wait = \&_wait; |
1542 | *wait = \&_wait; |
|
|
1543 | |
|
|
1544 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1545 | |
|
|
1546 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1547 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1548 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1549 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1550 | development. |
|
|
1551 | |
|
|
1552 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1553 | executing a callback), this is not only highly event-loop specific, but |
|
|
1554 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1555 | program. |
|
|
1556 | |
|
|
1557 | The pure perl event loop simply re-throws the exception (usually |
|
|
1558 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1559 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1560 | so on. |
|
|
1561 | |
|
|
1562 | =head1 ENVIRONMENT VARIABLES |
|
|
1563 | |
|
|
1564 | The following environment variables are used by this module or its |
|
|
1565 | submodules. |
|
|
1566 | |
|
|
1567 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1568 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1569 | enabled. |
|
|
1570 | |
|
|
1571 | =over 4 |
|
|
1572 | |
|
|
1573 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1574 | |
|
|
1575 | By default, AnyEvent will be completely silent except in fatal |
|
|
1576 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1577 | talkative. |
|
|
1578 | |
|
|
1579 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1580 | conditions, such as not being able to load the event model specified by |
|
|
1581 | C<PERL_ANYEVENT_MODEL>. |
|
|
1582 | |
|
|
1583 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1584 | model it chooses. |
|
|
1585 | |
|
|
1586 | When set to C<8> or higher, then AnyEvent will report extra information on |
|
|
1587 | which optional modules it loads and how it implements certain features. |
|
|
1588 | |
|
|
1589 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1590 | |
|
|
1591 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1592 | argument checking is very costly. Setting this variable to a true value |
|
|
1593 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1594 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1595 | it will croak. |
|
|
1596 | |
|
|
1597 | In other words, enables "strict" mode. |
|
|
1598 | |
|
|
1599 | Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> |
|
|
1600 | >>, it is definitely recommended to keep it off in production. Keeping |
|
|
1601 | C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs |
|
|
1602 | can be very useful, however. |
|
|
1603 | |
|
|
1604 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1605 | |
|
|
1606 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1607 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1608 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1609 | and the resulting module name is loaded and if the load was successful, |
|
|
1610 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1611 | auto detection and -probing. |
|
|
1612 | |
|
|
1613 | This functionality might change in future versions. |
|
|
1614 | |
|
|
1615 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1616 | could start your program like this: |
|
|
1617 | |
|
|
1618 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1619 | |
|
|
1620 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1621 | |
|
|
1622 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1623 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1624 | of auto probing). |
|
|
1625 | |
|
|
1626 | Must be set to a comma-separated list of protocols or address families, |
|
|
1627 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1628 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1629 | list. |
|
|
1630 | |
|
|
1631 | This variable can effectively be used for denial-of-service attacks |
|
|
1632 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1633 | small, as the program has to handle conenction and other failures anyways. |
|
|
1634 | |
|
|
1635 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1636 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1637 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1638 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1639 | IPv6, but prefer IPv6 over IPv4. |
|
|
1640 | |
|
|
1641 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1642 | |
|
|
1643 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1644 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1645 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1646 | default. |
|
|
1647 | |
|
|
1648 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1649 | EDNS0 in its DNS requests. |
|
|
1650 | |
|
|
1651 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1652 | |
|
|
1653 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1654 | will create in parallel. |
|
|
1655 | |
|
|
1656 | =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> |
|
|
1657 | |
|
|
1658 | The default value for the C<max_outstanding> parameter for the default DNS |
|
|
1659 | resolver - this is the maximum number of parallel DNS requests that are |
|
|
1660 | sent to the DNS server. |
|
|
1661 | |
|
|
1662 | =item C<PERL_ANYEVENT_RESOLV_CONF> |
|
|
1663 | |
|
|
1664 | The file to use instead of F</etc/resolv.conf> (or OS-specific |
|
|
1665 | configuration) in the default resolver. When set to the empty string, no |
|
|
1666 | default config will be used. |
|
|
1667 | |
|
|
1668 | =item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. |
|
|
1669 | |
|
|
1670 | When neither C<ca_file> nor C<ca_path> was specified during |
|
|
1671 | L<AnyEvent::TLS> context creation, and either of these environment |
|
|
1672 | variables exist, they will be used to specify CA certificate locations |
|
|
1673 | instead of a system-dependent default. |
|
|
1674 | |
|
|
1675 | =item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT> |
|
|
1676 | |
|
|
1677 | When these are set to C<1>, then the respective modules are not |
|
|
1678 | loaded. Mostly good for testing AnyEvent itself. |
|
|
1679 | |
|
|
1680 | =back |
955 | |
1681 | |
956 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1682 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
957 | |
1683 | |
958 | This is an advanced topic that you do not normally need to use AnyEvent in |
1684 | This is an advanced topic that you do not normally need to use AnyEvent in |
959 | a module. This section is only of use to event loop authors who want to |
1685 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
993 | |
1719 | |
994 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1720 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
995 | condition variables: code blocking while waiting for a condition will |
1721 | condition variables: code blocking while waiting for a condition will |
996 | C<die>. This still works with most modules/usages, and blocking calls must |
1722 | C<die>. This still works with most modules/usages, and blocking calls must |
997 | not be done in an interactive application, so it makes sense. |
1723 | not be done in an interactive application, so it makes sense. |
998 | |
|
|
999 | =head1 ENVIRONMENT VARIABLES |
|
|
1000 | |
|
|
1001 | The following environment variables are used by this module: |
|
|
1002 | |
|
|
1003 | =over 4 |
|
|
1004 | |
|
|
1005 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1006 | |
|
|
1007 | By default, AnyEvent will be completely silent except in fatal |
|
|
1008 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1009 | talkative. |
|
|
1010 | |
|
|
1011 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1012 | conditions, such as not being able to load the event model specified by |
|
|
1013 | C<PERL_ANYEVENT_MODEL>. |
|
|
1014 | |
|
|
1015 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1016 | model it chooses. |
|
|
1017 | |
|
|
1018 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1019 | |
|
|
1020 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1021 | autodetection and -probing kicks in. It must be a string consisting |
|
|
1022 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1023 | and the resulting module name is loaded and if the load was successful, |
|
|
1024 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1025 | autodetection and -probing. |
|
|
1026 | |
|
|
1027 | This functionality might change in future versions. |
|
|
1028 | |
|
|
1029 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1030 | could start your program like this: |
|
|
1031 | |
|
|
1032 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1033 | |
|
|
1034 | =back |
|
|
1035 | |
1724 | |
1036 | =head1 EXAMPLE PROGRAM |
1725 | =head1 EXAMPLE PROGRAM |
1037 | |
1726 | |
1038 | The following program uses an I/O watcher to read data from STDIN, a timer |
1727 | The following program uses an I/O watcher to read data from STDIN, a timer |
1039 | to display a message once per second, and a condition variable to quit the |
1728 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1123 | syswrite $txn->{fh}, $txn->{request} |
1812 | syswrite $txn->{fh}, $txn->{request} |
1124 | or die "connection or write error"; |
1813 | or die "connection or write error"; |
1125 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1814 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1126 | |
1815 | |
1127 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1816 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1128 | result and signals any possible waiters that the request ahs finished: |
1817 | result and signals any possible waiters that the request has finished: |
1129 | |
1818 | |
1130 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1819 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1131 | |
1820 | |
1132 | if (end-of-file or data complete) { |
1821 | if (end-of-file or data complete) { |
1133 | $txn->{result} = $txn->{buf}; |
1822 | $txn->{result} = $txn->{buf}; |
… | |
… | |
1141 | |
1830 | |
1142 | $txn->{finished}->recv; |
1831 | $txn->{finished}->recv; |
1143 | return $txn->{result}; |
1832 | return $txn->{result}; |
1144 | |
1833 | |
1145 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1834 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1146 | that occured during request processing. The C<result> method detects |
1835 | that occurred during request processing. The C<result> method detects |
1147 | whether an exception as thrown (it is stored inside the $txn object) |
1836 | whether an exception as thrown (it is stored inside the $txn object) |
1148 | and just throws the exception, which means connection errors and other |
1837 | and just throws the exception, which means connection errors and other |
1149 | problems get reported tot he code that tries to use the result, not in a |
1838 | problems get reported tot he code that tries to use the result, not in a |
1150 | random callback. |
1839 | random callback. |
1151 | |
1840 | |
… | |
… | |
1197 | of various event loops I prepared some benchmarks. |
1886 | of various event loops I prepared some benchmarks. |
1198 | |
1887 | |
1199 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1888 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1200 | |
1889 | |
1201 | Here is a benchmark of various supported event models used natively and |
1890 | Here is a benchmark of various supported event models used natively and |
1202 | through anyevent. The benchmark creates a lot of timers (with a zero |
1891 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1203 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1892 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1204 | which it is), lets them fire exactly once and destroys them again. |
1893 | which it is), lets them fire exactly once and destroys them again. |
1205 | |
1894 | |
1206 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1895 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1207 | distribution. |
1896 | distribution. |
… | |
… | |
1233 | watcher. |
1922 | watcher. |
1234 | |
1923 | |
1235 | =head3 Results |
1924 | =head3 Results |
1236 | |
1925 | |
1237 | name watchers bytes create invoke destroy comment |
1926 | name watchers bytes create invoke destroy comment |
1238 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1927 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1239 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1928 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1240 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1929 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1241 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1930 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1242 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1931 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1243 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1932 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1933 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1934 | IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll |
1244 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1935 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1245 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1936 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1246 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1937 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1247 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1938 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1248 | |
1939 | |
1249 | =head3 Discussion |
1940 | =head3 Discussion |
1250 | |
1941 | |
1251 | The benchmark does I<not> measure scalability of the event loop very |
1942 | The benchmark does I<not> measure scalability of the event loop very |
1252 | well. For example, a select-based event loop (such as the pure perl one) |
1943 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1277 | performance becomes really bad with lots of file descriptors (and few of |
1968 | performance becomes really bad with lots of file descriptors (and few of |
1278 | them active), of course, but this was not subject of this benchmark. |
1969 | them active), of course, but this was not subject of this benchmark. |
1279 | |
1970 | |
1280 | The C<Event> module has a relatively high setup and callback invocation |
1971 | The C<Event> module has a relatively high setup and callback invocation |
1281 | cost, but overall scores in on the third place. |
1972 | cost, but overall scores in on the third place. |
|
|
1973 | |
|
|
1974 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
1975 | when using its pure perl backend. |
1282 | |
1976 | |
1283 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1977 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1284 | faster callback invocation and overall ends up in the same class as |
1978 | faster callback invocation and overall ends up in the same class as |
1285 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1979 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1286 | watchers increases the processing time by more than a factor of four, |
1980 | watchers increases the processing time by more than a factor of four, |
… | |
… | |
1330 | |
2024 | |
1331 | =back |
2025 | =back |
1332 | |
2026 | |
1333 | =head2 BENCHMARKING THE LARGE SERVER CASE |
2027 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1334 | |
2028 | |
1335 | This benchmark atcually benchmarks the event loop itself. It works by |
2029 | This benchmark actually benchmarks the event loop itself. It works by |
1336 | creating a number of "servers": each server consists of a socketpair, a |
2030 | creating a number of "servers": each server consists of a socket pair, a |
1337 | timeout watcher that gets reset on activity (but never fires), and an I/O |
2031 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1338 | watcher waiting for input on one side of the socket. Each time the socket |
2032 | watcher waiting for input on one side of the socket. Each time the socket |
1339 | watcher reads a byte it will write that byte to a random other "server". |
2033 | watcher reads a byte it will write that byte to a random other "server". |
1340 | |
2034 | |
1341 | The effect is that there will be a lot of I/O watchers, only part of which |
2035 | The effect is that there will be a lot of I/O watchers, only part of which |
1342 | are active at any one point (so there is a constant number of active |
2036 | are active at any one point (so there is a constant number of active |
1343 | fds for each loop iterstaion, but which fds these are is random). The |
2037 | fds for each loop iteration, but which fds these are is random). The |
1344 | timeout is reset each time something is read because that reflects how |
2038 | timeout is reset each time something is read because that reflects how |
1345 | most timeouts work (and puts extra pressure on the event loops). |
2039 | most timeouts work (and puts extra pressure on the event loops). |
1346 | |
2040 | |
1347 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 |
2041 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1348 | (1%) are active. This mirrors the activity of large servers with many |
2042 | (1%) are active. This mirrors the activity of large servers with many |
1349 | connections, most of which are idle at any one point in time. |
2043 | connections, most of which are idle at any one point in time. |
1350 | |
2044 | |
1351 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
2045 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1352 | distribution. |
2046 | distribution. |
… | |
… | |
1354 | =head3 Explanation of the columns |
2048 | =head3 Explanation of the columns |
1355 | |
2049 | |
1356 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
2050 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1357 | each server has a read and write socket end). |
2051 | each server has a read and write socket end). |
1358 | |
2052 | |
1359 | I<create> is the time it takes to create a socketpair (which is |
2053 | I<create> is the time it takes to create a socket pair (which is |
1360 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
2054 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1361 | |
2055 | |
1362 | I<request>, the most important value, is the time it takes to handle a |
2056 | I<request>, the most important value, is the time it takes to handle a |
1363 | single "request", that is, reading the token from the pipe and forwarding |
2057 | single "request", that is, reading the token from the pipe and forwarding |
1364 | it to another server. This includes deleting the old timeout and creating |
2058 | it to another server. This includes deleting the old timeout and creating |
1365 | a new one that moves the timeout into the future. |
2059 | a new one that moves the timeout into the future. |
1366 | |
2060 | |
1367 | =head3 Results |
2061 | =head3 Results |
1368 | |
2062 | |
1369 | name sockets create request |
2063 | name sockets create request |
1370 | EV 20000 69.01 11.16 |
2064 | EV 20000 69.01 11.16 |
1371 | Perl 20000 73.32 35.87 |
2065 | Perl 20000 73.32 35.87 |
|
|
2066 | IOAsync 20000 157.00 98.14 epoll |
|
|
2067 | IOAsync 20000 159.31 616.06 poll |
1372 | Event 20000 212.62 257.32 |
2068 | Event 20000 212.62 257.32 |
1373 | Glib 20000 651.16 1896.30 |
2069 | Glib 20000 651.16 1896.30 |
1374 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
2070 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1375 | |
2071 | |
1376 | =head3 Discussion |
2072 | =head3 Discussion |
1377 | |
2073 | |
1378 | This benchmark I<does> measure scalability and overall performance of the |
2074 | This benchmark I<does> measure scalability and overall performance of the |
1379 | particular event loop. |
2075 | particular event loop. |
… | |
… | |
1381 | EV is again fastest. Since it is using epoll on my system, the setup time |
2077 | EV is again fastest. Since it is using epoll on my system, the setup time |
1382 | is relatively high, though. |
2078 | is relatively high, though. |
1383 | |
2079 | |
1384 | Perl surprisingly comes second. It is much faster than the C-based event |
2080 | Perl surprisingly comes second. It is much faster than the C-based event |
1385 | loops Event and Glib. |
2081 | loops Event and Glib. |
|
|
2082 | |
|
|
2083 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
2084 | good compared to Glib when using its pure perl backend. |
1386 | |
2085 | |
1387 | Event suffers from high setup time as well (look at its code and you will |
2086 | Event suffers from high setup time as well (look at its code and you will |
1388 | understand why). Callback invocation also has a high overhead compared to |
2087 | understand why). Callback invocation also has a high overhead compared to |
1389 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
2088 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1390 | uses select or poll in basically all documented configurations. |
2089 | uses select or poll in basically all documented configurations. |
… | |
… | |
1437 | speed most when you have lots of watchers, not when you only have a few of |
2136 | speed most when you have lots of watchers, not when you only have a few of |
1438 | them). |
2137 | them). |
1439 | |
2138 | |
1440 | EV is again fastest. |
2139 | EV is again fastest. |
1441 | |
2140 | |
1442 | Perl again comes second. It is noticably faster than the C-based event |
2141 | Perl again comes second. It is noticeably faster than the C-based event |
1443 | loops Event and Glib, although the difference is too small to really |
2142 | loops Event and Glib, although the difference is too small to really |
1444 | matter. |
2143 | matter. |
1445 | |
2144 | |
1446 | POE also performs much better in this case, but is is still far behind the |
2145 | POE also performs much better in this case, but is is still far behind the |
1447 | others. |
2146 | others. |
… | |
… | |
1450 | |
2149 | |
1451 | =over 4 |
2150 | =over 4 |
1452 | |
2151 | |
1453 | =item * C-based event loops perform very well with small number of |
2152 | =item * C-based event loops perform very well with small number of |
1454 | watchers, as the management overhead dominates. |
2153 | watchers, as the management overhead dominates. |
|
|
2154 | |
|
|
2155 | =back |
|
|
2156 | |
|
|
2157 | =head2 THE IO::Lambda BENCHMARK |
|
|
2158 | |
|
|
2159 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
2160 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
2161 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
2162 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
2163 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
2164 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
2165 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
2166 | |
|
|
2167 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
2168 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
2169 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
2170 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
2171 | benchmark nevertheless. |
|
|
2172 | |
|
|
2173 | name runtime |
|
|
2174 | Lambda/select 0.330 sec |
|
|
2175 | + optimized 0.122 sec |
|
|
2176 | Lambda/AnyEvent 0.327 sec |
|
|
2177 | + optimized 0.138 sec |
|
|
2178 | Raw sockets/select 0.077 sec |
|
|
2179 | POE/select, components 0.662 sec |
|
|
2180 | POE/select, raw sockets 0.226 sec |
|
|
2181 | POE/select, optimized 0.404 sec |
|
|
2182 | |
|
|
2183 | AnyEvent/select/nb 0.085 sec |
|
|
2184 | AnyEvent/EV/nb 0.068 sec |
|
|
2185 | +state machine 0.134 sec |
|
|
2186 | |
|
|
2187 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
2188 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
2189 | defeating the purpose of an event-based solution. All of the newly |
|
|
2190 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
2191 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
2192 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
2193 | generally require a lot more bookkeeping and event handling than blocking |
|
|
2194 | connects (which involve a single syscall only). |
|
|
2195 | |
|
|
2196 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
2197 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
2198 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
2199 | non-blocking, further placing it at a disadvantage. |
|
|
2200 | |
|
|
2201 | As you can see, the AnyEvent + EV combination even beats the |
|
|
2202 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
2203 | backend easily beats IO::Lambda and POE. |
|
|
2204 | |
|
|
2205 | And even the 100% non-blocking version written using the high-level (and |
|
|
2206 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
2207 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
2208 | in a non-blocking way. |
|
|
2209 | |
|
|
2210 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2211 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2212 | part of the IO::lambda distribution and were used without any changes. |
|
|
2213 | |
|
|
2214 | |
|
|
2215 | =head1 SIGNALS |
|
|
2216 | |
|
|
2217 | AnyEvent currently installs handlers for these signals: |
|
|
2218 | |
|
|
2219 | =over 4 |
|
|
2220 | |
|
|
2221 | =item SIGCHLD |
|
|
2222 | |
|
|
2223 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2224 | emulation for event loops that do not support them natively. Also, some |
|
|
2225 | event loops install a similar handler. |
|
|
2226 | |
|
|
2227 | Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then |
|
|
2228 | AnyEvent will reset it to default, to avoid losing child exit statuses. |
|
|
2229 | |
|
|
2230 | =item SIGPIPE |
|
|
2231 | |
|
|
2232 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2233 | when AnyEvent gets loaded. |
|
|
2234 | |
|
|
2235 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2236 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2237 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2238 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2239 | some random socket. |
|
|
2240 | |
|
|
2241 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2242 | that this way, the handler will be restored to defaults on exec. |
|
|
2243 | |
|
|
2244 | Feel free to install your own handler, or reset it to defaults. |
|
|
2245 | |
|
|
2246 | =back |
|
|
2247 | |
|
|
2248 | =cut |
|
|
2249 | |
|
|
2250 | undef $SIG{CHLD} |
|
|
2251 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2252 | |
|
|
2253 | $SIG{PIPE} = sub { } |
|
|
2254 | unless defined $SIG{PIPE}; |
|
|
2255 | |
|
|
2256 | =head1 RECOMMENDED/OPTIONAL MODULES |
|
|
2257 | |
|
|
2258 | One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and |
|
|
2259 | it's built-in modules) are required to use it. |
|
|
2260 | |
|
|
2261 | That does not mean that AnyEvent won't take advantage of some additional |
|
|
2262 | modules if they are installed. |
|
|
2263 | |
|
|
2264 | This section epxlains which additional modules will be used, and how they |
|
|
2265 | affect AnyEvent's operetion. |
|
|
2266 | |
|
|
2267 | =over 4 |
|
|
2268 | |
|
|
2269 | =item L<Async::Interrupt> |
|
|
2270 | |
|
|
2271 | This slightly arcane module is used to implement fast signal handling: To |
|
|
2272 | my knowledge, there is no way to do completely race-free and quick |
|
|
2273 | signal handling in pure perl. To ensure that signals still get |
|
|
2274 | delivered, AnyEvent will start an interval timer to wake up perl (and |
|
|
2275 | catch the signals) with soemd elay (default is 10 seconds, look for |
|
|
2276 | C<$AnyEvent::MAX_SIGNAL_LATENCY>). |
|
|
2277 | |
|
|
2278 | If this module is available, then it will be used to implement signal |
|
|
2279 | catching, which means that signals will not be delayed, and the event loop |
|
|
2280 | will not be interrupted regularly, which is more efficient (And good for |
|
|
2281 | battery life on laptops). |
|
|
2282 | |
|
|
2283 | This affects not just the pure-perl event loop, but also other event loops |
|
|
2284 | that have no signal handling on their own (e.g. Glib, Tk, Qt). |
|
|
2285 | |
|
|
2286 | =item L<EV> |
|
|
2287 | |
|
|
2288 | This module isn't really "optional", as it is simply one of the backend |
|
|
2289 | event loops that AnyEvent can use. However, it is simply the best event |
|
|
2290 | loop available in terms of features, speed and stability: It supports |
|
|
2291 | the AnyEvent API optimally, implements all the watcher types in XS, does |
|
|
2292 | automatic timer adjustments even when no monotonic clock is available, |
|
|
2293 | can take avdantage of advanced kernel interfaces such as C<epoll> and |
|
|
2294 | C<kqueue>, and is the fastest backend I<by far>. You can even embed |
|
|
2295 | L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). |
|
|
2296 | |
|
|
2297 | =item L<Guard> |
|
|
2298 | |
|
|
2299 | The guard module, when used, will be used to implement |
|
|
2300 | C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a |
|
|
2301 | lot less memory), but otherwise doesn't affect guard operation much. It is |
|
|
2302 | purely used for performance. |
|
|
2303 | |
|
|
2304 | =item L<JSON> and L<JSON::XS> |
|
|
2305 | |
|
|
2306 | This module is required when you want to read or write JSON data via |
|
|
2307 | L<AnyEvent::Handle>. It is also written in pure-perl, but can take |
|
|
2308 | advantage of the ulta-high-speed L<JSON::XS> module when it is installed. |
|
|
2309 | |
|
|
2310 | In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is |
|
|
2311 | installed. |
|
|
2312 | |
|
|
2313 | =item L<Net::SSLeay> |
|
|
2314 | |
|
|
2315 | Implementing TLS/SSL in Perl is certainly interesting, but not very |
|
|
2316 | worthwhile: If this module is installed, then L<AnyEvent::Handle> (with |
|
|
2317 | the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. |
|
|
2318 | |
|
|
2319 | =item L<Time::HiRes> |
|
|
2320 | |
|
|
2321 | This module is part of perl since release 5.008. It will be used when the |
|
|
2322 | chosen event library does not come with a timing source on it's own. The |
|
|
2323 | pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to |
|
|
2324 | try to use a monotonic clock for timing stability. |
1455 | |
2325 | |
1456 | =back |
2326 | =back |
1457 | |
2327 | |
1458 | |
2328 | |
1459 | =head1 FORK |
2329 | =head1 FORK |
… | |
… | |
1461 | Most event libraries are not fork-safe. The ones who are usually are |
2331 | Most event libraries are not fork-safe. The ones who are usually are |
1462 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2332 | because they rely on inefficient but fork-safe C<select> or C<poll> |
1463 | calls. Only L<EV> is fully fork-aware. |
2333 | calls. Only L<EV> is fully fork-aware. |
1464 | |
2334 | |
1465 | If you have to fork, you must either do so I<before> creating your first |
2335 | If you have to fork, you must either do so I<before> creating your first |
1466 | watcher OR you must not use AnyEvent at all in the child. |
2336 | watcher OR you must not use AnyEvent at all in the child OR you must do |
|
|
2337 | something completely out of the scope of AnyEvent. |
1467 | |
2338 | |
1468 | |
2339 | |
1469 | =head1 SECURITY CONSIDERATIONS |
2340 | =head1 SECURITY CONSIDERATIONS |
1470 | |
2341 | |
1471 | AnyEvent can be forced to load any event model via |
2342 | AnyEvent can be forced to load any event model via |
… | |
… | |
1476 | specified in the variable. |
2347 | specified in the variable. |
1477 | |
2348 | |
1478 | You can make AnyEvent completely ignore this variable by deleting it |
2349 | You can make AnyEvent completely ignore this variable by deleting it |
1479 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
2350 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1480 | |
2351 | |
1481 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
2352 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1482 | |
2353 | |
1483 | use AnyEvent; |
2354 | use AnyEvent; |
1484 | |
2355 | |
1485 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2356 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1486 | be used to probe what backend is used and gain other information (which is |
2357 | be used to probe what backend is used and gain other information (which is |
1487 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
2358 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
2359 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2360 | |
|
|
2361 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2362 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2363 | enabled. |
|
|
2364 | |
|
|
2365 | |
|
|
2366 | =head1 BUGS |
|
|
2367 | |
|
|
2368 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
|
|
2369 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
|
|
2370 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
|
|
2371 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
|
|
2372 | pronounced). |
1488 | |
2373 | |
1489 | |
2374 | |
1490 | =head1 SEE ALSO |
2375 | =head1 SEE ALSO |
|
|
2376 | |
|
|
2377 | Utility functions: L<AnyEvent::Util>. |
1491 | |
2378 | |
1492 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
2379 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
1493 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
2380 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1494 | |
2381 | |
1495 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
2382 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1496 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
2383 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1497 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
2384 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1498 | L<AnyEvent::Impl::POE>. |
2385 | L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>. |
|
|
2386 | |
|
|
2387 | Non-blocking file handles, sockets, TCP clients and |
|
|
2388 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. |
1499 | |
2389 | |
1500 | Asynchronous DNS: L<AnyEvent::DNS>. |
2390 | Asynchronous DNS: L<AnyEvent::DNS>. |
1501 | |
2391 | |
1502 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
2392 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, |
|
|
2393 | L<Coro::Event>, |
1503 | |
2394 | |
1504 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
2395 | Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, |
|
|
2396 | L<AnyEvent::HTTP>. |
1505 | |
2397 | |
1506 | |
2398 | |
1507 | =head1 AUTHOR |
2399 | =head1 AUTHOR |
1508 | |
2400 | |
1509 | Marc Lehmann <schmorp@schmorp.de> |
2401 | Marc Lehmann <schmorp@schmorp.de> |
1510 | http://home.schmorp.de/ |
2402 | http://home.schmorp.de/ |
1511 | |
2403 | |
1512 | =cut |
2404 | =cut |
1513 | |
2405 | |
1514 | 1 |
2406 | 1 |
1515 | |
2407 | |