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. |
249 | |
367 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
368 | This watcher might use C<%SIG>, so programs overwriting those signals |
… | |
… | |
257 | =head2 CHILD PROCESS WATCHERS |
375 | =head2 CHILD PROCESS WATCHERS |
258 | |
376 | |
259 | You can also watch on a child process exit and catch its exit status. |
377 | You can also watch on a child process exit and catch its exit status. |
260 | |
378 | |
261 | The child process is specified by the C<pid> argument (if set to C<0>, it |
379 | 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 |
380 | 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 |
381 | 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 |
382 | any trace events (stopped/continued). |
265 | and exit status (as returned by waitpid), so unlike other watcher types, |
383 | |
266 | you I<can> rely on child watcher callback arguments. |
384 | The callback will be called with the pid and exit status (as returned by |
|
|
385 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
|
386 | callback arguments. |
|
|
387 | |
|
|
388 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
|
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389 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
|
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390 | random child processes (waiting for specific child processes, e.g. inside |
|
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391 | C<system>, is just fine). |
267 | |
392 | |
268 | There is a slight catch to child watchers, however: you usually start them |
393 | 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 |
394 | I<after> the child process was created, and this means the process could |
270 | have exited already (and no SIGCHLD will be sent anymore). |
395 | have exited already (and no SIGCHLD will be sent anymore). |
271 | |
396 | |
272 | Not all event models handle this correctly (POE doesn't), but even for |
397 | Not all event models handle this correctly (neither POE nor IO::Async do, |
|
|
398 | 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 |
399 | 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). |
400 | the process exits (i.e. before you fork in the first place). AnyEvent's |
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401 | pure perl event loop handles all cases correctly regardless of when you |
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|
402 | start the watcher. |
275 | |
403 | |
276 | This means you cannot create a child watcher as the very first thing in an |
404 | 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 |
405 | 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>). |
406 | watcher before you C<fork> the child (alternatively, you can call |
|
|
407 | C<AnyEvent::detect>). |
279 | |
408 | |
280 | Example: fork a process and wait for it |
409 | Example: fork a process and wait for it |
281 | |
410 | |
282 | my $done = AnyEvent->condvar; |
411 | my $done = AnyEvent->condvar; |
283 | |
412 | |
284 | my $pid = fork or exit 5; |
413 | my $pid = fork or exit 5; |
285 | |
414 | |
286 | my $w = AnyEvent->child ( |
415 | my $w = AnyEvent->child ( |
287 | pid => $pid, |
416 | pid => $pid, |
288 | cb => sub { |
417 | cb => sub { |
289 | my ($pid, $status) = @_; |
418 | my ($pid, $status) = @_; |
290 | warn "pid $pid exited with status $status"; |
419 | warn "pid $pid exited with status $status"; |
291 | $done->send; |
420 | $done->send; |
292 | }, |
421 | }, |
293 | ); |
422 | ); |
294 | |
423 | |
295 | # do something else, then wait for process exit |
424 | # do something else, then wait for process exit |
296 | $done->recv; |
425 | $done->recv; |
|
|
426 | |
|
|
427 | =head2 IDLE WATCHERS |
|
|
428 | |
|
|
429 | Sometimes there is a need to do something, but it is not so important |
|
|
430 | to do it instantly, but only when there is nothing better to do. This |
|
|
431 | "nothing better to do" is usually defined to be "no other events need |
|
|
432 | attention by the event loop". |
|
|
433 | |
|
|
434 | Idle watchers ideally get invoked when the event loop has nothing |
|
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435 | better to do, just before it would block the process to wait for new |
|
|
436 | events. Instead of blocking, the idle watcher is invoked. |
|
|
437 | |
|
|
438 | Most event loops unfortunately do not really support idle watchers (only |
|
|
439 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
|
|
440 | will simply call the callback "from time to time". |
|
|
441 | |
|
|
442 | Example: read lines from STDIN, but only process them when the |
|
|
443 | program is otherwise idle: |
|
|
444 | |
|
|
445 | my @lines; # read data |
|
|
446 | my $idle_w; |
|
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447 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
|
|
448 | push @lines, scalar <STDIN>; |
|
|
449 | |
|
|
450 | # start an idle watcher, if not already done |
|
|
451 | $idle_w ||= AnyEvent->idle (cb => sub { |
|
|
452 | # handle only one line, when there are lines left |
|
|
453 | if (my $line = shift @lines) { |
|
|
454 | print "handled when idle: $line"; |
|
|
455 | } else { |
|
|
456 | # otherwise disable the idle watcher again |
|
|
457 | undef $idle_w; |
|
|
458 | } |
|
|
459 | }); |
|
|
460 | }); |
297 | |
461 | |
298 | =head2 CONDITION VARIABLES |
462 | =head2 CONDITION VARIABLES |
299 | |
463 | |
300 | If you are familiar with some event loops you will know that all of them |
464 | 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 |
465 | require you to run some blocking "loop", "run" or similar function that |
… | |
… | |
307 | The instrument to do that is called a "condition variable", so called |
471 | The instrument to do that is called a "condition variable", so called |
308 | because they represent a condition that must become true. |
472 | because they represent a condition that must become true. |
309 | |
473 | |
310 | Condition variables can be created by calling the C<< AnyEvent->condvar |
474 | Condition variables can be created by calling the C<< AnyEvent->condvar |
311 | >> method, usually without arguments. The only argument pair allowed is |
475 | >> method, usually without arguments. The only argument pair allowed is |
|
|
476 | |
312 | C<cb>, which specifies a callback to be called when the condition variable |
477 | C<cb>, which specifies a callback to be called when the condition variable |
313 | becomes true. |
478 | becomes true, with the condition variable as the first argument (but not |
|
|
479 | the results). |
314 | |
480 | |
315 | After creation, the conditon variable is "false" until it becomes "true" |
481 | After creation, the condition variable is "false" until it becomes "true" |
316 | by calling the C<send> method. |
482 | by calling the C<send> method (or calling the condition variable as if it |
|
|
483 | were a callback, read about the caveats in the description for the C<< |
|
|
484 | ->send >> method). |
317 | |
485 | |
318 | Condition variables are similar to callbacks, except that you can |
486 | Condition variables are similar to callbacks, except that you can |
319 | optionally wait for them. They can also be called merge points - points |
487 | optionally wait for them. They can also be called merge points - points |
320 | in time where multiple outstandign events have been processed. And yet |
488 | in time where multiple outstanding events have been processed. And yet |
321 | another way to call them is transations - each condition variable can be |
489 | 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 |
490 | used to represent a transaction, which finishes at some point and delivers |
323 | a result. |
491 | a result. |
324 | |
492 | |
325 | Condition variables are very useful to signal that something has finished, |
493 | Condition variables are very useful to signal that something has finished, |
326 | for example, if you write a module that does asynchronous http requests, |
494 | 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 |
500 | 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 |
501 | 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. |
502 | button of your app, which would C<< ->send >> the "quit" event. |
335 | |
503 | |
336 | Note that condition variables recurse into the event loop - if you have |
504 | 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 |
505 | 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 |
506 | 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, |
507 | you should avoid making a blocking wait yourself, at least in callbacks, |
340 | as this asks for trouble. |
508 | as this asks for trouble. |
341 | |
509 | |
342 | Condition variables are represented by hash refs in perl, and the keys |
510 | Condition variables are represented by hash refs in perl, and the keys |
… | |
… | |
347 | |
515 | |
348 | There are two "sides" to a condition variable - the "producer side" which |
516 | There are two "sides" to a condition variable - the "producer side" which |
349 | eventually calls C<< -> send >>, and the "consumer side", which waits |
517 | eventually calls C<< -> send >>, and the "consumer side", which waits |
350 | for the send to occur. |
518 | for the send to occur. |
351 | |
519 | |
352 | Example: |
520 | Example: wait for a timer. |
353 | |
521 | |
354 | # wait till the result is ready |
522 | # wait till the result is ready |
355 | my $result_ready = AnyEvent->condvar; |
523 | my $result_ready = AnyEvent->condvar; |
356 | |
524 | |
357 | # do something such as adding a timer |
525 | # do something such as adding a timer |
… | |
… | |
365 | |
533 | |
366 | # this "blocks" (while handling events) till the callback |
534 | # this "blocks" (while handling events) till the callback |
367 | # calls send |
535 | # calls send |
368 | $result_ready->recv; |
536 | $result_ready->recv; |
369 | |
537 | |
|
|
538 | Example: wait for a timer, but take advantage of the fact that |
|
|
539 | condition variables are also code references. |
|
|
540 | |
|
|
541 | my $done = AnyEvent->condvar; |
|
|
542 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
|
|
543 | $done->recv; |
|
|
544 | |
|
|
545 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
546 | callbacks. This is how you make a synchronous call, for example from |
|
|
547 | the main program: |
|
|
548 | |
|
|
549 | use AnyEvent::CouchDB; |
|
|
550 | |
|
|
551 | ... |
|
|
552 | |
|
|
553 | my @info = $couchdb->info->recv; |
|
|
554 | |
|
|
555 | And this is how you would just ste a callback to be called whenever the |
|
|
556 | results are available: |
|
|
557 | |
|
|
558 | $couchdb->info->cb (sub { |
|
|
559 | my @info = $_[0]->recv; |
|
|
560 | }); |
|
|
561 | |
370 | =head3 METHODS FOR PRODUCERS |
562 | =head3 METHODS FOR PRODUCERS |
371 | |
563 | |
372 | These methods should only be used by the producing side, i.e. the |
564 | 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 |
565 | code/module that eventually sends the signal. Note that it is also |
374 | the producer side which creates the condvar in most cases, but it isn't |
566 | the producer side which creates the condvar in most cases, but it isn't |
… | |
… | |
386 | immediately from within send. |
578 | immediately from within send. |
387 | |
579 | |
388 | Any arguments passed to the C<send> call will be returned by all |
580 | Any arguments passed to the C<send> call will be returned by all |
389 | future C<< ->recv >> calls. |
581 | future C<< ->recv >> calls. |
390 | |
582 | |
|
|
583 | Condition variables are overloaded so one can call them directly |
|
|
584 | (as a code reference). Calling them directly is the same as calling |
|
|
585 | C<send>. Note, however, that many C-based event loops do not handle |
|
|
586 | overloading, so as tempting as it may be, passing a condition variable |
|
|
587 | instead of a callback does not work. Both the pure perl and EV loops |
|
|
588 | support overloading, however, as well as all functions that use perl to |
|
|
589 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
|
|
590 | example). |
|
|
591 | |
391 | =item $cv->croak ($error) |
592 | =item $cv->croak ($error) |
392 | |
593 | |
393 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
594 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
394 | C<Carp::croak> with the given error message/object/scalar. |
595 | C<Carp::croak> with the given error message/object/scalar. |
395 | |
596 | |
… | |
… | |
397 | user/consumer. |
598 | user/consumer. |
398 | |
599 | |
399 | =item $cv->begin ([group callback]) |
600 | =item $cv->begin ([group callback]) |
400 | |
601 | |
401 | =item $cv->end |
602 | =item $cv->end |
402 | |
|
|
403 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
|
|
404 | |
603 | |
405 | These two methods can be used to combine many transactions/events into |
604 | 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 |
605 | one. For example, a function that pings many hosts in parallel might want |
407 | to use a condition variable for the whole process. |
606 | to use a condition variable for the whole process. |
408 | |
607 | |
… | |
… | |
410 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
609 | 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 |
610 | >>, 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 |
611 | 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. |
612 | callback was set, C<send> will be called without any arguments. |
414 | |
613 | |
415 | Let's clarify this with the ping example: |
614 | You can think of C<< $cv->send >> giving you an OR condition (one call |
|
|
615 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
|
|
616 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
|
|
617 | |
|
|
618 | Let's start with a simple example: you have two I/O watchers (for example, |
|
|
619 | STDOUT and STDERR for a program), and you want to wait for both streams to |
|
|
620 | close before activating a condvar: |
|
|
621 | |
|
|
622 | my $cv = AnyEvent->condvar; |
|
|
623 | |
|
|
624 | $cv->begin; # first watcher |
|
|
625 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
|
|
626 | defined sysread $fh1, my $buf, 4096 |
|
|
627 | or $cv->end; |
|
|
628 | }); |
|
|
629 | |
|
|
630 | $cv->begin; # second watcher |
|
|
631 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
632 | defined sysread $fh2, my $buf, 4096 |
|
|
633 | or $cv->end; |
|
|
634 | }); |
|
|
635 | |
|
|
636 | $cv->recv; |
|
|
637 | |
|
|
638 | This works because for every event source (EOF on file handle), there is |
|
|
639 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
|
|
640 | sending. |
|
|
641 | |
|
|
642 | The ping example mentioned above is slightly more complicated, as the |
|
|
643 | there are results to be passwd back, and the number of tasks that are |
|
|
644 | begung can potentially be zero: |
416 | |
645 | |
417 | my $cv = AnyEvent->condvar; |
646 | my $cv = AnyEvent->condvar; |
418 | |
647 | |
419 | my %result; |
648 | my %result; |
420 | $cv->begin (sub { $cv->send (\%result) }); |
649 | $cv->begin (sub { $cv->send (\%result) }); |
… | |
… | |
440 | loop, which serves two important purposes: first, it sets the callback |
669 | 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 |
670 | 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 |
671 | C<send> is called even when C<no> hosts are being pinged (the loop |
443 | doesn't execute once). |
672 | doesn't execute once). |
444 | |
673 | |
445 | This is the general pattern when you "fan out" into multiple subrequests: |
674 | 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> |
675 | 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 |
676 | 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>. |
677 | subrequest you start, call C<begin> and for each subrequest you finish, |
|
|
678 | call C<end>. |
449 | |
679 | |
450 | =back |
680 | =back |
451 | |
681 | |
452 | =head3 METHODS FOR CONSUMERS |
682 | =head3 METHODS FOR CONSUMERS |
453 | |
683 | |
… | |
… | |
475 | (programs might want to do that to stay interactive), so I<if you are |
705 | (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 |
706 | using this from a module, never require a blocking wait>, but let the |
477 | caller decide whether the call will block or not (for example, by coupling |
707 | caller decide whether the call will block or not (for example, by coupling |
478 | condition variables with some kind of request results and supporting |
708 | condition variables with some kind of request results and supporting |
479 | callbacks so the caller knows that getting the result will not block, |
709 | callbacks so the caller knows that getting the result will not block, |
480 | while still suppporting blocking waits if the caller so desires). |
710 | while still supporting blocking waits if the caller so desires). |
481 | |
711 | |
482 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
712 | 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 |
713 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
484 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
714 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
485 | can supply. |
715 | can supply. |
… | |
… | |
498 | =item $bool = $cv->ready |
728 | =item $bool = $cv->ready |
499 | |
729 | |
500 | Returns true when the condition is "true", i.e. whether C<send> or |
730 | Returns true when the condition is "true", i.e. whether C<send> or |
501 | C<croak> have been called. |
731 | C<croak> have been called. |
502 | |
732 | |
503 | =item $cb = $cv->cb ([new callback]) |
733 | =item $cb = $cv->cb ($cb->($cv)) |
504 | |
734 | |
505 | This is a mutator function that returns the callback set and optionally |
735 | This is a mutator function that returns the callback set and optionally |
506 | replaces it before doing so. |
736 | replaces it before doing so. |
507 | |
737 | |
508 | The callback will be called when the condition becomes "true", i.e. when |
738 | 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 |
739 | 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. |
740 | variable itself. Calling C<recv> inside the callback or at any later time |
|
|
741 | is guaranteed not to block. |
511 | |
742 | |
512 | =back |
743 | =back |
513 | |
744 | |
514 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
745 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
515 | |
746 | |
… | |
… | |
532 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
763 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
533 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
764 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
534 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
765 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
535 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
766 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
536 | |
767 | |
|
|
768 | # warning, support for IO::Async is only partial, as it is too broken |
|
|
769 | # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async. |
|
|
770 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs). |
|
|
771 | |
537 | There is no support for WxWidgets, as WxWidgets has no support for |
772 | There is no support for WxWidgets, as WxWidgets has no support for |
538 | watching file handles. However, you can use WxWidgets through the |
773 | 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 |
774 | 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 |
775 | 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 |
776 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
… | |
… | |
601 | |
836 | |
602 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
837 | 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 |
838 | 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. |
839 | decide which implementation to chose if some module relies on it. |
605 | |
840 | |
606 | If the main program relies on a specific event model. For example, in |
841 | 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 |
842 | 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 |
843 | 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 |
844 | 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 |
845 | 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 |
846 | 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. |
847 | might chose the wrong one unless you load the correct one yourself. |
613 | |
848 | |
614 | You can chose to use a rather inefficient pure-perl implementation by |
849 | You can chose to use a pure-perl implementation by loading the |
615 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
850 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
616 | behaviour everywhere, but letting AnyEvent chose is generally better. |
851 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
852 | |
|
|
853 | =head2 MAINLOOP EMULATION |
|
|
854 | |
|
|
855 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
856 | only want to use AnyEvent), you do not want to run a specific event loop. |
|
|
857 | |
|
|
858 | In that case, you can use a condition variable like this: |
|
|
859 | |
|
|
860 | AnyEvent->condvar->recv; |
|
|
861 | |
|
|
862 | This has the effect of entering the event loop and looping forever. |
|
|
863 | |
|
|
864 | Note that usually your program has some exit condition, in which case |
|
|
865 | it is better to use the "traditional" approach of storing a condition |
|
|
866 | variable somewhere, waiting for it, and sending it when the program should |
|
|
867 | exit cleanly. |
|
|
868 | |
617 | |
869 | |
618 | =head1 OTHER MODULES |
870 | =head1 OTHER MODULES |
619 | |
871 | |
620 | The following is a non-exhaustive list of additional modules that use |
872 | The following is a non-exhaustive list of additional modules that use |
621 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
873 | 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 |
874 | modules and other event loops in the same program. Some of the modules |
623 | available via CPAN. |
875 | come with AnyEvent, most are available via CPAN. |
624 | |
876 | |
625 | =over 4 |
877 | =over 4 |
626 | |
878 | |
627 | =item L<AnyEvent::Util> |
879 | =item L<AnyEvent::Util> |
628 | |
880 | |
629 | Contains various utility functions that replace often-used but blocking |
881 | Contains various utility functions that replace often-used but blocking |
630 | functions such as C<inet_aton> by event-/callback-based versions. |
882 | functions such as C<inet_aton> by event-/callback-based versions. |
631 | |
|
|
632 | =item L<AnyEvent::Handle> |
|
|
633 | |
|
|
634 | Provide read and write buffers and manages watchers for reads and writes. |
|
|
635 | |
883 | |
636 | =item L<AnyEvent::Socket> |
884 | =item L<AnyEvent::Socket> |
637 | |
885 | |
638 | Provides various utility functions for (internet protocol) sockets, |
886 | Provides various utility functions for (internet protocol) sockets, |
639 | addresses and name resolution. Also functions to create non-blocking tcp |
887 | addresses and name resolution. Also functions to create non-blocking tcp |
640 | connections or tcp servers, with IPv6 and SRV record support and more. |
888 | connections or tcp servers, with IPv6 and SRV record support and more. |
641 | |
889 | |
|
|
890 | =item L<AnyEvent::Handle> |
|
|
891 | |
|
|
892 | Provide read and write buffers, manages watchers for reads and writes, |
|
|
893 | supports raw and formatted I/O, I/O queued and fully transparent and |
|
|
894 | non-blocking SSL/TLS (via L<AnyEvent::TLS>. |
|
|
895 | |
|
|
896 | =item L<AnyEvent::DNS> |
|
|
897 | |
|
|
898 | Provides rich asynchronous DNS resolver capabilities. |
|
|
899 | |
|
|
900 | =item L<AnyEvent::HTTP> |
|
|
901 | |
|
|
902 | A simple-to-use HTTP library that is capable of making a lot of concurrent |
|
|
903 | HTTP requests. |
|
|
904 | |
642 | =item L<AnyEvent::HTTPD> |
905 | =item L<AnyEvent::HTTPD> |
643 | |
906 | |
644 | Provides a simple web application server framework. |
907 | Provides a simple web application server framework. |
645 | |
908 | |
646 | =item L<AnyEvent::DNS> |
|
|
647 | |
|
|
648 | Provides rich asynchronous DNS resolver capabilities. |
|
|
649 | |
|
|
650 | =item L<AnyEvent::FastPing> |
909 | =item L<AnyEvent::FastPing> |
651 | |
910 | |
652 | The fastest ping in the west. |
911 | The fastest ping in the west. |
653 | |
912 | |
|
|
913 | =item L<AnyEvent::DBI> |
|
|
914 | |
|
|
915 | Executes L<DBI> requests asynchronously in a proxy process. |
|
|
916 | |
|
|
917 | =item L<AnyEvent::AIO> |
|
|
918 | |
|
|
919 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
920 | programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent |
|
|
921 | together. |
|
|
922 | |
|
|
923 | =item L<AnyEvent::BDB> |
|
|
924 | |
|
|
925 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses |
|
|
926 | L<BDB> and AnyEvent together. |
|
|
927 | |
|
|
928 | =item L<AnyEvent::GPSD> |
|
|
929 | |
|
|
930 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
|
|
931 | |
654 | =item L<Net::IRC3> |
932 | =item L<AnyEvent::IRC> |
655 | |
933 | |
656 | AnyEvent based IRC client module family. |
934 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
657 | |
935 | |
658 | =item L<Net::XMPP2> |
936 | =item L<AnyEvent::XMPP> |
659 | |
937 | |
660 | AnyEvent based XMPP (Jabber protocol) module family. |
938 | AnyEvent based XMPP (Jabber protocol) module family (replacing the older |
|
|
939 | Net::XMPP2>. |
|
|
940 | |
|
|
941 | =item L<AnyEvent::IGS> |
|
|
942 | |
|
|
943 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
944 | L<App::IGS>). |
661 | |
945 | |
662 | =item L<Net::FCP> |
946 | =item L<Net::FCP> |
663 | |
947 | |
664 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
948 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
665 | of AnyEvent. |
949 | of AnyEvent. |
… | |
… | |
670 | |
954 | |
671 | =item L<Coro> |
955 | =item L<Coro> |
672 | |
956 | |
673 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
957 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
674 | |
958 | |
675 | =item L<AnyEvent::AIO>, L<IO::AIO> |
|
|
676 | |
|
|
677 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
678 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
679 | together. |
|
|
680 | |
|
|
681 | =item L<AnyEvent::BDB>, L<BDB> |
|
|
682 | |
|
|
683 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
|
|
684 | IO::AIO and AnyEvent together. |
|
|
685 | |
|
|
686 | =item L<IO::Lambda> |
|
|
687 | |
|
|
688 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
|
|
689 | |
|
|
690 | =back |
959 | =back |
691 | |
960 | |
692 | =cut |
961 | =cut |
693 | |
962 | |
694 | package AnyEvent; |
963 | package AnyEvent; |
695 | |
964 | |
696 | no warnings; |
965 | no warnings; |
697 | use strict; |
966 | use strict qw(vars subs); |
698 | |
967 | |
699 | use Carp; |
968 | use Carp; |
700 | |
969 | |
701 | our $VERSION = '3.6'; |
970 | our $VERSION = 4.8; |
702 | our $MODEL; |
971 | our $MODEL; |
703 | |
972 | |
704 | our $AUTOLOAD; |
973 | our $AUTOLOAD; |
705 | our @ISA; |
974 | our @ISA; |
706 | |
975 | |
|
|
976 | our @REGISTRY; |
|
|
977 | |
|
|
978 | our $WIN32; |
|
|
979 | |
|
|
980 | BEGIN { |
|
|
981 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
|
|
982 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
|
|
983 | |
|
|
984 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
985 | if ${^TAINT}; |
|
|
986 | } |
|
|
987 | |
707 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
988 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
708 | |
989 | |
709 | our @REGISTRY; |
990 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
710 | |
|
|
711 | our %PROTOCOL; # (ipv4|ipv6) => (1|2) |
|
|
712 | |
991 | |
713 | { |
992 | { |
714 | my $idx; |
993 | my $idx; |
715 | $PROTOCOL{$_} = ++$idx |
994 | $PROTOCOL{$_} = ++$idx |
|
|
995 | for reverse split /\s*,\s*/, |
716 | for split /\s*,\s*/, $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
996 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
717 | } |
997 | } |
718 | |
998 | |
719 | my @models = ( |
999 | my @models = ( |
720 | [EV:: => AnyEvent::Impl::EV::], |
1000 | [EV:: => AnyEvent::Impl::EV::], |
721 | [Event:: => AnyEvent::Impl::Event::], |
1001 | [Event:: => AnyEvent::Impl::Event::], |
722 | [Tk:: => AnyEvent::Impl::Tk::], |
|
|
723 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
724 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
725 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
1002 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
726 | # everything below here will not be autoprobed as the pureperl backend should work everywhere |
1003 | # everything below here will not be autoprobed |
727 | [Glib:: => AnyEvent::Impl::Glib::], |
1004 | # as the pureperl backend should work everywhere |
|
|
1005 | # and is usually faster |
|
|
1006 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
1007 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
728 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
1008 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
729 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1009 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
730 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1010 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
|
|
1011 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
1012 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
1013 | # IO::Async is just too broken - we would need workaorunds for its |
|
|
1014 | # byzantine signal and broken child handling, among others. |
|
|
1015 | # IO::Async is rather hard to detect, as it doesn't have any |
|
|
1016 | # obvious default class. |
|
|
1017 | # [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1018 | # [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1019 | # [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
731 | ); |
1020 | ); |
732 | |
1021 | |
733 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
1022 | our %method = map +($_ => 1), |
|
|
1023 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
734 | |
1024 | |
735 | our @post_detect; |
1025 | our @post_detect; |
736 | |
1026 | |
737 | sub post_detect(&) { |
1027 | sub post_detect(&) { |
738 | my ($cb) = @_; |
1028 | my ($cb) = @_; |
… | |
… | |
743 | 1 |
1033 | 1 |
744 | } else { |
1034 | } else { |
745 | push @post_detect, $cb; |
1035 | push @post_detect, $cb; |
746 | |
1036 | |
747 | defined wantarray |
1037 | defined wantarray |
748 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
1038 | ? bless \$cb, "AnyEvent::Util::postdetect" |
749 | : () |
1039 | : () |
750 | } |
1040 | } |
751 | } |
1041 | } |
752 | |
1042 | |
753 | sub AnyEvent::Util::PostDetect::DESTROY { |
1043 | sub AnyEvent::Util::postdetect::DESTROY { |
754 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
1044 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
755 | } |
1045 | } |
756 | |
1046 | |
757 | sub detect() { |
1047 | sub detect() { |
758 | unless ($MODEL) { |
1048 | unless ($MODEL) { |
759 | no strict 'refs'; |
1049 | no strict 'refs'; |
|
|
1050 | local $SIG{__DIE__}; |
760 | |
1051 | |
761 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
1052 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
762 | my $model = "AnyEvent::Impl::$1"; |
1053 | my $model = "AnyEvent::Impl::$1"; |
763 | if (eval "require $model") { |
1054 | if (eval "require $model") { |
764 | $MODEL = $model; |
1055 | $MODEL = $model; |
… | |
… | |
794 | last; |
1085 | last; |
795 | } |
1086 | } |
796 | } |
1087 | } |
797 | |
1088 | |
798 | $MODEL |
1089 | $MODEL |
799 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
1090 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
800 | } |
1091 | } |
801 | } |
1092 | } |
802 | |
1093 | |
|
|
1094 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
1095 | |
803 | unshift @ISA, $MODEL; |
1096 | unshift @ISA, $MODEL; |
804 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1097 | |
|
|
1098 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
805 | |
1099 | |
806 | (shift @post_detect)->() while @post_detect; |
1100 | (shift @post_detect)->() while @post_detect; |
807 | } |
1101 | } |
808 | |
1102 | |
809 | $MODEL |
1103 | $MODEL |
… | |
… | |
819 | |
1113 | |
820 | my $class = shift; |
1114 | my $class = shift; |
821 | $class->$func (@_); |
1115 | $class->$func (@_); |
822 | } |
1116 | } |
823 | |
1117 | |
|
|
1118 | # utility function to dup a filehandle. this is used by many backends |
|
|
1119 | # to support binding more than one watcher per filehandle (they usually |
|
|
1120 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1121 | sub _dupfh($$;$$) { |
|
|
1122 | my ($poll, $fh, $r, $w) = @_; |
|
|
1123 | |
|
|
1124 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1125 | my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">"); |
|
|
1126 | |
|
|
1127 | open my $fh2, "$mode&", $fh |
|
|
1128 | or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; |
|
|
1129 | |
|
|
1130 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1131 | |
|
|
1132 | ($fh2, $rw) |
|
|
1133 | } |
|
|
1134 | |
824 | package AnyEvent::Base; |
1135 | package AnyEvent::Base; |
825 | |
1136 | |
|
|
1137 | # default implementations for many methods |
|
|
1138 | |
|
|
1139 | BEGIN { |
|
|
1140 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1141 | *_time = \&Time::HiRes::time; |
|
|
1142 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1143 | } else { |
|
|
1144 | *_time = sub { time }; # epic fail |
|
|
1145 | } |
|
|
1146 | } |
|
|
1147 | |
|
|
1148 | sub time { _time } |
|
|
1149 | sub now { _time } |
|
|
1150 | sub now_update { } |
|
|
1151 | |
826 | # default implementation for ->condvar |
1152 | # default implementation for ->condvar |
827 | |
1153 | |
828 | sub condvar { |
1154 | sub condvar { |
829 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
1155 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
830 | } |
1156 | } |
831 | |
1157 | |
832 | # default implementation for ->signal |
1158 | # default implementation for ->signal |
833 | |
1159 | |
834 | our %SIG_CB; |
1160 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1161 | |
|
|
1162 | sub _signal_exec { |
|
|
1163 | sysread $SIGPIPE_R, my $dummy, 4; |
|
|
1164 | |
|
|
1165 | while (%SIG_EV) { |
|
|
1166 | for (keys %SIG_EV) { |
|
|
1167 | delete $SIG_EV{$_}; |
|
|
1168 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1169 | } |
|
|
1170 | } |
|
|
1171 | } |
835 | |
1172 | |
836 | sub signal { |
1173 | sub signal { |
837 | my (undef, %arg) = @_; |
1174 | my (undef, %arg) = @_; |
838 | |
1175 | |
|
|
1176 | unless ($SIGPIPE_R) { |
|
|
1177 | require Fcntl; |
|
|
1178 | |
|
|
1179 | if (AnyEvent::WIN32) { |
|
|
1180 | require AnyEvent::Util; |
|
|
1181 | |
|
|
1182 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1183 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1184 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1185 | } else { |
|
|
1186 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1187 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1188 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1189 | |
|
|
1190 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1191 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1192 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1193 | } |
|
|
1194 | |
|
|
1195 | $SIGPIPE_R |
|
|
1196 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1197 | |
|
|
1198 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1199 | } |
|
|
1200 | |
839 | my $signal = uc $arg{signal} |
1201 | my $signal = uc $arg{signal} |
840 | or Carp::croak "required option 'signal' is missing"; |
1202 | or Carp::croak "required option 'signal' is missing"; |
841 | |
1203 | |
842 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1204 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
843 | $SIG{$signal} ||= sub { |
1205 | $SIG{$signal} ||= sub { |
844 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1206 | local $!; |
|
|
1207 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1208 | undef $SIG_EV{$signal}; |
845 | }; |
1209 | }; |
846 | |
1210 | |
847 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1211 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
848 | } |
1212 | } |
849 | |
1213 | |
850 | sub AnyEvent::Base::Signal::DESTROY { |
1214 | sub AnyEvent::Base::signal::DESTROY { |
851 | my ($signal, $cb) = @{$_[0]}; |
1215 | my ($signal, $cb) = @{$_[0]}; |
852 | |
1216 | |
853 | delete $SIG_CB{$signal}{$cb}; |
1217 | delete $SIG_CB{$signal}{$cb}; |
854 | |
1218 | |
|
|
1219 | # delete doesn't work with older perls - they then |
|
|
1220 | # print weird messages, or just unconditionally exit |
|
|
1221 | # instead of getting the default action. |
855 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1222 | undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} }; |
856 | } |
1223 | } |
857 | |
1224 | |
858 | # default implementation for ->child |
1225 | # default implementation for ->child |
859 | |
1226 | |
860 | our %PID_CB; |
1227 | our %PID_CB; |
861 | our $CHLD_W; |
1228 | our $CHLD_W; |
862 | our $CHLD_DELAY_W; |
1229 | our $CHLD_DELAY_W; |
863 | our $PID_IDLE; |
|
|
864 | our $WNOHANG; |
1230 | our $WNOHANG; |
865 | |
1231 | |
866 | sub _child_wait { |
1232 | sub _sigchld { |
867 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1233 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
868 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1234 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
869 | (values %{ $PID_CB{0} || {} }); |
1235 | (values %{ $PID_CB{0} || {} }); |
870 | } |
1236 | } |
871 | |
|
|
872 | undef $PID_IDLE; |
|
|
873 | } |
|
|
874 | |
|
|
875 | sub _sigchld { |
|
|
876 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
877 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
878 | undef $CHLD_DELAY_W; |
|
|
879 | &_child_wait; |
|
|
880 | }); |
|
|
881 | } |
1237 | } |
882 | |
1238 | |
883 | sub child { |
1239 | sub child { |
884 | my (undef, %arg) = @_; |
1240 | my (undef, %arg) = @_; |
885 | |
1241 | |
886 | defined (my $pid = $arg{pid} + 0) |
1242 | defined (my $pid = $arg{pid} + 0) |
887 | or Carp::croak "required option 'pid' is missing"; |
1243 | or Carp::croak "required option 'pid' is missing"; |
888 | |
1244 | |
889 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1245 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
890 | |
1246 | |
891 | unless ($WNOHANG) { |
|
|
892 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
1247 | $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
893 | } |
|
|
894 | |
1248 | |
895 | unless ($CHLD_W) { |
1249 | unless ($CHLD_W) { |
896 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1250 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
897 | # child could be a zombie already, so make at least one round |
1251 | # child could be a zombie already, so make at least one round |
898 | &_sigchld; |
1252 | &_sigchld; |
899 | } |
1253 | } |
900 | |
1254 | |
901 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1255 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
902 | } |
1256 | } |
903 | |
1257 | |
904 | sub AnyEvent::Base::Child::DESTROY { |
1258 | sub AnyEvent::Base::child::DESTROY { |
905 | my ($pid, $cb) = @{$_[0]}; |
1259 | my ($pid, $cb) = @{$_[0]}; |
906 | |
1260 | |
907 | delete $PID_CB{$pid}{$cb}; |
1261 | delete $PID_CB{$pid}{$cb}; |
908 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1262 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
909 | |
1263 | |
910 | undef $CHLD_W unless keys %PID_CB; |
1264 | undef $CHLD_W unless keys %PID_CB; |
911 | } |
1265 | } |
912 | |
1266 | |
|
|
1267 | # idle emulation is done by simply using a timer, regardless |
|
|
1268 | # of whether the process is idle or not, and not letting |
|
|
1269 | # the callback use more than 50% of the time. |
|
|
1270 | sub idle { |
|
|
1271 | my (undef, %arg) = @_; |
|
|
1272 | |
|
|
1273 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1274 | |
|
|
1275 | $rcb = sub { |
|
|
1276 | if ($cb) { |
|
|
1277 | $w = _time; |
|
|
1278 | &$cb; |
|
|
1279 | $w = _time - $w; |
|
|
1280 | |
|
|
1281 | # never use more then 50% of the time for the idle watcher, |
|
|
1282 | # within some limits |
|
|
1283 | $w = 0.0001 if $w < 0.0001; |
|
|
1284 | $w = 5 if $w > 5; |
|
|
1285 | |
|
|
1286 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1287 | } else { |
|
|
1288 | # clean up... |
|
|
1289 | undef $w; |
|
|
1290 | undef $rcb; |
|
|
1291 | } |
|
|
1292 | }; |
|
|
1293 | |
|
|
1294 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1295 | |
|
|
1296 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1297 | } |
|
|
1298 | |
|
|
1299 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1300 | undef $${$_[0]}; |
|
|
1301 | } |
|
|
1302 | |
913 | package AnyEvent::CondVar; |
1303 | package AnyEvent::CondVar; |
914 | |
1304 | |
915 | our @ISA = AnyEvent::CondVar::Base::; |
1305 | our @ISA = AnyEvent::CondVar::Base::; |
916 | |
1306 | |
917 | package AnyEvent::CondVar::Base; |
1307 | package AnyEvent::CondVar::Base; |
|
|
1308 | |
|
|
1309 | use overload |
|
|
1310 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
|
|
1311 | fallback => 1; |
918 | |
1312 | |
919 | sub _send { |
1313 | sub _send { |
920 | # nop |
1314 | # nop |
921 | } |
1315 | } |
922 | |
1316 | |
… | |
… | |
963 | } |
1357 | } |
964 | |
1358 | |
965 | # undocumented/compatibility with pre-3.4 |
1359 | # undocumented/compatibility with pre-3.4 |
966 | *broadcast = \&send; |
1360 | *broadcast = \&send; |
967 | *wait = \&_wait; |
1361 | *wait = \&_wait; |
|
|
1362 | |
|
|
1363 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1364 | |
|
|
1365 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1366 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1367 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1368 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1369 | development. |
|
|
1370 | |
|
|
1371 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1372 | executing a callback), this is not only highly event-loop specific, but |
|
|
1373 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1374 | program. |
|
|
1375 | |
|
|
1376 | The pure perl event loop simply re-throws the exception (usually |
|
|
1377 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1378 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1379 | so on. |
|
|
1380 | |
|
|
1381 | =head1 ENVIRONMENT VARIABLES |
|
|
1382 | |
|
|
1383 | The following environment variables are used by this module or its |
|
|
1384 | submodules. |
|
|
1385 | |
|
|
1386 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1387 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1388 | enabled. |
|
|
1389 | |
|
|
1390 | =over 4 |
|
|
1391 | |
|
|
1392 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1393 | |
|
|
1394 | By default, AnyEvent will be completely silent except in fatal |
|
|
1395 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1396 | talkative. |
|
|
1397 | |
|
|
1398 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1399 | conditions, such as not being able to load the event model specified by |
|
|
1400 | C<PERL_ANYEVENT_MODEL>. |
|
|
1401 | |
|
|
1402 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1403 | model it chooses. |
|
|
1404 | |
|
|
1405 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1406 | |
|
|
1407 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1408 | argument checking is very costly. Setting this variable to a true value |
|
|
1409 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1410 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1411 | it will croak. |
|
|
1412 | |
|
|
1413 | In other words, enables "strict" mode. |
|
|
1414 | |
|
|
1415 | Unlike C<use strict>, it is definitely recommended to keep it off in |
|
|
1416 | production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while |
|
|
1417 | developing programs can be very useful, however. |
|
|
1418 | |
|
|
1419 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1420 | |
|
|
1421 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1422 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1423 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1424 | and the resulting module name is loaded and if the load was successful, |
|
|
1425 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1426 | auto detection and -probing. |
|
|
1427 | |
|
|
1428 | This functionality might change in future versions. |
|
|
1429 | |
|
|
1430 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1431 | could start your program like this: |
|
|
1432 | |
|
|
1433 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1434 | |
|
|
1435 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1436 | |
|
|
1437 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1438 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1439 | of auto probing). |
|
|
1440 | |
|
|
1441 | Must be set to a comma-separated list of protocols or address families, |
|
|
1442 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1443 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1444 | list. |
|
|
1445 | |
|
|
1446 | This variable can effectively be used for denial-of-service attacks |
|
|
1447 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1448 | small, as the program has to handle conenction and other failures anyways. |
|
|
1449 | |
|
|
1450 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1451 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1452 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1453 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1454 | IPv6, but prefer IPv6 over IPv4. |
|
|
1455 | |
|
|
1456 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1457 | |
|
|
1458 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1459 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1460 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1461 | default. |
|
|
1462 | |
|
|
1463 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1464 | EDNS0 in its DNS requests. |
|
|
1465 | |
|
|
1466 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1467 | |
|
|
1468 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1469 | will create in parallel. |
|
|
1470 | |
|
|
1471 | =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> |
|
|
1472 | |
|
|
1473 | The default value for the C<max_outstanding> parameter for the default DNS |
|
|
1474 | resolver - this is the maximum number of parallel DNS requests that are |
|
|
1475 | sent to the DNS server. |
|
|
1476 | |
|
|
1477 | =item C<PERL_ANYEVENT_RESOLV_CONF> |
|
|
1478 | |
|
|
1479 | The file to use instead of F</etc/resolv.conf> (or OS-specific |
|
|
1480 | configuration) in the default resolver. When set to the empty string, no |
|
|
1481 | default config will be used. |
|
|
1482 | |
|
|
1483 | =item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. |
|
|
1484 | |
|
|
1485 | When neither C<ca_file> nor C<ca_path> was specified during |
|
|
1486 | L<AnyEvent::TLS> context creation, and either of these environment |
|
|
1487 | variables exist, they will be used to specify CA certificate locations |
|
|
1488 | instead of a system-dependent default. |
|
|
1489 | |
|
|
1490 | =back |
968 | |
1491 | |
969 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1492 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
970 | |
1493 | |
971 | This is an advanced topic that you do not normally need to use AnyEvent in |
1494 | This is an advanced topic that you do not normally need to use AnyEvent in |
972 | a module. This section is only of use to event loop authors who want to |
1495 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1006 | |
1529 | |
1007 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1530 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1008 | condition variables: code blocking while waiting for a condition will |
1531 | condition variables: code blocking while waiting for a condition will |
1009 | C<die>. This still works with most modules/usages, and blocking calls must |
1532 | C<die>. This still works with most modules/usages, and blocking calls must |
1010 | not be done in an interactive application, so it makes sense. |
1533 | not be done in an interactive application, so it makes sense. |
1011 | |
|
|
1012 | =head1 ENVIRONMENT VARIABLES |
|
|
1013 | |
|
|
1014 | The following environment variables are used by this module: |
|
|
1015 | |
|
|
1016 | =over 4 |
|
|
1017 | |
|
|
1018 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1019 | |
|
|
1020 | By default, AnyEvent will be completely silent except in fatal |
|
|
1021 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1022 | talkative. |
|
|
1023 | |
|
|
1024 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1025 | conditions, such as not being able to load the event model specified by |
|
|
1026 | C<PERL_ANYEVENT_MODEL>. |
|
|
1027 | |
|
|
1028 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1029 | model it chooses. |
|
|
1030 | |
|
|
1031 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1032 | |
|
|
1033 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1034 | autodetection and -probing kicks in. It must be a string consisting |
|
|
1035 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1036 | and the resulting module name is loaded and if the load was successful, |
|
|
1037 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1038 | autodetection and -probing. |
|
|
1039 | |
|
|
1040 | This functionality might change in future versions. |
|
|
1041 | |
|
|
1042 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1043 | could start your program like this: |
|
|
1044 | |
|
|
1045 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1046 | |
|
|
1047 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1048 | |
|
|
1049 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1050 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1051 | of autoprobing). |
|
|
1052 | |
|
|
1053 | Must be set to a comma-separated list of protocols or address families, |
|
|
1054 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1055 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1056 | list. |
|
|
1057 | |
|
|
1058 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1059 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1060 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1061 | addressses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1062 | IPv6, but prefer IPv6 over IPv4. |
|
|
1063 | |
|
|
1064 | =back |
|
|
1065 | |
1534 | |
1066 | =head1 EXAMPLE PROGRAM |
1535 | =head1 EXAMPLE PROGRAM |
1067 | |
1536 | |
1068 | The following program uses an I/O watcher to read data from STDIN, a timer |
1537 | The following program uses an I/O watcher to read data from STDIN, a timer |
1069 | to display a message once per second, and a condition variable to quit the |
1538 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1153 | syswrite $txn->{fh}, $txn->{request} |
1622 | syswrite $txn->{fh}, $txn->{request} |
1154 | or die "connection or write error"; |
1623 | or die "connection or write error"; |
1155 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1624 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1156 | |
1625 | |
1157 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1626 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1158 | result and signals any possible waiters that the request ahs finished: |
1627 | result and signals any possible waiters that the request has finished: |
1159 | |
1628 | |
1160 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1629 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1161 | |
1630 | |
1162 | if (end-of-file or data complete) { |
1631 | if (end-of-file or data complete) { |
1163 | $txn->{result} = $txn->{buf}; |
1632 | $txn->{result} = $txn->{buf}; |
… | |
… | |
1171 | |
1640 | |
1172 | $txn->{finished}->recv; |
1641 | $txn->{finished}->recv; |
1173 | return $txn->{result}; |
1642 | return $txn->{result}; |
1174 | |
1643 | |
1175 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1644 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1176 | that occured during request processing. The C<result> method detects |
1645 | that occurred during request processing. The C<result> method detects |
1177 | whether an exception as thrown (it is stored inside the $txn object) |
1646 | whether an exception as thrown (it is stored inside the $txn object) |
1178 | and just throws the exception, which means connection errors and other |
1647 | and just throws the exception, which means connection errors and other |
1179 | problems get reported tot he code that tries to use the result, not in a |
1648 | problems get reported tot he code that tries to use the result, not in a |
1180 | random callback. |
1649 | random callback. |
1181 | |
1650 | |
… | |
… | |
1227 | of various event loops I prepared some benchmarks. |
1696 | of various event loops I prepared some benchmarks. |
1228 | |
1697 | |
1229 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1698 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
1230 | |
1699 | |
1231 | Here is a benchmark of various supported event models used natively and |
1700 | Here is a benchmark of various supported event models used natively and |
1232 | through anyevent. The benchmark creates a lot of timers (with a zero |
1701 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1233 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1702 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1234 | which it is), lets them fire exactly once and destroys them again. |
1703 | which it is), lets them fire exactly once and destroys them again. |
1235 | |
1704 | |
1236 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1705 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1237 | distribution. |
1706 | distribution. |
… | |
… | |
1263 | watcher. |
1732 | watcher. |
1264 | |
1733 | |
1265 | =head3 Results |
1734 | =head3 Results |
1266 | |
1735 | |
1267 | name watchers bytes create invoke destroy comment |
1736 | name watchers bytes create invoke destroy comment |
1268 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
1737 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
1269 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
1738 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
1270 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
1739 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
1271 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
1740 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
1272 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
1741 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
1273 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
1742 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1743 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1744 | IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll |
1274 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
1745 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
1275 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
1746 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
1276 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
1747 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
1277 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
1748 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
1278 | |
1749 | |
1279 | =head3 Discussion |
1750 | =head3 Discussion |
1280 | |
1751 | |
1281 | The benchmark does I<not> measure scalability of the event loop very |
1752 | The benchmark does I<not> measure scalability of the event loop very |
1282 | well. For example, a select-based event loop (such as the pure perl one) |
1753 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1307 | performance becomes really bad with lots of file descriptors (and few of |
1778 | performance becomes really bad with lots of file descriptors (and few of |
1308 | them active), of course, but this was not subject of this benchmark. |
1779 | them active), of course, but this was not subject of this benchmark. |
1309 | |
1780 | |
1310 | The C<Event> module has a relatively high setup and callback invocation |
1781 | The C<Event> module has a relatively high setup and callback invocation |
1311 | cost, but overall scores in on the third place. |
1782 | cost, but overall scores in on the third place. |
|
|
1783 | |
|
|
1784 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
1785 | when using its pure perl backend. |
1312 | |
1786 | |
1313 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1787 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1314 | faster callback invocation and overall ends up in the same class as |
1788 | faster callback invocation and overall ends up in the same class as |
1315 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1789 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1316 | watchers increases the processing time by more than a factor of four, |
1790 | watchers increases the processing time by more than a factor of four, |
… | |
… | |
1360 | |
1834 | |
1361 | =back |
1835 | =back |
1362 | |
1836 | |
1363 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1837 | =head2 BENCHMARKING THE LARGE SERVER CASE |
1364 | |
1838 | |
1365 | This benchmark atcually benchmarks the event loop itself. It works by |
1839 | This benchmark actually benchmarks the event loop itself. It works by |
1366 | creating a number of "servers": each server consists of a socketpair, a |
1840 | creating a number of "servers": each server consists of a socket pair, a |
1367 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1841 | timeout watcher that gets reset on activity (but never fires), and an I/O |
1368 | watcher waiting for input on one side of the socket. Each time the socket |
1842 | watcher waiting for input on one side of the socket. Each time the socket |
1369 | watcher reads a byte it will write that byte to a random other "server". |
1843 | watcher reads a byte it will write that byte to a random other "server". |
1370 | |
1844 | |
1371 | The effect is that there will be a lot of I/O watchers, only part of which |
1845 | The effect is that there will be a lot of I/O watchers, only part of which |
1372 | are active at any one point (so there is a constant number of active |
1846 | are active at any one point (so there is a constant number of active |
1373 | fds for each loop iterstaion, but which fds these are is random). The |
1847 | fds for each loop iteration, but which fds these are is random). The |
1374 | timeout is reset each time something is read because that reflects how |
1848 | timeout is reset each time something is read because that reflects how |
1375 | most timeouts work (and puts extra pressure on the event loops). |
1849 | most timeouts work (and puts extra pressure on the event loops). |
1376 | |
1850 | |
1377 | In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100 |
1851 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1378 | (1%) are active. This mirrors the activity of large servers with many |
1852 | (1%) are active. This mirrors the activity of large servers with many |
1379 | connections, most of which are idle at any one point in time. |
1853 | connections, most of which are idle at any one point in time. |
1380 | |
1854 | |
1381 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1855 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1382 | distribution. |
1856 | distribution. |
… | |
… | |
1384 | =head3 Explanation of the columns |
1858 | =head3 Explanation of the columns |
1385 | |
1859 | |
1386 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1860 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1387 | each server has a read and write socket end). |
1861 | each server has a read and write socket end). |
1388 | |
1862 | |
1389 | I<create> is the time it takes to create a socketpair (which is |
1863 | I<create> is the time it takes to create a socket pair (which is |
1390 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1864 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
1391 | |
1865 | |
1392 | I<request>, the most important value, is the time it takes to handle a |
1866 | I<request>, the most important value, is the time it takes to handle a |
1393 | single "request", that is, reading the token from the pipe and forwarding |
1867 | single "request", that is, reading the token from the pipe and forwarding |
1394 | it to another server. This includes deleting the old timeout and creating |
1868 | it to another server. This includes deleting the old timeout and creating |
1395 | a new one that moves the timeout into the future. |
1869 | a new one that moves the timeout into the future. |
1396 | |
1870 | |
1397 | =head3 Results |
1871 | =head3 Results |
1398 | |
1872 | |
1399 | name sockets create request |
1873 | name sockets create request |
1400 | EV 20000 69.01 11.16 |
1874 | EV 20000 69.01 11.16 |
1401 | Perl 20000 73.32 35.87 |
1875 | Perl 20000 73.32 35.87 |
|
|
1876 | IOAsync 20000 157.00 98.14 epoll |
|
|
1877 | IOAsync 20000 159.31 616.06 poll |
1402 | Event 20000 212.62 257.32 |
1878 | Event 20000 212.62 257.32 |
1403 | Glib 20000 651.16 1896.30 |
1879 | Glib 20000 651.16 1896.30 |
1404 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1880 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
1405 | |
1881 | |
1406 | =head3 Discussion |
1882 | =head3 Discussion |
1407 | |
1883 | |
1408 | This benchmark I<does> measure scalability and overall performance of the |
1884 | This benchmark I<does> measure scalability and overall performance of the |
1409 | particular event loop. |
1885 | particular event loop. |
… | |
… | |
1411 | EV is again fastest. Since it is using epoll on my system, the setup time |
1887 | EV is again fastest. Since it is using epoll on my system, the setup time |
1412 | is relatively high, though. |
1888 | is relatively high, though. |
1413 | |
1889 | |
1414 | Perl surprisingly comes second. It is much faster than the C-based event |
1890 | Perl surprisingly comes second. It is much faster than the C-based event |
1415 | loops Event and Glib. |
1891 | loops Event and Glib. |
|
|
1892 | |
|
|
1893 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
1894 | good compared to Glib when using its pure perl backend. |
1416 | |
1895 | |
1417 | Event suffers from high setup time as well (look at its code and you will |
1896 | Event suffers from high setup time as well (look at its code and you will |
1418 | understand why). Callback invocation also has a high overhead compared to |
1897 | understand why). Callback invocation also has a high overhead compared to |
1419 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1898 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1420 | uses select or poll in basically all documented configurations. |
1899 | uses select or poll in basically all documented configurations. |
… | |
… | |
1467 | speed most when you have lots of watchers, not when you only have a few of |
1946 | speed most when you have lots of watchers, not when you only have a few of |
1468 | them). |
1947 | them). |
1469 | |
1948 | |
1470 | EV is again fastest. |
1949 | EV is again fastest. |
1471 | |
1950 | |
1472 | Perl again comes second. It is noticably faster than the C-based event |
1951 | Perl again comes second. It is noticeably faster than the C-based event |
1473 | loops Event and Glib, although the difference is too small to really |
1952 | loops Event and Glib, although the difference is too small to really |
1474 | matter. |
1953 | matter. |
1475 | |
1954 | |
1476 | POE also performs much better in this case, but is is still far behind the |
1955 | POE also performs much better in this case, but is is still far behind the |
1477 | others. |
1956 | others. |
… | |
… | |
1483 | =item * C-based event loops perform very well with small number of |
1962 | =item * C-based event loops perform very well with small number of |
1484 | watchers, as the management overhead dominates. |
1963 | watchers, as the management overhead dominates. |
1485 | |
1964 | |
1486 | =back |
1965 | =back |
1487 | |
1966 | |
|
|
1967 | =head2 THE IO::Lambda BENCHMARK |
|
|
1968 | |
|
|
1969 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
1970 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
1971 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
1972 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
1973 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
1974 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
1975 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
1976 | |
|
|
1977 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
1978 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
1979 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
1980 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
1981 | benchmark nevertheless. |
|
|
1982 | |
|
|
1983 | name runtime |
|
|
1984 | Lambda/select 0.330 sec |
|
|
1985 | + optimized 0.122 sec |
|
|
1986 | Lambda/AnyEvent 0.327 sec |
|
|
1987 | + optimized 0.138 sec |
|
|
1988 | Raw sockets/select 0.077 sec |
|
|
1989 | POE/select, components 0.662 sec |
|
|
1990 | POE/select, raw sockets 0.226 sec |
|
|
1991 | POE/select, optimized 0.404 sec |
|
|
1992 | |
|
|
1993 | AnyEvent/select/nb 0.085 sec |
|
|
1994 | AnyEvent/EV/nb 0.068 sec |
|
|
1995 | +state machine 0.134 sec |
|
|
1996 | |
|
|
1997 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
1998 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
1999 | defeating the purpose of an event-based solution. All of the newly |
|
|
2000 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
2001 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
2002 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
2003 | generally require a lot more bookkeeping and event handling than blocking |
|
|
2004 | connects (which involve a single syscall only). |
|
|
2005 | |
|
|
2006 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
2007 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
2008 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
2009 | non-blocking, further placing it at a disadvantage. |
|
|
2010 | |
|
|
2011 | As you can see, the AnyEvent + EV combination even beats the |
|
|
2012 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
2013 | backend easily beats IO::Lambda and POE. |
|
|
2014 | |
|
|
2015 | And even the 100% non-blocking version written using the high-level (and |
|
|
2016 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
2017 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
2018 | in a non-blocking way. |
|
|
2019 | |
|
|
2020 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2021 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2022 | part of the IO::lambda distribution and were used without any changes. |
|
|
2023 | |
|
|
2024 | |
|
|
2025 | =head1 SIGNALS |
|
|
2026 | |
|
|
2027 | AnyEvent currently installs handlers for these signals: |
|
|
2028 | |
|
|
2029 | =over 4 |
|
|
2030 | |
|
|
2031 | =item SIGCHLD |
|
|
2032 | |
|
|
2033 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2034 | emulation for event loops that do not support them natively. Also, some |
|
|
2035 | event loops install a similar handler. |
|
|
2036 | |
|
|
2037 | If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will |
|
|
2038 | reset it to default, to avoid losing child exit statuses. |
|
|
2039 | |
|
|
2040 | =item SIGPIPE |
|
|
2041 | |
|
|
2042 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2043 | when AnyEvent gets loaded. |
|
|
2044 | |
|
|
2045 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2046 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2047 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2048 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2049 | some random socket. |
|
|
2050 | |
|
|
2051 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2052 | that this way, the handler will be restored to defaults on exec. |
|
|
2053 | |
|
|
2054 | Feel free to install your own handler, or reset it to defaults. |
|
|
2055 | |
|
|
2056 | =back |
|
|
2057 | |
|
|
2058 | =cut |
|
|
2059 | |
|
|
2060 | undef $SIG{CHLD} |
|
|
2061 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2062 | |
|
|
2063 | $SIG{PIPE} = sub { } |
|
|
2064 | unless defined $SIG{PIPE}; |
1488 | |
2065 | |
1489 | =head1 FORK |
2066 | =head1 FORK |
1490 | |
2067 | |
1491 | Most event libraries are not fork-safe. The ones who are usually are |
2068 | Most event libraries are not fork-safe. The ones who are usually are |
1492 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2069 | because they rely on inefficient but fork-safe C<select> or C<poll> |
… | |
… | |
1506 | specified in the variable. |
2083 | specified in the variable. |
1507 | |
2084 | |
1508 | You can make AnyEvent completely ignore this variable by deleting it |
2085 | You can make AnyEvent completely ignore this variable by deleting it |
1509 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
2086 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1510 | |
2087 | |
1511 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
2088 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1512 | |
2089 | |
1513 | use AnyEvent; |
2090 | use AnyEvent; |
1514 | |
2091 | |
1515 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2092 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1516 | be used to probe what backend is used and gain other information (which is |
2093 | be used to probe what backend is used and gain other information (which is |
1517 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
2094 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
2095 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2096 | |
|
|
2097 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2098 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2099 | enabled. |
|
|
2100 | |
|
|
2101 | |
|
|
2102 | =head1 BUGS |
|
|
2103 | |
|
|
2104 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
|
|
2105 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
|
|
2106 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
|
|
2107 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
|
|
2108 | pronounced). |
1518 | |
2109 | |
1519 | |
2110 | |
1520 | =head1 SEE ALSO |
2111 | =head1 SEE ALSO |
1521 | |
2112 | |
1522 | Utility functions: L<AnyEvent::Util>. |
2113 | Utility functions: L<AnyEvent::Util>. |
… | |
… | |
1525 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
2116 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
1526 | |
2117 | |
1527 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
2118 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1528 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
2119 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1529 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
2120 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
1530 | L<AnyEvent::Impl::POE>. |
2121 | L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>. |
1531 | |
2122 | |
1532 | Non-blocking file handles, sockets, TCP clients and |
2123 | Non-blocking file handles, sockets, TCP clients and |
1533 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
2124 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. |
1534 | |
2125 | |
1535 | Asynchronous DNS: L<AnyEvent::DNS>. |
2126 | Asynchronous DNS: L<AnyEvent::DNS>. |
1536 | |
2127 | |
1537 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
2128 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, |
|
|
2129 | L<Coro::Event>, |
1538 | |
2130 | |
1539 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
2131 | Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, |
|
|
2132 | L<AnyEvent::HTTP>. |
1540 | |
2133 | |
1541 | |
2134 | |
1542 | =head1 AUTHOR |
2135 | =head1 AUTHOR |
1543 | |
2136 | |
1544 | Marc Lehmann <schmorp@schmorp.de> |
2137 | Marc Lehmann <schmorp@schmorp.de> |
1545 | http://home.schmorp.de/ |
2138 | http://home.schmorp.de/ |
1546 | |
2139 | |
1547 | =cut |
2140 | =cut |
1548 | |
2141 | |
1549 | 1 |
2142 | 1 |
1550 | |
2143 | |