1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - provide framework for multiple event loops |
4 | |
4 | |
5 | EV, Event, Coro::EV, Coro::Event, Glib, Tk, Perl, Event::Lib, Qt - 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 |
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35 | $w->send; # wake up current and all future recv's |
20 | $w->wait; # enters "main loop" till $condvar gets ->broadcast |
36 | $w->recv; # enters "main loop" till $condvar gets ->send |
21 | $w->broadcast; # wake up current and all future wait's |
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 | |
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71 | |
100 | |
72 | =head1 DESCRIPTION |
101 | =head1 DESCRIPTION |
73 | |
102 | |
74 | L<AnyEvent> provides an identical interface to multiple event loops. This |
103 | L<AnyEvent> provides an identical interface to multiple event loops. This |
75 | allows module authors to utilise an event loop without forcing module |
104 | allows module authors to utilise an event loop without forcing module |
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79 | The interface itself is vaguely similar, but not identical to the L<Event> |
108 | The interface itself is vaguely similar, but not identical to the L<Event> |
80 | module. |
109 | module. |
81 | |
110 | |
82 | During the first call of any watcher-creation method, the module tries |
111 | During the first call of any watcher-creation method, the module tries |
83 | to detect the currently loaded event loop by probing whether one of the |
112 | to detect the currently loaded event loop by probing whether one of the |
84 | following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>, |
113 | following modules is already loaded: L<EV>, |
85 | L<Event>, L<Glib>, L<Tk>. The first one found is used. If none are found, |
114 | L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>, |
86 | the module tries to load these modules in the stated order. The first one |
115 | L<POE>. The first one found is used. If none are found, the module tries |
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116 | to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl |
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117 | adaptor should always succeed) in the order given. The first one that can |
87 | that can be successfully loaded will be used. If, after this, still none |
118 | be successfully loaded will be used. If, after this, still none could be |
88 | could be found, AnyEvent will fall back to a pure-perl event loop, which |
119 | found, AnyEvent will fall back to a pure-perl event loop, which is not |
89 | is not very efficient, but should work everywhere. |
120 | very efficient, but should work everywhere. |
90 | |
121 | |
91 | Because AnyEvent first checks for modules that are already loaded, loading |
122 | Because AnyEvent first checks for modules that are already loaded, loading |
92 | an event model explicitly before first using AnyEvent will likely make |
123 | an event model explicitly before first using AnyEvent will likely make |
93 | that model the default. For example: |
124 | that model the default. For example: |
94 | |
125 | |
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101 | 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 |
102 | use AnyEvent so their modules work together with others seamlessly... |
133 | use AnyEvent so their modules work together with others seamlessly... |
103 | |
134 | |
104 | The pure-perl implementation of AnyEvent is called |
135 | The pure-perl implementation of AnyEvent is called |
105 | 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 |
106 | explicitly. |
137 | explicitly and enjoy the high availability of that event loop :) |
107 | |
138 | |
108 | =head1 WATCHERS |
139 | =head1 WATCHERS |
109 | |
140 | |
110 | 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 |
111 | 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 |
112 | the callback to call, the filehandle to watch, etc. |
143 | the callback to call, the file handle to watch, etc. |
113 | |
144 | |
114 | These watchers are normal Perl objects with normal Perl lifetime. After |
145 | These watchers are normal Perl objects with normal Perl lifetime. After |
115 | 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 |
116 | 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 |
117 | is in control). |
148 | is in control). |
118 | |
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 | |
119 | 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 |
120 | 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 |
121 | to it). |
158 | to it). |
122 | |
159 | |
123 | 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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125 | Many watchers either are used with "recursion" (repeating timers for |
162 | Many watchers either are used with "recursion" (repeating timers for |
126 | 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. |
127 | |
164 | |
128 | An any way to achieve that is this pattern: |
165 | An any way to achieve that is this pattern: |
129 | |
166 | |
130 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
167 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
131 | # you can use $w here, for example to undef it |
168 | # you can use $w here, for example to undef it |
132 | undef $w; |
169 | undef $w; |
133 | }); |
170 | }); |
134 | |
171 | |
135 | 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, |
136 | 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 |
137 | declared. |
174 | declared. |
138 | |
175 | |
139 | =head2 IO WATCHERS |
176 | =head2 I/O WATCHERS |
140 | |
177 | |
141 | 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 |
142 | with the following mandatory key-value pairs as arguments: |
179 | with the following mandatory key-value pairs as arguments: |
143 | |
180 | |
144 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for |
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 | |
145 | events. C<poll> must be a string that is either C<r> or C<w>, which |
188 | C<poll> must be a string that is either C<r> or C<w>, which creates a |
146 | 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 | |
147 | 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. |
148 | becomes ready. |
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149 | |
192 | |
150 | As long as the I/O watcher exists it will keep the file descriptor or a |
193 | Although the callback might get passed parameters, their value and |
151 | copy of it alive/open. |
194 | presence is undefined and you cannot rely on them. Portable AnyEvent |
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195 | callbacks cannot use arguments passed to I/O watcher callbacks. |
152 | |
196 | |
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197 | The I/O watcher might use the underlying file descriptor or a copy of it. |
153 | It is not allowed to close a file handle as long as any watcher is active |
198 | You must not close a file handle as long as any watcher is active on the |
154 | on the underlying file descriptor. |
199 | underlying file descriptor. |
155 | |
200 | |
156 | Some event loops issue spurious readyness notifications, so you should |
201 | Some event loops issue spurious readyness notifications, so you should |
157 | 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 |
158 | handles. |
203 | handles. |
159 | |
204 | |
160 | Example: |
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161 | |
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162 | # 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 | |
163 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
208 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
164 | chomp (my $input = <STDIN>); |
209 | chomp (my $input = <STDIN>); |
165 | warn "read: $input\n"; |
210 | warn "read: $input\n"; |
166 | undef $w; |
211 | undef $w; |
167 | }); |
212 | }); |
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170 | |
215 | |
171 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
216 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
172 | method with the following mandatory arguments: |
217 | method with the following mandatory arguments: |
173 | |
218 | |
174 | C<after> specifies after how many seconds (fractional values are |
219 | C<after> specifies after how many seconds (fractional values are |
175 | supported) should the timer activate. C<cb> the callback to invoke in that |
220 | supported) the callback should be invoked. C<cb> is the callback to invoke |
176 | case. |
221 | in that case. |
177 | |
222 | |
178 | The timer callback will be invoked at most once: if you want a repeating |
223 | Although the callback might get passed parameters, their value and |
179 | timer you have to create a new watcher (this is a limitation by both Tk |
224 | presence is undefined and you cannot rely on them. Portable AnyEvent |
180 | and Glib). |
225 | callbacks cannot use arguments passed to time watcher callbacks. |
181 | |
226 | |
182 | Example: |
227 | The callback will normally be invoked once only. If you specify another |
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228 | parameter, C<interval>, as a strictly positive number (> 0), then the |
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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. |
183 | |
232 | |
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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. |
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236 | |
184 | # fire an event after 7.7 seconds |
237 | Example: fire an event after 7.7 seconds. |
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238 | |
185 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
239 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
186 | warn "timeout\n"; |
240 | warn "timeout\n"; |
187 | }); |
241 | }); |
188 | |
242 | |
189 | # to cancel the timer: |
243 | # to cancel the timer: |
190 | undef $w; |
244 | undef $w; |
191 | |
245 | |
192 | Example 2: |
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193 | |
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194 | # 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. |
195 | my $w; |
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196 | |
247 | |
197 | my $cb = sub { |
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198 | # cancel the old timer while creating a new one |
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199 | $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"; |
200 | }; |
250 | }; |
201 | |
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202 | # start the "loop" by creating the first watcher |
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203 | $w = AnyEvent->timer (after => 0.5, cb => $cb); |
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204 | |
251 | |
205 | =head3 TIMING ISSUES |
252 | =head3 TIMING ISSUES |
206 | |
253 | |
207 | 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 |
208 | 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 |
209 | o'clock"). |
256 | o'clock"). |
210 | |
257 | |
211 | While most event loops expect timers to specified in a relative way, they use |
258 | While most event loops expect timers to specified in a relative way, they |
212 | absolute time internally. This makes a difference when your clock "jumps", |
259 | use absolute time internally. This makes a difference when your clock |
213 | for example, when ntp decides to set your clock backwards from the wrong 2014-01-01 to |
260 | "jumps", for example, when ntp decides to set your clock backwards from |
214 | 2008-01-01, a watcher that you created to fire "after" a second might actually take |
261 | the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to |
215 | six years to finally fire. |
262 | fire "after" a second might actually take six years to finally fire. |
216 | |
263 | |
217 | AnyEvent cannot compensate for this. The only event loop that is conscious |
264 | AnyEvent cannot compensate for this. The only event loop that is conscious |
218 | about these issues is L<EV>, which offers both relative (ev_timer) and |
265 | about these issues is L<EV>, which offers both relative (ev_timer, based |
219 | absolute (ev_periodic) timers. |
266 | on true relative time) and absolute (ev_periodic, based on wallclock time) |
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267 | timers. |
220 | |
268 | |
221 | AnyEvent always prefers relative timers, if available, matching the |
269 | AnyEvent always prefers relative timers, if available, matching the |
222 | AnyEvent API. |
270 | AnyEvent API. |
223 | |
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 |
|
|
312 | both return C<501>, because that is the current time, and the timer will |
|
|
313 | be scheduled to fire at time=504 (C<501> + C<3>). |
|
|
314 | |
|
|
315 | With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current |
|
|
316 | time), but C<< AnyEvent->now >> returns C<500>, as that is the time the |
|
|
317 | last event processing phase started. With L<EV>, your timer gets scheduled |
|
|
318 | to run at time=503 (C<500> + C<3>). |
|
|
319 | |
|
|
320 | In one sense, L<Event::Lib> is more exact, as it uses the current time |
|
|
321 | regardless of any delays introduced by event processing. However, most |
|
|
322 | callbacks do not expect large delays in processing, so this causes a |
|
|
323 | higher drift (and a lot more system calls to get the current time). |
|
|
324 | |
|
|
325 | In another sense, L<EV> is more exact, as your timer will be scheduled at |
|
|
326 | the same time, regardless of how long event processing actually took. |
|
|
327 | |
|
|
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 |
|
|
330 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
|
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331 | account. |
|
|
332 | |
|
|
333 | =item AnyEvent->now_update |
|
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334 | |
|
|
335 | Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache |
|
|
336 | the current time for each loop iteration (see the discussion of L<< |
|
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337 | AnyEvent->now >>, above). |
|
|
338 | |
|
|
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. |
|
|
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". |
|
|
345 | |
|
|
346 | Note that updating the time I<might> cause some events to be handled. |
|
|
347 | |
|
|
348 | =back |
|
|
349 | |
224 | =head2 SIGNAL WATCHERS |
350 | =head2 SIGNAL WATCHERS |
225 | |
351 | |
226 | 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 |
227 | 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 |
228 | be invoked whenever a signal occurs. |
354 | callback to be invoked whenever a signal occurs. |
229 | |
355 | |
|
|
356 | Although the callback might get passed parameters, their value and |
|
|
357 | presence is undefined and you cannot rely on them. Portable AnyEvent |
|
|
358 | callbacks cannot use arguments passed to signal watcher callbacks. |
|
|
359 | |
230 | Multiple signals occurances can be clumped together into one callback |
360 | Multiple signal occurrences can be clumped together into one callback |
231 | invocation, and callback invocation will be synchronous. synchronous means |
361 | invocation, and callback invocation will be synchronous. Synchronous means |
232 | 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, |
233 | but it is guarenteed not to interrupt any other callbacks. |
363 | but it is guaranteed not to interrupt any other callbacks. |
234 | |
364 | |
235 | 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 |
236 | between multiple watchers. |
366 | between multiple watchers, and AnyEvent will ensure that signals will not |
|
|
367 | interrupt your program at bad times. |
237 | |
368 | |
238 | This watcher might use C<%SIG>, so programs overwriting those signals |
369 | This watcher might use C<%SIG> (depending on the event loop used), |
239 | directly will likely not work correctly. |
370 | so programs overwriting those signals directly will likely not work |
|
|
371 | correctly. |
240 | |
372 | |
241 | Example: exit on SIGINT |
373 | Example: exit on SIGINT |
242 | |
374 | |
243 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
375 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
244 | |
376 | |
|
|
377 | =head3 Signal Races, Delays and Workarounds |
|
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378 | |
|
|
379 | Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching |
|
|
380 | callbacks to signals in a generic way, which is a pity, as you cannot do |
|
|
381 | race-free signal handling in perl. AnyEvent will try to do it's best, but |
|
|
382 | in some cases, signals will be delayed. The maximum time a signal might |
|
|
383 | be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 |
|
|
384 | seconds). This variable can be changed only before the first signal |
|
|
385 | watcher is created, and should be left alone otherwise. Higher values |
|
|
386 | will cause fewer spurious wake-ups, which is better for power and CPU |
|
|
387 | saving. All these problems can be avoided by installing the optional |
|
|
388 | L<Async::Interrupt> module. This will not work with inherently broken |
|
|
389 | event loops such as L<Event> or L<Event::Lib> (and not with L<POE> |
|
|
390 | currently, as POE does it's own workaround with one-second latency). With |
|
|
391 | those, you just have to suffer the delays. |
|
|
392 | |
245 | =head2 CHILD PROCESS WATCHERS |
393 | =head2 CHILD PROCESS WATCHERS |
246 | |
394 | |
247 | You can also watch on a child process exit and catch its exit status. |
395 | You can also watch on a child process exit and catch its exit status. |
248 | |
396 | |
249 | The child process is specified by the C<pid> argument (if set to C<0>, it |
397 | The child process is specified by the C<pid> argument (if set to C<0>, it |
250 | watches for any child process exit). The watcher will trigger as often |
398 | watches for any child process exit). The watcher will triggered only when |
251 | as status change for the child are received. This works by installing a |
399 | the child process has finished and an exit status is available, not on |
252 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
400 | any trace events (stopped/continued). |
253 | and exit status (as returned by waitpid). |
|
|
254 | |
401 | |
255 | Example: wait for pid 1333 |
402 | The callback will be called with the pid and exit status (as returned by |
|
|
403 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
|
404 | callback arguments. |
256 | |
405 | |
|
|
406 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
|
|
407 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
|
|
408 | random child processes (waiting for specific child processes, e.g. inside |
|
|
409 | C<system>, is just fine). |
|
|
410 | |
|
|
411 | There is a slight catch to child watchers, however: you usually start them |
|
|
412 | I<after> the child process was created, and this means the process could |
|
|
413 | have exited already (and no SIGCHLD will be sent anymore). |
|
|
414 | |
|
|
415 | Not all event models handle this correctly (neither POE nor IO::Async do, |
|
|
416 | see their AnyEvent::Impl manpages for details), but even for event models |
|
|
417 | that I<do> handle this correctly, they usually need to be loaded before |
|
|
418 | the process exits (i.e. before you fork in the first place). AnyEvent's |
|
|
419 | pure perl event loop handles all cases correctly regardless of when you |
|
|
420 | start the watcher. |
|
|
421 | |
|
|
422 | This means you cannot create a child watcher as the very first |
|
|
423 | thing in an AnyEvent program, you I<have> to create at least one |
|
|
424 | watcher before you C<fork> the child (alternatively, you can call |
|
|
425 | C<AnyEvent::detect>). |
|
|
426 | |
|
|
427 | As most event loops do not support waiting for child events, they will be |
|
|
428 | emulated by AnyEvent in most cases, in which the latency and race problems |
|
|
429 | mentioned in the description of signal watchers apply. |
|
|
430 | |
|
|
431 | Example: fork a process and wait for it |
|
|
432 | |
|
|
433 | my $done = AnyEvent->condvar; |
|
|
434 | |
|
|
435 | my $pid = fork or exit 5; |
|
|
436 | |
257 | my $w = AnyEvent->child ( |
437 | my $w = AnyEvent->child ( |
258 | pid => 1333, |
438 | pid => $pid, |
259 | cb => sub { |
439 | cb => sub { |
260 | my ($pid, $status) = @_; |
440 | my ($pid, $status) = @_; |
261 | warn "pid $pid exited with status $status"; |
441 | warn "pid $pid exited with status $status"; |
|
|
442 | $done->send; |
262 | }, |
443 | }, |
263 | ); |
444 | ); |
|
|
445 | |
|
|
446 | # do something else, then wait for process exit |
|
|
447 | $done->recv; |
|
|
448 | |
|
|
449 | =head2 IDLE WATCHERS |
|
|
450 | |
|
|
451 | Sometimes there is a need to do something, but it is not so important |
|
|
452 | to do it instantly, but only when there is nothing better to do. This |
|
|
453 | "nothing better to do" is usually defined to be "no other events need |
|
|
454 | attention by the event loop". |
|
|
455 | |
|
|
456 | Idle watchers ideally get invoked when the event loop has nothing |
|
|
457 | better to do, just before it would block the process to wait for new |
|
|
458 | events. Instead of blocking, the idle watcher is invoked. |
|
|
459 | |
|
|
460 | Most event loops unfortunately do not really support idle watchers (only |
|
|
461 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
|
|
462 | will simply call the callback "from time to time". |
|
|
463 | |
|
|
464 | Example: read lines from STDIN, but only process them when the |
|
|
465 | program is otherwise idle: |
|
|
466 | |
|
|
467 | my @lines; # read data |
|
|
468 | my $idle_w; |
|
|
469 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
|
|
470 | push @lines, scalar <STDIN>; |
|
|
471 | |
|
|
472 | # start an idle watcher, if not already done |
|
|
473 | $idle_w ||= AnyEvent->idle (cb => sub { |
|
|
474 | # handle only one line, when there are lines left |
|
|
475 | if (my $line = shift @lines) { |
|
|
476 | print "handled when idle: $line"; |
|
|
477 | } else { |
|
|
478 | # otherwise disable the idle watcher again |
|
|
479 | undef $idle_w; |
|
|
480 | } |
|
|
481 | }); |
|
|
482 | }); |
264 | |
483 | |
265 | =head2 CONDITION VARIABLES |
484 | =head2 CONDITION VARIABLES |
266 | |
485 | |
|
|
486 | If you are familiar with some event loops you will know that all of them |
|
|
487 | require you to run some blocking "loop", "run" or similar function that |
|
|
488 | will actively watch for new events and call your callbacks. |
|
|
489 | |
|
|
490 | AnyEvent is slightly different: it expects somebody else to run the event |
|
|
491 | loop and will only block when necessary (usually when told by the user). |
|
|
492 | |
|
|
493 | The instrument to do that is called a "condition variable", so called |
|
|
494 | because they represent a condition that must become true. |
|
|
495 | |
|
|
496 | Now is probably a good time to look at the examples further below. |
|
|
497 | |
267 | Condition variables can be created by calling the C<< AnyEvent->condvar >> |
498 | Condition variables can be created by calling the C<< AnyEvent->condvar |
268 | method without any arguments. |
499 | >> method, usually without arguments. The only argument pair allowed is |
|
|
500 | C<cb>, which specifies a callback to be called when the condition variable |
|
|
501 | becomes true, with the condition variable as the first argument (but not |
|
|
502 | the results). |
269 | |
503 | |
270 | A condition variable waits for a condition - precisely that the C<< |
504 | After creation, the condition variable is "false" until it becomes "true" |
271 | ->broadcast >> method has been called. |
505 | by calling the C<send> method (or calling the condition variable as if it |
|
|
506 | were a callback, read about the caveats in the description for the C<< |
|
|
507 | ->send >> method). |
272 | |
508 | |
273 | They are very useful to signal that a condition has been fulfilled, for |
509 | Condition variables are similar to callbacks, except that you can |
|
|
510 | optionally wait for them. They can also be called merge points - points |
|
|
511 | in time where multiple outstanding events have been processed. And yet |
|
|
512 | another way to call them is transactions - each condition variable can be |
|
|
513 | used to represent a transaction, which finishes at some point and delivers |
|
|
514 | a result. |
|
|
515 | |
|
|
516 | Condition variables are very useful to signal that something has finished, |
274 | example, if you write a module that does asynchronous http requests, |
517 | for example, if you write a module that does asynchronous http requests, |
275 | then a condition variable would be the ideal candidate to signal the |
518 | then a condition variable would be the ideal candidate to signal the |
276 | availability of results. |
519 | availability of results. The user can either act when the callback is |
|
|
520 | called or can synchronously C<< ->recv >> for the results. |
277 | |
521 | |
278 | You can also use condition variables to block your main program until |
522 | You can also use them to simulate traditional event loops - for example, |
279 | an event occurs - for example, you could C<< ->wait >> in your main |
523 | you can block your main program until an event occurs - for example, you |
280 | program until the user clicks the Quit button in your app, which would C<< |
524 | could C<< ->recv >> in your main program until the user clicks the Quit |
281 | ->broadcast >> the "quit" event. |
525 | button of your app, which would C<< ->send >> the "quit" event. |
282 | |
526 | |
283 | Note that condition variables recurse into the event loop - if you have |
527 | Note that condition variables recurse into the event loop - if you have |
284 | two pirces of code that call C<< ->wait >> in a round-robbin fashion, you |
528 | two pieces of code that call C<< ->recv >> in a round-robin fashion, you |
285 | lose. Therefore, condition variables are good to export to your caller, but |
529 | lose. Therefore, condition variables are good to export to your caller, but |
286 | you should avoid making a blocking wait yourself, at least in callbacks, |
530 | you should avoid making a blocking wait yourself, at least in callbacks, |
287 | as this asks for trouble. |
531 | as this asks for trouble. |
288 | |
532 | |
289 | This object has two methods: |
533 | Condition variables are represented by hash refs in perl, and the keys |
|
|
534 | used by AnyEvent itself are all named C<_ae_XXX> to make subclassing |
|
|
535 | easy (it is often useful to build your own transaction class on top of |
|
|
536 | AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call |
|
|
537 | it's C<new> method in your own C<new> method. |
290 | |
538 | |
291 | =over 4 |
539 | There are two "sides" to a condition variable - the "producer side" which |
|
|
540 | eventually calls C<< -> send >>, and the "consumer side", which waits |
|
|
541 | for the send to occur. |
292 | |
542 | |
293 | =item $cv->wait |
543 | Example: wait for a timer. |
294 | |
|
|
295 | Wait (blocking if necessary) until the C<< ->broadcast >> method has been |
|
|
296 | called on c<$cv>, while servicing other watchers normally. |
|
|
297 | |
|
|
298 | You can only wait once on a condition - additional calls will return |
|
|
299 | immediately. |
|
|
300 | |
|
|
301 | Not all event models support a blocking wait - some die in that case |
|
|
302 | (programs might want to do that to stay interactive), so I<if you are |
|
|
303 | using this from a module, never require a blocking wait>, but let the |
|
|
304 | caller decide whether the call will block or not (for example, by coupling |
|
|
305 | condition variables with some kind of request results and supporting |
|
|
306 | callbacks so the caller knows that getting the result will not block, |
|
|
307 | while still suppporting blocking waits if the caller so desires). |
|
|
308 | |
|
|
309 | Another reason I<never> to C<< ->wait >> in a module is that you cannot |
|
|
310 | sensibly have two C<< ->wait >>'s in parallel, as that would require |
|
|
311 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
|
|
312 | can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and |
|
|
313 | L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s |
|
|
314 | from different coroutines, however). |
|
|
315 | |
|
|
316 | =item $cv->broadcast |
|
|
317 | |
|
|
318 | Flag the condition as ready - a running C<< ->wait >> and all further |
|
|
319 | calls to C<wait> will (eventually) return after this method has been |
|
|
320 | called. If nobody is waiting the broadcast will be remembered.. |
|
|
321 | |
|
|
322 | =back |
|
|
323 | |
|
|
324 | Example: |
|
|
325 | |
544 | |
326 | # wait till the result is ready |
545 | # wait till the result is ready |
327 | my $result_ready = AnyEvent->condvar; |
546 | my $result_ready = AnyEvent->condvar; |
328 | |
547 | |
329 | # do something such as adding a timer |
548 | # do something such as adding a timer |
330 | # or socket watcher the calls $result_ready->broadcast |
549 | # or socket watcher the calls $result_ready->send |
331 | # when the "result" is ready. |
550 | # when the "result" is ready. |
332 | # in this case, we simply use a timer: |
551 | # in this case, we simply use a timer: |
333 | my $w = AnyEvent->timer ( |
552 | my $w = AnyEvent->timer ( |
334 | after => 1, |
553 | after => 1, |
335 | cb => sub { $result_ready->broadcast }, |
554 | cb => sub { $result_ready->send }, |
336 | ); |
555 | ); |
337 | |
556 | |
338 | # this "blocks" (while handling events) till the watcher |
557 | # this "blocks" (while handling events) till the callback |
339 | # calls broadcast |
558 | # calls -<send |
340 | $result_ready->wait; |
559 | $result_ready->recv; |
|
|
560 | |
|
|
561 | Example: wait for a timer, but take advantage of the fact that condition |
|
|
562 | variables are also callable directly. |
|
|
563 | |
|
|
564 | my $done = AnyEvent->condvar; |
|
|
565 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
|
|
566 | $done->recv; |
|
|
567 | |
|
|
568 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
569 | callbacks. This is how you make a synchronous call, for example from |
|
|
570 | the main program: |
|
|
571 | |
|
|
572 | use AnyEvent::CouchDB; |
|
|
573 | |
|
|
574 | ... |
|
|
575 | |
|
|
576 | my @info = $couchdb->info->recv; |
|
|
577 | |
|
|
578 | And this is how you would just set a callback to be called whenever the |
|
|
579 | results are available: |
|
|
580 | |
|
|
581 | $couchdb->info->cb (sub { |
|
|
582 | my @info = $_[0]->recv; |
|
|
583 | }); |
|
|
584 | |
|
|
585 | =head3 METHODS FOR PRODUCERS |
|
|
586 | |
|
|
587 | These methods should only be used by the producing side, i.e. the |
|
|
588 | code/module that eventually sends the signal. Note that it is also |
|
|
589 | the producer side which creates the condvar in most cases, but it isn't |
|
|
590 | uncommon for the consumer to create it as well. |
|
|
591 | |
|
|
592 | =over 4 |
|
|
593 | |
|
|
594 | =item $cv->send (...) |
|
|
595 | |
|
|
596 | Flag the condition as ready - a running C<< ->recv >> and all further |
|
|
597 | calls to C<recv> will (eventually) return after this method has been |
|
|
598 | called. If nobody is waiting the send will be remembered. |
|
|
599 | |
|
|
600 | If a callback has been set on the condition variable, it is called |
|
|
601 | immediately from within send. |
|
|
602 | |
|
|
603 | Any arguments passed to the C<send> call will be returned by all |
|
|
604 | future C<< ->recv >> calls. |
|
|
605 | |
|
|
606 | Condition variables are overloaded so one can call them directly (as if |
|
|
607 | they were a code reference). Calling them directly is the same as calling |
|
|
608 | C<send>. |
|
|
609 | |
|
|
610 | =item $cv->croak ($error) |
|
|
611 | |
|
|
612 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
|
|
613 | C<Carp::croak> with the given error message/object/scalar. |
|
|
614 | |
|
|
615 | This can be used to signal any errors to the condition variable |
|
|
616 | user/consumer. Doing it this way instead of calling C<croak> directly |
|
|
617 | delays the error detetcion, but has the overwhelmign advantage that it |
|
|
618 | diagnoses the error at the place where the result is expected, and not |
|
|
619 | deep in some event clalback without connection to the actual code causing |
|
|
620 | the problem. |
|
|
621 | |
|
|
622 | =item $cv->begin ([group callback]) |
|
|
623 | |
|
|
624 | =item $cv->end |
|
|
625 | |
|
|
626 | These two methods can be used to combine many transactions/events into |
|
|
627 | one. For example, a function that pings many hosts in parallel might want |
|
|
628 | to use a condition variable for the whole process. |
|
|
629 | |
|
|
630 | Every call to C<< ->begin >> will increment a counter, and every call to |
|
|
631 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
|
|
632 | >>, the (last) callback passed to C<begin> will be executed. That callback |
|
|
633 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
|
|
634 | callback was set, C<send> will be called without any arguments. |
|
|
635 | |
|
|
636 | You can think of C<< $cv->send >> giving you an OR condition (one call |
|
|
637 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
|
|
638 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
|
|
639 | |
|
|
640 | Let's start with a simple example: you have two I/O watchers (for example, |
|
|
641 | STDOUT and STDERR for a program), and you want to wait for both streams to |
|
|
642 | close before activating a condvar: |
|
|
643 | |
|
|
644 | my $cv = AnyEvent->condvar; |
|
|
645 | |
|
|
646 | $cv->begin; # first watcher |
|
|
647 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
|
|
648 | defined sysread $fh1, my $buf, 4096 |
|
|
649 | or $cv->end; |
|
|
650 | }); |
|
|
651 | |
|
|
652 | $cv->begin; # second watcher |
|
|
653 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
654 | defined sysread $fh2, my $buf, 4096 |
|
|
655 | or $cv->end; |
|
|
656 | }); |
|
|
657 | |
|
|
658 | $cv->recv; |
|
|
659 | |
|
|
660 | This works because for every event source (EOF on file handle), there is |
|
|
661 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
|
|
662 | sending. |
|
|
663 | |
|
|
664 | The ping example mentioned above is slightly more complicated, as the |
|
|
665 | there are results to be passwd back, and the number of tasks that are |
|
|
666 | begung can potentially be zero: |
|
|
667 | |
|
|
668 | my $cv = AnyEvent->condvar; |
|
|
669 | |
|
|
670 | my %result; |
|
|
671 | $cv->begin (sub { $cv->send (\%result) }); |
|
|
672 | |
|
|
673 | for my $host (@list_of_hosts) { |
|
|
674 | $cv->begin; |
|
|
675 | ping_host_then_call_callback $host, sub { |
|
|
676 | $result{$host} = ...; |
|
|
677 | $cv->end; |
|
|
678 | }; |
|
|
679 | } |
|
|
680 | |
|
|
681 | $cv->end; |
|
|
682 | |
|
|
683 | This code fragment supposedly pings a number of hosts and calls |
|
|
684 | C<send> after results for all then have have been gathered - in any |
|
|
685 | order. To achieve this, the code issues a call to C<begin> when it starts |
|
|
686 | each ping request and calls C<end> when it has received some result for |
|
|
687 | it. Since C<begin> and C<end> only maintain a counter, the order in which |
|
|
688 | results arrive is not relevant. |
|
|
689 | |
|
|
690 | There is an additional bracketing call to C<begin> and C<end> outside the |
|
|
691 | loop, which serves two important purposes: first, it sets the callback |
|
|
692 | to be called once the counter reaches C<0>, and second, it ensures that |
|
|
693 | C<send> is called even when C<no> hosts are being pinged (the loop |
|
|
694 | doesn't execute once). |
|
|
695 | |
|
|
696 | This is the general pattern when you "fan out" into multiple (but |
|
|
697 | potentially none) subrequests: use an outer C<begin>/C<end> pair to set |
|
|
698 | the callback and ensure C<end> is called at least once, and then, for each |
|
|
699 | subrequest you start, call C<begin> and for each subrequest you finish, |
|
|
700 | call C<end>. |
|
|
701 | |
|
|
702 | =back |
|
|
703 | |
|
|
704 | =head3 METHODS FOR CONSUMERS |
|
|
705 | |
|
|
706 | These methods should only be used by the consuming side, i.e. the |
|
|
707 | code awaits the condition. |
|
|
708 | |
|
|
709 | =over 4 |
|
|
710 | |
|
|
711 | =item $cv->recv |
|
|
712 | |
|
|
713 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
|
|
714 | >> methods have been called on c<$cv>, while servicing other watchers |
|
|
715 | normally. |
|
|
716 | |
|
|
717 | You can only wait once on a condition - additional calls are valid but |
|
|
718 | will return immediately. |
|
|
719 | |
|
|
720 | If an error condition has been set by calling C<< ->croak >>, then this |
|
|
721 | function will call C<croak>. |
|
|
722 | |
|
|
723 | In list context, all parameters passed to C<send> will be returned, |
|
|
724 | in scalar context only the first one will be returned. |
|
|
725 | |
|
|
726 | Note that doing a blocking wait in a callback is not supported by any |
|
|
727 | event loop, that is, recursive invocation of a blocking C<< ->recv |
|
|
728 | >> is not allowed, and the C<recv> call will C<croak> if such a |
|
|
729 | condition is detected. This condition can be slightly loosened by using |
|
|
730 | L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from |
|
|
731 | any thread that doesn't run the event loop itself. |
|
|
732 | |
|
|
733 | Not all event models support a blocking wait - some die in that case |
|
|
734 | (programs might want to do that to stay interactive), so I<if you are |
|
|
735 | using this from a module, never require a blocking wait>. Instead, let the |
|
|
736 | caller decide whether the call will block or not (for example, by coupling |
|
|
737 | condition variables with some kind of request results and supporting |
|
|
738 | callbacks so the caller knows that getting the result will not block, |
|
|
739 | while still supporting blocking waits if the caller so desires). |
|
|
740 | |
|
|
741 | You can ensure that C<< -recv >> never blocks by setting a callback and |
|
|
742 | only calling C<< ->recv >> from within that callback (or at a later |
|
|
743 | time). This will work even when the event loop does not support blocking |
|
|
744 | waits otherwise. |
|
|
745 | |
|
|
746 | =item $bool = $cv->ready |
|
|
747 | |
|
|
748 | Returns true when the condition is "true", i.e. whether C<send> or |
|
|
749 | C<croak> have been called. |
|
|
750 | |
|
|
751 | =item $cb = $cv->cb ($cb->($cv)) |
|
|
752 | |
|
|
753 | This is a mutator function that returns the callback set and optionally |
|
|
754 | replaces it before doing so. |
|
|
755 | |
|
|
756 | The callback will be called when the condition becomes "true", i.e. when |
|
|
757 | C<send> or C<croak> are called, with the only argument being the condition |
|
|
758 | variable itself. Calling C<recv> inside the callback or at any later time |
|
|
759 | is guaranteed not to block. |
|
|
760 | |
|
|
761 | =back |
|
|
762 | |
|
|
763 | =head1 SUPPORTED EVENT LOOPS/BACKENDS |
|
|
764 | |
|
|
765 | The available backend classes are (every class has its own manpage): |
|
|
766 | |
|
|
767 | =over 4 |
|
|
768 | |
|
|
769 | =item Backends that are autoprobed when no other event loop can be found. |
|
|
770 | |
|
|
771 | EV is the preferred backend when no other event loop seems to be in |
|
|
772 | use. If EV is not installed, then AnyEvent will try Event, and, failing |
|
|
773 | that, will fall back to its own pure-perl implementation, which is |
|
|
774 | available everywhere as it comes with AnyEvent itself. |
|
|
775 | |
|
|
776 | AnyEvent::Impl::EV based on EV (interface to libev, best choice). |
|
|
777 | AnyEvent::Impl::Event based on Event, very stable, few glitches. |
|
|
778 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
779 | |
|
|
780 | =item Backends that are transparently being picked up when they are used. |
|
|
781 | |
|
|
782 | These will be used when they are currently loaded when the first watcher |
|
|
783 | is created, in which case it is assumed that the application is using |
|
|
784 | them. This means that AnyEvent will automatically pick the right backend |
|
|
785 | when the main program loads an event module before anything starts to |
|
|
786 | create watchers. Nothing special needs to be done by the main program. |
|
|
787 | |
|
|
788 | AnyEvent::Impl::Glib based on Glib, slow but very stable. |
|
|
789 | AnyEvent::Impl::Tk based on Tk, very broken. |
|
|
790 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
791 | AnyEvent::Impl::POE based on POE, very slow, some limitations. |
|
|
792 | |
|
|
793 | =item Backends with special needs. |
|
|
794 | |
|
|
795 | Qt requires the Qt::Application to be instantiated first, but will |
|
|
796 | otherwise be picked up automatically. As long as the main program |
|
|
797 | instantiates the application before any AnyEvent watchers are created, |
|
|
798 | everything should just work. |
|
|
799 | |
|
|
800 | AnyEvent::Impl::Qt based on Qt. |
|
|
801 | |
|
|
802 | Support for IO::Async can only be partial, as it is too broken and |
|
|
803 | architecturally limited to even support the AnyEvent API. It also |
|
|
804 | is the only event loop that needs the loop to be set explicitly, so |
|
|
805 | it can only be used by a main program knowing about AnyEvent. See |
|
|
806 | L<AnyEvent::Impl::Async> for the gory details. |
|
|
807 | |
|
|
808 | AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed. |
|
|
809 | |
|
|
810 | =item Event loops that are indirectly supported via other backends. |
|
|
811 | |
|
|
812 | Some event loops can be supported via other modules: |
|
|
813 | |
|
|
814 | There is no direct support for WxWidgets (L<Wx>) or L<Prima>. |
|
|
815 | |
|
|
816 | B<WxWidgets> has no support for watching file handles. However, you can |
|
|
817 | use WxWidgets through the POE adaptor, as POE has a Wx backend that simply |
|
|
818 | polls 20 times per second, which was considered to be too horrible to even |
|
|
819 | consider for AnyEvent. |
|
|
820 | |
|
|
821 | B<Prima> is not supported as nobody seems to be using it, but it has a POE |
|
|
822 | backend, so it can be supported through POE. |
|
|
823 | |
|
|
824 | AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to |
|
|
825 | load L<POE> when detecting them, in the hope that POE will pick them up, |
|
|
826 | in which case everything will be automatic. |
|
|
827 | |
|
|
828 | =back |
341 | |
829 | |
342 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
830 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
343 | |
831 | |
|
|
832 | These are not normally required to use AnyEvent, but can be useful to |
|
|
833 | write AnyEvent extension modules. |
|
|
834 | |
344 | =over 4 |
835 | =over 4 |
345 | |
836 | |
346 | =item $AnyEvent::MODEL |
837 | =item $AnyEvent::MODEL |
347 | |
838 | |
348 | Contains C<undef> until the first watcher is being created. Then it |
839 | Contains C<undef> until the first watcher is being created, before the |
|
|
840 | backend has been autodetected. |
|
|
841 | |
349 | contains the event model that is being used, which is the name of the |
842 | Afterwards it contains the event model that is being used, which is the |
350 | Perl class implementing the model. This class is usually one of the |
843 | name of the Perl class implementing the model. This class is usually one |
351 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
844 | of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the |
352 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
845 | case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it |
353 | |
846 | will be C<urxvt::anyevent>). |
354 | The known classes so far are: |
|
|
355 | |
|
|
356 | AnyEvent::Impl::CoroEV based on Coro::EV, best choice. |
|
|
357 | AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice. |
|
|
358 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
|
|
359 | AnyEvent::Impl::Event based on Event, second best choice. |
|
|
360 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
|
|
361 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
|
|
362 | AnyEvent::Impl::Perl pure-perl implementation, inefficient but portable. |
|
|
363 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
|
|
364 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
365 | |
847 | |
366 | =item AnyEvent::detect |
848 | =item AnyEvent::detect |
367 | |
849 | |
368 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
850 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
369 | if necessary. You should only call this function right before you would |
851 | if necessary. You should only call this function right before you would |
370 | have created an AnyEvent watcher anyway, that is, as late as possible at |
852 | have created an AnyEvent watcher anyway, that is, as late as possible at |
371 | runtime. |
853 | runtime, and not e.g. while initialising of your module. |
|
|
854 | |
|
|
855 | If you need to do some initialisation before AnyEvent watchers are |
|
|
856 | created, use C<post_detect>. |
|
|
857 | |
|
|
858 | =item $guard = AnyEvent::post_detect { BLOCK } |
|
|
859 | |
|
|
860 | Arranges for the code block to be executed as soon as the event model is |
|
|
861 | autodetected (or immediately if this has already happened). |
|
|
862 | |
|
|
863 | The block will be executed I<after> the actual backend has been detected |
|
|
864 | (C<$AnyEvent::MODEL> is set), but I<before> any watchers have been |
|
|
865 | created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do |
|
|
866 | other initialisations - see the sources of L<AnyEvent::Strict> or |
|
|
867 | L<AnyEvent::AIO> to see how this is used. |
|
|
868 | |
|
|
869 | The most common usage is to create some global watchers, without forcing |
|
|
870 | event module detection too early, for example, L<AnyEvent::AIO> creates |
|
|
871 | and installs the global L<IO::AIO> watcher in a C<post_detect> block to |
|
|
872 | avoid autodetecting the event module at load time. |
|
|
873 | |
|
|
874 | If called in scalar or list context, then it creates and returns an object |
|
|
875 | that automatically removes the callback again when it is destroyed. See |
|
|
876 | L<Coro::BDB> for a case where this is useful. |
|
|
877 | |
|
|
878 | =item @AnyEvent::post_detect |
|
|
879 | |
|
|
880 | If there are any code references in this array (you can C<push> to it |
|
|
881 | before or after loading AnyEvent), then they will called directly after |
|
|
882 | the event loop has been chosen. |
|
|
883 | |
|
|
884 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
|
|
885 | if it is defined then the event loop has already been detected, and the |
|
|
886 | array will be ignored. |
|
|
887 | |
|
|
888 | Best use C<AnyEvent::post_detect { BLOCK }> when your application allows |
|
|
889 | it,as it takes care of these details. |
|
|
890 | |
|
|
891 | This variable is mainly useful for modules that can do something useful |
|
|
892 | when AnyEvent is used and thus want to know when it is initialised, but do |
|
|
893 | not need to even load it by default. This array provides the means to hook |
|
|
894 | into AnyEvent passively, without loading it. |
372 | |
895 | |
373 | =back |
896 | =back |
374 | |
897 | |
375 | =head1 WHAT TO DO IN A MODULE |
898 | =head1 WHAT TO DO IN A MODULE |
376 | |
899 | |
… | |
… | |
380 | Be careful when you create watchers in the module body - AnyEvent will |
903 | Be careful when you create watchers in the module body - AnyEvent will |
381 | decide which event module to use as soon as the first method is called, so |
904 | decide which event module to use as soon as the first method is called, so |
382 | by calling AnyEvent in your module body you force the user of your module |
905 | by calling AnyEvent in your module body you force the user of your module |
383 | to load the event module first. |
906 | to load the event module first. |
384 | |
907 | |
385 | Never call C<< ->wait >> on a condition variable unless you I<know> that |
908 | Never call C<< ->recv >> on a condition variable unless you I<know> that |
386 | the C<< ->broadcast >> method has been called on it already. This is |
909 | the C<< ->send >> method has been called on it already. This is |
387 | because it will stall the whole program, and the whole point of using |
910 | because it will stall the whole program, and the whole point of using |
388 | events is to stay interactive. |
911 | events is to stay interactive. |
389 | |
912 | |
390 | It is fine, however, to call C<< ->wait >> when the user of your module |
913 | It is fine, however, to call C<< ->recv >> when the user of your module |
391 | requests it (i.e. if you create a http request object ad have a method |
914 | requests it (i.e. if you create a http request object ad have a method |
392 | called C<results> that returns the results, it should call C<< ->wait >> |
915 | called C<results> that returns the results, it should call C<< ->recv >> |
393 | freely, as the user of your module knows what she is doing. always). |
916 | freely, as the user of your module knows what she is doing. always). |
394 | |
917 | |
395 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
918 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
396 | |
919 | |
397 | There will always be a single main program - the only place that should |
920 | There will always be a single main program - the only place that should |
… | |
… | |
399 | |
922 | |
400 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
923 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
401 | do anything special (it does not need to be event-based) and let AnyEvent |
924 | do anything special (it does not need to be event-based) and let AnyEvent |
402 | decide which implementation to chose if some module relies on it. |
925 | decide which implementation to chose if some module relies on it. |
403 | |
926 | |
404 | If the main program relies on a specific event model. For example, in |
927 | If the main program relies on a specific event model - for example, in |
405 | Gtk2 programs you have to rely on the Glib module. You should load the |
928 | Gtk2 programs you have to rely on the Glib module - you should load the |
406 | event module before loading AnyEvent or any module that uses it: generally |
929 | event module before loading AnyEvent or any module that uses it: generally |
407 | speaking, you should load it as early as possible. The reason is that |
930 | speaking, you should load it as early as possible. The reason is that |
408 | modules might create watchers when they are loaded, and AnyEvent will |
931 | modules might create watchers when they are loaded, and AnyEvent will |
409 | decide on the event model to use as soon as it creates watchers, and it |
932 | decide on the event model to use as soon as it creates watchers, and it |
410 | might chose the wrong one unless you load the correct one yourself. |
933 | might chose the wrong one unless you load the correct one yourself. |
411 | |
934 | |
412 | You can chose to use a rather inefficient pure-perl implementation by |
935 | You can chose to use a pure-perl implementation by loading the |
413 | loading the C<AnyEvent::Impl::Perl> module, which gives you similar |
936 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
414 | behaviour everywhere, but letting AnyEvent chose is generally better. |
937 | everywhere, but letting AnyEvent chose the model is generally better. |
|
|
938 | |
|
|
939 | =head2 MAINLOOP EMULATION |
|
|
940 | |
|
|
941 | Sometimes (often for short test scripts, or even standalone programs who |
|
|
942 | only want to use AnyEvent), you do not want to run a specific event loop. |
|
|
943 | |
|
|
944 | In that case, you can use a condition variable like this: |
|
|
945 | |
|
|
946 | AnyEvent->condvar->recv; |
|
|
947 | |
|
|
948 | This has the effect of entering the event loop and looping forever. |
|
|
949 | |
|
|
950 | Note that usually your program has some exit condition, in which case |
|
|
951 | it is better to use the "traditional" approach of storing a condition |
|
|
952 | variable somewhere, waiting for it, and sending it when the program should |
|
|
953 | exit cleanly. |
|
|
954 | |
|
|
955 | |
|
|
956 | =head1 OTHER MODULES |
|
|
957 | |
|
|
958 | The following is a non-exhaustive list of additional modules that use |
|
|
959 | AnyEvent as a client and can therefore be mixed easily with other AnyEvent |
|
|
960 | modules and other event loops in the same program. Some of the modules |
|
|
961 | come with AnyEvent, most are available via CPAN. |
|
|
962 | |
|
|
963 | =over 4 |
|
|
964 | |
|
|
965 | =item L<AnyEvent::Util> |
|
|
966 | |
|
|
967 | Contains various utility functions that replace often-used but blocking |
|
|
968 | functions such as C<inet_aton> by event-/callback-based versions. |
|
|
969 | |
|
|
970 | =item L<AnyEvent::Socket> |
|
|
971 | |
|
|
972 | Provides various utility functions for (internet protocol) sockets, |
|
|
973 | addresses and name resolution. Also functions to create non-blocking tcp |
|
|
974 | connections or tcp servers, with IPv6 and SRV record support and more. |
|
|
975 | |
|
|
976 | =item L<AnyEvent::Handle> |
|
|
977 | |
|
|
978 | Provide read and write buffers, manages watchers for reads and writes, |
|
|
979 | supports raw and formatted I/O, I/O queued and fully transparent and |
|
|
980 | non-blocking SSL/TLS (via L<AnyEvent::TLS>. |
|
|
981 | |
|
|
982 | =item L<AnyEvent::DNS> |
|
|
983 | |
|
|
984 | Provides rich asynchronous DNS resolver capabilities. |
|
|
985 | |
|
|
986 | =item L<AnyEvent::HTTP> |
|
|
987 | |
|
|
988 | A simple-to-use HTTP library that is capable of making a lot of concurrent |
|
|
989 | HTTP requests. |
|
|
990 | |
|
|
991 | =item L<AnyEvent::HTTPD> |
|
|
992 | |
|
|
993 | Provides a simple web application server framework. |
|
|
994 | |
|
|
995 | =item L<AnyEvent::FastPing> |
|
|
996 | |
|
|
997 | The fastest ping in the west. |
|
|
998 | |
|
|
999 | =item L<AnyEvent::DBI> |
|
|
1000 | |
|
|
1001 | Executes L<DBI> requests asynchronously in a proxy process. |
|
|
1002 | |
|
|
1003 | =item L<AnyEvent::AIO> |
|
|
1004 | |
|
|
1005 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
1006 | programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent |
|
|
1007 | together. |
|
|
1008 | |
|
|
1009 | =item L<AnyEvent::BDB> |
|
|
1010 | |
|
|
1011 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses |
|
|
1012 | L<BDB> and AnyEvent together. |
|
|
1013 | |
|
|
1014 | =item L<AnyEvent::GPSD> |
|
|
1015 | |
|
|
1016 | A non-blocking interface to gpsd, a daemon delivering GPS information. |
|
|
1017 | |
|
|
1018 | =item L<AnyEvent::IRC> |
|
|
1019 | |
|
|
1020 | AnyEvent based IRC client module family (replacing the older Net::IRC3). |
|
|
1021 | |
|
|
1022 | =item L<AnyEvent::XMPP> |
|
|
1023 | |
|
|
1024 | AnyEvent based XMPP (Jabber protocol) module family (replacing the older |
|
|
1025 | Net::XMPP2>. |
|
|
1026 | |
|
|
1027 | =item L<AnyEvent::IGS> |
|
|
1028 | |
|
|
1029 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
1030 | L<App::IGS>). |
|
|
1031 | |
|
|
1032 | =item L<Net::FCP> |
|
|
1033 | |
|
|
1034 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
|
|
1035 | of AnyEvent. |
|
|
1036 | |
|
|
1037 | =item L<Event::ExecFlow> |
|
|
1038 | |
|
|
1039 | High level API for event-based execution flow control. |
|
|
1040 | |
|
|
1041 | =item L<Coro> |
|
|
1042 | |
|
|
1043 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
|
|
1044 | |
|
|
1045 | =back |
415 | |
1046 | |
416 | =cut |
1047 | =cut |
417 | |
1048 | |
418 | package AnyEvent; |
1049 | package AnyEvent; |
419 | |
1050 | |
|
|
1051 | # basically a tuned-down version of common::sense |
|
|
1052 | sub common_sense { |
420 | no warnings; |
1053 | # no warnings |
421 | use strict; |
1054 | ${^WARNING_BITS} ^= ${^WARNING_BITS}; |
|
|
1055 | # use strict vars subs |
|
|
1056 | $^H |= 0x00000600; |
|
|
1057 | } |
422 | |
1058 | |
|
|
1059 | BEGIN { AnyEvent::common_sense } |
|
|
1060 | |
423 | use Carp; |
1061 | use Carp (); |
424 | |
1062 | |
425 | our $VERSION = '3.12'; |
1063 | our $VERSION = 4.85; |
426 | our $MODEL; |
1064 | our $MODEL; |
427 | |
1065 | |
428 | our $AUTOLOAD; |
1066 | our $AUTOLOAD; |
429 | our @ISA; |
1067 | our @ISA; |
430 | |
1068 | |
431 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
|
|
432 | |
|
|
433 | our @REGISTRY; |
1069 | our @REGISTRY; |
434 | |
1070 | |
|
|
1071 | our $WIN32; |
|
|
1072 | |
|
|
1073 | our $VERBOSE; |
|
|
1074 | |
|
|
1075 | BEGIN { |
|
|
1076 | eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; |
|
|
1077 | eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; |
|
|
1078 | |
|
|
1079 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
1080 | if ${^TAINT}; |
|
|
1081 | |
|
|
1082 | $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
|
|
1083 | |
|
|
1084 | } |
|
|
1085 | |
|
|
1086 | our $MAX_SIGNAL_LATENCY = 10; |
|
|
1087 | |
|
|
1088 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
|
|
1089 | |
|
|
1090 | { |
|
|
1091 | my $idx; |
|
|
1092 | $PROTOCOL{$_} = ++$idx |
|
|
1093 | for reverse split /\s*,\s*/, |
|
|
1094 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
|
|
1095 | } |
|
|
1096 | |
435 | my @models = ( |
1097 | my @models = ( |
436 | [Coro::EV:: => AnyEvent::Impl::CoroEV::], |
|
|
437 | [Coro::Event:: => AnyEvent::Impl::CoroEvent::], |
|
|
438 | [EV:: => AnyEvent::Impl::EV::], |
1098 | [EV:: => AnyEvent::Impl::EV::], |
439 | [Event:: => AnyEvent::Impl::Event::], |
1099 | [Event:: => AnyEvent::Impl::Event::], |
440 | [Glib:: => AnyEvent::Impl::Glib::], |
|
|
441 | [Tk:: => AnyEvent::Impl::Tk::], |
|
|
442 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
1100 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
|
|
1101 | # everything below here will not be autoprobed |
|
|
1102 | # as the pureperl backend should work everywhere |
|
|
1103 | # and is usually faster |
|
|
1104 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
|
|
1105 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
|
|
1106 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
|
|
1107 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
|
|
1108 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
|
|
1109 | [Wx:: => AnyEvent::Impl::POE::], |
|
|
1110 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
1111 | # IO::Async is just too broken - we would need workarounds for its |
|
|
1112 | # byzantine signal and broken child handling, among others. |
|
|
1113 | # IO::Async is rather hard to detect, as it doesn't have any |
|
|
1114 | # obvious default class. |
|
|
1115 | # [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1116 | # [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program |
|
|
1117 | # [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program |
443 | ); |
1118 | ); |
444 | my @models_detect = ( |
|
|
445 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
|
|
446 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
|
|
447 | ); |
|
|
448 | |
1119 | |
449 | our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY); |
1120 | our %method = map +($_ => 1), |
|
|
1121 | qw(io timer time now now_update signal child idle condvar one_event DESTROY); |
|
|
1122 | |
|
|
1123 | our @post_detect; |
|
|
1124 | |
|
|
1125 | sub post_detect(&) { |
|
|
1126 | my ($cb) = @_; |
|
|
1127 | |
|
|
1128 | if ($MODEL) { |
|
|
1129 | $cb->(); |
|
|
1130 | |
|
|
1131 | 1 |
|
|
1132 | } else { |
|
|
1133 | push @post_detect, $cb; |
|
|
1134 | |
|
|
1135 | defined wantarray |
|
|
1136 | ? bless \$cb, "AnyEvent::Util::postdetect" |
|
|
1137 | : () |
|
|
1138 | } |
|
|
1139 | } |
|
|
1140 | |
|
|
1141 | sub AnyEvent::Util::postdetect::DESTROY { |
|
|
1142 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
|
|
1143 | } |
450 | |
1144 | |
451 | sub detect() { |
1145 | sub detect() { |
452 | unless ($MODEL) { |
1146 | unless ($MODEL) { |
453 | no strict 'refs'; |
1147 | local $SIG{__DIE__}; |
454 | |
1148 | |
455 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
1149 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
456 | my $model = "AnyEvent::Impl::$1"; |
1150 | my $model = "AnyEvent::Impl::$1"; |
457 | if (eval "require $model") { |
1151 | if (eval "require $model") { |
458 | $MODEL = $model; |
1152 | $MODEL = $model; |
459 | warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; |
1153 | warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; |
|
|
1154 | } else { |
|
|
1155 | warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE; |
460 | } |
1156 | } |
461 | } |
1157 | } |
462 | |
1158 | |
463 | # check for already loaded models |
1159 | # check for already loaded models |
464 | unless ($MODEL) { |
1160 | unless ($MODEL) { |
465 | for (@REGISTRY, @models, @models_detect) { |
1161 | for (@REGISTRY, @models) { |
466 | my ($package, $model) = @$_; |
1162 | my ($package, $model) = @$_; |
467 | if (${"$package\::VERSION"} > 0) { |
1163 | if (${"$package\::VERSION"} > 0) { |
468 | if (eval "require $model") { |
1164 | if (eval "require $model") { |
469 | $MODEL = $model; |
1165 | $MODEL = $model; |
470 | warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; |
1166 | warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2; |
471 | last; |
1167 | last; |
472 | } |
1168 | } |
473 | } |
1169 | } |
474 | } |
1170 | } |
475 | |
1171 | |
… | |
… | |
480 | my ($package, $model) = @$_; |
1176 | my ($package, $model) = @$_; |
481 | if (eval "require $package" |
1177 | if (eval "require $package" |
482 | and ${"$package\::VERSION"} > 0 |
1178 | and ${"$package\::VERSION"} > 0 |
483 | and eval "require $model") { |
1179 | and eval "require $model") { |
484 | $MODEL = $model; |
1180 | $MODEL = $model; |
485 | warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; |
1181 | warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2; |
486 | last; |
1182 | last; |
487 | } |
1183 | } |
488 | } |
1184 | } |
489 | |
1185 | |
490 | $MODEL |
1186 | $MODEL |
491 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV (or Coro+EV), Event (or Coro+Event) or Glib."; |
1187 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; |
492 | } |
1188 | } |
493 | } |
1189 | } |
494 | |
1190 | |
|
|
1191 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
1192 | |
495 | unshift @ISA, $MODEL; |
1193 | unshift @ISA, $MODEL; |
496 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
1194 | |
|
|
1195 | require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; |
|
|
1196 | |
|
|
1197 | (shift @post_detect)->() while @post_detect; |
497 | } |
1198 | } |
498 | |
1199 | |
499 | $MODEL |
1200 | $MODEL |
500 | } |
1201 | } |
501 | |
1202 | |
502 | sub AUTOLOAD { |
1203 | sub AUTOLOAD { |
503 | (my $func = $AUTOLOAD) =~ s/.*://; |
1204 | (my $func = $AUTOLOAD) =~ s/.*://; |
504 | |
1205 | |
505 | $method{$func} |
1206 | $method{$func} |
506 | or croak "$func: not a valid method for AnyEvent objects"; |
1207 | or Carp::croak "$func: not a valid method for AnyEvent objects"; |
507 | |
1208 | |
508 | detect unless $MODEL; |
1209 | detect unless $MODEL; |
509 | |
1210 | |
510 | my $class = shift; |
1211 | my $class = shift; |
511 | $class->$func (@_); |
1212 | $class->$func (@_); |
512 | } |
1213 | } |
513 | |
1214 | |
|
|
1215 | # utility function to dup a filehandle. this is used by many backends |
|
|
1216 | # to support binding more than one watcher per filehandle (they usually |
|
|
1217 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1218 | sub _dupfh($$;$$) { |
|
|
1219 | my ($poll, $fh, $r, $w) = @_; |
|
|
1220 | |
|
|
1221 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1222 | my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&"); |
|
|
1223 | |
|
|
1224 | open my $fh2, $mode, $fh |
|
|
1225 | or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; |
|
|
1226 | |
|
|
1227 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1228 | |
|
|
1229 | ($fh2, $rw) |
|
|
1230 | } |
|
|
1231 | |
514 | package AnyEvent::Base; |
1232 | package AnyEvent::Base; |
515 | |
1233 | |
|
|
1234 | # default implementations for many methods |
|
|
1235 | |
|
|
1236 | sub _time { |
|
|
1237 | # probe for availability of Time::HiRes |
|
|
1238 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1239 | warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; |
|
|
1240 | *_time = \&Time::HiRes::time; |
|
|
1241 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1242 | } else { |
|
|
1243 | warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; |
|
|
1244 | *_time = sub { time }; # epic fail |
|
|
1245 | } |
|
|
1246 | |
|
|
1247 | &_time |
|
|
1248 | } |
|
|
1249 | |
|
|
1250 | sub time { _time } |
|
|
1251 | sub now { _time } |
|
|
1252 | sub now_update { } |
|
|
1253 | |
516 | # default implementation for ->condvar, ->wait, ->broadcast |
1254 | # default implementation for ->condvar |
517 | |
1255 | |
518 | sub condvar { |
1256 | sub condvar { |
519 | bless \my $flag, "AnyEvent::Base::CondVar" |
1257 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
520 | } |
|
|
521 | |
|
|
522 | sub AnyEvent::Base::CondVar::broadcast { |
|
|
523 | ${$_[0]}++; |
|
|
524 | } |
|
|
525 | |
|
|
526 | sub AnyEvent::Base::CondVar::wait { |
|
|
527 | AnyEvent->one_event while !${$_[0]}; |
|
|
528 | } |
1258 | } |
529 | |
1259 | |
530 | # default implementation for ->signal |
1260 | # default implementation for ->signal |
531 | |
1261 | |
532 | our %SIG_CB; |
1262 | our $HAVE_ASYNC_INTERRUPT; |
|
|
1263 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1264 | our (%SIG_ASY, %SIG_ASY_W); |
|
|
1265 | our ($SIG_COUNT, $SIG_TW); |
533 | |
1266 | |
|
|
1267 | sub _signal_exec { |
|
|
1268 | $HAVE_ASYNC_INTERRUPT |
|
|
1269 | ? $SIGPIPE_R->drain |
|
|
1270 | : sysread $SIGPIPE_R, my $dummy, 9; |
|
|
1271 | |
|
|
1272 | while (%SIG_EV) { |
|
|
1273 | for (keys %SIG_EV) { |
|
|
1274 | delete $SIG_EV{$_}; |
|
|
1275 | $_->() for values %{ $SIG_CB{$_} || {} }; |
|
|
1276 | } |
|
|
1277 | } |
|
|
1278 | } |
|
|
1279 | |
|
|
1280 | # install a dumym wakeupw atcher to reduce signal catching latency |
|
|
1281 | sub _sig_add() { |
|
|
1282 | unless ($SIG_COUNT++) { |
|
|
1283 | # try to align timer on a full-second boundary, if possible |
|
|
1284 | my $NOW = AnyEvent->now; |
|
|
1285 | |
|
|
1286 | $SIG_TW = AnyEvent->timer ( |
|
|
1287 | after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW), |
|
|
1288 | interval => $MAX_SIGNAL_LATENCY, |
|
|
1289 | cb => sub { }, # just for the PERL_ASYNC_CHECK |
|
|
1290 | ); |
|
|
1291 | } |
|
|
1292 | } |
|
|
1293 | |
|
|
1294 | sub _sig_del { |
|
|
1295 | undef $SIG_TW |
|
|
1296 | unless --$SIG_COUNT; |
|
|
1297 | } |
|
|
1298 | |
534 | sub signal { |
1299 | sub _signal { |
535 | my (undef, %arg) = @_; |
1300 | my (undef, %arg) = @_; |
536 | |
1301 | |
537 | my $signal = uc $arg{signal} |
1302 | my $signal = uc $arg{signal} |
538 | or Carp::croak "required option 'signal' is missing"; |
1303 | or Carp::croak "required option 'signal' is missing"; |
539 | |
1304 | |
540 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
1305 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
1306 | |
|
|
1307 | if ($HAVE_ASYNC_INTERRUPT) { |
|
|
1308 | # async::interrupt |
|
|
1309 | |
|
|
1310 | $SIG_ASY{$signal} ||= do { |
|
|
1311 | my $asy = new Async::Interrupt |
|
|
1312 | cb => sub { undef $SIG_EV{$signal} }, |
|
|
1313 | signal => $signal, |
|
|
1314 | pipe => [$SIGPIPE_R->filenos], |
|
|
1315 | ; |
|
|
1316 | $asy->pipe_autodrain (0); |
|
|
1317 | |
|
|
1318 | $asy |
|
|
1319 | }; |
|
|
1320 | |
|
|
1321 | } else { |
|
|
1322 | # pure perl |
|
|
1323 | |
541 | $SIG{$signal} ||= sub { |
1324 | $SIG{$signal} ||= sub { |
542 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
1325 | local $!; |
|
|
1326 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1327 | undef $SIG_EV{$signal}; |
|
|
1328 | }; |
|
|
1329 | |
|
|
1330 | # can't do signal processing without introducing races in pure perl, |
|
|
1331 | # so limit the signal latency. |
|
|
1332 | _sig_add; |
543 | }; |
1333 | } |
544 | |
1334 | |
545 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1335 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
546 | } |
1336 | } |
547 | |
1337 | |
|
|
1338 | sub signal { |
|
|
1339 | # probe for availability of Async::Interrupt |
|
|
1340 | if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") { |
|
|
1341 | warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8; |
|
|
1342 | |
|
|
1343 | $HAVE_ASYNC_INTERRUPT = 1; |
|
|
1344 | $SIGPIPE_R = new Async::Interrupt::EventPipe; |
|
|
1345 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec); |
|
|
1346 | |
|
|
1347 | } else { |
|
|
1348 | warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; |
|
|
1349 | |
|
|
1350 | require Fcntl; |
|
|
1351 | |
|
|
1352 | if (AnyEvent::WIN32) { |
|
|
1353 | require AnyEvent::Util; |
|
|
1354 | |
|
|
1355 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1356 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R; |
|
|
1357 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case |
|
|
1358 | } else { |
|
|
1359 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1360 | fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; |
|
|
1361 | fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1362 | |
|
|
1363 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1364 | fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1365 | fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; |
|
|
1366 | } |
|
|
1367 | |
|
|
1368 | $SIGPIPE_R |
|
|
1369 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1370 | |
|
|
1371 | $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); |
|
|
1372 | } |
|
|
1373 | |
|
|
1374 | *signal = \&_signal; |
|
|
1375 | &signal |
|
|
1376 | } |
|
|
1377 | |
548 | sub AnyEvent::Base::Signal::DESTROY { |
1378 | sub AnyEvent::Base::signal::DESTROY { |
549 | my ($signal, $cb) = @{$_[0]}; |
1379 | my ($signal, $cb) = @{$_[0]}; |
550 | |
1380 | |
|
|
1381 | _sig_del; |
|
|
1382 | |
551 | delete $SIG_CB{$signal}{$cb}; |
1383 | delete $SIG_CB{$signal}{$cb}; |
552 | |
1384 | |
553 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
1385 | $HAVE_ASYNC_INTERRUPT |
|
|
1386 | ? delete $SIG_ASY{$signal} |
|
|
1387 | : # delete doesn't work with older perls - they then |
|
|
1388 | # print weird messages, or just unconditionally exit |
|
|
1389 | # instead of getting the default action. |
|
|
1390 | undef $SIG{$signal} |
|
|
1391 | unless keys %{ $SIG_CB{$signal} }; |
554 | } |
1392 | } |
555 | |
1393 | |
556 | # default implementation for ->child |
1394 | # default implementation for ->child |
557 | |
1395 | |
558 | our %PID_CB; |
1396 | our %PID_CB; |
559 | our $CHLD_W; |
1397 | our $CHLD_W; |
560 | our $CHLD_DELAY_W; |
1398 | our $CHLD_DELAY_W; |
561 | our $PID_IDLE; |
|
|
562 | our $WNOHANG; |
1399 | our $WNOHANG; |
563 | |
1400 | |
564 | sub _child_wait { |
1401 | sub _sigchld { |
565 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1402 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
|
|
1403 | $_->($pid, $?) |
566 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1404 | for values %{ $PID_CB{$pid} || {} }, |
567 | (values %{ $PID_CB{0} || {} }); |
1405 | values %{ $PID_CB{0} || {} }; |
568 | } |
1406 | } |
569 | |
|
|
570 | undef $PID_IDLE; |
|
|
571 | } |
|
|
572 | |
|
|
573 | sub _sigchld { |
|
|
574 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
575 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
576 | undef $CHLD_DELAY_W; |
|
|
577 | &_child_wait; |
|
|
578 | }); |
|
|
579 | } |
1407 | } |
580 | |
1408 | |
581 | sub child { |
1409 | sub child { |
582 | my (undef, %arg) = @_; |
1410 | my (undef, %arg) = @_; |
583 | |
1411 | |
584 | defined (my $pid = $arg{pid} + 0) |
1412 | defined (my $pid = $arg{pid} + 0) |
585 | or Carp::croak "required option 'pid' is missing"; |
1413 | or Carp::croak "required option 'pid' is missing"; |
586 | |
1414 | |
587 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1415 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
588 | |
1416 | |
589 | unless ($WNOHANG) { |
1417 | # WNOHANG is almost cetrainly 1 everywhere |
590 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
1418 | $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ |
591 | } |
1419 | ? 1 |
|
|
1420 | : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; |
592 | |
1421 | |
593 | unless ($CHLD_W) { |
1422 | unless ($CHLD_W) { |
594 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1423 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
595 | # child could be a zombie already, so make at least one round |
1424 | # child could be a zombie already, so make at least one round |
596 | &_sigchld; |
1425 | &_sigchld; |
597 | } |
1426 | } |
598 | |
1427 | |
599 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1428 | bless [$pid, $arg{cb}], "AnyEvent::Base::child" |
600 | } |
1429 | } |
601 | |
1430 | |
602 | sub AnyEvent::Base::Child::DESTROY { |
1431 | sub AnyEvent::Base::child::DESTROY { |
603 | my ($pid, $cb) = @{$_[0]}; |
1432 | my ($pid, $cb) = @{$_[0]}; |
604 | |
1433 | |
605 | delete $PID_CB{$pid}{$cb}; |
1434 | delete $PID_CB{$pid}{$cb}; |
606 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1435 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
607 | |
1436 | |
608 | undef $CHLD_W unless keys %PID_CB; |
1437 | undef $CHLD_W unless keys %PID_CB; |
609 | } |
1438 | } |
|
|
1439 | |
|
|
1440 | # idle emulation is done by simply using a timer, regardless |
|
|
1441 | # of whether the process is idle or not, and not letting |
|
|
1442 | # the callback use more than 50% of the time. |
|
|
1443 | sub idle { |
|
|
1444 | my (undef, %arg) = @_; |
|
|
1445 | |
|
|
1446 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1447 | |
|
|
1448 | $rcb = sub { |
|
|
1449 | if ($cb) { |
|
|
1450 | $w = _time; |
|
|
1451 | &$cb; |
|
|
1452 | $w = _time - $w; |
|
|
1453 | |
|
|
1454 | # never use more then 50% of the time for the idle watcher, |
|
|
1455 | # within some limits |
|
|
1456 | $w = 0.0001 if $w < 0.0001; |
|
|
1457 | $w = 5 if $w > 5; |
|
|
1458 | |
|
|
1459 | $w = AnyEvent->timer (after => $w, cb => $rcb); |
|
|
1460 | } else { |
|
|
1461 | # clean up... |
|
|
1462 | undef $w; |
|
|
1463 | undef $rcb; |
|
|
1464 | } |
|
|
1465 | }; |
|
|
1466 | |
|
|
1467 | $w = AnyEvent->timer (after => 0.05, cb => $rcb); |
|
|
1468 | |
|
|
1469 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1470 | } |
|
|
1471 | |
|
|
1472 | sub AnyEvent::Base::idle::DESTROY { |
|
|
1473 | undef $${$_[0]}; |
|
|
1474 | } |
|
|
1475 | |
|
|
1476 | package AnyEvent::CondVar; |
|
|
1477 | |
|
|
1478 | our @ISA = AnyEvent::CondVar::Base::; |
|
|
1479 | |
|
|
1480 | package AnyEvent::CondVar::Base; |
|
|
1481 | |
|
|
1482 | #use overload |
|
|
1483 | # '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
|
|
1484 | # fallback => 1; |
|
|
1485 | |
|
|
1486 | # save 300+ kilobytes by dirtily hardcoding overloading |
|
|
1487 | ${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching. |
|
|
1488 | *{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod." |
|
|
1489 | *{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{} |
|
|
1490 | ${'AnyEvent::CondVar::Base::()'} = 1; # fallback |
|
|
1491 | |
|
|
1492 | our $WAITING; |
|
|
1493 | |
|
|
1494 | sub _send { |
|
|
1495 | # nop |
|
|
1496 | } |
|
|
1497 | |
|
|
1498 | sub send { |
|
|
1499 | my $cv = shift; |
|
|
1500 | $cv->{_ae_sent} = [@_]; |
|
|
1501 | (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; |
|
|
1502 | $cv->_send; |
|
|
1503 | } |
|
|
1504 | |
|
|
1505 | sub croak { |
|
|
1506 | $_[0]{_ae_croak} = $_[1]; |
|
|
1507 | $_[0]->send; |
|
|
1508 | } |
|
|
1509 | |
|
|
1510 | sub ready { |
|
|
1511 | $_[0]{_ae_sent} |
|
|
1512 | } |
|
|
1513 | |
|
|
1514 | sub _wait { |
|
|
1515 | $WAITING |
|
|
1516 | and !$_[0]{_ae_sent} |
|
|
1517 | and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected"; |
|
|
1518 | |
|
|
1519 | local $WAITING = 1; |
|
|
1520 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
|
|
1521 | } |
|
|
1522 | |
|
|
1523 | sub recv { |
|
|
1524 | $_[0]->_wait; |
|
|
1525 | |
|
|
1526 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
|
|
1527 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
|
|
1528 | } |
|
|
1529 | |
|
|
1530 | sub cb { |
|
|
1531 | $_[0]{_ae_cb} = $_[1] if @_ > 1; |
|
|
1532 | $_[0]{_ae_cb} |
|
|
1533 | } |
|
|
1534 | |
|
|
1535 | sub begin { |
|
|
1536 | ++$_[0]{_ae_counter}; |
|
|
1537 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
|
|
1538 | } |
|
|
1539 | |
|
|
1540 | sub end { |
|
|
1541 | return if --$_[0]{_ae_counter}; |
|
|
1542 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
|
|
1543 | } |
|
|
1544 | |
|
|
1545 | # undocumented/compatibility with pre-3.4 |
|
|
1546 | *broadcast = \&send; |
|
|
1547 | *wait = \&_wait; |
|
|
1548 | |
|
|
1549 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1550 | |
|
|
1551 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1552 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1553 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1554 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1555 | development. |
|
|
1556 | |
|
|
1557 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1558 | executing a callback), this is not only highly event-loop specific, but |
|
|
1559 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1560 | program. |
|
|
1561 | |
|
|
1562 | The pure perl event loop simply re-throws the exception (usually |
|
|
1563 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
1564 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
1565 | so on. |
|
|
1566 | |
|
|
1567 | =head1 ENVIRONMENT VARIABLES |
|
|
1568 | |
|
|
1569 | The following environment variables are used by this module or its |
|
|
1570 | submodules. |
|
|
1571 | |
|
|
1572 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
1573 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
1574 | enabled. |
|
|
1575 | |
|
|
1576 | =over 4 |
|
|
1577 | |
|
|
1578 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1579 | |
|
|
1580 | By default, AnyEvent will be completely silent except in fatal |
|
|
1581 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1582 | talkative. |
|
|
1583 | |
|
|
1584 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1585 | conditions, such as not being able to load the event model specified by |
|
|
1586 | C<PERL_ANYEVENT_MODEL>. |
|
|
1587 | |
|
|
1588 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1589 | model it chooses. |
|
|
1590 | |
|
|
1591 | When set to C<8> or higher, then AnyEvent will report extra information on |
|
|
1592 | which optional modules it loads and how it implements certain features. |
|
|
1593 | |
|
|
1594 | =item C<PERL_ANYEVENT_STRICT> |
|
|
1595 | |
|
|
1596 | AnyEvent does not do much argument checking by default, as thorough |
|
|
1597 | argument checking is very costly. Setting this variable to a true value |
|
|
1598 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
1599 | check the arguments passed to most method calls. If it finds any problems, |
|
|
1600 | it will croak. |
|
|
1601 | |
|
|
1602 | In other words, enables "strict" mode. |
|
|
1603 | |
|
|
1604 | Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> |
|
|
1605 | >>, it is definitely recommended to keep it off in production. Keeping |
|
|
1606 | C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs |
|
|
1607 | can be very useful, however. |
|
|
1608 | |
|
|
1609 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1610 | |
|
|
1611 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1612 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1613 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1614 | and the resulting module name is loaded and if the load was successful, |
|
|
1615 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1616 | auto detection and -probing. |
|
|
1617 | |
|
|
1618 | This functionality might change in future versions. |
|
|
1619 | |
|
|
1620 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1621 | could start your program like this: |
|
|
1622 | |
|
|
1623 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1624 | |
|
|
1625 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1626 | |
|
|
1627 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1628 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1629 | of auto probing). |
|
|
1630 | |
|
|
1631 | Must be set to a comma-separated list of protocols or address families, |
|
|
1632 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1633 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1634 | list. |
|
|
1635 | |
|
|
1636 | This variable can effectively be used for denial-of-service attacks |
|
|
1637 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1638 | small, as the program has to handle conenction and other failures anyways. |
|
|
1639 | |
|
|
1640 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1641 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1642 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1643 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1644 | IPv6, but prefer IPv6 over IPv4. |
|
|
1645 | |
|
|
1646 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1647 | |
|
|
1648 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1649 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1650 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1651 | default. |
|
|
1652 | |
|
|
1653 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1654 | EDNS0 in its DNS requests. |
|
|
1655 | |
|
|
1656 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
1657 | |
|
|
1658 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
1659 | will create in parallel. |
|
|
1660 | |
|
|
1661 | =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> |
|
|
1662 | |
|
|
1663 | The default value for the C<max_outstanding> parameter for the default DNS |
|
|
1664 | resolver - this is the maximum number of parallel DNS requests that are |
|
|
1665 | sent to the DNS server. |
|
|
1666 | |
|
|
1667 | =item C<PERL_ANYEVENT_RESOLV_CONF> |
|
|
1668 | |
|
|
1669 | The file to use instead of F</etc/resolv.conf> (or OS-specific |
|
|
1670 | configuration) in the default resolver. When set to the empty string, no |
|
|
1671 | default config will be used. |
|
|
1672 | |
|
|
1673 | =item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. |
|
|
1674 | |
|
|
1675 | When neither C<ca_file> nor C<ca_path> was specified during |
|
|
1676 | L<AnyEvent::TLS> context creation, and either of these environment |
|
|
1677 | variables exist, they will be used to specify CA certificate locations |
|
|
1678 | instead of a system-dependent default. |
|
|
1679 | |
|
|
1680 | =item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT> |
|
|
1681 | |
|
|
1682 | When these are set to C<1>, then the respective modules are not |
|
|
1683 | loaded. Mostly good for testing AnyEvent itself. |
|
|
1684 | |
|
|
1685 | =back |
610 | |
1686 | |
611 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1687 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
612 | |
1688 | |
613 | This is an advanced topic that you do not normally need to use AnyEvent in |
1689 | This is an advanced topic that you do not normally need to use AnyEvent in |
614 | a module. This section is only of use to event loop authors who want to |
1690 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
649 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1725 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
650 | condition variables: code blocking while waiting for a condition will |
1726 | condition variables: code blocking while waiting for a condition will |
651 | C<die>. This still works with most modules/usages, and blocking calls must |
1727 | C<die>. This still works with most modules/usages, and blocking calls must |
652 | not be done in an interactive application, so it makes sense. |
1728 | not be done in an interactive application, so it makes sense. |
653 | |
1729 | |
654 | =head1 ENVIRONMENT VARIABLES |
|
|
655 | |
|
|
656 | The following environment variables are used by this module: |
|
|
657 | |
|
|
658 | =over 4 |
|
|
659 | |
|
|
660 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
661 | |
|
|
662 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
663 | model it chooses. |
|
|
664 | |
|
|
665 | =item C<PERL_ANYEVENT_MODEL> |
|
|
666 | |
|
|
667 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
668 | autodetection and -probing kicks in. It must be a string consisting |
|
|
669 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
670 | and the resulting module name is loaded and if the load was successful, |
|
|
671 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
672 | autodetection and -probing. |
|
|
673 | |
|
|
674 | This functionality might change in future versions. |
|
|
675 | |
|
|
676 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
677 | could start your program like this: |
|
|
678 | |
|
|
679 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
680 | |
|
|
681 | =back |
|
|
682 | |
|
|
683 | =head1 EXAMPLE PROGRAM |
1730 | =head1 EXAMPLE PROGRAM |
684 | |
1731 | |
685 | The following program uses an IO watcher to read data from STDIN, a timer |
1732 | The following program uses an I/O watcher to read data from STDIN, a timer |
686 | to display a message once per second, and a condition variable to quit the |
1733 | to display a message once per second, and a condition variable to quit the |
687 | program when the user enters quit: |
1734 | program when the user enters quit: |
688 | |
1735 | |
689 | use AnyEvent; |
1736 | use AnyEvent; |
690 | |
1737 | |
… | |
… | |
695 | poll => 'r', |
1742 | poll => 'r', |
696 | cb => sub { |
1743 | cb => sub { |
697 | warn "io event <$_[0]>\n"; # will always output <r> |
1744 | warn "io event <$_[0]>\n"; # will always output <r> |
698 | chomp (my $input = <STDIN>); # read a line |
1745 | chomp (my $input = <STDIN>); # read a line |
699 | warn "read: $input\n"; # output what has been read |
1746 | warn "read: $input\n"; # output what has been read |
700 | $cv->broadcast if $input =~ /^q/i; # quit program if /^q/i |
1747 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
701 | }, |
1748 | }, |
702 | ); |
1749 | ); |
703 | |
1750 | |
704 | my $time_watcher; # can only be used once |
1751 | my $time_watcher; # can only be used once |
705 | |
1752 | |
… | |
… | |
710 | }); |
1757 | }); |
711 | } |
1758 | } |
712 | |
1759 | |
713 | new_timer; # create first timer |
1760 | new_timer; # create first timer |
714 | |
1761 | |
715 | $cv->wait; # wait until user enters /^q/i |
1762 | $cv->recv; # wait until user enters /^q/i |
716 | |
1763 | |
717 | =head1 REAL-WORLD EXAMPLE |
1764 | =head1 REAL-WORLD EXAMPLE |
718 | |
1765 | |
719 | Consider the L<Net::FCP> module. It features (among others) the following |
1766 | Consider the L<Net::FCP> module. It features (among others) the following |
720 | API calls, which are to freenet what HTTP GET requests are to http: |
1767 | API calls, which are to freenet what HTTP GET requests are to http: |
… | |
… | |
770 | syswrite $txn->{fh}, $txn->{request} |
1817 | syswrite $txn->{fh}, $txn->{request} |
771 | or die "connection or write error"; |
1818 | or die "connection or write error"; |
772 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
1819 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r }); |
773 | |
1820 | |
774 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
1821 | Again, C<fh_ready_r> waits till all data has arrived, and then stores the |
775 | result and signals any possible waiters that the request ahs finished: |
1822 | result and signals any possible waiters that the request has finished: |
776 | |
1823 | |
777 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
1824 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
778 | |
1825 | |
779 | if (end-of-file or data complete) { |
1826 | if (end-of-file or data complete) { |
780 | $txn->{result} = $txn->{buf}; |
1827 | $txn->{result} = $txn->{buf}; |
781 | $txn->{finished}->broadcast; |
1828 | $txn->{finished}->send; |
782 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
1829 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
783 | } |
1830 | } |
784 | |
1831 | |
785 | The C<result> method, finally, just waits for the finished signal (if the |
1832 | The C<result> method, finally, just waits for the finished signal (if the |
786 | request was already finished, it doesn't wait, of course, and returns the |
1833 | request was already finished, it doesn't wait, of course, and returns the |
787 | data: |
1834 | data: |
788 | |
1835 | |
789 | $txn->{finished}->wait; |
1836 | $txn->{finished}->recv; |
790 | return $txn->{result}; |
1837 | return $txn->{result}; |
791 | |
1838 | |
792 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1839 | The actual code goes further and collects all errors (C<die>s, exceptions) |
793 | that occured during request processing. The C<result> method detects |
1840 | that occurred during request processing. The C<result> method detects |
794 | whether an exception as thrown (it is stored inside the $txn object) |
1841 | whether an exception as thrown (it is stored inside the $txn object) |
795 | and just throws the exception, which means connection errors and other |
1842 | and just throws the exception, which means connection errors and other |
796 | problems get reported tot he code that tries to use the result, not in a |
1843 | problems get reported tot he code that tries to use the result, not in a |
797 | random callback. |
1844 | random callback. |
798 | |
1845 | |
… | |
… | |
829 | |
1876 | |
830 | my $quit = AnyEvent->condvar; |
1877 | my $quit = AnyEvent->condvar; |
831 | |
1878 | |
832 | $fcp->txn_client_get ($url)->cb (sub { |
1879 | $fcp->txn_client_get ($url)->cb (sub { |
833 | ... |
1880 | ... |
834 | $quit->broadcast; |
1881 | $quit->send; |
835 | }); |
1882 | }); |
836 | |
1883 | |
837 | $quit->wait; |
1884 | $quit->recv; |
|
|
1885 | |
|
|
1886 | |
|
|
1887 | =head1 BENCHMARKS |
|
|
1888 | |
|
|
1889 | To give you an idea of the performance and overheads that AnyEvent adds |
|
|
1890 | over the event loops themselves and to give you an impression of the speed |
|
|
1891 | of various event loops I prepared some benchmarks. |
|
|
1892 | |
|
|
1893 | =head2 BENCHMARKING ANYEVENT OVERHEAD |
|
|
1894 | |
|
|
1895 | Here is a benchmark of various supported event models used natively and |
|
|
1896 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
|
|
1897 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
|
|
1898 | which it is), lets them fire exactly once and destroys them again. |
|
|
1899 | |
|
|
1900 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
|
|
1901 | distribution. |
|
|
1902 | |
|
|
1903 | =head3 Explanation of the columns |
|
|
1904 | |
|
|
1905 | I<watcher> is the number of event watchers created/destroyed. Since |
|
|
1906 | different event models feature vastly different performances, each event |
|
|
1907 | loop was given a number of watchers so that overall runtime is acceptable |
|
|
1908 | and similar between tested event loop (and keep them from crashing): Glib |
|
|
1909 | would probably take thousands of years if asked to process the same number |
|
|
1910 | of watchers as EV in this benchmark. |
|
|
1911 | |
|
|
1912 | I<bytes> is the number of bytes (as measured by the resident set size, |
|
|
1913 | RSS) consumed by each watcher. This method of measuring captures both C |
|
|
1914 | and Perl-based overheads. |
|
|
1915 | |
|
|
1916 | I<create> is the time, in microseconds (millionths of seconds), that it |
|
|
1917 | takes to create a single watcher. The callback is a closure shared between |
|
|
1918 | all watchers, to avoid adding memory overhead. That means closure creation |
|
|
1919 | and memory usage is not included in the figures. |
|
|
1920 | |
|
|
1921 | I<invoke> is the time, in microseconds, used to invoke a simple |
|
|
1922 | callback. The callback simply counts down a Perl variable and after it was |
|
|
1923 | invoked "watcher" times, it would C<< ->send >> a condvar once to |
|
|
1924 | signal the end of this phase. |
|
|
1925 | |
|
|
1926 | I<destroy> is the time, in microseconds, that it takes to destroy a single |
|
|
1927 | watcher. |
|
|
1928 | |
|
|
1929 | =head3 Results |
|
|
1930 | |
|
|
1931 | name watchers bytes create invoke destroy comment |
|
|
1932 | EV/EV 400000 224 0.47 0.35 0.27 EV native interface |
|
|
1933 | EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers |
|
|
1934 | CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal |
|
|
1935 | Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation |
|
|
1936 | Event/Event 16000 517 32.20 31.80 0.81 Event native interface |
|
|
1937 | Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers |
|
|
1938 | IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll |
|
|
1939 | IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll |
|
|
1940 | Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour |
|
|
1941 | Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers |
|
|
1942 | POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event |
|
|
1943 | POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select |
|
|
1944 | |
|
|
1945 | =head3 Discussion |
|
|
1946 | |
|
|
1947 | The benchmark does I<not> measure scalability of the event loop very |
|
|
1948 | well. For example, a select-based event loop (such as the pure perl one) |
|
|
1949 | can never compete with an event loop that uses epoll when the number of |
|
|
1950 | file descriptors grows high. In this benchmark, all events become ready at |
|
|
1951 | the same time, so select/poll-based implementations get an unnatural speed |
|
|
1952 | boost. |
|
|
1953 | |
|
|
1954 | Also, note that the number of watchers usually has a nonlinear effect on |
|
|
1955 | overall speed, that is, creating twice as many watchers doesn't take twice |
|
|
1956 | the time - usually it takes longer. This puts event loops tested with a |
|
|
1957 | higher number of watchers at a disadvantage. |
|
|
1958 | |
|
|
1959 | To put the range of results into perspective, consider that on the |
|
|
1960 | benchmark machine, handling an event takes roughly 1600 CPU cycles with |
|
|
1961 | EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU |
|
|
1962 | cycles with POE. |
|
|
1963 | |
|
|
1964 | C<EV> is the sole leader regarding speed and memory use, which are both |
|
|
1965 | maximal/minimal, respectively. Even when going through AnyEvent, it uses |
|
|
1966 | far less memory than any other event loop and is still faster than Event |
|
|
1967 | natively. |
|
|
1968 | |
|
|
1969 | The pure perl implementation is hit in a few sweet spots (both the |
|
|
1970 | constant timeout and the use of a single fd hit optimisations in the perl |
|
|
1971 | interpreter and the backend itself). Nevertheless this shows that it |
|
|
1972 | adds very little overhead in itself. Like any select-based backend its |
|
|
1973 | performance becomes really bad with lots of file descriptors (and few of |
|
|
1974 | them active), of course, but this was not subject of this benchmark. |
|
|
1975 | |
|
|
1976 | The C<Event> module has a relatively high setup and callback invocation |
|
|
1977 | cost, but overall scores in on the third place. |
|
|
1978 | |
|
|
1979 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
1980 | when using its pure perl backend. |
|
|
1981 | |
|
|
1982 | C<Glib>'s memory usage is quite a bit higher, but it features a |
|
|
1983 | faster callback invocation and overall ends up in the same class as |
|
|
1984 | C<Event>. However, Glib scales extremely badly, doubling the number of |
|
|
1985 | watchers increases the processing time by more than a factor of four, |
|
|
1986 | making it completely unusable when using larger numbers of watchers |
|
|
1987 | (note that only a single file descriptor was used in the benchmark, so |
|
|
1988 | inefficiencies of C<poll> do not account for this). |
|
|
1989 | |
|
|
1990 | The C<Tk> adaptor works relatively well. The fact that it crashes with |
|
|
1991 | more than 2000 watchers is a big setback, however, as correctness takes |
|
|
1992 | precedence over speed. Nevertheless, its performance is surprising, as the |
|
|
1993 | file descriptor is dup()ed for each watcher. This shows that the dup() |
|
|
1994 | employed by some adaptors is not a big performance issue (it does incur a |
|
|
1995 | hidden memory cost inside the kernel which is not reflected in the figures |
|
|
1996 | above). |
|
|
1997 | |
|
|
1998 | C<POE>, regardless of underlying event loop (whether using its pure perl |
|
|
1999 | select-based backend or the Event module, the POE-EV backend couldn't |
|
|
2000 | be tested because it wasn't working) shows abysmal performance and |
|
|
2001 | memory usage with AnyEvent: Watchers use almost 30 times as much memory |
|
|
2002 | as EV watchers, and 10 times as much memory as Event (the high memory |
|
|
2003 | requirements are caused by requiring a session for each watcher). Watcher |
|
|
2004 | invocation speed is almost 900 times slower than with AnyEvent's pure perl |
|
|
2005 | implementation. |
|
|
2006 | |
|
|
2007 | The design of the POE adaptor class in AnyEvent can not really account |
|
|
2008 | for the performance issues, though, as session creation overhead is |
|
|
2009 | small compared to execution of the state machine, which is coded pretty |
|
|
2010 | optimally within L<AnyEvent::Impl::POE> (and while everybody agrees that |
|
|
2011 | using multiple sessions is not a good approach, especially regarding |
|
|
2012 | memory usage, even the author of POE could not come up with a faster |
|
|
2013 | design). |
|
|
2014 | |
|
|
2015 | =head3 Summary |
|
|
2016 | |
|
|
2017 | =over 4 |
|
|
2018 | |
|
|
2019 | =item * Using EV through AnyEvent is faster than any other event loop |
|
|
2020 | (even when used without AnyEvent), but most event loops have acceptable |
|
|
2021 | performance with or without AnyEvent. |
|
|
2022 | |
|
|
2023 | =item * The overhead AnyEvent adds is usually much smaller than the overhead of |
|
|
2024 | the actual event loop, only with extremely fast event loops such as EV |
|
|
2025 | adds AnyEvent significant overhead. |
|
|
2026 | |
|
|
2027 | =item * You should avoid POE like the plague if you want performance or |
|
|
2028 | reasonable memory usage. |
|
|
2029 | |
|
|
2030 | =back |
|
|
2031 | |
|
|
2032 | =head2 BENCHMARKING THE LARGE SERVER CASE |
|
|
2033 | |
|
|
2034 | This benchmark actually benchmarks the event loop itself. It works by |
|
|
2035 | creating a number of "servers": each server consists of a socket pair, a |
|
|
2036 | timeout watcher that gets reset on activity (but never fires), and an I/O |
|
|
2037 | watcher waiting for input on one side of the socket. Each time the socket |
|
|
2038 | watcher reads a byte it will write that byte to a random other "server". |
|
|
2039 | |
|
|
2040 | The effect is that there will be a lot of I/O watchers, only part of which |
|
|
2041 | are active at any one point (so there is a constant number of active |
|
|
2042 | fds for each loop iteration, but which fds these are is random). The |
|
|
2043 | timeout is reset each time something is read because that reflects how |
|
|
2044 | most timeouts work (and puts extra pressure on the event loops). |
|
|
2045 | |
|
|
2046 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
|
|
2047 | (1%) are active. This mirrors the activity of large servers with many |
|
|
2048 | connections, most of which are idle at any one point in time. |
|
|
2049 | |
|
|
2050 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
|
|
2051 | distribution. |
|
|
2052 | |
|
|
2053 | =head3 Explanation of the columns |
|
|
2054 | |
|
|
2055 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
|
|
2056 | each server has a read and write socket end). |
|
|
2057 | |
|
|
2058 | I<create> is the time it takes to create a socket pair (which is |
|
|
2059 | nontrivial) and two watchers: an I/O watcher and a timeout watcher. |
|
|
2060 | |
|
|
2061 | I<request>, the most important value, is the time it takes to handle a |
|
|
2062 | single "request", that is, reading the token from the pipe and forwarding |
|
|
2063 | it to another server. This includes deleting the old timeout and creating |
|
|
2064 | a new one that moves the timeout into the future. |
|
|
2065 | |
|
|
2066 | =head3 Results |
|
|
2067 | |
|
|
2068 | name sockets create request |
|
|
2069 | EV 20000 69.01 11.16 |
|
|
2070 | Perl 20000 73.32 35.87 |
|
|
2071 | IOAsync 20000 157.00 98.14 epoll |
|
|
2072 | IOAsync 20000 159.31 616.06 poll |
|
|
2073 | Event 20000 212.62 257.32 |
|
|
2074 | Glib 20000 651.16 1896.30 |
|
|
2075 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
|
|
2076 | |
|
|
2077 | =head3 Discussion |
|
|
2078 | |
|
|
2079 | This benchmark I<does> measure scalability and overall performance of the |
|
|
2080 | particular event loop. |
|
|
2081 | |
|
|
2082 | EV is again fastest. Since it is using epoll on my system, the setup time |
|
|
2083 | is relatively high, though. |
|
|
2084 | |
|
|
2085 | Perl surprisingly comes second. It is much faster than the C-based event |
|
|
2086 | loops Event and Glib. |
|
|
2087 | |
|
|
2088 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
2089 | good compared to Glib when using its pure perl backend. |
|
|
2090 | |
|
|
2091 | Event suffers from high setup time as well (look at its code and you will |
|
|
2092 | understand why). Callback invocation also has a high overhead compared to |
|
|
2093 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
|
|
2094 | uses select or poll in basically all documented configurations. |
|
|
2095 | |
|
|
2096 | Glib is hit hard by its quadratic behaviour w.r.t. many watchers. It |
|
|
2097 | clearly fails to perform with many filehandles or in busy servers. |
|
|
2098 | |
|
|
2099 | POE is still completely out of the picture, taking over 1000 times as long |
|
|
2100 | as EV, and over 100 times as long as the Perl implementation, even though |
|
|
2101 | it uses a C-based event loop in this case. |
|
|
2102 | |
|
|
2103 | =head3 Summary |
|
|
2104 | |
|
|
2105 | =over 4 |
|
|
2106 | |
|
|
2107 | =item * The pure perl implementation performs extremely well. |
|
|
2108 | |
|
|
2109 | =item * Avoid Glib or POE in large projects where performance matters. |
|
|
2110 | |
|
|
2111 | =back |
|
|
2112 | |
|
|
2113 | =head2 BENCHMARKING SMALL SERVERS |
|
|
2114 | |
|
|
2115 | While event loops should scale (and select-based ones do not...) even to |
|
|
2116 | large servers, most programs we (or I :) actually write have only a few |
|
|
2117 | I/O watchers. |
|
|
2118 | |
|
|
2119 | In this benchmark, I use the same benchmark program as in the large server |
|
|
2120 | case, but it uses only eight "servers", of which three are active at any |
|
|
2121 | one time. This should reflect performance for a small server relatively |
|
|
2122 | well. |
|
|
2123 | |
|
|
2124 | The columns are identical to the previous table. |
|
|
2125 | |
|
|
2126 | =head3 Results |
|
|
2127 | |
|
|
2128 | name sockets create request |
|
|
2129 | EV 16 20.00 6.54 |
|
|
2130 | Perl 16 25.75 12.62 |
|
|
2131 | Event 16 81.27 35.86 |
|
|
2132 | Glib 16 32.63 15.48 |
|
|
2133 | POE 16 261.87 276.28 uses POE::Loop::Event |
|
|
2134 | |
|
|
2135 | =head3 Discussion |
|
|
2136 | |
|
|
2137 | The benchmark tries to test the performance of a typical small |
|
|
2138 | server. While knowing how various event loops perform is interesting, keep |
|
|
2139 | in mind that their overhead in this case is usually not as important, due |
|
|
2140 | to the small absolute number of watchers (that is, you need efficiency and |
|
|
2141 | speed most when you have lots of watchers, not when you only have a few of |
|
|
2142 | them). |
|
|
2143 | |
|
|
2144 | EV is again fastest. |
|
|
2145 | |
|
|
2146 | Perl again comes second. It is noticeably faster than the C-based event |
|
|
2147 | loops Event and Glib, although the difference is too small to really |
|
|
2148 | matter. |
|
|
2149 | |
|
|
2150 | POE also performs much better in this case, but is is still far behind the |
|
|
2151 | others. |
|
|
2152 | |
|
|
2153 | =head3 Summary |
|
|
2154 | |
|
|
2155 | =over 4 |
|
|
2156 | |
|
|
2157 | =item * C-based event loops perform very well with small number of |
|
|
2158 | watchers, as the management overhead dominates. |
|
|
2159 | |
|
|
2160 | =back |
|
|
2161 | |
|
|
2162 | =head2 THE IO::Lambda BENCHMARK |
|
|
2163 | |
|
|
2164 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
2165 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
2166 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
2167 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
2168 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
2169 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
2170 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
2171 | |
|
|
2172 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
2173 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
2174 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
2175 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
2176 | benchmark nevertheless. |
|
|
2177 | |
|
|
2178 | name runtime |
|
|
2179 | Lambda/select 0.330 sec |
|
|
2180 | + optimized 0.122 sec |
|
|
2181 | Lambda/AnyEvent 0.327 sec |
|
|
2182 | + optimized 0.138 sec |
|
|
2183 | Raw sockets/select 0.077 sec |
|
|
2184 | POE/select, components 0.662 sec |
|
|
2185 | POE/select, raw sockets 0.226 sec |
|
|
2186 | POE/select, optimized 0.404 sec |
|
|
2187 | |
|
|
2188 | AnyEvent/select/nb 0.085 sec |
|
|
2189 | AnyEvent/EV/nb 0.068 sec |
|
|
2190 | +state machine 0.134 sec |
|
|
2191 | |
|
|
2192 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
2193 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
2194 | defeating the purpose of an event-based solution. All of the newly |
|
|
2195 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
2196 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
2197 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
2198 | generally require a lot more bookkeeping and event handling than blocking |
|
|
2199 | connects (which involve a single syscall only). |
|
|
2200 | |
|
|
2201 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
2202 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
2203 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
2204 | non-blocking, further placing it at a disadvantage. |
|
|
2205 | |
|
|
2206 | As you can see, the AnyEvent + EV combination even beats the |
|
|
2207 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
2208 | backend easily beats IO::Lambda and POE. |
|
|
2209 | |
|
|
2210 | And even the 100% non-blocking version written using the high-level (and |
|
|
2211 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a |
|
|
2212 | large margin, even though it does all of DNS, tcp-connect and socket I/O |
|
|
2213 | in a non-blocking way. |
|
|
2214 | |
|
|
2215 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2216 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2217 | part of the IO::lambda distribution and were used without any changes. |
|
|
2218 | |
|
|
2219 | |
|
|
2220 | =head1 SIGNALS |
|
|
2221 | |
|
|
2222 | AnyEvent currently installs handlers for these signals: |
|
|
2223 | |
|
|
2224 | =over 4 |
|
|
2225 | |
|
|
2226 | =item SIGCHLD |
|
|
2227 | |
|
|
2228 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2229 | emulation for event loops that do not support them natively. Also, some |
|
|
2230 | event loops install a similar handler. |
|
|
2231 | |
|
|
2232 | Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then |
|
|
2233 | AnyEvent will reset it to default, to avoid losing child exit statuses. |
|
|
2234 | |
|
|
2235 | =item SIGPIPE |
|
|
2236 | |
|
|
2237 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2238 | when AnyEvent gets loaded. |
|
|
2239 | |
|
|
2240 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2241 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2242 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2243 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2244 | some random socket. |
|
|
2245 | |
|
|
2246 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2247 | that this way, the handler will be restored to defaults on exec. |
|
|
2248 | |
|
|
2249 | Feel free to install your own handler, or reset it to defaults. |
|
|
2250 | |
|
|
2251 | =back |
|
|
2252 | |
|
|
2253 | =cut |
|
|
2254 | |
|
|
2255 | undef $SIG{CHLD} |
|
|
2256 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2257 | |
|
|
2258 | $SIG{PIPE} = sub { } |
|
|
2259 | unless defined $SIG{PIPE}; |
|
|
2260 | |
|
|
2261 | =head1 RECOMMENDED/OPTIONAL MODULES |
|
|
2262 | |
|
|
2263 | One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and |
|
|
2264 | it's built-in modules) are required to use it. |
|
|
2265 | |
|
|
2266 | That does not mean that AnyEvent won't take advantage of some additional |
|
|
2267 | modules if they are installed. |
|
|
2268 | |
|
|
2269 | This section epxlains which additional modules will be used, and how they |
|
|
2270 | affect AnyEvent's operetion. |
|
|
2271 | |
|
|
2272 | =over 4 |
|
|
2273 | |
|
|
2274 | =item L<Async::Interrupt> |
|
|
2275 | |
|
|
2276 | This slightly arcane module is used to implement fast signal handling: To |
|
|
2277 | my knowledge, there is no way to do completely race-free and quick |
|
|
2278 | signal handling in pure perl. To ensure that signals still get |
|
|
2279 | delivered, AnyEvent will start an interval timer to wake up perl (and |
|
|
2280 | catch the signals) with some delay (default is 10 seconds, look for |
|
|
2281 | C<$AnyEvent::MAX_SIGNAL_LATENCY>). |
|
|
2282 | |
|
|
2283 | If this module is available, then it will be used to implement signal |
|
|
2284 | catching, which means that signals will not be delayed, and the event loop |
|
|
2285 | will not be interrupted regularly, which is more efficient (And good for |
|
|
2286 | battery life on laptops). |
|
|
2287 | |
|
|
2288 | This affects not just the pure-perl event loop, but also other event loops |
|
|
2289 | that have no signal handling on their own (e.g. Glib, Tk, Qt). |
|
|
2290 | |
|
|
2291 | Some event loops (POE, Event, Event::Lib) offer signal watchers natively, |
|
|
2292 | and either employ their own workarounds (POE) or use AnyEvent's workaround |
|
|
2293 | (using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt> |
|
|
2294 | does nothing for those backends. |
|
|
2295 | |
|
|
2296 | =item L<EV> |
|
|
2297 | |
|
|
2298 | This module isn't really "optional", as it is simply one of the backend |
|
|
2299 | event loops that AnyEvent can use. However, it is simply the best event |
|
|
2300 | loop available in terms of features, speed and stability: It supports |
|
|
2301 | the AnyEvent API optimally, implements all the watcher types in XS, does |
|
|
2302 | automatic timer adjustments even when no monotonic clock is available, |
|
|
2303 | can take avdantage of advanced kernel interfaces such as C<epoll> and |
|
|
2304 | C<kqueue>, and is the fastest backend I<by far>. You can even embed |
|
|
2305 | L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). |
|
|
2306 | |
|
|
2307 | =item L<Guard> |
|
|
2308 | |
|
|
2309 | The guard module, when used, will be used to implement |
|
|
2310 | C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a |
|
|
2311 | lot less memory), but otherwise doesn't affect guard operation much. It is |
|
|
2312 | purely used for performance. |
|
|
2313 | |
|
|
2314 | =item L<JSON> and L<JSON::XS> |
|
|
2315 | |
|
|
2316 | This module is required when you want to read or write JSON data via |
|
|
2317 | L<AnyEvent::Handle>. It is also written in pure-perl, but can take |
|
|
2318 | advantage of the ulta-high-speed L<JSON::XS> module when it is installed. |
|
|
2319 | |
|
|
2320 | In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is |
|
|
2321 | installed. |
|
|
2322 | |
|
|
2323 | =item L<Net::SSLeay> |
|
|
2324 | |
|
|
2325 | Implementing TLS/SSL in Perl is certainly interesting, but not very |
|
|
2326 | worthwhile: If this module is installed, then L<AnyEvent::Handle> (with |
|
|
2327 | the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. |
|
|
2328 | |
|
|
2329 | =item L<Time::HiRes> |
|
|
2330 | |
|
|
2331 | This module is part of perl since release 5.008. It will be used when the |
|
|
2332 | chosen event library does not come with a timing source on it's own. The |
|
|
2333 | pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to |
|
|
2334 | try to use a monotonic clock for timing stability. |
|
|
2335 | |
|
|
2336 | =back |
|
|
2337 | |
838 | |
2338 | |
839 | =head1 FORK |
2339 | =head1 FORK |
840 | |
2340 | |
841 | Most event libraries are not fork-safe. The ones who are usually are |
2341 | Most event libraries are not fork-safe. The ones who are usually are |
842 | because they are so inefficient. Only L<EV> is fully fork-aware. |
2342 | because they rely on inefficient but fork-safe C<select> or C<poll> |
|
|
2343 | calls. Only L<EV> is fully fork-aware. |
843 | |
2344 | |
844 | If you have to fork, you must either do so I<before> creating your first |
2345 | If you have to fork, you must either do so I<before> creating your first |
845 | watcher OR you must not use AnyEvent at all in the child. |
2346 | watcher OR you must not use AnyEvent at all in the child OR you must do |
|
|
2347 | something completely out of the scope of AnyEvent. |
|
|
2348 | |
846 | |
2349 | |
847 | =head1 SECURITY CONSIDERATIONS |
2350 | =head1 SECURITY CONSIDERATIONS |
848 | |
2351 | |
849 | AnyEvent can be forced to load any event model via |
2352 | AnyEvent can be forced to load any event model via |
850 | $ENV{PERL_ANYEVENT_MODEL}. While this cannot (to my knowledge) be used to |
2353 | $ENV{PERL_ANYEVENT_MODEL}. While this cannot (to my knowledge) be used to |
… | |
… | |
854 | specified in the variable. |
2357 | specified in the variable. |
855 | |
2358 | |
856 | You can make AnyEvent completely ignore this variable by deleting it |
2359 | You can make AnyEvent completely ignore this variable by deleting it |
857 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
2360 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
858 | |
2361 | |
859 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
2362 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
860 | |
2363 | |
861 | use AnyEvent; |
2364 | use AnyEvent; |
|
|
2365 | |
|
|
2366 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
|
|
2367 | be used to probe what backend is used and gain other information (which is |
|
|
2368 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
2369 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2370 | |
|
|
2371 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2372 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2373 | enabled. |
|
|
2374 | |
|
|
2375 | |
|
|
2376 | =head1 BUGS |
|
|
2377 | |
|
|
2378 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
|
|
2379 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
|
|
2380 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
|
|
2381 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
|
|
2382 | pronounced). |
|
|
2383 | |
862 | |
2384 | |
863 | =head1 SEE ALSO |
2385 | =head1 SEE ALSO |
864 | |
2386 | |
865 | Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>, |
2387 | Utility functions: L<AnyEvent::Util>. |
866 | L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>, |
|
|
867 | L<Event::Lib>, L<Qt>. |
|
|
868 | |
2388 | |
869 | Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>, |
2389 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
870 | L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>, |
2390 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
871 | L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>, |
|
|
872 | L<AnyEvent::Impl::Qt>. |
|
|
873 | |
2391 | |
|
|
2392 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
|
|
2393 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
|
|
2394 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
|
|
2395 | L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>. |
|
|
2396 | |
|
|
2397 | Non-blocking file handles, sockets, TCP clients and |
|
|
2398 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. |
|
|
2399 | |
|
|
2400 | Asynchronous DNS: L<AnyEvent::DNS>. |
|
|
2401 | |
|
|
2402 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, |
|
|
2403 | L<Coro::Event>, |
|
|
2404 | |
874 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>. |
2405 | Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, |
|
|
2406 | L<AnyEvent::HTTP>. |
|
|
2407 | |
875 | |
2408 | |
876 | =head1 AUTHOR |
2409 | =head1 AUTHOR |
877 | |
2410 | |
878 | Marc Lehmann <schmorp@schmorp.de> |
2411 | Marc Lehmann <schmorp@schmorp.de> |
879 | http://home.schmorp.de/ |
2412 | http://home.schmorp.de/ |
880 | |
2413 | |
881 | =cut |
2414 | =cut |
882 | |
2415 | |
883 | 1 |
2416 | 1 |
884 | |
2417 | |