1 | =head1 => NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | AnyEvent - provide framework for multiple event loops |
3 | AnyEvent - the DBI of event loop programming |
4 | |
4 | |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops |
5 | EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt, |
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6 | FLTK and POE are various supported event loops/environments. |
6 | |
7 | |
7 | =head1 SYNOPSIS |
8 | =head1 SYNOPSIS |
8 | |
9 | |
9 | use AnyEvent; |
10 | use AnyEvent; |
10 | |
11 | |
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12 | # if you prefer function calls, look at the AE manpage for |
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13 | # an alternative API. |
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14 | |
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15 | # file handle or descriptor readable |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { |
16 | my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); |
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17 | |
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18 | # one-shot or repeating timers |
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19 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
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20 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...); |
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21 | |
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22 | print AnyEvent->now; # prints current event loop time |
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23 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
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24 | |
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25 | # POSIX signal |
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26 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
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27 | |
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28 | # child process exit |
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29 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
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30 | my ($pid, $status) = @_; |
12 | ... |
31 | ... |
13 | }); |
32 | }); |
14 | |
33 | |
15 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
34 | # called when event loop idle (if applicable) |
16 | ... |
35 | my $w = AnyEvent->idle (cb => sub { ... }); |
17 | }); |
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18 | |
36 | |
19 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
37 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
20 | $w->send; # wake up current and all future recv's |
38 | $w->send; # wake up current and all future recv's |
21 | $w->recv; # enters "main loop" till $condvar gets ->send |
39 | $w->recv; # enters "main loop" till $condvar gets ->send |
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40 | # use a condvar in callback mode: |
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41 | $w->cb (sub { $_[0]->recv }); |
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42 | |
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43 | =head1 INTRODUCTION/TUTORIAL |
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44 | |
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45 | This manpage is mainly a reference manual. If you are interested |
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46 | in a tutorial or some gentle introduction, have a look at the |
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47 | L<AnyEvent::Intro> manpage. |
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48 | |
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49 | =head1 SUPPORT |
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50 | |
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51 | An FAQ document is available as L<AnyEvent::FAQ>. |
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52 | |
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53 | There also is a mailinglist for discussing all things AnyEvent, and an IRC |
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54 | channel, too. |
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55 | |
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56 | See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software |
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57 | Repository>, at L<http://anyevent.schmorp.de>, for more info. |
22 | |
58 | |
23 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
59 | =head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) |
24 | |
60 | |
25 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
61 | Glib, POE, IO::Async, Event... CPAN offers event models by the dozen |
26 | nowadays. So what is different about AnyEvent? |
62 | nowadays. So what is different about AnyEvent? |
27 | |
63 | |
28 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
64 | Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of |
29 | policy> and AnyEvent is I<small and efficient>. |
65 | policy> and AnyEvent is I<small and efficient>. |
30 | |
66 | |
31 | First and foremost, I<AnyEvent is not an event model> itself, it only |
67 | 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 |
68 | 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, |
69 | 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, |
70 | 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 |
71 | only one event loop can be active at the same time in a process. AnyEvent |
36 | helps hiding the differences between those event loops. |
72 | cannot change this, but it can hide the differences between those event |
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73 | loops. |
37 | |
74 | |
38 | The goal of AnyEvent is to offer module authors the ability to do event |
75 | 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 |
76 | programming (waiting for I/O or timer events) without subscribing to a |
40 | religion, a way of living, and most importantly: without forcing your |
77 | 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 |
78 | module users into the same thing by forcing them to use the same event |
42 | model you use. |
79 | model you use. |
43 | |
80 | |
44 | For modules like POE or IO::Async (which is a total misnomer as it is |
81 | 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 |
82 | 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 |
83 | like joining a cult: After you join, you are dependent on them and you |
47 | cannot use anything else, as it is simply incompatible to everything that |
84 | 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 |
85 | 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. |
86 | module are I<also> forced to use the same event loop you use. |
50 | |
87 | |
51 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
88 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
52 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
89 | 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 |
90 | with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module |
54 | your module uses one of those, every user of your module has to use it, |
91 | uses one of those, every user of your module has to use it, too. But if |
55 | too. But if your module uses AnyEvent, it works transparently with all |
92 | your module uses AnyEvent, it works transparently with all event models it |
56 | event models it supports (including stuff like POE and IO::Async, as long |
93 | supports (including stuff like IO::Async, as long as those use one of the |
57 | as those use one of the supported event loops. It is trivial to add new |
94 | supported event loops. It is easy to add new event loops to AnyEvent, too, |
58 | event loops to AnyEvent, too, so it is future-proof). |
95 | so it is future-proof). |
59 | |
96 | |
60 | In addition to being free of having to use I<the one and only true event |
97 | 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 |
98 | model>, AnyEvent also is free of bloat and policy: with POE or similar |
62 | modules, you get an enormous amount of code and strict rules you have to |
99 | 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 |
100 | follow. AnyEvent, on the other hand, is lean and to the point, by only |
64 | offering the functionality that is necessary, in as thin as a wrapper as |
101 | offering the functionality that is necessary, in as thin as a wrapper as |
65 | technically possible. |
102 | technically possible. |
66 | |
103 | |
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104 | Of course, AnyEvent comes with a big (and fully optional!) toolbox |
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105 | of useful functionality, such as an asynchronous DNS resolver, 100% |
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106 | non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms |
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107 | such as Windows) and lots of real-world knowledge and workarounds for |
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108 | platform bugs and differences. |
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109 | |
67 | Of course, if you want lots of policy (this can arguably be somewhat |
110 | 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 |
111 | useful) and you want to force your users to use the one and only event |
69 | model, you should I<not> use this module. |
112 | model, you should I<not> use this module. |
70 | |
113 | |
71 | =head1 DESCRIPTION |
114 | =head1 DESCRIPTION |
72 | |
115 | |
73 | L<AnyEvent> provides an identical interface to multiple event loops. This |
116 | L<AnyEvent> provides a uniform interface to various event loops. This |
74 | allows module authors to utilise an event loop without forcing module |
117 | allows module authors to use event loop functionality without forcing |
75 | users to use the same event loop (as only a single event loop can coexist |
118 | module users to use a specific event loop implementation (since more |
76 | peacefully at any one time). |
119 | than one event loop cannot coexist peacefully). |
77 | |
120 | |
78 | The interface itself is vaguely similar, but not identical to the L<Event> |
121 | The interface itself is vaguely similar, but not identical to the L<Event> |
79 | module. |
122 | module. |
80 | |
123 | |
81 | During the first call of any watcher-creation method, the module tries |
124 | During the first call of any watcher-creation method, the module tries |
82 | to detect the currently loaded event loop by probing whether one of the |
125 | to detect the currently loaded event loop by probing whether one of the |
83 | following modules is already loaded: L<EV>, |
126 | following modules is already loaded: L<EV>, L<AnyEvent::Loop>, |
84 | L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>, |
127 | L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one |
85 | L<POE>. The first one found is used. If none are found, the module tries |
128 | found is used. If none are detected, the module tries to load the first |
86 | to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl |
129 | four modules in the order given; but note that if L<EV> is not |
87 | adaptor should always succeed) in the order given. The first one that can |
130 | available, the pure-perl L<AnyEvent::Loop> should always work, so |
88 | be successfully loaded will be used. If, after this, still none could be |
131 | the other two are not normally tried. |
89 | found, AnyEvent will fall back to a pure-perl event loop, which is not |
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90 | very efficient, but should work everywhere. |
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91 | |
132 | |
92 | Because AnyEvent first checks for modules that are already loaded, loading |
133 | Because AnyEvent first checks for modules that are already loaded, loading |
93 | an event model explicitly before first using AnyEvent will likely make |
134 | an event model explicitly before first using AnyEvent will likely make |
94 | that model the default. For example: |
135 | that model the default. For example: |
95 | |
136 | |
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97 | use AnyEvent; |
138 | use AnyEvent; |
98 | |
139 | |
99 | # .. AnyEvent will likely default to Tk |
140 | # .. AnyEvent will likely default to Tk |
100 | |
141 | |
101 | The I<likely> means that, if any module loads another event model and |
142 | The I<likely> means that, if any module loads another event model and |
102 | starts using it, all bets are off. Maybe you should tell their authors to |
143 | starts using it, all bets are off - this case should be very rare though, |
103 | use AnyEvent so their modules work together with others seamlessly... |
144 | as very few modules hardcode event loops without announcing this very |
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145 | loudly. |
104 | |
146 | |
105 | The pure-perl implementation of AnyEvent is called |
147 | The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like |
106 | C<AnyEvent::Impl::Perl>. Like other event modules you can load it |
148 | other event modules you can load it explicitly and enjoy the high |
107 | explicitly. |
149 | availability of that event loop :) |
108 | |
150 | |
109 | =head1 WATCHERS |
151 | =head1 WATCHERS |
110 | |
152 | |
111 | AnyEvent has the central concept of a I<watcher>, which is an object that |
153 | AnyEvent has the central concept of a I<watcher>, which is an object that |
112 | stores relevant data for each kind of event you are waiting for, such as |
154 | stores relevant data for each kind of event you are waiting for, such as |
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115 | These watchers are normal Perl objects with normal Perl lifetime. After |
157 | These watchers are normal Perl objects with normal Perl lifetime. After |
116 | creating a watcher it will immediately "watch" for events and invoke the |
158 | creating a watcher it will immediately "watch" for events and invoke the |
117 | callback when the event occurs (of course, only when the event model |
159 | callback when the event occurs (of course, only when the event model |
118 | is in control). |
160 | is in control). |
119 | |
161 | |
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162 | Note that B<callbacks must not permanently change global variables> |
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163 | potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< |
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164 | callbacks must not C<die> >>. The former is good programming practice in |
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165 | Perl and the latter stems from the fact that exception handling differs |
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166 | widely between event loops. |
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167 | |
120 | To disable the watcher you have to destroy it (e.g. by setting the |
168 | To disable a watcher you have to destroy it (e.g. by setting the |
121 | variable you store it in to C<undef> or otherwise deleting all references |
169 | variable you store it in to C<undef> or otherwise deleting all references |
122 | to it). |
170 | to it). |
123 | |
171 | |
124 | All watchers are created by calling a method on the C<AnyEvent> class. |
172 | All watchers are created by calling a method on the C<AnyEvent> class. |
125 | |
173 | |
126 | Many watchers either are used with "recursion" (repeating timers for |
174 | Many watchers either are used with "recursion" (repeating timers for |
127 | example), or need to refer to their watcher object in other ways. |
175 | example), or need to refer to their watcher object in other ways. |
128 | |
176 | |
129 | An any way to achieve that is this pattern: |
177 | One way to achieve that is this pattern: |
130 | |
178 | |
131 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
179 | my $w; $w = AnyEvent->type (arg => value ..., cb => sub { |
132 | # you can use $w here, for example to undef it |
180 | # you can use $w here, for example to undef it |
133 | undef $w; |
181 | undef $w; |
134 | }); |
182 | }); |
135 | |
183 | |
136 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
184 | Note that C<my $w; $w => combination. This is necessary because in Perl, |
137 | my variables are only visible after the statement in which they are |
185 | my variables are only visible after the statement in which they are |
138 | declared. |
186 | declared. |
139 | |
187 | |
140 | =head2 I/O WATCHERS |
188 | =head2 I/O WATCHERS |
141 | |
189 | |
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190 | $w = AnyEvent->io ( |
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191 | fh => <filehandle_or_fileno>, |
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192 | poll => <"r" or "w">, |
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193 | cb => <callback>, |
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194 | ); |
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195 | |
142 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
196 | You can create an I/O watcher by calling the C<< AnyEvent->io >> method |
143 | with the following mandatory key-value pairs as arguments: |
197 | with the following mandatory key-value pairs as arguments: |
144 | |
198 | |
145 | C<fh> the Perl I<file handle> (I<not> file descriptor) to watch |
199 | C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch |
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200 | for events (AnyEvent might or might not keep a reference to this file |
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201 | handle). Note that only file handles pointing to things for which |
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202 | non-blocking operation makes sense are allowed. This includes sockets, |
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203 | most character devices, pipes, fifos and so on, but not for example files |
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204 | or block devices. |
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205 | |
146 | for events. C<poll> must be a string that is either C<r> or C<w>, |
206 | C<poll> must be a string that is either C<r> or C<w>, which creates a |
147 | which creates a watcher waiting for "r"eadable or "w"ritable events, |
207 | watcher waiting for "r"eadable or "w"ritable events, respectively. |
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208 | |
148 | respectively. C<cb> is the callback to invoke each time the file handle |
209 | C<cb> is the callback to invoke each time the file handle becomes ready. |
149 | becomes ready. |
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150 | |
210 | |
151 | Although the callback might get passed parameters, their value and |
211 | Although the callback might get passed parameters, their value and |
152 | presence is undefined and you cannot rely on them. Portable AnyEvent |
212 | presence is undefined and you cannot rely on them. Portable AnyEvent |
153 | callbacks cannot use arguments passed to I/O watcher callbacks. |
213 | callbacks cannot use arguments passed to I/O watcher callbacks. |
154 | |
214 | |
155 | The I/O watcher might use the underlying file descriptor or a copy of it. |
215 | The I/O watcher might use the underlying file descriptor or a copy of it. |
156 | You must not close a file handle as long as any watcher is active on the |
216 | You must not close a file handle as long as any watcher is active on the |
157 | underlying file descriptor. |
217 | underlying file descriptor. |
158 | |
218 | |
159 | Some event loops issue spurious readyness notifications, so you should |
219 | Some event loops issue spurious readiness notifications, so you should |
160 | always use non-blocking calls when reading/writing from/to your file |
220 | always use non-blocking calls when reading/writing from/to your file |
161 | handles. |
221 | handles. |
162 | |
222 | |
163 | Example: |
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164 | |
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165 | # wait for readability of STDIN, then read a line and disable the watcher |
223 | Example: wait for readability of STDIN, then read a line and disable the |
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224 | watcher. |
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225 | |
166 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
226 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
167 | chomp (my $input = <STDIN>); |
227 | chomp (my $input = <STDIN>); |
168 | warn "read: $input\n"; |
228 | warn "read: $input\n"; |
169 | undef $w; |
229 | undef $w; |
170 | }); |
230 | }); |
171 | |
231 | |
172 | =head2 TIME WATCHERS |
232 | =head2 TIME WATCHERS |
173 | |
233 | |
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234 | $w = AnyEvent->timer (after => <seconds>, cb => <callback>); |
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235 | |
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236 | $w = AnyEvent->timer ( |
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237 | after => <fractional_seconds>, |
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238 | interval => <fractional_seconds>, |
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239 | cb => <callback>, |
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240 | ); |
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241 | |
174 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
242 | You can create a time watcher by calling the C<< AnyEvent->timer >> |
175 | method with the following mandatory arguments: |
243 | method with the following mandatory arguments: |
176 | |
244 | |
177 | C<after> specifies after how many seconds (fractional values are |
245 | C<after> specifies after how many seconds (fractional values are |
178 | supported) the callback should be invoked. C<cb> is the callback to invoke |
246 | supported) the callback should be invoked. C<cb> is the callback to invoke |
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180 | |
248 | |
181 | Although the callback might get passed parameters, their value and |
249 | Although the callback might get passed parameters, their value and |
182 | presence is undefined and you cannot rely on them. Portable AnyEvent |
250 | presence is undefined and you cannot rely on them. Portable AnyEvent |
183 | callbacks cannot use arguments passed to time watcher callbacks. |
251 | callbacks cannot use arguments passed to time watcher callbacks. |
184 | |
252 | |
185 | The timer callback will be invoked at most once: if you want a repeating |
253 | The callback will normally be invoked only once. If you specify another |
186 | timer you have to create a new watcher (this is a limitation by both Tk |
254 | parameter, C<interval>, as a strictly positive number (> 0), then the |
187 | and Glib). |
255 | callback will be invoked regularly at that interval (in fractional |
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256 | seconds) after the first invocation. If C<interval> is specified with a |
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257 | false value, then it is treated as if it were not specified at all. |
188 | |
258 | |
189 | Example: |
259 | The callback will be rescheduled before invoking the callback, but no |
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260 | attempt is made to avoid timer drift in most backends, so the interval is |
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261 | only approximate. |
190 | |
262 | |
191 | # fire an event after 7.7 seconds |
263 | Example: fire an event after 7.7 seconds. |
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264 | |
192 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
265 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
193 | warn "timeout\n"; |
266 | warn "timeout\n"; |
194 | }); |
267 | }); |
195 | |
268 | |
196 | # to cancel the timer: |
269 | # to cancel the timer: |
197 | undef $w; |
270 | undef $w; |
198 | |
271 | |
199 | Example 2: |
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200 | |
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201 | # fire an event after 0.5 seconds, then roughly every second |
272 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
202 | my $w; |
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203 | |
273 | |
204 | my $cb = sub { |
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205 | # cancel the old timer while creating a new one |
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206 | $w = AnyEvent->timer (after => 1, cb => $cb); |
274 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
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275 | warn "timeout\n"; |
207 | }; |
276 | }; |
208 | |
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209 | # start the "loop" by creating the first watcher |
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210 | $w = AnyEvent->timer (after => 0.5, cb => $cb); |
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211 | |
277 | |
212 | =head3 TIMING ISSUES |
278 | =head3 TIMING ISSUES |
213 | |
279 | |
214 | There are two ways to handle timers: based on real time (relative, "fire |
280 | There are two ways to handle timers: based on real time (relative, "fire |
215 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
281 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
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217 | |
283 | |
218 | While most event loops expect timers to specified in a relative way, they |
284 | While most event loops expect timers to specified in a relative way, they |
219 | use absolute time internally. This makes a difference when your clock |
285 | use absolute time internally. This makes a difference when your clock |
220 | "jumps", for example, when ntp decides to set your clock backwards from |
286 | "jumps", for example, when ntp decides to set your clock backwards from |
221 | the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to |
287 | the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to |
222 | fire "after" a second might actually take six years to finally fire. |
288 | fire "after a second" might actually take six years to finally fire. |
223 | |
289 | |
224 | AnyEvent cannot compensate for this. The only event loop that is conscious |
290 | AnyEvent cannot compensate for this. The only event loop that is conscious |
225 | about these issues is L<EV>, which offers both relative (ev_timer, based |
291 | of these issues is L<EV>, which offers both relative (ev_timer, based |
226 | on true relative time) and absolute (ev_periodic, based on wallclock time) |
292 | on true relative time) and absolute (ev_periodic, based on wallclock time) |
227 | timers. |
293 | timers. |
228 | |
294 | |
229 | AnyEvent always prefers relative timers, if available, matching the |
295 | AnyEvent always prefers relative timers, if available, matching the |
230 | AnyEvent API. |
296 | AnyEvent API. |
231 | |
297 | |
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298 | AnyEvent has two additional methods that return the "current time": |
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299 | |
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300 | =over 4 |
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301 | |
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302 | =item AnyEvent->time |
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303 | |
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304 | This returns the "current wallclock time" as a fractional number of |
|
|
305 | seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time> |
|
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306 | return, and the result is guaranteed to be compatible with those). |
|
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307 | |
|
|
308 | It progresses independently of any event loop processing, i.e. each call |
|
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309 | will check the system clock, which usually gets updated frequently. |
|
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310 | |
|
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311 | =item AnyEvent->now |
|
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312 | |
|
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313 | This also returns the "current wallclock time", but unlike C<time>, above, |
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314 | this value might change only once per event loop iteration, depending on |
|
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315 | the event loop (most return the same time as C<time>, above). This is the |
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316 | time that AnyEvent's timers get scheduled against. |
|
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317 | |
|
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318 | I<In almost all cases (in all cases if you don't care), this is the |
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319 | function to call when you want to know the current time.> |
|
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320 | |
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321 | This function is also often faster then C<< AnyEvent->time >>, and |
|
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322 | thus the preferred method if you want some timestamp (for example, |
|
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323 | L<AnyEvent::Handle> uses this to update its activity timeouts). |
|
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324 | |
|
|
325 | The rest of this section is only of relevance if you try to be very exact |
|
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326 | with your timing; you can skip it without a bad conscience. |
|
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327 | |
|
|
328 | For a practical example of when these times differ, consider L<Event::Lib> |
|
|
329 | and L<EV> and the following set-up: |
|
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330 | |
|
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331 | The event loop is running and has just invoked one of your callbacks at |
|
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332 | time=500 (assume no other callbacks delay processing). In your callback, |
|
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333 | you wait a second by executing C<sleep 1> (blocking the process for a |
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334 | second) and then (at time=501) you create a relative timer that fires |
|
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335 | after three seconds. |
|
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336 | |
|
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337 | With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will |
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338 | both return C<501>, because that is the current time, and the timer will |
|
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339 | be scheduled to fire at time=504 (C<501> + C<3>). |
|
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340 | |
|
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341 | With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current |
|
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342 | time), but C<< AnyEvent->now >> returns C<500>, as that is the time the |
|
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343 | last event processing phase started. With L<EV>, your timer gets scheduled |
|
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344 | to run at time=503 (C<500> + C<3>). |
|
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345 | |
|
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346 | In one sense, L<Event::Lib> is more exact, as it uses the current time |
|
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347 | regardless of any delays introduced by event processing. However, most |
|
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348 | callbacks do not expect large delays in processing, so this causes a |
|
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349 | higher drift (and a lot more system calls to get the current time). |
|
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350 | |
|
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351 | In another sense, L<EV> is more exact, as your timer will be scheduled at |
|
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352 | the same time, regardless of how long event processing actually took. |
|
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353 | |
|
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354 | In either case, if you care (and in most cases, you don't), then you |
|
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355 | can get whatever behaviour you want with any event loop, by taking the |
|
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356 | difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into |
|
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357 | account. |
|
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358 | |
|
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359 | =item AnyEvent->now_update |
|
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360 | |
|
|
361 | Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current |
|
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362 | time for each loop iteration (see the discussion of L<< AnyEvent->now >>, |
|
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363 | above). |
|
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364 | |
|
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365 | When a callback runs for a long time (or when the process sleeps), then |
|
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366 | this "current" time will differ substantially from the real time, which |
|
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367 | might affect timers and time-outs. |
|
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368 | |
|
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369 | When this is the case, you can call this method, which will update the |
|
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370 | event loop's idea of "current time". |
|
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371 | |
|
|
372 | A typical example would be a script in a web server (e.g. C<mod_perl>) - |
|
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373 | when mod_perl executes the script, then the event loop will have the wrong |
|
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374 | idea about the "current time" (being potentially far in the past, when the |
|
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375 | script ran the last time). In that case you should arrange a call to C<< |
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376 | AnyEvent->now_update >> each time the web server process wakes up again |
|
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377 | (e.g. at the start of your script, or in a handler). |
|
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378 | |
|
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379 | Note that updating the time I<might> cause some events to be handled. |
|
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380 | |
|
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381 | =back |
|
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382 | |
232 | =head2 SIGNAL WATCHERS |
383 | =head2 SIGNAL WATCHERS |
233 | |
384 | |
|
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385 | $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>); |
|
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386 | |
234 | You can watch for signals using a signal watcher, C<signal> is the signal |
387 | You can watch for signals using a signal watcher, C<signal> is the signal |
235 | I<name> without any C<SIG> prefix, C<cb> is the Perl callback to |
388 | I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl |
236 | be invoked whenever a signal occurs. |
389 | callback to be invoked whenever a signal occurs. |
237 | |
390 | |
238 | Although the callback might get passed parameters, their value and |
391 | Although the callback might get passed parameters, their value and |
239 | presence is undefined and you cannot rely on them. Portable AnyEvent |
392 | presence is undefined and you cannot rely on them. Portable AnyEvent |
240 | callbacks cannot use arguments passed to signal watcher callbacks. |
393 | callbacks cannot use arguments passed to signal watcher callbacks. |
241 | |
394 | |
… | |
… | |
243 | invocation, and callback invocation will be synchronous. Synchronous means |
396 | invocation, and callback invocation will be synchronous. Synchronous means |
244 | that it might take a while until the signal gets handled by the process, |
397 | that it might take a while until the signal gets handled by the process, |
245 | but it is guaranteed not to interrupt any other callbacks. |
398 | but it is guaranteed not to interrupt any other callbacks. |
246 | |
399 | |
247 | The main advantage of using these watchers is that you can share a signal |
400 | The main advantage of using these watchers is that you can share a signal |
248 | between multiple watchers. |
401 | between multiple watchers, and AnyEvent will ensure that signals will not |
|
|
402 | interrupt your program at bad times. |
249 | |
403 | |
250 | This watcher might use C<%SIG>, so programs overwriting those signals |
404 | This watcher might use C<%SIG> (depending on the event loop used), |
251 | directly will likely not work correctly. |
405 | so programs overwriting those signals directly will likely not work |
|
|
406 | correctly. |
252 | |
407 | |
253 | Example: exit on SIGINT |
408 | Example: exit on SIGINT |
254 | |
409 | |
255 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
410 | my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); |
256 | |
411 | |
|
|
412 | =head3 Restart Behaviour |
|
|
413 | |
|
|
414 | While restart behaviour is up to the event loop implementation, most will |
|
|
415 | not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's |
|
|
416 | pure perl implementation). |
|
|
417 | |
|
|
418 | =head3 Safe/Unsafe Signals |
|
|
419 | |
|
|
420 | Perl signals can be either "safe" (synchronous to opcode handling) or |
|
|
421 | "unsafe" (asynchronous) - the former might get delayed indefinitely, the |
|
|
422 | latter might corrupt your memory. |
|
|
423 | |
|
|
424 | AnyEvent signal handlers are, in addition, synchronous to the event loop, |
|
|
425 | i.e. they will not interrupt your running perl program but will only be |
|
|
426 | called as part of the normal event handling (just like timer, I/O etc. |
|
|
427 | callbacks, too). |
|
|
428 | |
|
|
429 | =head3 Signal Races, Delays and Workarounds |
|
|
430 | |
|
|
431 | Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching |
|
|
432 | callbacks to signals in a generic way, which is a pity, as you cannot |
|
|
433 | do race-free signal handling in perl, requiring C libraries for |
|
|
434 | this. AnyEvent will try to do its best, which means in some cases, |
|
|
435 | signals will be delayed. The maximum time a signal might be delayed is |
|
|
436 | specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This |
|
|
437 | variable can be changed only before the first signal watcher is created, |
|
|
438 | and should be left alone otherwise. This variable determines how often |
|
|
439 | AnyEvent polls for signals (in case a wake-up was missed). Higher values |
|
|
440 | will cause fewer spurious wake-ups, which is better for power and CPU |
|
|
441 | saving. |
|
|
442 | |
|
|
443 | All these problems can be avoided by installing the optional |
|
|
444 | L<Async::Interrupt> module, which works with most event loops. It will not |
|
|
445 | work with inherently broken event loops such as L<Event> or L<Event::Lib> |
|
|
446 | (and not with L<POE> currently, as POE does its own workaround with |
|
|
447 | one-second latency). For those, you just have to suffer the delays. |
|
|
448 | |
257 | =head2 CHILD PROCESS WATCHERS |
449 | =head2 CHILD PROCESS WATCHERS |
258 | |
450 | |
|
|
451 | $w = AnyEvent->child (pid => <process id>, cb => <callback>); |
|
|
452 | |
259 | You can also watch on a child process exit and catch its exit status. |
453 | You can also watch for a child process exit and catch its exit status. |
260 | |
454 | |
261 | The child process is specified by the C<pid> argument (if set to C<0>, it |
455 | The child process is specified by the C<pid> argument (on some backends, |
262 | watches for any child process exit). The watcher will trigger as often |
456 | using C<0> watches for any child process exit, on others this will |
263 | as status change for the child are received. This works by installing a |
457 | croak). The watcher will be triggered only when the child process has |
264 | signal handler for C<SIGCHLD>. The callback will be called with the pid |
458 | finished and an exit status is available, not on any trace events |
265 | and exit status (as returned by waitpid), so unlike other watcher types, |
459 | (stopped/continued). |
266 | you I<can> rely on child watcher callback arguments. |
460 | |
|
|
461 | The callback will be called with the pid and exit status (as returned by |
|
|
462 | waitpid), so unlike other watcher types, you I<can> rely on child watcher |
|
|
463 | callback arguments. |
|
|
464 | |
|
|
465 | This watcher type works by installing a signal handler for C<SIGCHLD>, |
|
|
466 | and since it cannot be shared, nothing else should use SIGCHLD or reap |
|
|
467 | random child processes (waiting for specific child processes, e.g. inside |
|
|
468 | C<system>, is just fine). |
267 | |
469 | |
268 | There is a slight catch to child watchers, however: you usually start them |
470 | There is a slight catch to child watchers, however: you usually start them |
269 | I<after> the child process was created, and this means the process could |
471 | I<after> the child process was created, and this means the process could |
270 | have exited already (and no SIGCHLD will be sent anymore). |
472 | have exited already (and no SIGCHLD will be sent anymore). |
271 | |
473 | |
272 | Not all event models handle this correctly (POE doesn't), but even for |
474 | Not all event models handle this correctly (neither POE nor IO::Async do, |
|
|
475 | see their AnyEvent::Impl manpages for details), but even for event models |
273 | event models that I<do> handle this correctly, they usually need to be |
476 | that I<do> handle this correctly, they usually need to be loaded before |
274 | loaded before the process exits (i.e. before you fork in the first place). |
477 | the process exits (i.e. before you fork in the first place). AnyEvent's |
|
|
478 | pure perl event loop handles all cases correctly regardless of when you |
|
|
479 | start the watcher. |
275 | |
480 | |
276 | This means you cannot create a child watcher as the very first thing in an |
481 | This means you cannot create a child watcher as the very first |
277 | AnyEvent program, you I<have> to create at least one watcher before you |
482 | thing in an AnyEvent program, you I<have> to create at least one |
278 | C<fork> the child (alternatively, you can call C<AnyEvent::detect>). |
483 | watcher before you C<fork> the child (alternatively, you can call |
|
|
484 | C<AnyEvent::detect>). |
|
|
485 | |
|
|
486 | As most event loops do not support waiting for child events, they will be |
|
|
487 | emulated by AnyEvent in most cases, in which case the latency and race |
|
|
488 | problems mentioned in the description of signal watchers apply. |
279 | |
489 | |
280 | Example: fork a process and wait for it |
490 | Example: fork a process and wait for it |
281 | |
491 | |
282 | my $done = AnyEvent->condvar; |
492 | my $done = AnyEvent->condvar; |
283 | |
493 | |
284 | my $pid = fork or exit 5; |
494 | my $pid = fork or exit 5; |
285 | |
495 | |
286 | my $w = AnyEvent->child ( |
496 | my $w = AnyEvent->child ( |
287 | pid => $pid, |
497 | pid => $pid, |
288 | cb => sub { |
498 | cb => sub { |
289 | my ($pid, $status) = @_; |
499 | my ($pid, $status) = @_; |
290 | warn "pid $pid exited with status $status"; |
500 | warn "pid $pid exited with status $status"; |
291 | $done->send; |
501 | $done->send; |
292 | }, |
502 | }, |
293 | ); |
503 | ); |
294 | |
504 | |
295 | # do something else, then wait for process exit |
505 | # do something else, then wait for process exit |
296 | $done->recv; |
506 | $done->recv; |
|
|
507 | |
|
|
508 | =head2 IDLE WATCHERS |
|
|
509 | |
|
|
510 | $w = AnyEvent->idle (cb => <callback>); |
|
|
511 | |
|
|
512 | This will repeatedly invoke the callback after the process becomes idle, |
|
|
513 | until either the watcher is destroyed or new events have been detected. |
|
|
514 | |
|
|
515 | Idle watchers are useful when there is a need to do something, but it |
|
|
516 | is not so important (or wise) to do it instantly. The callback will be |
|
|
517 | invoked only when there is "nothing better to do", which is usually |
|
|
518 | defined as "all outstanding events have been handled and no new events |
|
|
519 | have been detected". That means that idle watchers ideally get invoked |
|
|
520 | when the event loop has just polled for new events but none have been |
|
|
521 | detected. Instead of blocking to wait for more events, the idle watchers |
|
|
522 | will be invoked. |
|
|
523 | |
|
|
524 | Unfortunately, most event loops do not really support idle watchers (only |
|
|
525 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
|
|
526 | will simply call the callback "from time to time". |
|
|
527 | |
|
|
528 | Example: read lines from STDIN, but only process them when the |
|
|
529 | program is otherwise idle: |
|
|
530 | |
|
|
531 | my @lines; # read data |
|
|
532 | my $idle_w; |
|
|
533 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
|
|
534 | push @lines, scalar <STDIN>; |
|
|
535 | |
|
|
536 | # start an idle watcher, if not already done |
|
|
537 | $idle_w ||= AnyEvent->idle (cb => sub { |
|
|
538 | # handle only one line, when there are lines left |
|
|
539 | if (my $line = shift @lines) { |
|
|
540 | print "handled when idle: $line"; |
|
|
541 | } else { |
|
|
542 | # otherwise disable the idle watcher again |
|
|
543 | undef $idle_w; |
|
|
544 | } |
|
|
545 | }); |
|
|
546 | }); |
297 | |
547 | |
298 | =head2 CONDITION VARIABLES |
548 | =head2 CONDITION VARIABLES |
|
|
549 | |
|
|
550 | $cv = AnyEvent->condvar; |
|
|
551 | |
|
|
552 | $cv->send (<list>); |
|
|
553 | my @res = $cv->recv; |
299 | |
554 | |
300 | If you are familiar with some event loops you will know that all of them |
555 | If you are familiar with some event loops you will know that all of them |
301 | require you to run some blocking "loop", "run" or similar function that |
556 | require you to run some blocking "loop", "run" or similar function that |
302 | will actively watch for new events and call your callbacks. |
557 | will actively watch for new events and call your callbacks. |
303 | |
558 | |
304 | AnyEvent is different, it expects somebody else to run the event loop and |
559 | AnyEvent is slightly different: it expects somebody else to run the event |
305 | will only block when necessary (usually when told by the user). |
560 | loop and will only block when necessary (usually when told by the user). |
306 | |
561 | |
307 | The instrument to do that is called a "condition variable", so called |
562 | The tool to do that is called a "condition variable", so called because |
308 | because they represent a condition that must become true. |
563 | they represent a condition that must become true. |
|
|
564 | |
|
|
565 | Now is probably a good time to look at the examples further below. |
309 | |
566 | |
310 | Condition variables can be created by calling the C<< AnyEvent->condvar |
567 | Condition variables can be created by calling the C<< AnyEvent->condvar |
311 | >> method, usually without arguments. The only argument pair allowed is |
568 | >> method, usually without arguments. The only argument pair allowed is |
312 | C<cb>, which specifies a callback to be called when the condition variable |
569 | C<cb>, which specifies a callback to be called when the condition variable |
313 | becomes true. |
570 | becomes true, with the condition variable as the first argument (but not |
|
|
571 | the results). |
314 | |
572 | |
315 | After creation, the condition variable is "false" until it becomes "true" |
573 | After creation, the condition variable is "false" until it becomes "true" |
316 | by calling the C<send> method (or calling the condition variable as if it |
574 | by calling the C<send> method (or calling the condition variable as if it |
317 | were a callback, read about the caveats in the description for the C<< |
575 | were a callback, read about the caveats in the description for the C<< |
318 | ->send >> method). |
576 | ->send >> method). |
319 | |
577 | |
320 | Condition variables are similar to callbacks, except that you can |
578 | Since condition variables are the most complex part of the AnyEvent API, here are |
321 | optionally wait for them. They can also be called merge points - points |
579 | some different mental models of what they are - pick the ones you can connect to: |
322 | in time where multiple outstanding events have been processed. And yet |
580 | |
323 | another way to call them is transactions - each condition variable can be |
581 | =over 4 |
324 | used to represent a transaction, which finishes at some point and delivers |
582 | |
325 | a result. |
583 | =item * Condition variables are like callbacks - you can call them (and pass them instead |
|
|
584 | of callbacks). Unlike callbacks however, you can also wait for them to be called. |
|
|
585 | |
|
|
586 | =item * Condition variables are signals - one side can emit or send them, |
|
|
587 | the other side can wait for them, or install a handler that is called when |
|
|
588 | the signal fires. |
|
|
589 | |
|
|
590 | =item * Condition variables are like "Merge Points" - points in your program |
|
|
591 | where you merge multiple independent results/control flows into one. |
|
|
592 | |
|
|
593 | =item * Condition variables represent a transaction - functions that start |
|
|
594 | some kind of transaction can return them, leaving the caller the choice |
|
|
595 | between waiting in a blocking fashion, or setting a callback. |
|
|
596 | |
|
|
597 | =item * Condition variables represent future values, or promises to deliver |
|
|
598 | some result, long before the result is available. |
|
|
599 | |
|
|
600 | =back |
326 | |
601 | |
327 | Condition variables are very useful to signal that something has finished, |
602 | Condition variables are very useful to signal that something has finished, |
328 | for example, if you write a module that does asynchronous http requests, |
603 | for example, if you write a module that does asynchronous http requests, |
329 | then a condition variable would be the ideal candidate to signal the |
604 | then a condition variable would be the ideal candidate to signal the |
330 | availability of results. The user can either act when the callback is |
605 | availability of results. The user can either act when the callback is |
… | |
… | |
343 | |
618 | |
344 | Condition variables are represented by hash refs in perl, and the keys |
619 | Condition variables are represented by hash refs in perl, and the keys |
345 | used by AnyEvent itself are all named C<_ae_XXX> to make subclassing |
620 | used by AnyEvent itself are all named C<_ae_XXX> to make subclassing |
346 | easy (it is often useful to build your own transaction class on top of |
621 | easy (it is often useful to build your own transaction class on top of |
347 | AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call |
622 | AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call |
348 | it's C<new> method in your own C<new> method. |
623 | its C<new> method in your own C<new> method. |
349 | |
624 | |
350 | There are two "sides" to a condition variable - the "producer side" which |
625 | There are two "sides" to a condition variable - the "producer side" which |
351 | eventually calls C<< -> send >>, and the "consumer side", which waits |
626 | eventually calls C<< -> send >>, and the "consumer side", which waits |
352 | for the send to occur. |
627 | for the send to occur. |
353 | |
628 | |
354 | Example: wait for a timer. |
629 | Example: wait for a timer. |
355 | |
630 | |
356 | # wait till the result is ready |
631 | # condition: "wait till the timer is fired" |
357 | my $result_ready = AnyEvent->condvar; |
632 | my $timer_fired = AnyEvent->condvar; |
358 | |
633 | |
359 | # do something such as adding a timer |
634 | # create the timer - we could wait for, say |
360 | # or socket watcher the calls $result_ready->send |
635 | # a handle becomign ready, or even an |
361 | # when the "result" is ready. |
636 | # AnyEvent::HTTP request to finish, but |
362 | # in this case, we simply use a timer: |
637 | # in this case, we simply use a timer: |
363 | my $w = AnyEvent->timer ( |
638 | my $w = AnyEvent->timer ( |
364 | after => 1, |
639 | after => 1, |
365 | cb => sub { $result_ready->send }, |
640 | cb => sub { $timer_fired->send }, |
366 | ); |
641 | ); |
367 | |
642 | |
368 | # this "blocks" (while handling events) till the callback |
643 | # this "blocks" (while handling events) till the callback |
369 | # calls send |
644 | # calls ->send |
370 | $result_ready->recv; |
645 | $timer_fired->recv; |
371 | |
646 | |
372 | Example: wait for a timer, but take advantage of the fact that |
647 | Example: wait for a timer, but take advantage of the fact that condition |
373 | condition variables are also code references. |
648 | variables are also callable directly. |
374 | |
649 | |
375 | my $done = AnyEvent->condvar; |
650 | my $done = AnyEvent->condvar; |
376 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
651 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
377 | $done->recv; |
652 | $done->recv; |
|
|
653 | |
|
|
654 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
655 | callbacks. This is how you make a synchronous call, for example from |
|
|
656 | the main program: |
|
|
657 | |
|
|
658 | use AnyEvent::CouchDB; |
|
|
659 | |
|
|
660 | ... |
|
|
661 | |
|
|
662 | my @info = $couchdb->info->recv; |
|
|
663 | |
|
|
664 | And this is how you would just set a callback to be called whenever the |
|
|
665 | results are available: |
|
|
666 | |
|
|
667 | $couchdb->info->cb (sub { |
|
|
668 | my @info = $_[0]->recv; |
|
|
669 | }); |
378 | |
670 | |
379 | =head3 METHODS FOR PRODUCERS |
671 | =head3 METHODS FOR PRODUCERS |
380 | |
672 | |
381 | These methods should only be used by the producing side, i.e. the |
673 | These methods should only be used by the producing side, i.e. the |
382 | code/module that eventually sends the signal. Note that it is also |
674 | code/module that eventually sends the signal. Note that it is also |
… | |
… | |
395 | immediately from within send. |
687 | immediately from within send. |
396 | |
688 | |
397 | Any arguments passed to the C<send> call will be returned by all |
689 | Any arguments passed to the C<send> call will be returned by all |
398 | future C<< ->recv >> calls. |
690 | future C<< ->recv >> calls. |
399 | |
691 | |
400 | Condition variables are overloaded so one can call them directly |
692 | Condition variables are overloaded so one can call them directly (as if |
401 | (as a code reference). Calling them directly is the same as calling |
693 | they were a code reference). Calling them directly is the same as calling |
402 | C<send>. Note, however, that many C-based event loops do not handle |
694 | C<send>. |
403 | overloading, so as tempting as it may be, passing a condition variable |
|
|
404 | instead of a callback does not work. Both the pure perl and EV loops |
|
|
405 | support overloading, however, as well as all functions that use perl to |
|
|
406 | invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for |
|
|
407 | example). |
|
|
408 | |
695 | |
409 | =item $cv->croak ($error) |
696 | =item $cv->croak ($error) |
410 | |
697 | |
411 | Similar to send, but causes all call's to C<< ->recv >> to invoke |
698 | Similar to send, but causes all calls to C<< ->recv >> to invoke |
412 | C<Carp::croak> with the given error message/object/scalar. |
699 | C<Carp::croak> with the given error message/object/scalar. |
413 | |
700 | |
414 | This can be used to signal any errors to the condition variable |
701 | This can be used to signal any errors to the condition variable |
415 | user/consumer. |
702 | user/consumer. Doing it this way instead of calling C<croak> directly |
|
|
703 | delays the error detection, but has the overwhelming advantage that it |
|
|
704 | diagnoses the error at the place where the result is expected, and not |
|
|
705 | deep in some event callback with no connection to the actual code causing |
|
|
706 | the problem. |
416 | |
707 | |
417 | =item $cv->begin ([group callback]) |
708 | =item $cv->begin ([group callback]) |
418 | |
709 | |
419 | =item $cv->end |
710 | =item $cv->end |
420 | |
|
|
421 | These two methods are EXPERIMENTAL and MIGHT CHANGE. |
|
|
422 | |
711 | |
423 | These two methods can be used to combine many transactions/events into |
712 | These two methods can be used to combine many transactions/events into |
424 | one. For example, a function that pings many hosts in parallel might want |
713 | one. For example, a function that pings many hosts in parallel might want |
425 | to use a condition variable for the whole process. |
714 | to use a condition variable for the whole process. |
426 | |
715 | |
427 | Every call to C<< ->begin >> will increment a counter, and every call to |
716 | Every call to C<< ->begin >> will increment a counter, and every call to |
428 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
717 | C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end |
429 | >>, the (last) callback passed to C<begin> will be executed. That callback |
718 | >>, the (last) callback passed to C<begin> will be executed, passing the |
430 | is I<supposed> to call C<< ->send >>, but that is not required. If no |
719 | condvar as first argument. That callback is I<supposed> to call C<< ->send |
431 | callback was set, C<send> will be called without any arguments. |
720 | >>, but that is not required. If no group callback was set, C<send> will |
|
|
721 | be called without any arguments. |
432 | |
722 | |
433 | Let's clarify this with the ping example: |
723 | You can think of C<< $cv->send >> giving you an OR condition (one call |
|
|
724 | sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND |
|
|
725 | condition (all C<begin> calls must be C<end>'ed before the condvar sends). |
|
|
726 | |
|
|
727 | Let's start with a simple example: you have two I/O watchers (for example, |
|
|
728 | STDOUT and STDERR for a program), and you want to wait for both streams to |
|
|
729 | close before activating a condvar: |
434 | |
730 | |
435 | my $cv = AnyEvent->condvar; |
731 | my $cv = AnyEvent->condvar; |
436 | |
732 | |
|
|
733 | $cv->begin; # first watcher |
|
|
734 | my $w1 = AnyEvent->io (fh => $fh1, cb => sub { |
|
|
735 | defined sysread $fh1, my $buf, 4096 |
|
|
736 | or $cv->end; |
|
|
737 | }); |
|
|
738 | |
|
|
739 | $cv->begin; # second watcher |
|
|
740 | my $w2 = AnyEvent->io (fh => $fh2, cb => sub { |
|
|
741 | defined sysread $fh2, my $buf, 4096 |
|
|
742 | or $cv->end; |
|
|
743 | }); |
|
|
744 | |
|
|
745 | $cv->recv; |
|
|
746 | |
|
|
747 | This works because for every event source (EOF on file handle), there is |
|
|
748 | one call to C<begin>, so the condvar waits for all calls to C<end> before |
|
|
749 | sending. |
|
|
750 | |
|
|
751 | The ping example mentioned above is slightly more complicated, as the |
|
|
752 | there are results to be passwd back, and the number of tasks that are |
|
|
753 | begun can potentially be zero: |
|
|
754 | |
|
|
755 | my $cv = AnyEvent->condvar; |
|
|
756 | |
437 | my %result; |
757 | my %result; |
438 | $cv->begin (sub { $cv->send (\%result) }); |
758 | $cv->begin (sub { shift->send (\%result) }); |
439 | |
759 | |
440 | for my $host (@list_of_hosts) { |
760 | for my $host (@list_of_hosts) { |
441 | $cv->begin; |
761 | $cv->begin; |
442 | ping_host_then_call_callback $host, sub { |
762 | ping_host_then_call_callback $host, sub { |
443 | $result{$host} = ...; |
763 | $result{$host} = ...; |
… | |
… | |
458 | loop, which serves two important purposes: first, it sets the callback |
778 | loop, which serves two important purposes: first, it sets the callback |
459 | to be called once the counter reaches C<0>, and second, it ensures that |
779 | to be called once the counter reaches C<0>, and second, it ensures that |
460 | C<send> is called even when C<no> hosts are being pinged (the loop |
780 | C<send> is called even when C<no> hosts are being pinged (the loop |
461 | doesn't execute once). |
781 | doesn't execute once). |
462 | |
782 | |
463 | This is the general pattern when you "fan out" into multiple subrequests: |
783 | This is the general pattern when you "fan out" into multiple (but |
464 | use an outer C<begin>/C<end> pair to set the callback and ensure C<end> |
784 | potentially zero) subrequests: use an outer C<begin>/C<end> pair to set |
465 | is called at least once, and then, for each subrequest you start, call |
785 | the callback and ensure C<end> is called at least once, and then, for each |
466 | C<begin> and for each subrequest you finish, call C<end>. |
786 | subrequest you start, call C<begin> and for each subrequest you finish, |
|
|
787 | call C<end>. |
467 | |
788 | |
468 | =back |
789 | =back |
469 | |
790 | |
470 | =head3 METHODS FOR CONSUMERS |
791 | =head3 METHODS FOR CONSUMERS |
471 | |
792 | |
… | |
… | |
475 | =over 4 |
796 | =over 4 |
476 | |
797 | |
477 | =item $cv->recv |
798 | =item $cv->recv |
478 | |
799 | |
479 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
800 | Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak |
480 | >> methods have been called on c<$cv>, while servicing other watchers |
801 | >> methods have been called on C<$cv>, while servicing other watchers |
481 | normally. |
802 | normally. |
482 | |
803 | |
483 | You can only wait once on a condition - additional calls are valid but |
804 | You can only wait once on a condition - additional calls are valid but |
484 | will return immediately. |
805 | will return immediately. |
485 | |
806 | |
… | |
… | |
487 | function will call C<croak>. |
808 | function will call C<croak>. |
488 | |
809 | |
489 | In list context, all parameters passed to C<send> will be returned, |
810 | In list context, all parameters passed to C<send> will be returned, |
490 | in scalar context only the first one will be returned. |
811 | in scalar context only the first one will be returned. |
491 | |
812 | |
|
|
813 | Note that doing a blocking wait in a callback is not supported by any |
|
|
814 | event loop, that is, recursive invocation of a blocking C<< ->recv |
|
|
815 | >> is not allowed, and the C<recv> call will C<croak> if such a |
|
|
816 | condition is detected. This condition can be slightly loosened by using |
|
|
817 | L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from |
|
|
818 | any thread that doesn't run the event loop itself. |
|
|
819 | |
492 | Not all event models support a blocking wait - some die in that case |
820 | Not all event models support a blocking wait - some die in that case |
493 | (programs might want to do that to stay interactive), so I<if you are |
821 | (programs might want to do that to stay interactive), so I<if you are |
494 | using this from a module, never require a blocking wait>, but let the |
822 | using this from a module, never require a blocking wait>. Instead, let the |
495 | caller decide whether the call will block or not (for example, by coupling |
823 | caller decide whether the call will block or not (for example, by coupling |
496 | condition variables with some kind of request results and supporting |
824 | condition variables with some kind of request results and supporting |
497 | callbacks so the caller knows that getting the result will not block, |
825 | callbacks so the caller knows that getting the result will not block, |
498 | while still supporting blocking waits if the caller so desires). |
826 | while still supporting blocking waits if the caller so desires). |
499 | |
827 | |
500 | Another reason I<never> to C<< ->recv >> in a module is that you cannot |
|
|
501 | sensibly have two C<< ->recv >>'s in parallel, as that would require |
|
|
502 | multiple interpreters or coroutines/threads, none of which C<AnyEvent> |
|
|
503 | can supply. |
|
|
504 | |
|
|
505 | The L<Coro> module, however, I<can> and I<does> supply coroutines and, in |
|
|
506 | fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe |
|
|
507 | versions and also integrates coroutines into AnyEvent, making blocking |
|
|
508 | C<< ->recv >> calls perfectly safe as long as they are done from another |
|
|
509 | coroutine (one that doesn't run the event loop). |
|
|
510 | |
|
|
511 | You can ensure that C<< -recv >> never blocks by setting a callback and |
828 | You can ensure that C<< ->recv >> never blocks by setting a callback and |
512 | only calling C<< ->recv >> from within that callback (or at a later |
829 | only calling C<< ->recv >> from within that callback (or at a later |
513 | time). This will work even when the event loop does not support blocking |
830 | time). This will work even when the event loop does not support blocking |
514 | waits otherwise. |
831 | waits otherwise. |
515 | |
832 | |
516 | =item $bool = $cv->ready |
833 | =item $bool = $cv->ready |
517 | |
834 | |
518 | Returns true when the condition is "true", i.e. whether C<send> or |
835 | Returns true when the condition is "true", i.e. whether C<send> or |
519 | C<croak> have been called. |
836 | C<croak> have been called. |
520 | |
837 | |
521 | =item $cb = $cv->cb ([new callback]) |
838 | =item $cb = $cv->cb ($cb->($cv)) |
522 | |
839 | |
523 | This is a mutator function that returns the callback set and optionally |
840 | This is a mutator function that returns the callback set and optionally |
524 | replaces it before doing so. |
841 | replaces it before doing so. |
525 | |
842 | |
526 | The callback will be called when the condition becomes "true", i.e. when |
843 | The callback will be called when the condition becomes "true", i.e. when |
527 | C<send> or C<croak> are called. Calling C<recv> inside the callback |
844 | C<send> or C<croak> are called, with the only argument being the |
|
|
845 | condition variable itself. If the condition is already true, the |
|
|
846 | callback is called immediately when it is set. Calling C<recv> inside |
528 | or at any later time is guaranteed not to block. |
847 | the callback or at any later time is guaranteed not to block. |
529 | |
848 | |
530 | =back |
849 | =back |
531 | |
850 | |
|
|
851 | =head1 SUPPORTED EVENT LOOPS/BACKENDS |
|
|
852 | |
|
|
853 | The available backend classes are (every class has its own manpage): |
|
|
854 | |
|
|
855 | =over 4 |
|
|
856 | |
|
|
857 | =item Backends that are autoprobed when no other event loop can be found. |
|
|
858 | |
|
|
859 | EV is the preferred backend when no other event loop seems to be in |
|
|
860 | use. If EV is not installed, then AnyEvent will fall back to its own |
|
|
861 | pure-perl implementation, which is available everywhere as it comes with |
|
|
862 | AnyEvent itself. |
|
|
863 | |
|
|
864 | AnyEvent::Impl::EV based on EV (interface to libev, best choice). |
|
|
865 | AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable. |
|
|
866 | |
|
|
867 | =item Backends that are transparently being picked up when they are used. |
|
|
868 | |
|
|
869 | These will be used if they are already loaded when the first watcher |
|
|
870 | is created, in which case it is assumed that the application is using |
|
|
871 | them. This means that AnyEvent will automatically pick the right backend |
|
|
872 | when the main program loads an event module before anything starts to |
|
|
873 | create watchers. Nothing special needs to be done by the main program. |
|
|
874 | |
|
|
875 | AnyEvent::Impl::Event based on Event, very stable, few glitches. |
|
|
876 | AnyEvent::Impl::Glib based on Glib, slow but very stable. |
|
|
877 | AnyEvent::Impl::Tk based on Tk, very broken. |
|
|
878 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
879 | AnyEvent::Impl::POE based on POE, very slow, some limitations. |
|
|
880 | AnyEvent::Impl::Irssi used when running within irssi. |
|
|
881 | AnyEvent::Impl::IOAsync based on IO::Async. |
|
|
882 | AnyEvent::Impl::Cocoa based on Cocoa::EventLoop. |
|
|
883 | AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding). |
|
|
884 | |
|
|
885 | =item Backends with special needs. |
|
|
886 | |
|
|
887 | Qt requires the Qt::Application to be instantiated first, but will |
|
|
888 | otherwise be picked up automatically. As long as the main program |
|
|
889 | instantiates the application before any AnyEvent watchers are created, |
|
|
890 | everything should just work. |
|
|
891 | |
|
|
892 | AnyEvent::Impl::Qt based on Qt. |
|
|
893 | |
|
|
894 | =item Event loops that are indirectly supported via other backends. |
|
|
895 | |
|
|
896 | Some event loops can be supported via other modules: |
|
|
897 | |
|
|
898 | There is no direct support for WxWidgets (L<Wx>) or L<Prima>. |
|
|
899 | |
|
|
900 | B<WxWidgets> has no support for watching file handles. However, you can |
|
|
901 | use WxWidgets through the POE adaptor, as POE has a Wx backend that simply |
|
|
902 | polls 20 times per second, which was considered to be too horrible to even |
|
|
903 | consider for AnyEvent. |
|
|
904 | |
|
|
905 | B<Prima> is not supported as nobody seems to be using it, but it has a POE |
|
|
906 | backend, so it can be supported through POE. |
|
|
907 | |
|
|
908 | AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to |
|
|
909 | load L<POE> when detecting them, in the hope that POE will pick them up, |
|
|
910 | in which case everything will be automatic. |
|
|
911 | |
|
|
912 | =back |
|
|
913 | |
532 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
914 | =head1 GLOBAL VARIABLES AND FUNCTIONS |
533 | |
915 | |
|
|
916 | These are not normally required to use AnyEvent, but can be useful to |
|
|
917 | write AnyEvent extension modules. |
|
|
918 | |
534 | =over 4 |
919 | =over 4 |
535 | |
920 | |
536 | =item $AnyEvent::MODEL |
921 | =item $AnyEvent::MODEL |
537 | |
922 | |
538 | Contains C<undef> until the first watcher is being created. Then it |
923 | Contains C<undef> until the first watcher is being created, before the |
|
|
924 | backend has been autodetected. |
|
|
925 | |
539 | contains the event model that is being used, which is the name of the |
926 | Afterwards it contains the event model that is being used, which is the |
540 | Perl class implementing the model. This class is usually one of the |
927 | name of the Perl class implementing the model. This class is usually one |
541 | C<AnyEvent::Impl:xxx> modules, but can be any other class in the case |
928 | of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the |
542 | AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). |
929 | case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it |
543 | |
930 | will be C<urxvt::anyevent>). |
544 | The known classes so far are: |
|
|
545 | |
|
|
546 | AnyEvent::Impl::EV based on EV (an interface to libev, best choice). |
|
|
547 | AnyEvent::Impl::Event based on Event, second best choice. |
|
|
548 | AnyEvent::Impl::Perl pure-perl implementation, fast and portable. |
|
|
549 | AnyEvent::Impl::Glib based on Glib, third-best choice. |
|
|
550 | AnyEvent::Impl::Tk based on Tk, very bad choice. |
|
|
551 | AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs). |
|
|
552 | AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. |
|
|
553 | AnyEvent::Impl::POE based on POE, not generic enough for full support. |
|
|
554 | |
|
|
555 | There is no support for WxWidgets, as WxWidgets has no support for |
|
|
556 | watching file handles. However, you can use WxWidgets through the |
|
|
557 | POE Adaptor, as POE has a Wx backend that simply polls 20 times per |
|
|
558 | second, which was considered to be too horrible to even consider for |
|
|
559 | AnyEvent. Likewise, other POE backends can be used by AnyEvent by using |
|
|
560 | it's adaptor. |
|
|
561 | |
|
|
562 | AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when |
|
|
563 | autodetecting them. |
|
|
564 | |
931 | |
565 | =item AnyEvent::detect |
932 | =item AnyEvent::detect |
566 | |
933 | |
567 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
934 | Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model |
568 | if necessary. You should only call this function right before you would |
935 | if necessary. You should only call this function right before you would |
569 | have created an AnyEvent watcher anyway, that is, as late as possible at |
936 | have created an AnyEvent watcher anyway, that is, as late as possible at |
570 | runtime. |
937 | runtime, and not e.g. during initialisation of your module. |
|
|
938 | |
|
|
939 | The effect of calling this function is as if a watcher had been created |
|
|
940 | (specifically, actions that happen "when the first watcher is created" |
|
|
941 | happen when calling detetc as well). |
|
|
942 | |
|
|
943 | If you need to do some initialisation before AnyEvent watchers are |
|
|
944 | created, use C<post_detect>. |
571 | |
945 | |
572 | =item $guard = AnyEvent::post_detect { BLOCK } |
946 | =item $guard = AnyEvent::post_detect { BLOCK } |
573 | |
947 | |
574 | Arranges for the code block to be executed as soon as the event model is |
948 | Arranges for the code block to be executed as soon as the event model is |
575 | autodetected (or immediately if this has already happened). |
949 | autodetected (or immediately if that has already happened). |
|
|
950 | |
|
|
951 | The block will be executed I<after> the actual backend has been detected |
|
|
952 | (C<$AnyEvent::MODEL> is set), but I<before> any watchers have been |
|
|
953 | created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do |
|
|
954 | other initialisations - see the sources of L<AnyEvent::Strict> or |
|
|
955 | L<AnyEvent::AIO> to see how this is used. |
|
|
956 | |
|
|
957 | The most common usage is to create some global watchers, without forcing |
|
|
958 | event module detection too early, for example, L<AnyEvent::AIO> creates |
|
|
959 | and installs the global L<IO::AIO> watcher in a C<post_detect> block to |
|
|
960 | avoid autodetecting the event module at load time. |
576 | |
961 | |
577 | If called in scalar or list context, then it creates and returns an object |
962 | If called in scalar or list context, then it creates and returns an object |
578 | that automatically removes the callback again when it is destroyed. See |
963 | that automatically removes the callback again when it is destroyed (or |
|
|
964 | C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for |
579 | L<Coro::BDB> for a case where this is useful. |
965 | a case where this is useful. |
|
|
966 | |
|
|
967 | Example: Create a watcher for the IO::AIO module and store it in |
|
|
968 | C<$WATCHER>, but do so only do so after the event loop is initialised. |
|
|
969 | |
|
|
970 | our WATCHER; |
|
|
971 | |
|
|
972 | my $guard = AnyEvent::post_detect { |
|
|
973 | $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb); |
|
|
974 | }; |
|
|
975 | |
|
|
976 | # the ||= is important in case post_detect immediately runs the block, |
|
|
977 | # as to not clobber the newly-created watcher. assigning both watcher and |
|
|
978 | # post_detect guard to the same variable has the advantage of users being |
|
|
979 | # able to just C<undef $WATCHER> if the watcher causes them grief. |
|
|
980 | |
|
|
981 | $WATCHER ||= $guard; |
580 | |
982 | |
581 | =item @AnyEvent::post_detect |
983 | =item @AnyEvent::post_detect |
582 | |
984 | |
583 | If there are any code references in this array (you can C<push> to it |
985 | If there are any code references in this array (you can C<push> to it |
584 | before or after loading AnyEvent), then they will called directly after |
986 | before or after loading AnyEvent), then they will be called directly |
585 | the event loop has been chosen. |
987 | after the event loop has been chosen. |
586 | |
988 | |
587 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
989 | You should check C<$AnyEvent::MODEL> before adding to this array, though: |
588 | if it contains a true value then the event loop has already been detected, |
990 | if it is defined then the event loop has already been detected, and the |
589 | and the array will be ignored. |
991 | array will be ignored. |
590 | |
992 | |
591 | Best use C<AnyEvent::post_detect { BLOCK }> instead. |
993 | Best use C<AnyEvent::post_detect { BLOCK }> when your application allows |
|
|
994 | it, as it takes care of these details. |
|
|
995 | |
|
|
996 | This variable is mainly useful for modules that can do something useful |
|
|
997 | when AnyEvent is used and thus want to know when it is initialised, but do |
|
|
998 | not need to even load it by default. This array provides the means to hook |
|
|
999 | into AnyEvent passively, without loading it. |
|
|
1000 | |
|
|
1001 | Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used |
|
|
1002 | together, you could put this into Coro (this is the actual code used by |
|
|
1003 | Coro to accomplish this): |
|
|
1004 | |
|
|
1005 | if (defined $AnyEvent::MODEL) { |
|
|
1006 | # AnyEvent already initialised, so load Coro::AnyEvent |
|
|
1007 | require Coro::AnyEvent; |
|
|
1008 | } else { |
|
|
1009 | # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent |
|
|
1010 | # as soon as it is |
|
|
1011 | push @AnyEvent::post_detect, sub { require Coro::AnyEvent }; |
|
|
1012 | } |
|
|
1013 | |
|
|
1014 | =item AnyEvent::postpone { BLOCK } |
|
|
1015 | |
|
|
1016 | Arranges for the block to be executed as soon as possible, but not before |
|
|
1017 | the call itself returns. In practise, the block will be executed just |
|
|
1018 | before the event loop polls for new events, or shortly afterwards. |
|
|
1019 | |
|
|
1020 | This function never returns anything (to make the C<return postpone { ... |
|
|
1021 | }> idiom more useful. |
|
|
1022 | |
|
|
1023 | To understand the usefulness of this function, consider a function that |
|
|
1024 | asynchronously does something for you and returns some transaction |
|
|
1025 | object or guard to let you cancel the operation. For example, |
|
|
1026 | C<AnyEvent::Socket::tcp_connect>: |
|
|
1027 | |
|
|
1028 | # start a conenction attempt unless one is active |
|
|
1029 | $self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub { |
|
|
1030 | delete $self->{connect_guard}; |
|
|
1031 | ... |
|
|
1032 | }; |
|
|
1033 | |
|
|
1034 | Imagine that this function could instantly call the callback, for |
|
|
1035 | example, because it detects an obvious error such as a negative port |
|
|
1036 | number. Invoking the callback before the function returns causes problems |
|
|
1037 | however: the callback will be called and will try to delete the guard |
|
|
1038 | object. But since the function hasn't returned yet, there is nothing to |
|
|
1039 | delete. When the function eventually returns it will assign the guard |
|
|
1040 | object to C<< $self->{connect_guard} >>, where it will likely never be |
|
|
1041 | deleted, so the program thinks it is still trying to connect. |
|
|
1042 | |
|
|
1043 | This is where C<AnyEvent::postpone> should be used. Instead of calling the |
|
|
1044 | callback directly on error: |
|
|
1045 | |
|
|
1046 | $cb->(undef), return # signal error to callback, BAD! |
|
|
1047 | if $some_error_condition; |
|
|
1048 | |
|
|
1049 | It should use C<postpone>: |
|
|
1050 | |
|
|
1051 | AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later |
|
|
1052 | if $some_error_condition; |
|
|
1053 | |
|
|
1054 | =item AnyEvent::log $level, $msg[, @args] |
|
|
1055 | |
|
|
1056 | Log the given C<$msg> at the given C<$level>. |
|
|
1057 | |
|
|
1058 | If L<AnyEvent::Log> is not loaded then this function makes a simple test |
|
|
1059 | to see whether the message will be logged. If the test succeeds it will |
|
|
1060 | load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at |
|
|
1061 | the L<AnyEvent::Log> documentation for details. |
|
|
1062 | |
|
|
1063 | If the test fails it will simply return. Right now this happens when a |
|
|
1064 | numerical loglevel is used and it is larger than the level specified via |
|
|
1065 | C<$ENV{PERL_ANYEVENT_VERBOSE}>. |
|
|
1066 | |
|
|
1067 | If you want to sprinkle loads of logging calls around your code, consider |
|
|
1068 | creating a logger callback with the C<AnyEvent::Log::logger> function, |
|
|
1069 | which can reduce typing, codesize and can reduce the logging overhead |
|
|
1070 | enourmously. |
592 | |
1071 | |
593 | =back |
1072 | =back |
594 | |
1073 | |
595 | =head1 WHAT TO DO IN A MODULE |
1074 | =head1 WHAT TO DO IN A MODULE |
596 | |
1075 | |
… | |
… | |
607 | because it will stall the whole program, and the whole point of using |
1086 | because it will stall the whole program, and the whole point of using |
608 | events is to stay interactive. |
1087 | events is to stay interactive. |
609 | |
1088 | |
610 | It is fine, however, to call C<< ->recv >> when the user of your module |
1089 | It is fine, however, to call C<< ->recv >> when the user of your module |
611 | requests it (i.e. if you create a http request object ad have a method |
1090 | requests it (i.e. if you create a http request object ad have a method |
612 | called C<results> that returns the results, it should call C<< ->recv >> |
1091 | called C<results> that returns the results, it may call C<< ->recv >> |
613 | freely, as the user of your module knows what she is doing. always). |
1092 | freely, as the user of your module knows what she is doing. Always). |
614 | |
1093 | |
615 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
1094 | =head1 WHAT TO DO IN THE MAIN PROGRAM |
616 | |
1095 | |
617 | There will always be a single main program - the only place that should |
1096 | There will always be a single main program - the only place that should |
618 | dictate which event model to use. |
1097 | dictate which event model to use. |
619 | |
1098 | |
620 | If it doesn't care, it can just "use AnyEvent" and use it itself, or not |
1099 | If the program is not event-based, it need not do anything special, even |
621 | do anything special (it does not need to be event-based) and let AnyEvent |
1100 | when it depends on a module that uses an AnyEvent. If the program itself |
622 | decide which implementation to chose if some module relies on it. |
1101 | uses AnyEvent, but does not care which event loop is used, all it needs |
|
|
1102 | to do is C<use AnyEvent>. In either case, AnyEvent will choose the best |
|
|
1103 | available loop implementation. |
623 | |
1104 | |
624 | If the main program relies on a specific event model - for example, in |
1105 | If the main program relies on a specific event model - for example, in |
625 | Gtk2 programs you have to rely on the Glib module - you should load the |
1106 | Gtk2 programs you have to rely on the Glib module - you should load the |
626 | event module before loading AnyEvent or any module that uses it: generally |
1107 | event module before loading AnyEvent or any module that uses it: generally |
627 | speaking, you should load it as early as possible. The reason is that |
1108 | speaking, you should load it as early as possible. The reason is that |
628 | modules might create watchers when they are loaded, and AnyEvent will |
1109 | modules might create watchers when they are loaded, and AnyEvent will |
629 | decide on the event model to use as soon as it creates watchers, and it |
1110 | decide on the event model to use as soon as it creates watchers, and it |
630 | might chose the wrong one unless you load the correct one yourself. |
1111 | might choose the wrong one unless you load the correct one yourself. |
631 | |
1112 | |
632 | You can chose to use a pure-perl implementation by loading the |
1113 | You can chose to use a pure-perl implementation by loading the |
633 | C<AnyEvent::Impl::Perl> module, which gives you similar behaviour |
1114 | C<AnyEvent::Loop> module, which gives you similar behaviour |
634 | everywhere, but letting AnyEvent chose the model is generally better. |
1115 | everywhere, but letting AnyEvent chose the model is generally better. |
635 | |
1116 | |
636 | =head2 MAINLOOP EMULATION |
1117 | =head2 MAINLOOP EMULATION |
637 | |
1118 | |
638 | Sometimes (often for short test scripts, or even standalone programs who |
1119 | Sometimes (often for short test scripts, or even standalone programs who |
… | |
… | |
651 | |
1132 | |
652 | |
1133 | |
653 | =head1 OTHER MODULES |
1134 | =head1 OTHER MODULES |
654 | |
1135 | |
655 | The following is a non-exhaustive list of additional modules that use |
1136 | The following is a non-exhaustive list of additional modules that use |
656 | AnyEvent and can therefore be mixed easily with other AnyEvent modules |
1137 | AnyEvent as a client and can therefore be mixed easily with other |
657 | in the same program. Some of the modules come with AnyEvent, some are |
1138 | AnyEvent modules and other event loops in the same program. Some of the |
658 | available via CPAN. |
1139 | modules come as part of AnyEvent, the others are available via CPAN (see |
|
|
1140 | L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for |
|
|
1141 | a longer non-exhaustive list), and the list is heavily biased towards |
|
|
1142 | modules of the AnyEvent author himself :) |
659 | |
1143 | |
660 | =over 4 |
1144 | =over 4 |
661 | |
1145 | |
662 | =item L<AnyEvent::Util> |
1146 | =item L<AnyEvent::Util> |
663 | |
1147 | |
664 | Contains various utility functions that replace often-used but blocking |
1148 | Contains various utility functions that replace often-used blocking |
665 | functions such as C<inet_aton> by event-/callback-based versions. |
1149 | functions such as C<inet_aton> with event/callback-based versions. |
666 | |
|
|
667 | =item L<AnyEvent::Handle> |
|
|
668 | |
|
|
669 | Provide read and write buffers and manages watchers for reads and writes. |
|
|
670 | |
1150 | |
671 | =item L<AnyEvent::Socket> |
1151 | =item L<AnyEvent::Socket> |
672 | |
1152 | |
673 | Provides various utility functions for (internet protocol) sockets, |
1153 | Provides various utility functions for (internet protocol) sockets, |
674 | addresses and name resolution. Also functions to create non-blocking tcp |
1154 | addresses and name resolution. Also functions to create non-blocking tcp |
675 | connections or tcp servers, with IPv6 and SRV record support and more. |
1155 | connections or tcp servers, with IPv6 and SRV record support and more. |
676 | |
1156 | |
|
|
1157 | =item L<AnyEvent::Handle> |
|
|
1158 | |
|
|
1159 | Provide read and write buffers, manages watchers for reads and writes, |
|
|
1160 | supports raw and formatted I/O, I/O queued and fully transparent and |
|
|
1161 | non-blocking SSL/TLS (via L<AnyEvent::TLS>). |
|
|
1162 | |
677 | =item L<AnyEvent::DNS> |
1163 | =item L<AnyEvent::DNS> |
678 | |
1164 | |
679 | Provides rich asynchronous DNS resolver capabilities. |
1165 | Provides rich asynchronous DNS resolver capabilities. |
680 | |
1166 | |
|
|
1167 | =item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP> |
|
|
1168 | |
|
|
1169 | Implement event-based interfaces to the protocols of the same name (for |
|
|
1170 | the curious, IGS is the International Go Server and FCP is the Freenet |
|
|
1171 | Client Protocol). |
|
|
1172 | |
|
|
1173 | =item L<AnyEvent::AIO> |
|
|
1174 | |
|
|
1175 | Truly asynchronous (as opposed to non-blocking) I/O, should be in the |
|
|
1176 | toolbox of every event programmer. AnyEvent::AIO transparently fuses |
|
|
1177 | L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based |
|
|
1178 | file I/O, and much more. |
|
|
1179 | |
|
|
1180 | =item L<AnyEvent::Filesys::Notify> |
|
|
1181 | |
|
|
1182 | AnyEvent is good for non-blocking stuff, but it can't detect file or |
|
|
1183 | path changes (e.g. "watch this directory for new files", "watch this |
|
|
1184 | file for changes"). The L<AnyEvent::Filesys::Notify> module promises to |
|
|
1185 | do just that in a portbale fashion, supporting inotify on GNU/Linux and |
|
|
1186 | some weird, without doubt broken, stuff on OS X to monitor files. It can |
|
|
1187 | fall back to blocking scans at regular intervals transparently on other |
|
|
1188 | platforms, so it's about as portable as it gets. |
|
|
1189 | |
|
|
1190 | (I haven't used it myself, but I haven't heard anybody complaining about |
|
|
1191 | it yet). |
|
|
1192 | |
|
|
1193 | =item L<AnyEvent::DBI> |
|
|
1194 | |
|
|
1195 | Executes L<DBI> requests asynchronously in a proxy process for you, |
|
|
1196 | notifying you in an event-based way when the operation is finished. |
|
|
1197 | |
681 | =item L<AnyEvent::HTTPD> |
1198 | =item L<AnyEvent::HTTPD> |
682 | |
1199 | |
683 | Provides a simple web application server framework. |
1200 | A simple embedded webserver. |
684 | |
1201 | |
685 | =item L<AnyEvent::FastPing> |
1202 | =item L<AnyEvent::FastPing> |
686 | |
1203 | |
687 | The fastest ping in the west. |
1204 | The fastest ping in the west. |
688 | |
1205 | |
689 | =item L<Net::IRC3> |
|
|
690 | |
|
|
691 | AnyEvent based IRC client module family. |
|
|
692 | |
|
|
693 | =item L<Net::XMPP2> |
|
|
694 | |
|
|
695 | AnyEvent based XMPP (Jabber protocol) module family. |
|
|
696 | |
|
|
697 | =item L<Net::FCP> |
|
|
698 | |
|
|
699 | AnyEvent-based implementation of the Freenet Client Protocol, birthplace |
|
|
700 | of AnyEvent. |
|
|
701 | |
|
|
702 | =item L<Event::ExecFlow> |
|
|
703 | |
|
|
704 | High level API for event-based execution flow control. |
|
|
705 | |
|
|
706 | =item L<Coro> |
1206 | =item L<Coro> |
707 | |
1207 | |
708 | Has special support for AnyEvent via L<Coro::AnyEvent>. |
1208 | Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you |
|
|
1209 | to simply invert the flow control - don't call us, we will call you: |
709 | |
1210 | |
710 | =item L<AnyEvent::AIO>, L<IO::AIO> |
1211 | async { |
|
|
1212 | Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it |
|
|
1213 | print "5 seconds later!\n"; |
711 | |
1214 | |
712 | Truly asynchronous I/O, should be in the toolbox of every event |
1215 | Coro::AnyEvent::readable *STDIN; # uses an I/O watcher |
713 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
1216 | my $line = <STDIN>; # works for ttys |
714 | together. |
|
|
715 | |
1217 | |
716 | =item L<AnyEvent::BDB>, L<BDB> |
1218 | AnyEvent::HTTP::http_get "url", Coro::rouse_cb; |
717 | |
1219 | my ($body, $hdr) = Coro::rouse_wait; |
718 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses |
1220 | }; |
719 | IO::AIO and AnyEvent together. |
|
|
720 | |
|
|
721 | =item L<IO::Lambda> |
|
|
722 | |
|
|
723 | The lambda approach to I/O - don't ask, look there. Can use AnyEvent. |
|
|
724 | |
1221 | |
725 | =back |
1222 | =back |
726 | |
1223 | |
727 | =cut |
1224 | =cut |
728 | |
1225 | |
729 | package AnyEvent; |
1226 | package AnyEvent; |
730 | |
1227 | |
731 | no warnings; |
1228 | # basically a tuned-down version of common::sense |
732 | use strict; |
1229 | sub common_sense { |
|
|
1230 | # from common:.sense 3.4 |
|
|
1231 | ${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00"; |
|
|
1232 | # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl) |
|
|
1233 | $^H |= 0x00000600; |
|
|
1234 | } |
733 | |
1235 | |
|
|
1236 | BEGIN { AnyEvent::common_sense } |
|
|
1237 | |
734 | use Carp; |
1238 | use Carp (); |
735 | |
1239 | |
736 | our $VERSION = '4.03'; |
1240 | our $VERSION = '6.02'; |
737 | our $MODEL; |
1241 | our $MODEL; |
738 | |
1242 | |
739 | our $AUTOLOAD; |
|
|
740 | our @ISA; |
1243 | our @ISA; |
741 | |
1244 | |
742 | our @REGISTRY; |
1245 | our @REGISTRY; |
743 | |
1246 | |
744 | our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; |
1247 | our $VERBOSE; |
|
|
1248 | |
|
|
1249 | BEGIN { |
|
|
1250 | require "AnyEvent/constants.pl"; |
|
|
1251 | |
|
|
1252 | eval "sub TAINT (){" . (${^TAINT}*1) . "}"; |
|
|
1253 | |
|
|
1254 | delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} |
|
|
1255 | if ${^TAINT}; |
|
|
1256 | |
|
|
1257 | $ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"} |
|
|
1258 | for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV; |
|
|
1259 | |
|
|
1260 | @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = () |
|
|
1261 | if ${^TAINT}; |
|
|
1262 | |
|
|
1263 | # $ENV{PERL_ANYEVENT_xxx} now valid |
|
|
1264 | |
|
|
1265 | $VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 3; |
|
|
1266 | } |
|
|
1267 | |
|
|
1268 | our $MAX_SIGNAL_LATENCY = 10; |
745 | |
1269 | |
746 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
1270 | our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred |
747 | |
1271 | |
748 | { |
1272 | { |
749 | my $idx; |
1273 | my $idx; |
750 | $PROTOCOL{$_} = ++$idx |
1274 | $PROTOCOL{$_} = ++$idx |
751 | for reverse split /\s*,\s*/, |
1275 | for reverse split /\s*,\s*/, |
752 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
1276 | $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; |
753 | } |
1277 | } |
754 | |
1278 | |
|
|
1279 | our @post_detect; |
|
|
1280 | |
|
|
1281 | sub post_detect(&) { |
|
|
1282 | my ($cb) = @_; |
|
|
1283 | |
|
|
1284 | push @post_detect, $cb; |
|
|
1285 | |
|
|
1286 | defined wantarray |
|
|
1287 | ? bless \$cb, "AnyEvent::Util::postdetect" |
|
|
1288 | : () |
|
|
1289 | } |
|
|
1290 | |
|
|
1291 | sub AnyEvent::Util::postdetect::DESTROY { |
|
|
1292 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
|
|
1293 | } |
|
|
1294 | |
|
|
1295 | our $POSTPONE_W; |
|
|
1296 | our @POSTPONE; |
|
|
1297 | |
|
|
1298 | sub _postpone_exec { |
|
|
1299 | undef $POSTPONE_W; |
|
|
1300 | |
|
|
1301 | &{ shift @POSTPONE } |
|
|
1302 | while @POSTPONE; |
|
|
1303 | } |
|
|
1304 | |
|
|
1305 | sub postpone(&) { |
|
|
1306 | push @POSTPONE, shift; |
|
|
1307 | |
|
|
1308 | $POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec); |
|
|
1309 | |
|
|
1310 | () |
|
|
1311 | } |
|
|
1312 | |
|
|
1313 | sub log($$;@) { |
|
|
1314 | # only load the big bloated module when we actually are about to log something |
|
|
1315 | if ($_[0] <= $VERBOSE) { # also catches non-numeric levels(!) |
|
|
1316 | require AnyEvent::Log; |
|
|
1317 | # AnyEvent::Log overwrites this function |
|
|
1318 | goto &log; |
|
|
1319 | } |
|
|
1320 | |
|
|
1321 | 0 # not logged |
|
|
1322 | } |
|
|
1323 | |
|
|
1324 | if (length $ENV{PERL_ANYEVENT_LOG}) { |
|
|
1325 | require AnyEvent::Log; # AnyEvent::Log does the thing for us |
|
|
1326 | } |
|
|
1327 | |
755 | my @models = ( |
1328 | our @models = ( |
756 | [EV:: => AnyEvent::Impl::EV::], |
1329 | [EV:: => AnyEvent::Impl::EV:: , 1], |
757 | [Event:: => AnyEvent::Impl::Event::], |
1330 | [AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1], |
758 | [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], |
|
|
759 | # everything below here will not be autoprobed |
1331 | # everything below here will not (normally) be autoprobed |
760 | # as the pureperl backend should work everywhere |
1332 | # as the pure perl backend should work everywhere |
761 | # and is usually faster |
1333 | # and is usually faster |
|
|
1334 | [Event:: => AnyEvent::Impl::Event::, 1], |
|
|
1335 | [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers |
|
|
1336 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
|
|
1337 | [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package |
762 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
1338 | [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles |
763 | [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers |
|
|
764 | [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy |
|
|
765 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
1339 | [Qt:: => AnyEvent::Impl::Qt::], # requires special main program |
766 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
1340 | [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza |
767 | [Wx:: => AnyEvent::Impl::POE::], |
1341 | [Wx:: => AnyEvent::Impl::POE::], |
768 | [Prima:: => AnyEvent::Impl::POE::], |
1342 | [Prima:: => AnyEvent::Impl::POE::], |
|
|
1343 | [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect |
|
|
1344 | [Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::], |
|
|
1345 | [FLTK:: => AnyEvent::Impl::FLTK::], |
769 | ); |
1346 | ); |
770 | |
1347 | |
771 | our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); |
1348 | our @isa_hook; |
772 | |
1349 | |
773 | our @post_detect; |
1350 | sub _isa_set { |
|
|
1351 | my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL); |
774 | |
1352 | |
|
|
1353 | @{"$pkg[$_-1]::ISA"} = $pkg[$_] |
|
|
1354 | for 1 .. $#pkg; |
|
|
1355 | |
|
|
1356 | grep $_ && $_->[1], @isa_hook |
|
|
1357 | and AE::_reset (); |
|
|
1358 | } |
|
|
1359 | |
|
|
1360 | # used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy |
|
|
1361 | sub _isa_hook($$;$) { |
|
|
1362 | my ($i, $pkg, $reset_ae) = @_; |
|
|
1363 | |
|
|
1364 | $isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef; |
|
|
1365 | |
|
|
1366 | _isa_set; |
|
|
1367 | } |
|
|
1368 | |
|
|
1369 | # all autoloaded methods reserve the complete glob, not just the method slot. |
|
|
1370 | # due to bugs in perls method cache implementation. |
|
|
1371 | our @methods = qw(io timer time now now_update signal child idle condvar); |
|
|
1372 | |
775 | sub post_detect(&) { |
1373 | sub detect() { |
776 | my ($cb) = @_; |
1374 | return $MODEL if $MODEL; # some programs keep references to detect |
777 | |
1375 | |
778 | if ($MODEL) { |
1376 | local $!; # for good measure |
779 | $cb->(); |
1377 | local $SIG{__DIE__}; # we use eval |
780 | |
1378 | |
781 | 1 |
1379 | # free some memory |
|
|
1380 | *detect = sub () { $MODEL }; |
|
|
1381 | # undef &func doesn't correctly update the method cache. grmbl. |
|
|
1382 | # so we delete the whole glob. grmbl. |
|
|
1383 | # otoh, perl doesn't let me undef an active usb, but it lets me free |
|
|
1384 | # a glob with an active sub. hrm. i hope it works, but perl is |
|
|
1385 | # usually buggy in this department. sigh. |
|
|
1386 | delete @{"AnyEvent::"}{@methods}; |
|
|
1387 | undef @methods; |
|
|
1388 | |
|
|
1389 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) { |
|
|
1390 | my $model = $1; |
|
|
1391 | $model = "AnyEvent::Impl::$model" unless $model =~ s/::$//; |
|
|
1392 | if (eval "require $model") { |
|
|
1393 | AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it."; |
|
|
1394 | $MODEL = $model; |
782 | } else { |
1395 | } else { |
783 | push @post_detect, $cb; |
1396 | AnyEvent::log 5 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@"; |
784 | |
1397 | } |
785 | defined wantarray |
|
|
786 | ? bless \$cb, "AnyEvent::Util::PostDetect" |
|
|
787 | : () |
|
|
788 | } |
1398 | } |
789 | } |
|
|
790 | |
1399 | |
791 | sub AnyEvent::Util::PostDetect::DESTROY { |
1400 | # check for already loaded models |
792 | @post_detect = grep $_ != ${$_[0]}, @post_detect; |
|
|
793 | } |
|
|
794 | |
|
|
795 | sub detect() { |
|
|
796 | unless ($MODEL) { |
1401 | unless ($MODEL) { |
797 | no strict 'refs'; |
1402 | for (@REGISTRY, @models) { |
798 | |
1403 | my ($package, $model) = @$_; |
799 | if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { |
1404 | if (${"$package\::VERSION"} > 0) { |
800 | my $model = "AnyEvent::Impl::$1"; |
|
|
801 | if (eval "require $model") { |
1405 | if (eval "require $model") { |
|
|
1406 | AnyEvent::log 7 => "autodetected model '$model', using it."; |
802 | $MODEL = $model; |
1407 | $MODEL = $model; |
803 | warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; |
1408 | last; |
804 | } else { |
1409 | } |
805 | warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; |
|
|
806 | } |
1410 | } |
807 | } |
1411 | } |
808 | |
1412 | |
809 | # check for already loaded models |
|
|
810 | unless ($MODEL) { |
1413 | unless ($MODEL) { |
|
|
1414 | # try to autoload a model |
811 | for (@REGISTRY, @models) { |
1415 | for (@REGISTRY, @models) { |
812 | my ($package, $model) = @$_; |
1416 | my ($package, $model, $autoload) = @$_; |
|
|
1417 | if ( |
|
|
1418 | $autoload |
|
|
1419 | and eval "require $package" |
813 | if (${"$package\::VERSION"} > 0) { |
1420 | and ${"$package\::VERSION"} > 0 |
814 | if (eval "require $model") { |
1421 | and eval "require $model" |
|
|
1422 | ) { |
|
|
1423 | AnyEvent::log 7 => "autoloaded model '$model', using it."; |
815 | $MODEL = $model; |
1424 | $MODEL = $model; |
816 | warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; |
|
|
817 | last; |
1425 | last; |
818 | } |
|
|
819 | } |
1426 | } |
820 | } |
1427 | } |
821 | |
1428 | |
822 | unless ($MODEL) { |
1429 | $MODEL |
823 | # try to load a model |
1430 | or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?"; |
|
|
1431 | } |
|
|
1432 | } |
824 | |
1433 | |
825 | for (@REGISTRY, @models) { |
1434 | # free memory only needed for probing |
826 | my ($package, $model) = @$_; |
1435 | undef @models; |
827 | if (eval "require $package" |
1436 | undef @REGISTRY; |
828 | and ${"$package\::VERSION"} > 0 |
1437 | |
829 | and eval "require $model") { |
1438 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
830 | $MODEL = $model; |
1439 | |
831 | warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; |
1440 | # now nuke some methods that are overridden by the backend. |
|
|
1441 | # SUPER usage is not allowed in these. |
|
|
1442 | for (qw(time signal child idle)) { |
|
|
1443 | undef &{"AnyEvent::Base::$_"} |
|
|
1444 | if defined &{"$MODEL\::$_"}; |
|
|
1445 | } |
|
|
1446 | |
|
|
1447 | _isa_set; |
|
|
1448 | |
|
|
1449 | # we're officially open! |
|
|
1450 | |
|
|
1451 | if ($ENV{PERL_ANYEVENT_STRICT}) { |
|
|
1452 | require AnyEvent::Strict; |
|
|
1453 | } |
|
|
1454 | |
|
|
1455 | if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) { |
|
|
1456 | require AnyEvent::Debug; |
|
|
1457 | AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP}); |
|
|
1458 | } |
|
|
1459 | |
|
|
1460 | if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) { |
|
|
1461 | require AnyEvent::Socket; |
|
|
1462 | require AnyEvent::Debug; |
|
|
1463 | |
|
|
1464 | my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL}; |
|
|
1465 | $shell =~ s/\$\$/$$/g; |
|
|
1466 | |
|
|
1467 | my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell); |
|
|
1468 | $AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service); |
|
|
1469 | } |
|
|
1470 | |
|
|
1471 | # now the anyevent environment is set up as the user told us to, so |
|
|
1472 | # call the actual user code - post detects |
|
|
1473 | |
|
|
1474 | (shift @post_detect)->() while @post_detect; |
|
|
1475 | undef @post_detect; |
|
|
1476 | |
|
|
1477 | *post_detect = sub(&) { |
|
|
1478 | shift->(); |
|
|
1479 | |
|
|
1480 | undef |
|
|
1481 | }; |
|
|
1482 | |
|
|
1483 | $MODEL |
|
|
1484 | } |
|
|
1485 | |
|
|
1486 | for my $name (@methods) { |
|
|
1487 | *$name = sub { |
|
|
1488 | detect; |
|
|
1489 | # we use goto because |
|
|
1490 | # a) it makes the thunk more transparent |
|
|
1491 | # b) it allows us to delete the thunk later |
|
|
1492 | goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" } |
|
|
1493 | }; |
|
|
1494 | } |
|
|
1495 | |
|
|
1496 | # utility function to dup a filehandle. this is used by many backends |
|
|
1497 | # to support binding more than one watcher per filehandle (they usually |
|
|
1498 | # allow only one watcher per fd, so we dup it to get a different one). |
|
|
1499 | sub _dupfh($$;$$) { |
|
|
1500 | my ($poll, $fh, $r, $w) = @_; |
|
|
1501 | |
|
|
1502 | # cygwin requires the fh mode to be matching, unix doesn't |
|
|
1503 | my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&"); |
|
|
1504 | |
|
|
1505 | open my $fh2, $mode, $fh |
|
|
1506 | or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; |
|
|
1507 | |
|
|
1508 | # we assume CLOEXEC is already set by perl in all important cases |
|
|
1509 | |
|
|
1510 | ($fh2, $rw) |
|
|
1511 | } |
|
|
1512 | |
|
|
1513 | =head1 SIMPLIFIED AE API |
|
|
1514 | |
|
|
1515 | Starting with version 5.0, AnyEvent officially supports a second, much |
|
|
1516 | simpler, API that is designed to reduce the calling, typing and memory |
|
|
1517 | overhead by using function call syntax and a fixed number of parameters. |
|
|
1518 | |
|
|
1519 | See the L<AE> manpage for details. |
|
|
1520 | |
|
|
1521 | =cut |
|
|
1522 | |
|
|
1523 | package AE; |
|
|
1524 | |
|
|
1525 | our $VERSION = $AnyEvent::VERSION; |
|
|
1526 | |
|
|
1527 | sub _reset() { |
|
|
1528 | eval q{ |
|
|
1529 | # fall back to the main API by default - backends and AnyEvent::Base |
|
|
1530 | # implementations can overwrite these. |
|
|
1531 | |
|
|
1532 | sub io($$$) { |
|
|
1533 | AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2]) |
|
|
1534 | } |
|
|
1535 | |
|
|
1536 | sub timer($$$) { |
|
|
1537 | AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]) |
|
|
1538 | } |
|
|
1539 | |
|
|
1540 | sub signal($$) { |
|
|
1541 | AnyEvent->signal (signal => $_[0], cb => $_[1]) |
|
|
1542 | } |
|
|
1543 | |
|
|
1544 | sub child($$) { |
|
|
1545 | AnyEvent->child (pid => $_[0], cb => $_[1]) |
|
|
1546 | } |
|
|
1547 | |
|
|
1548 | sub idle($) { |
|
|
1549 | AnyEvent->idle (cb => $_[0]); |
|
|
1550 | } |
|
|
1551 | |
|
|
1552 | sub cv(;&) { |
|
|
1553 | AnyEvent->condvar (@_ ? (cb => $_[0]) : ()) |
|
|
1554 | } |
|
|
1555 | |
|
|
1556 | sub now() { |
|
|
1557 | AnyEvent->now |
|
|
1558 | } |
|
|
1559 | |
|
|
1560 | sub now_update() { |
|
|
1561 | AnyEvent->now_update |
|
|
1562 | } |
|
|
1563 | |
|
|
1564 | sub time() { |
|
|
1565 | AnyEvent->time |
|
|
1566 | } |
|
|
1567 | |
|
|
1568 | *postpone = \&AnyEvent::postpone; |
|
|
1569 | *log = \&AnyEvent::log; |
|
|
1570 | }; |
|
|
1571 | die if $@; |
|
|
1572 | } |
|
|
1573 | |
|
|
1574 | BEGIN { _reset } |
|
|
1575 | |
|
|
1576 | package AnyEvent::Base; |
|
|
1577 | |
|
|
1578 | # default implementations for many methods |
|
|
1579 | |
|
|
1580 | sub time { |
|
|
1581 | eval q{ # poor man's autoloading {} |
|
|
1582 | # probe for availability of Time::HiRes |
|
|
1583 | if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { |
|
|
1584 | *time = sub { Time::HiRes::time () }; |
|
|
1585 | *AE::time = \& Time::HiRes::time ; |
|
|
1586 | *now = \&time; |
|
|
1587 | AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy."; |
|
|
1588 | # if (eval "use POSIX (); (POSIX::times())... |
|
|
1589 | } else { |
|
|
1590 | *time = sub { CORE::time }; |
|
|
1591 | *AE::time = sub (){ CORE::time }; |
|
|
1592 | *now = \&time; |
|
|
1593 | AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!"; |
|
|
1594 | } |
|
|
1595 | }; |
|
|
1596 | die if $@; |
|
|
1597 | |
|
|
1598 | &time |
|
|
1599 | } |
|
|
1600 | |
|
|
1601 | *now = \&time; |
|
|
1602 | sub now_update { } |
|
|
1603 | |
|
|
1604 | sub _poll { |
|
|
1605 | Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught"; |
|
|
1606 | } |
|
|
1607 | |
|
|
1608 | # default implementation for ->condvar |
|
|
1609 | # in fact, the default should not be overwritten |
|
|
1610 | |
|
|
1611 | sub condvar { |
|
|
1612 | eval q{ # poor man's autoloading {} |
|
|
1613 | *condvar = sub { |
|
|
1614 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" |
|
|
1615 | }; |
|
|
1616 | |
|
|
1617 | *AE::cv = sub (;&) { |
|
|
1618 | bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar" |
|
|
1619 | }; |
|
|
1620 | }; |
|
|
1621 | die if $@; |
|
|
1622 | |
|
|
1623 | &condvar |
|
|
1624 | } |
|
|
1625 | |
|
|
1626 | # default implementation for ->signal |
|
|
1627 | |
|
|
1628 | our $HAVE_ASYNC_INTERRUPT; |
|
|
1629 | |
|
|
1630 | sub _have_async_interrupt() { |
|
|
1631 | $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} |
|
|
1632 | && eval "use Async::Interrupt 1.02 (); 1") |
|
|
1633 | unless defined $HAVE_ASYNC_INTERRUPT; |
|
|
1634 | |
|
|
1635 | $HAVE_ASYNC_INTERRUPT |
|
|
1636 | } |
|
|
1637 | |
|
|
1638 | our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); |
|
|
1639 | our (%SIG_ASY, %SIG_ASY_W); |
|
|
1640 | our ($SIG_COUNT, $SIG_TW); |
|
|
1641 | |
|
|
1642 | # install a dummy wakeup watcher to reduce signal catching latency |
|
|
1643 | # used by Impls |
|
|
1644 | sub _sig_add() { |
|
|
1645 | unless ($SIG_COUNT++) { |
|
|
1646 | # try to align timer on a full-second boundary, if possible |
|
|
1647 | my $NOW = AE::now; |
|
|
1648 | |
|
|
1649 | $SIG_TW = AE::timer |
|
|
1650 | $MAX_SIGNAL_LATENCY - ($NOW - int $NOW), |
|
|
1651 | $MAX_SIGNAL_LATENCY, |
|
|
1652 | sub { } # just for the PERL_ASYNC_CHECK |
|
|
1653 | ; |
|
|
1654 | } |
|
|
1655 | } |
|
|
1656 | |
|
|
1657 | sub _sig_del { |
|
|
1658 | undef $SIG_TW |
|
|
1659 | unless --$SIG_COUNT; |
|
|
1660 | } |
|
|
1661 | |
|
|
1662 | our $_sig_name_init; $_sig_name_init = sub { |
|
|
1663 | eval q{ # poor man's autoloading {} |
|
|
1664 | undef $_sig_name_init; |
|
|
1665 | |
|
|
1666 | if (_have_async_interrupt) { |
|
|
1667 | *sig2num = \&Async::Interrupt::sig2num; |
|
|
1668 | *sig2name = \&Async::Interrupt::sig2name; |
|
|
1669 | } else { |
|
|
1670 | require Config; |
|
|
1671 | |
|
|
1672 | my %signame2num; |
|
|
1673 | @signame2num{ split ' ', $Config::Config{sig_name} } |
|
|
1674 | = split ' ', $Config::Config{sig_num}; |
|
|
1675 | |
|
|
1676 | my @signum2name; |
|
|
1677 | @signum2name[values %signame2num] = keys %signame2num; |
|
|
1678 | |
|
|
1679 | *sig2num = sub($) { |
|
|
1680 | $_[0] > 0 ? shift : $signame2num{+shift} |
|
|
1681 | }; |
|
|
1682 | *sig2name = sub ($) { |
|
|
1683 | $_[0] > 0 ? $signum2name[+shift] : shift |
|
|
1684 | }; |
|
|
1685 | } |
|
|
1686 | }; |
|
|
1687 | die if $@; |
|
|
1688 | }; |
|
|
1689 | |
|
|
1690 | sub sig2num ($) { &$_sig_name_init; &sig2num } |
|
|
1691 | sub sig2name($) { &$_sig_name_init; &sig2name } |
|
|
1692 | |
|
|
1693 | sub signal { |
|
|
1694 | eval q{ # poor man's autoloading {} |
|
|
1695 | # probe for availability of Async::Interrupt |
|
|
1696 | if (_have_async_interrupt) { |
|
|
1697 | AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling."; |
|
|
1698 | |
|
|
1699 | $SIGPIPE_R = new Async::Interrupt::EventPipe; |
|
|
1700 | $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec; |
|
|
1701 | |
|
|
1702 | } else { |
|
|
1703 | AnyEvent::log 8 => "using emulated perl signal handling with latency timer."; |
|
|
1704 | |
|
|
1705 | if (AnyEvent::WIN32) { |
|
|
1706 | require AnyEvent::Util; |
|
|
1707 | |
|
|
1708 | ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); |
|
|
1709 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R; |
|
|
1710 | AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case |
|
|
1711 | } else { |
|
|
1712 | pipe $SIGPIPE_R, $SIGPIPE_W; |
|
|
1713 | fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R; |
|
|
1714 | fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case |
|
|
1715 | |
|
|
1716 | # not strictly required, as $^F is normally 2, but let's make sure... |
|
|
1717 | fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC; |
|
|
1718 | fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC; |
|
|
1719 | } |
|
|
1720 | |
|
|
1721 | $SIGPIPE_R |
|
|
1722 | or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; |
|
|
1723 | |
|
|
1724 | $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec; |
|
|
1725 | } |
|
|
1726 | |
|
|
1727 | *signal = $HAVE_ASYNC_INTERRUPT |
|
|
1728 | ? sub { |
|
|
1729 | my (undef, %arg) = @_; |
|
|
1730 | |
|
|
1731 | # async::interrupt |
|
|
1732 | my $signal = sig2num $arg{signal}; |
|
|
1733 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
1734 | |
|
|
1735 | $SIG_ASY{$signal} ||= new Async::Interrupt |
|
|
1736 | cb => sub { undef $SIG_EV{$signal} }, |
|
|
1737 | signal => $signal, |
|
|
1738 | pipe => [$SIGPIPE_R->filenos], |
|
|
1739 | pipe_autodrain => 0, |
|
|
1740 | ; |
|
|
1741 | |
|
|
1742 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
|
|
1743 | } |
|
|
1744 | : sub { |
|
|
1745 | my (undef, %arg) = @_; |
|
|
1746 | |
|
|
1747 | # pure perl |
|
|
1748 | my $signal = sig2name $arg{signal}; |
|
|
1749 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
1750 | |
|
|
1751 | $SIG{$signal} ||= sub { |
832 | last; |
1752 | local $!; |
|
|
1753 | syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; |
|
|
1754 | undef $SIG_EV{$signal}; |
833 | } |
1755 | }; |
|
|
1756 | |
|
|
1757 | # can't do signal processing without introducing races in pure perl, |
|
|
1758 | # so limit the signal latency. |
|
|
1759 | _sig_add; |
|
|
1760 | |
|
|
1761 | bless [$signal, $arg{cb}], "AnyEvent::Base::signal" |
|
|
1762 | } |
|
|
1763 | ; |
|
|
1764 | |
|
|
1765 | *AnyEvent::Base::signal::DESTROY = sub { |
|
|
1766 | my ($signal, $cb) = @{$_[0]}; |
|
|
1767 | |
|
|
1768 | _sig_del; |
|
|
1769 | |
|
|
1770 | delete $SIG_CB{$signal}{$cb}; |
|
|
1771 | |
|
|
1772 | $HAVE_ASYNC_INTERRUPT |
|
|
1773 | ? delete $SIG_ASY{$signal} |
|
|
1774 | : # delete doesn't work with older perls - they then |
|
|
1775 | # print weird messages, or just unconditionally exit |
|
|
1776 | # instead of getting the default action. |
|
|
1777 | undef $SIG{$signal} |
|
|
1778 | unless keys %{ $SIG_CB{$signal} }; |
|
|
1779 | }; |
|
|
1780 | |
|
|
1781 | *_signal_exec = sub { |
|
|
1782 | $HAVE_ASYNC_INTERRUPT |
|
|
1783 | ? $SIGPIPE_R->drain |
|
|
1784 | : sysread $SIGPIPE_R, (my $dummy), 9; |
|
|
1785 | |
|
|
1786 | while (%SIG_EV) { |
|
|
1787 | for (keys %SIG_EV) { |
|
|
1788 | delete $SIG_EV{$_}; |
|
|
1789 | &$_ for values %{ $SIG_CB{$_} || {} }; |
834 | } |
1790 | } |
835 | |
|
|
836 | $MODEL |
|
|
837 | or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; |
|
|
838 | } |
1791 | } |
839 | } |
1792 | }; |
840 | |
|
|
841 | unshift @ISA, $MODEL; |
|
|
842 | push @{"$MODEL\::ISA"}, "AnyEvent::Base"; |
|
|
843 | |
|
|
844 | (shift @post_detect)->() while @post_detect; |
|
|
845 | } |
|
|
846 | |
|
|
847 | $MODEL |
|
|
848 | } |
|
|
849 | |
|
|
850 | sub AUTOLOAD { |
|
|
851 | (my $func = $AUTOLOAD) =~ s/.*://; |
|
|
852 | |
|
|
853 | $method{$func} |
|
|
854 | or croak "$func: not a valid method for AnyEvent objects"; |
|
|
855 | |
|
|
856 | detect unless $MODEL; |
|
|
857 | |
|
|
858 | my $class = shift; |
|
|
859 | $class->$func (@_); |
|
|
860 | } |
|
|
861 | |
|
|
862 | package AnyEvent::Base; |
|
|
863 | |
|
|
864 | # default implementation for ->condvar |
|
|
865 | |
|
|
866 | sub condvar { |
|
|
867 | bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: |
|
|
868 | } |
|
|
869 | |
|
|
870 | # default implementation for ->signal |
|
|
871 | |
|
|
872 | our %SIG_CB; |
|
|
873 | |
|
|
874 | sub signal { |
|
|
875 | my (undef, %arg) = @_; |
|
|
876 | |
|
|
877 | my $signal = uc $arg{signal} |
|
|
878 | or Carp::croak "required option 'signal' is missing"; |
|
|
879 | |
|
|
880 | $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; |
|
|
881 | $SIG{$signal} ||= sub { |
|
|
882 | $_->() for values %{ $SIG_CB{$signal} || {} }; |
|
|
883 | }; |
1793 | }; |
|
|
1794 | die if $@; |
884 | |
1795 | |
885 | bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" |
1796 | &signal |
886 | } |
|
|
887 | |
|
|
888 | sub AnyEvent::Base::Signal::DESTROY { |
|
|
889 | my ($signal, $cb) = @{$_[0]}; |
|
|
890 | |
|
|
891 | delete $SIG_CB{$signal}{$cb}; |
|
|
892 | |
|
|
893 | $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; |
|
|
894 | } |
1797 | } |
895 | |
1798 | |
896 | # default implementation for ->child |
1799 | # default implementation for ->child |
897 | |
1800 | |
898 | our %PID_CB; |
1801 | our %PID_CB; |
899 | our $CHLD_W; |
1802 | our $CHLD_W; |
900 | our $CHLD_DELAY_W; |
1803 | our $CHLD_DELAY_W; |
901 | our $PID_IDLE; |
|
|
902 | our $WNOHANG; |
|
|
903 | |
1804 | |
904 | sub _child_wait { |
1805 | # used by many Impl's |
905 | while (0 < (my $pid = waitpid -1, $WNOHANG)) { |
1806 | sub _emit_childstatus($$) { |
|
|
1807 | my (undef, $rpid, $rstatus) = @_; |
|
|
1808 | |
|
|
1809 | $_->($rpid, $rstatus) |
906 | $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), |
1810 | for values %{ $PID_CB{$rpid} || {} }, |
907 | (values %{ $PID_CB{0} || {} }); |
1811 | values %{ $PID_CB{0} || {} }; |
908 | } |
|
|
909 | |
|
|
910 | undef $PID_IDLE; |
|
|
911 | } |
|
|
912 | |
|
|
913 | sub _sigchld { |
|
|
914 | # make sure we deliver these changes "synchronous" with the event loop. |
|
|
915 | $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { |
|
|
916 | undef $CHLD_DELAY_W; |
|
|
917 | &_child_wait; |
|
|
918 | }); |
|
|
919 | } |
1812 | } |
920 | |
1813 | |
921 | sub child { |
1814 | sub child { |
|
|
1815 | eval q{ # poor man's autoloading {} |
|
|
1816 | *_sigchld = sub { |
|
|
1817 | my $pid; |
|
|
1818 | |
|
|
1819 | AnyEvent->_emit_childstatus ($pid, $?) |
|
|
1820 | while ($pid = waitpid -1, WNOHANG) > 0; |
|
|
1821 | }; |
|
|
1822 | |
|
|
1823 | *child = sub { |
922 | my (undef, %arg) = @_; |
1824 | my (undef, %arg) = @_; |
923 | |
1825 | |
924 | defined (my $pid = $arg{pid} + 0) |
1826 | my $pid = $arg{pid}; |
925 | or Carp::croak "required option 'pid' is missing"; |
1827 | my $cb = $arg{cb}; |
926 | |
1828 | |
927 | $PID_CB{$pid}{$arg{cb}} = $arg{cb}; |
1829 | $PID_CB{$pid}{$cb+0} = $cb; |
928 | |
1830 | |
929 | unless ($WNOHANG) { |
|
|
930 | $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; |
|
|
931 | } |
|
|
932 | |
|
|
933 | unless ($CHLD_W) { |
1831 | unless ($CHLD_W) { |
934 | $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); |
1832 | $CHLD_W = AE::signal CHLD => \&_sigchld; |
935 | # child could be a zombie already, so make at least one round |
1833 | # child could be a zombie already, so make at least one round |
936 | &_sigchld; |
1834 | &_sigchld; |
937 | } |
1835 | } |
938 | |
1836 | |
939 | bless [$pid, $arg{cb}], "AnyEvent::Base::Child" |
1837 | bless [$pid, $cb+0], "AnyEvent::Base::child" |
940 | } |
1838 | }; |
941 | |
1839 | |
942 | sub AnyEvent::Base::Child::DESTROY { |
1840 | *AnyEvent::Base::child::DESTROY = sub { |
943 | my ($pid, $cb) = @{$_[0]}; |
1841 | my ($pid, $icb) = @{$_[0]}; |
944 | |
1842 | |
945 | delete $PID_CB{$pid}{$cb}; |
1843 | delete $PID_CB{$pid}{$icb}; |
946 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
1844 | delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; |
947 | |
1845 | |
948 | undef $CHLD_W unless keys %PID_CB; |
1846 | undef $CHLD_W unless keys %PID_CB; |
|
|
1847 | }; |
|
|
1848 | }; |
|
|
1849 | die if $@; |
|
|
1850 | |
|
|
1851 | &child |
|
|
1852 | } |
|
|
1853 | |
|
|
1854 | # idle emulation is done by simply using a timer, regardless |
|
|
1855 | # of whether the process is idle or not, and not letting |
|
|
1856 | # the callback use more than 50% of the time. |
|
|
1857 | sub idle { |
|
|
1858 | eval q{ # poor man's autoloading {} |
|
|
1859 | *idle = sub { |
|
|
1860 | my (undef, %arg) = @_; |
|
|
1861 | |
|
|
1862 | my ($cb, $w, $rcb) = $arg{cb}; |
|
|
1863 | |
|
|
1864 | $rcb = sub { |
|
|
1865 | if ($cb) { |
|
|
1866 | $w = AE::time; |
|
|
1867 | &$cb; |
|
|
1868 | $w = AE::time - $w; |
|
|
1869 | |
|
|
1870 | # never use more then 50% of the time for the idle watcher, |
|
|
1871 | # within some limits |
|
|
1872 | $w = 0.0001 if $w < 0.0001; |
|
|
1873 | $w = 5 if $w > 5; |
|
|
1874 | |
|
|
1875 | $w = AE::timer $w, 0, $rcb; |
|
|
1876 | } else { |
|
|
1877 | # clean up... |
|
|
1878 | undef $w; |
|
|
1879 | undef $rcb; |
|
|
1880 | } |
|
|
1881 | }; |
|
|
1882 | |
|
|
1883 | $w = AE::timer 0.05, 0, $rcb; |
|
|
1884 | |
|
|
1885 | bless \\$cb, "AnyEvent::Base::idle" |
|
|
1886 | }; |
|
|
1887 | |
|
|
1888 | *AnyEvent::Base::idle::DESTROY = sub { |
|
|
1889 | undef $${$_[0]}; |
|
|
1890 | }; |
|
|
1891 | }; |
|
|
1892 | die if $@; |
|
|
1893 | |
|
|
1894 | &idle |
949 | } |
1895 | } |
950 | |
1896 | |
951 | package AnyEvent::CondVar; |
1897 | package AnyEvent::CondVar; |
952 | |
1898 | |
953 | our @ISA = AnyEvent::CondVar::Base::; |
1899 | our @ISA = AnyEvent::CondVar::Base::; |
954 | |
1900 | |
|
|
1901 | # only to be used for subclassing |
|
|
1902 | sub new { |
|
|
1903 | my $class = shift; |
|
|
1904 | bless AnyEvent->condvar (@_), $class |
|
|
1905 | } |
|
|
1906 | |
955 | package AnyEvent::CondVar::Base; |
1907 | package AnyEvent::CondVar::Base; |
956 | |
1908 | |
957 | use overload |
1909 | #use overload |
958 | '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
1910 | # '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, |
959 | fallback => 1; |
1911 | # fallback => 1; |
|
|
1912 | |
|
|
1913 | # save 300+ kilobytes by dirtily hardcoding overloading |
|
|
1914 | ${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching. |
|
|
1915 | *{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod." |
|
|
1916 | *{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{} |
|
|
1917 | ${'AnyEvent::CondVar::Base::()'} = 1; # fallback |
|
|
1918 | |
|
|
1919 | our $WAITING; |
960 | |
1920 | |
961 | sub _send { |
1921 | sub _send { |
962 | # nop |
1922 | # nop |
|
|
1923 | } |
|
|
1924 | |
|
|
1925 | sub _wait { |
|
|
1926 | AnyEvent->_poll until $_[0]{_ae_sent}; |
963 | } |
1927 | } |
964 | |
1928 | |
965 | sub send { |
1929 | sub send { |
966 | my $cv = shift; |
1930 | my $cv = shift; |
967 | $cv->{_ae_sent} = [@_]; |
1931 | $cv->{_ae_sent} = [@_]; |
… | |
… | |
976 | |
1940 | |
977 | sub ready { |
1941 | sub ready { |
978 | $_[0]{_ae_sent} |
1942 | $_[0]{_ae_sent} |
979 | } |
1943 | } |
980 | |
1944 | |
981 | sub _wait { |
|
|
982 | AnyEvent->one_event while !$_[0]{_ae_sent}; |
|
|
983 | } |
|
|
984 | |
|
|
985 | sub recv { |
1945 | sub recv { |
|
|
1946 | unless ($_[0]{_ae_sent}) { |
|
|
1947 | $WAITING |
|
|
1948 | and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted"; |
|
|
1949 | |
|
|
1950 | local $WAITING = 1; |
986 | $_[0]->_wait; |
1951 | $_[0]->_wait; |
|
|
1952 | } |
987 | |
1953 | |
988 | Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; |
1954 | $_[0]{_ae_croak} |
989 | wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] |
1955 | and Carp::croak $_[0]{_ae_croak}; |
|
|
1956 | |
|
|
1957 | wantarray |
|
|
1958 | ? @{ $_[0]{_ae_sent} } |
|
|
1959 | : $_[0]{_ae_sent}[0] |
990 | } |
1960 | } |
991 | |
1961 | |
992 | sub cb { |
1962 | sub cb { |
993 | $_[0]{_ae_cb} = $_[1] if @_ > 1; |
1963 | my $cv = shift; |
|
|
1964 | |
|
|
1965 | @_ |
|
|
1966 | and $cv->{_ae_cb} = shift |
|
|
1967 | and $cv->{_ae_sent} |
|
|
1968 | and (delete $cv->{_ae_cb})->($cv); |
|
|
1969 | |
994 | $_[0]{_ae_cb} |
1970 | $cv->{_ae_cb} |
995 | } |
1971 | } |
996 | |
1972 | |
997 | sub begin { |
1973 | sub begin { |
998 | ++$_[0]{_ae_counter}; |
1974 | ++$_[0]{_ae_counter}; |
999 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
1975 | $_[0]{_ae_end_cb} = $_[1] if @_ > 1; |
… | |
… | |
1004 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
1980 | &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; |
1005 | } |
1981 | } |
1006 | |
1982 | |
1007 | # undocumented/compatibility with pre-3.4 |
1983 | # undocumented/compatibility with pre-3.4 |
1008 | *broadcast = \&send; |
1984 | *broadcast = \&send; |
1009 | *wait = \&_wait; |
1985 | *wait = \&recv; |
|
|
1986 | |
|
|
1987 | =head1 ERROR AND EXCEPTION HANDLING |
|
|
1988 | |
|
|
1989 | In general, AnyEvent does not do any error handling - it relies on the |
|
|
1990 | caller to do that if required. The L<AnyEvent::Strict> module (see also |
|
|
1991 | the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict |
|
|
1992 | checking of all AnyEvent methods, however, which is highly useful during |
|
|
1993 | development. |
|
|
1994 | |
|
|
1995 | As for exception handling (i.e. runtime errors and exceptions thrown while |
|
|
1996 | executing a callback), this is not only highly event-loop specific, but |
|
|
1997 | also not in any way wrapped by this module, as this is the job of the main |
|
|
1998 | program. |
|
|
1999 | |
|
|
2000 | The pure perl event loop simply re-throws the exception (usually |
|
|
2001 | within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<< |
|
|
2002 | $Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and |
|
|
2003 | so on. |
|
|
2004 | |
|
|
2005 | =head1 ENVIRONMENT VARIABLES |
|
|
2006 | |
|
|
2007 | AnyEvent supports a number of environment variables that tune the |
|
|
2008 | runtime behaviour. They are usually evaluated when AnyEvent is |
|
|
2009 | loaded, initialised, or a submodule that uses them is loaded. Many of |
|
|
2010 | them also cause AnyEvent to load additional modules - for example, |
|
|
2011 | C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be |
|
|
2012 | loaded. |
|
|
2013 | |
|
|
2014 | All the environment variables documented here start with |
|
|
2015 | C<PERL_ANYEVENT_>, which is what AnyEvent considers its own |
|
|
2016 | namespace. Other modules are encouraged (but by no means required) to use |
|
|
2017 | C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule |
|
|
2018 | namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could |
|
|
2019 | be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env |
|
|
2020 | variables starting with C<AE_>, see below). |
|
|
2021 | |
|
|
2022 | All variables can also be set via the C<AE_> prefix, that is, instead |
|
|
2023 | of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In |
|
|
2024 | case there is a clash btween anyevent and another program that uses |
|
|
2025 | C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something> |
|
|
2026 | variable to the empty string, as those variables take precedence. |
|
|
2027 | |
|
|
2028 | When AnyEvent is first loaded, it copies all C<AE_xxx> env variables |
|
|
2029 | to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already |
|
|
2030 | exists. If taint mode is on, then AnyEvent will remove I<all> environment |
|
|
2031 | variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them |
|
|
2032 | with C<undef> or the empty string, if the corresaponding C<AE_> variable |
|
|
2033 | is set). |
|
|
2034 | |
|
|
2035 | The exact algorithm is currently: |
|
|
2036 | |
|
|
2037 | 1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV |
|
|
2038 | 2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists |
|
|
2039 | 3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef. |
|
|
2040 | |
|
|
2041 | This ensures that child processes will not see the C<AE_> variables. |
|
|
2042 | |
|
|
2043 | The following environment variables are currently known to AnyEvent: |
|
|
2044 | |
|
|
2045 | =over 4 |
|
|
2046 | |
|
|
2047 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
2048 | |
|
|
2049 | By default, AnyEvent will only log messages with loglevel C<3> |
|
|
2050 | (C<critical>) or higher (see L<AnyEvent::Log>). You can set this |
|
|
2051 | environment variable to a numerical loglevel to make AnyEvent more (or |
|
|
2052 | less) talkative. |
|
|
2053 | |
|
|
2054 | If you want to do more than just set the global logging level |
|
|
2055 | you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more |
|
|
2056 | complex specifications. |
|
|
2057 | |
|
|
2058 | When set to C<0> (C<off>), then no messages whatsoever will be logged with |
|
|
2059 | the default logging settings. |
|
|
2060 | |
|
|
2061 | When set to C<5> or higher (C<warn>), causes AnyEvent to warn about |
|
|
2062 | unexpected conditions, such as not being able to load the event model |
|
|
2063 | specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an |
|
|
2064 | exception - this is the minimum recommended level. |
|
|
2065 | |
|
|
2066 | When set to C<7> or higher (info), cause AnyEvent to report which event model it |
|
|
2067 | chooses. |
|
|
2068 | |
|
|
2069 | When set to C<8> or higher (debug), then AnyEvent will report extra information on |
|
|
2070 | which optional modules it loads and how it implements certain features. |
|
|
2071 | |
|
|
2072 | =item C<PERL_ANYEVENT_LOG> |
|
|
2073 | |
|
|
2074 | Accepts rather complex logging specifications. For example, you could log |
|
|
2075 | all C<debug> messages of some module to stderr, warnings and above to |
|
|
2076 | stderr, and errors and above to syslog, with: |
|
|
2077 | |
|
|
2078 | PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog |
|
|
2079 | |
|
|
2080 | For the rather extensive details, see L<AnyEvent::Log>. |
|
|
2081 | |
|
|
2082 | This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded, |
|
|
2083 | so will take effect even before AnyEvent has initialised itself. |
|
|
2084 | |
|
|
2085 | Note that specifying this environment variable causes the L<AnyEvent::Log> |
|
|
2086 | module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only |
|
|
2087 | using the latter saves a few hundred kB of memory until the first message |
|
|
2088 | is being logged. |
|
|
2089 | |
|
|
2090 | =item C<PERL_ANYEVENT_STRICT> |
|
|
2091 | |
|
|
2092 | AnyEvent does not do much argument checking by default, as thorough |
|
|
2093 | argument checking is very costly. Setting this variable to a true value |
|
|
2094 | will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly |
|
|
2095 | check the arguments passed to most method calls. If it finds any problems, |
|
|
2096 | it will croak. |
|
|
2097 | |
|
|
2098 | In other words, enables "strict" mode. |
|
|
2099 | |
|
|
2100 | Unlike C<use strict> (or its modern cousin, C<< use L<common::sense> |
|
|
2101 | >>, it is definitely recommended to keep it off in production. Keeping |
|
|
2102 | C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs |
|
|
2103 | can be very useful, however. |
|
|
2104 | |
|
|
2105 | =item C<PERL_ANYEVENT_DEBUG_SHELL> |
|
|
2106 | |
|
|
2107 | If this env variable is set, then its contents will be interpreted by |
|
|
2108 | C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of |
|
|
2109 | C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on |
|
|
2110 | that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>. |
|
|
2111 | |
|
|
2112 | This happens when the first watcher is created. |
|
|
2113 | |
|
|
2114 | For example, to bind a debug shell on a unix domain socket in |
|
|
2115 | F<< /tmp/debug<pid>.sock >>, you could use this: |
|
|
2116 | |
|
|
2117 | PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog |
|
|
2118 | |
|
|
2119 | Note that creating sockets in F</tmp> is very unsafe on multiuser |
|
|
2120 | systems. |
|
|
2121 | |
|
|
2122 | =item C<PERL_ANYEVENT_DEBUG_WRAP> |
|
|
2123 | |
|
|
2124 | Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for |
|
|
2125 | debugging purposes. See C<AnyEvent::Debug::wrap> for details. |
|
|
2126 | |
|
|
2127 | =item C<PERL_ANYEVENT_MODEL> |
|
|
2128 | |
|
|
2129 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
2130 | auto detection and -probing kicks in. |
|
|
2131 | |
|
|
2132 | It normally is a string consisting entirely of ASCII letters (e.g. C<EV> |
|
|
2133 | or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the |
|
|
2134 | resulting module name is loaded and - if the load was successful - used as |
|
|
2135 | event model backend. If it fails to load then AnyEvent will proceed with |
|
|
2136 | auto detection and -probing. |
|
|
2137 | |
|
|
2138 | If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then |
|
|
2139 | nothing gets prepended and the module name is used as-is (hint: C<::> at |
|
|
2140 | the end of a string designates a module name and quotes it appropriately). |
|
|
2141 | |
|
|
2142 | For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you |
|
|
2143 | could start your program like this: |
|
|
2144 | |
|
|
2145 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
2146 | |
|
|
2147 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
2148 | |
|
|
2149 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
2150 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
2151 | of auto probing). |
|
|
2152 | |
|
|
2153 | Must be set to a comma-separated list of protocols or address families, |
|
|
2154 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
2155 | used, and preference will be given to protocols mentioned earlier in the |
|
|
2156 | list. |
|
|
2157 | |
|
|
2158 | This variable can effectively be used for denial-of-service attacks |
|
|
2159 | against local programs (e.g. when setuid), although the impact is likely |
|
|
2160 | small, as the program has to handle conenction and other failures anyways. |
|
|
2161 | |
|
|
2162 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
2163 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
2164 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
2165 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
2166 | IPv6, but prefer IPv6 over IPv4. |
|
|
2167 | |
|
|
2168 | =item C<PERL_ANYEVENT_HOSTS> |
|
|
2169 | |
|
|
2170 | This variable, if specified, overrides the F</etc/hosts> file used by |
|
|
2171 | L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read |
|
|
2172 | from that file instead. |
|
|
2173 | |
|
|
2174 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
2175 | |
|
|
2176 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for |
|
|
2177 | DNS. This extension is generally useful to reduce DNS traffic, especially |
|
|
2178 | when DNSSEC is involved, but some (broken) firewalls drop such DNS |
|
|
2179 | packets, which is why it is off by default. |
|
|
2180 | |
|
|
2181 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
2182 | EDNS0 in its DNS requests. |
|
|
2183 | |
|
|
2184 | =item C<PERL_ANYEVENT_MAX_FORKS> |
|
|
2185 | |
|
|
2186 | The maximum number of child processes that C<AnyEvent::Util::fork_call> |
|
|
2187 | will create in parallel. |
|
|
2188 | |
|
|
2189 | =item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS> |
|
|
2190 | |
|
|
2191 | The default value for the C<max_outstanding> parameter for the default DNS |
|
|
2192 | resolver - this is the maximum number of parallel DNS requests that are |
|
|
2193 | sent to the DNS server. |
|
|
2194 | |
|
|
2195 | =item C<PERL_ANYEVENT_RESOLV_CONF> |
|
|
2196 | |
|
|
2197 | The absolute path to a F<resolv.conf>-style file to use instead of |
|
|
2198 | F</etc/resolv.conf> (or the OS-specific configuration) in the default |
|
|
2199 | resolver, or the empty string to select the default configuration. |
|
|
2200 | |
|
|
2201 | =item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. |
|
|
2202 | |
|
|
2203 | When neither C<ca_file> nor C<ca_path> was specified during |
|
|
2204 | L<AnyEvent::TLS> context creation, and either of these environment |
|
|
2205 | variables are nonempty, they will be used to specify CA certificate |
|
|
2206 | locations instead of a system-dependent default. |
|
|
2207 | |
|
|
2208 | =item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT> |
|
|
2209 | |
|
|
2210 | When these are set to C<1>, then the respective modules are not |
|
|
2211 | loaded. Mostly good for testing AnyEvent itself. |
|
|
2212 | |
|
|
2213 | =back |
1010 | |
2214 | |
1011 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
2215 | =head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
1012 | |
2216 | |
1013 | This is an advanced topic that you do not normally need to use AnyEvent in |
2217 | This is an advanced topic that you do not normally need to use AnyEvent in |
1014 | a module. This section is only of use to event loop authors who want to |
2218 | a module. This section is only of use to event loop authors who want to |
… | |
… | |
1048 | |
2252 | |
1049 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
2253 | I<rxvt-unicode> also cheats a bit by not providing blocking access to |
1050 | condition variables: code blocking while waiting for a condition will |
2254 | condition variables: code blocking while waiting for a condition will |
1051 | C<die>. This still works with most modules/usages, and blocking calls must |
2255 | C<die>. This still works with most modules/usages, and blocking calls must |
1052 | not be done in an interactive application, so it makes sense. |
2256 | not be done in an interactive application, so it makes sense. |
1053 | |
|
|
1054 | =head1 ENVIRONMENT VARIABLES |
|
|
1055 | |
|
|
1056 | The following environment variables are used by this module: |
|
|
1057 | |
|
|
1058 | =over 4 |
|
|
1059 | |
|
|
1060 | =item C<PERL_ANYEVENT_VERBOSE> |
|
|
1061 | |
|
|
1062 | By default, AnyEvent will be completely silent except in fatal |
|
|
1063 | conditions. You can set this environment variable to make AnyEvent more |
|
|
1064 | talkative. |
|
|
1065 | |
|
|
1066 | When set to C<1> or higher, causes AnyEvent to warn about unexpected |
|
|
1067 | conditions, such as not being able to load the event model specified by |
|
|
1068 | C<PERL_ANYEVENT_MODEL>. |
|
|
1069 | |
|
|
1070 | When set to C<2> or higher, cause AnyEvent to report to STDERR which event |
|
|
1071 | model it chooses. |
|
|
1072 | |
|
|
1073 | =item C<PERL_ANYEVENT_MODEL> |
|
|
1074 | |
|
|
1075 | This can be used to specify the event model to be used by AnyEvent, before |
|
|
1076 | auto detection and -probing kicks in. It must be a string consisting |
|
|
1077 | entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended |
|
|
1078 | and the resulting module name is loaded and if the load was successful, |
|
|
1079 | used as event model. If it fails to load AnyEvent will proceed with |
|
|
1080 | auto detection and -probing. |
|
|
1081 | |
|
|
1082 | This functionality might change in future versions. |
|
|
1083 | |
|
|
1084 | For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you |
|
|
1085 | could start your program like this: |
|
|
1086 | |
|
|
1087 | PERL_ANYEVENT_MODEL=Perl perl ... |
|
|
1088 | |
|
|
1089 | =item C<PERL_ANYEVENT_PROTOCOLS> |
|
|
1090 | |
|
|
1091 | Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences |
|
|
1092 | for IPv4 or IPv6. The default is unspecified (and might change, or be the result |
|
|
1093 | of auto probing). |
|
|
1094 | |
|
|
1095 | Must be set to a comma-separated list of protocols or address families, |
|
|
1096 | current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be |
|
|
1097 | used, and preference will be given to protocols mentioned earlier in the |
|
|
1098 | list. |
|
|
1099 | |
|
|
1100 | This variable can effectively be used for denial-of-service attacks |
|
|
1101 | against local programs (e.g. when setuid), although the impact is likely |
|
|
1102 | small, as the program has to handle connection errors already- |
|
|
1103 | |
|
|
1104 | Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6, |
|
|
1105 | but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> |
|
|
1106 | - only support IPv4, never try to resolve or contact IPv6 |
|
|
1107 | addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or |
|
|
1108 | IPv6, but prefer IPv6 over IPv4. |
|
|
1109 | |
|
|
1110 | =item C<PERL_ANYEVENT_EDNS0> |
|
|
1111 | |
|
|
1112 | Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension |
|
|
1113 | for DNS. This extension is generally useful to reduce DNS traffic, but |
|
|
1114 | some (broken) firewalls drop such DNS packets, which is why it is off by |
|
|
1115 | default. |
|
|
1116 | |
|
|
1117 | Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce |
|
|
1118 | EDNS0 in its DNS requests. |
|
|
1119 | |
|
|
1120 | =back |
|
|
1121 | |
2257 | |
1122 | =head1 EXAMPLE PROGRAM |
2258 | =head1 EXAMPLE PROGRAM |
1123 | |
2259 | |
1124 | The following program uses an I/O watcher to read data from STDIN, a timer |
2260 | The following program uses an I/O watcher to read data from STDIN, a timer |
1125 | to display a message once per second, and a condition variable to quit the |
2261 | to display a message once per second, and a condition variable to quit the |
… | |
… | |
1138 | warn "read: $input\n"; # output what has been read |
2274 | warn "read: $input\n"; # output what has been read |
1139 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
2275 | $cv->send if $input =~ /^q/i; # quit program if /^q/i |
1140 | }, |
2276 | }, |
1141 | ); |
2277 | ); |
1142 | |
2278 | |
1143 | my $time_watcher; # can only be used once |
|
|
1144 | |
|
|
1145 | sub new_timer { |
|
|
1146 | $timer = AnyEvent->timer (after => 1, cb => sub { |
2279 | my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub { |
1147 | warn "timeout\n"; # print 'timeout' about every second |
2280 | warn "timeout\n"; # print 'timeout' at most every second |
1148 | &new_timer; # and restart the time |
|
|
1149 | }); |
2281 | }); |
1150 | } |
|
|
1151 | |
|
|
1152 | new_timer; # create first timer |
|
|
1153 | |
2282 | |
1154 | $cv->recv; # wait until user enters /^q/i |
2283 | $cv->recv; # wait until user enters /^q/i |
1155 | |
2284 | |
1156 | =head1 REAL-WORLD EXAMPLE |
2285 | =head1 REAL-WORLD EXAMPLE |
1157 | |
2286 | |
… | |
… | |
1230 | |
2359 | |
1231 | The actual code goes further and collects all errors (C<die>s, exceptions) |
2360 | The actual code goes further and collects all errors (C<die>s, exceptions) |
1232 | that occurred during request processing. The C<result> method detects |
2361 | that occurred during request processing. The C<result> method detects |
1233 | whether an exception as thrown (it is stored inside the $txn object) |
2362 | whether an exception as thrown (it is stored inside the $txn object) |
1234 | and just throws the exception, which means connection errors and other |
2363 | and just throws the exception, which means connection errors and other |
1235 | problems get reported tot he code that tries to use the result, not in a |
2364 | problems get reported to the code that tries to use the result, not in a |
1236 | random callback. |
2365 | random callback. |
1237 | |
2366 | |
1238 | All of this enables the following usage styles: |
2367 | All of this enables the following usage styles: |
1239 | |
2368 | |
1240 | 1. Blocking: |
2369 | 1. Blocking: |
… | |
… | |
1288 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
2417 | through AnyEvent. The benchmark creates a lot of timers (with a zero |
1289 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
2418 | timeout) and I/O watchers (watching STDOUT, a pty, to become writable, |
1290 | which it is), lets them fire exactly once and destroys them again. |
2419 | which it is), lets them fire exactly once and destroys them again. |
1291 | |
2420 | |
1292 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
2421 | Source code for this benchmark is found as F<eg/bench> in the AnyEvent |
1293 | distribution. |
2422 | distribution. It uses the L<AE> interface, which makes a real difference |
|
|
2423 | for the EV and Perl backends only. |
1294 | |
2424 | |
1295 | =head3 Explanation of the columns |
2425 | =head3 Explanation of the columns |
1296 | |
2426 | |
1297 | I<watcher> is the number of event watchers created/destroyed. Since |
2427 | I<watcher> is the number of event watchers created/destroyed. Since |
1298 | different event models feature vastly different performances, each event |
2428 | different event models feature vastly different performances, each event |
… | |
… | |
1319 | watcher. |
2449 | watcher. |
1320 | |
2450 | |
1321 | =head3 Results |
2451 | =head3 Results |
1322 | |
2452 | |
1323 | name watchers bytes create invoke destroy comment |
2453 | name watchers bytes create invoke destroy comment |
1324 | EV/EV 400000 244 0.56 0.46 0.31 EV native interface |
2454 | EV/EV 100000 223 0.47 0.43 0.27 EV native interface |
1325 | EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers |
2455 | EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers |
1326 | CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal |
2456 | Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal |
1327 | Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation |
2457 | Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation |
1328 | Event/Event 16000 516 31.88 31.30 0.85 Event native interface |
2458 | Event/Event 16000 516 31.16 31.84 0.82 Event native interface |
1329 | Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers |
2459 | Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers |
|
|
2460 | IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll |
|
|
2461 | IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll |
1330 | Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour |
2462 | Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour |
1331 | Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers |
2463 | Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers |
1332 | POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event |
2464 | POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event |
1333 | POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select |
2465 | POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select |
1334 | |
2466 | |
1335 | =head3 Discussion |
2467 | =head3 Discussion |
1336 | |
2468 | |
1337 | The benchmark does I<not> measure scalability of the event loop very |
2469 | The benchmark does I<not> measure scalability of the event loop very |
1338 | well. For example, a select-based event loop (such as the pure perl one) |
2470 | well. For example, a select-based event loop (such as the pure perl one) |
… | |
… | |
1350 | benchmark machine, handling an event takes roughly 1600 CPU cycles with |
2482 | benchmark machine, handling an event takes roughly 1600 CPU cycles with |
1351 | EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU |
2483 | EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU |
1352 | cycles with POE. |
2484 | cycles with POE. |
1353 | |
2485 | |
1354 | C<EV> is the sole leader regarding speed and memory use, which are both |
2486 | C<EV> is the sole leader regarding speed and memory use, which are both |
1355 | maximal/minimal, respectively. Even when going through AnyEvent, it uses |
2487 | maximal/minimal, respectively. When using the L<AE> API there is zero |
|
|
2488 | overhead (when going through the AnyEvent API create is about 5-6 times |
|
|
2489 | slower, with other times being equal, so still uses far less memory than |
1356 | far less memory than any other event loop and is still faster than Event |
2490 | any other event loop and is still faster than Event natively). |
1357 | natively. |
|
|
1358 | |
2491 | |
1359 | The pure perl implementation is hit in a few sweet spots (both the |
2492 | The pure perl implementation is hit in a few sweet spots (both the |
1360 | constant timeout and the use of a single fd hit optimisations in the perl |
2493 | constant timeout and the use of a single fd hit optimisations in the perl |
1361 | interpreter and the backend itself). Nevertheless this shows that it |
2494 | interpreter and the backend itself). Nevertheless this shows that it |
1362 | adds very little overhead in itself. Like any select-based backend its |
2495 | adds very little overhead in itself. Like any select-based backend its |
1363 | performance becomes really bad with lots of file descriptors (and few of |
2496 | performance becomes really bad with lots of file descriptors (and few of |
1364 | them active), of course, but this was not subject of this benchmark. |
2497 | them active), of course, but this was not subject of this benchmark. |
1365 | |
2498 | |
1366 | The C<Event> module has a relatively high setup and callback invocation |
2499 | The C<Event> module has a relatively high setup and callback invocation |
1367 | cost, but overall scores in on the third place. |
2500 | cost, but overall scores in on the third place. |
|
|
2501 | |
|
|
2502 | C<IO::Async> performs admirably well, about on par with C<Event>, even |
|
|
2503 | when using its pure perl backend. |
1368 | |
2504 | |
1369 | C<Glib>'s memory usage is quite a bit higher, but it features a |
2505 | C<Glib>'s memory usage is quite a bit higher, but it features a |
1370 | faster callback invocation and overall ends up in the same class as |
2506 | faster callback invocation and overall ends up in the same class as |
1371 | C<Event>. However, Glib scales extremely badly, doubling the number of |
2507 | C<Event>. However, Glib scales extremely badly, doubling the number of |
1372 | watchers increases the processing time by more than a factor of four, |
2508 | watchers increases the processing time by more than a factor of four, |
… | |
… | |
1407 | (even when used without AnyEvent), but most event loops have acceptable |
2543 | (even when used without AnyEvent), but most event loops have acceptable |
1408 | performance with or without AnyEvent. |
2544 | performance with or without AnyEvent. |
1409 | |
2545 | |
1410 | =item * The overhead AnyEvent adds is usually much smaller than the overhead of |
2546 | =item * The overhead AnyEvent adds is usually much smaller than the overhead of |
1411 | the actual event loop, only with extremely fast event loops such as EV |
2547 | the actual event loop, only with extremely fast event loops such as EV |
1412 | adds AnyEvent significant overhead. |
2548 | does AnyEvent add significant overhead. |
1413 | |
2549 | |
1414 | =item * You should avoid POE like the plague if you want performance or |
2550 | =item * You should avoid POE like the plague if you want performance or |
1415 | reasonable memory usage. |
2551 | reasonable memory usage. |
1416 | |
2552 | |
1417 | =back |
2553 | =back |
… | |
… | |
1433 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
2569 | In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 |
1434 | (1%) are active. This mirrors the activity of large servers with many |
2570 | (1%) are active. This mirrors the activity of large servers with many |
1435 | connections, most of which are idle at any one point in time. |
2571 | connections, most of which are idle at any one point in time. |
1436 | |
2572 | |
1437 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
2573 | Source code for this benchmark is found as F<eg/bench2> in the AnyEvent |
1438 | distribution. |
2574 | distribution. It uses the L<AE> interface, which makes a real difference |
|
|
2575 | for the EV and Perl backends only. |
1439 | |
2576 | |
1440 | =head3 Explanation of the columns |
2577 | =head3 Explanation of the columns |
1441 | |
2578 | |
1442 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
2579 | I<sockets> is the number of sockets, and twice the number of "servers" (as |
1443 | each server has a read and write socket end). |
2580 | each server has a read and write socket end). |
… | |
… | |
1450 | it to another server. This includes deleting the old timeout and creating |
2587 | it to another server. This includes deleting the old timeout and creating |
1451 | a new one that moves the timeout into the future. |
2588 | a new one that moves the timeout into the future. |
1452 | |
2589 | |
1453 | =head3 Results |
2590 | =head3 Results |
1454 | |
2591 | |
1455 | name sockets create request |
2592 | name sockets create request |
1456 | EV 20000 69.01 11.16 |
2593 | EV 20000 62.66 7.99 |
1457 | Perl 20000 73.32 35.87 |
2594 | Perl 20000 68.32 32.64 |
1458 | Event 20000 212.62 257.32 |
2595 | IOAsync 20000 174.06 101.15 epoll |
1459 | Glib 20000 651.16 1896.30 |
2596 | IOAsync 20000 174.67 610.84 poll |
|
|
2597 | Event 20000 202.69 242.91 |
|
|
2598 | Glib 20000 557.01 1689.52 |
1460 | POE 20000 349.67 12317.24 uses POE::Loop::Event |
2599 | POE 20000 341.54 12086.32 uses POE::Loop::Event |
1461 | |
2600 | |
1462 | =head3 Discussion |
2601 | =head3 Discussion |
1463 | |
2602 | |
1464 | This benchmark I<does> measure scalability and overall performance of the |
2603 | This benchmark I<does> measure scalability and overall performance of the |
1465 | particular event loop. |
2604 | particular event loop. |
… | |
… | |
1467 | EV is again fastest. Since it is using epoll on my system, the setup time |
2606 | EV is again fastest. Since it is using epoll on my system, the setup time |
1468 | is relatively high, though. |
2607 | is relatively high, though. |
1469 | |
2608 | |
1470 | Perl surprisingly comes second. It is much faster than the C-based event |
2609 | Perl surprisingly comes second. It is much faster than the C-based event |
1471 | loops Event and Glib. |
2610 | loops Event and Glib. |
|
|
2611 | |
|
|
2612 | IO::Async performs very well when using its epoll backend, and still quite |
|
|
2613 | good compared to Glib when using its pure perl backend. |
1472 | |
2614 | |
1473 | Event suffers from high setup time as well (look at its code and you will |
2615 | Event suffers from high setup time as well (look at its code and you will |
1474 | understand why). Callback invocation also has a high overhead compared to |
2616 | understand why). Callback invocation also has a high overhead compared to |
1475 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
2617 | the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event |
1476 | uses select or poll in basically all documented configurations. |
2618 | uses select or poll in basically all documented configurations. |
… | |
… | |
1539 | =item * C-based event loops perform very well with small number of |
2681 | =item * C-based event loops perform very well with small number of |
1540 | watchers, as the management overhead dominates. |
2682 | watchers, as the management overhead dominates. |
1541 | |
2683 | |
1542 | =back |
2684 | =back |
1543 | |
2685 | |
|
|
2686 | =head2 THE IO::Lambda BENCHMARK |
|
|
2687 | |
|
|
2688 | Recently I was told about the benchmark in the IO::Lambda manpage, which |
|
|
2689 | could be misinterpreted to make AnyEvent look bad. In fact, the benchmark |
|
|
2690 | simply compares IO::Lambda with POE, and IO::Lambda looks better (which |
|
|
2691 | shouldn't come as a surprise to anybody). As such, the benchmark is |
|
|
2692 | fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't |
|
|
2693 | very optimal. But how would AnyEvent compare when used without the extra |
|
|
2694 | baggage? To explore this, I wrote the equivalent benchmark for AnyEvent. |
|
|
2695 | |
|
|
2696 | The benchmark itself creates an echo-server, and then, for 500 times, |
|
|
2697 | connects to the echo server, sends a line, waits for the reply, and then |
|
|
2698 | creates the next connection. This is a rather bad benchmark, as it doesn't |
|
|
2699 | test the efficiency of the framework or much non-blocking I/O, but it is a |
|
|
2700 | benchmark nevertheless. |
|
|
2701 | |
|
|
2702 | name runtime |
|
|
2703 | Lambda/select 0.330 sec |
|
|
2704 | + optimized 0.122 sec |
|
|
2705 | Lambda/AnyEvent 0.327 sec |
|
|
2706 | + optimized 0.138 sec |
|
|
2707 | Raw sockets/select 0.077 sec |
|
|
2708 | POE/select, components 0.662 sec |
|
|
2709 | POE/select, raw sockets 0.226 sec |
|
|
2710 | POE/select, optimized 0.404 sec |
|
|
2711 | |
|
|
2712 | AnyEvent/select/nb 0.085 sec |
|
|
2713 | AnyEvent/EV/nb 0.068 sec |
|
|
2714 | +state machine 0.134 sec |
|
|
2715 | |
|
|
2716 | The benchmark is also a bit unfair (my fault): the IO::Lambda/POE |
|
|
2717 | benchmarks actually make blocking connects and use 100% blocking I/O, |
|
|
2718 | defeating the purpose of an event-based solution. All of the newly |
|
|
2719 | written AnyEvent benchmarks use 100% non-blocking connects (using |
|
|
2720 | AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS |
|
|
2721 | resolver), so AnyEvent is at a disadvantage here, as non-blocking connects |
|
|
2722 | generally require a lot more bookkeeping and event handling than blocking |
|
|
2723 | connects (which involve a single syscall only). |
|
|
2724 | |
|
|
2725 | The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which |
|
|
2726 | offers similar expressive power as POE and IO::Lambda, using conventional |
|
|
2727 | Perl syntax. This means that both the echo server and the client are 100% |
|
|
2728 | non-blocking, further placing it at a disadvantage. |
|
|
2729 | |
|
|
2730 | As you can see, the AnyEvent + EV combination even beats the |
|
|
2731 | hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl |
|
|
2732 | backend easily beats IO::Lambda and POE. |
|
|
2733 | |
|
|
2734 | And even the 100% non-blocking version written using the high-level (and |
|
|
2735 | slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda |
|
|
2736 | higher level ("unoptimised") abstractions by a large margin, even though |
|
|
2737 | it does all of DNS, tcp-connect and socket I/O in a non-blocking way. |
|
|
2738 | |
|
|
2739 | The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and |
|
|
2740 | F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are |
|
|
2741 | part of the IO::Lambda distribution and were used without any changes. |
|
|
2742 | |
|
|
2743 | |
|
|
2744 | =head1 SIGNALS |
|
|
2745 | |
|
|
2746 | AnyEvent currently installs handlers for these signals: |
|
|
2747 | |
|
|
2748 | =over 4 |
|
|
2749 | |
|
|
2750 | =item SIGCHLD |
|
|
2751 | |
|
|
2752 | A handler for C<SIGCHLD> is installed by AnyEvent's child watcher |
|
|
2753 | emulation for event loops that do not support them natively. Also, some |
|
|
2754 | event loops install a similar handler. |
|
|
2755 | |
|
|
2756 | Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then |
|
|
2757 | AnyEvent will reset it to default, to avoid losing child exit statuses. |
|
|
2758 | |
|
|
2759 | =item SIGPIPE |
|
|
2760 | |
|
|
2761 | A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> |
|
|
2762 | when AnyEvent gets loaded. |
|
|
2763 | |
|
|
2764 | The rationale for this is that AnyEvent users usually do not really depend |
|
|
2765 | on SIGPIPE delivery (which is purely an optimisation for shell use, or |
|
|
2766 | badly-written programs), but C<SIGPIPE> can cause spurious and rare |
|
|
2767 | program exits as a lot of people do not expect C<SIGPIPE> when writing to |
|
|
2768 | some random socket. |
|
|
2769 | |
|
|
2770 | The rationale for installing a no-op handler as opposed to ignoring it is |
|
|
2771 | that this way, the handler will be restored to defaults on exec. |
|
|
2772 | |
|
|
2773 | Feel free to install your own handler, or reset it to defaults. |
|
|
2774 | |
|
|
2775 | =back |
|
|
2776 | |
|
|
2777 | =cut |
|
|
2778 | |
|
|
2779 | undef $SIG{CHLD} |
|
|
2780 | if $SIG{CHLD} eq 'IGNORE'; |
|
|
2781 | |
|
|
2782 | $SIG{PIPE} = sub { } |
|
|
2783 | unless defined $SIG{PIPE}; |
|
|
2784 | |
|
|
2785 | =head1 RECOMMENDED/OPTIONAL MODULES |
|
|
2786 | |
|
|
2787 | One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and |
|
|
2788 | its built-in modules) are required to use it. |
|
|
2789 | |
|
|
2790 | That does not mean that AnyEvent won't take advantage of some additional |
|
|
2791 | modules if they are installed. |
|
|
2792 | |
|
|
2793 | This section explains which additional modules will be used, and how they |
|
|
2794 | affect AnyEvent's operation. |
|
|
2795 | |
|
|
2796 | =over 4 |
|
|
2797 | |
|
|
2798 | =item L<Async::Interrupt> |
|
|
2799 | |
|
|
2800 | This slightly arcane module is used to implement fast signal handling: To |
|
|
2801 | my knowledge, there is no way to do completely race-free and quick |
|
|
2802 | signal handling in pure perl. To ensure that signals still get |
|
|
2803 | delivered, AnyEvent will start an interval timer to wake up perl (and |
|
|
2804 | catch the signals) with some delay (default is 10 seconds, look for |
|
|
2805 | C<$AnyEvent::MAX_SIGNAL_LATENCY>). |
|
|
2806 | |
|
|
2807 | If this module is available, then it will be used to implement signal |
|
|
2808 | catching, which means that signals will not be delayed, and the event loop |
|
|
2809 | will not be interrupted regularly, which is more efficient (and good for |
|
|
2810 | battery life on laptops). |
|
|
2811 | |
|
|
2812 | This affects not just the pure-perl event loop, but also other event loops |
|
|
2813 | that have no signal handling on their own (e.g. Glib, Tk, Qt). |
|
|
2814 | |
|
|
2815 | Some event loops (POE, Event, Event::Lib) offer signal watchers natively, |
|
|
2816 | and either employ their own workarounds (POE) or use AnyEvent's workaround |
|
|
2817 | (using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt> |
|
|
2818 | does nothing for those backends. |
|
|
2819 | |
|
|
2820 | =item L<EV> |
|
|
2821 | |
|
|
2822 | This module isn't really "optional", as it is simply one of the backend |
|
|
2823 | event loops that AnyEvent can use. However, it is simply the best event |
|
|
2824 | loop available in terms of features, speed and stability: It supports |
|
|
2825 | the AnyEvent API optimally, implements all the watcher types in XS, does |
|
|
2826 | automatic timer adjustments even when no monotonic clock is available, |
|
|
2827 | can take avdantage of advanced kernel interfaces such as C<epoll> and |
|
|
2828 | C<kqueue>, and is the fastest backend I<by far>. You can even embed |
|
|
2829 | L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). |
|
|
2830 | |
|
|
2831 | If you only use backends that rely on another event loop (e.g. C<Tk>), |
|
|
2832 | then this module will do nothing for you. |
|
|
2833 | |
|
|
2834 | =item L<Guard> |
|
|
2835 | |
|
|
2836 | The guard module, when used, will be used to implement |
|
|
2837 | C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a |
|
|
2838 | lot less memory), but otherwise doesn't affect guard operation much. It is |
|
|
2839 | purely used for performance. |
|
|
2840 | |
|
|
2841 | =item L<JSON> and L<JSON::XS> |
|
|
2842 | |
|
|
2843 | One of these modules is required when you want to read or write JSON data |
|
|
2844 | via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take |
|
|
2845 | advantage of the ultra-high-speed L<JSON::XS> module when it is installed. |
|
|
2846 | |
|
|
2847 | =item L<Net::SSLeay> |
|
|
2848 | |
|
|
2849 | Implementing TLS/SSL in Perl is certainly interesting, but not very |
|
|
2850 | worthwhile: If this module is installed, then L<AnyEvent::Handle> (with |
|
|
2851 | the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. |
|
|
2852 | |
|
|
2853 | =item L<Time::HiRes> |
|
|
2854 | |
|
|
2855 | This module is part of perl since release 5.008. It will be used when the |
|
|
2856 | chosen event library does not come with a timing source of its own. The |
|
|
2857 | pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to |
|
|
2858 | try to use a monotonic clock for timing stability. |
|
|
2859 | |
|
|
2860 | =back |
|
|
2861 | |
1544 | |
2862 | |
1545 | =head1 FORK |
2863 | =head1 FORK |
1546 | |
2864 | |
1547 | Most event libraries are not fork-safe. The ones who are usually are |
2865 | Most event libraries are not fork-safe. The ones who are usually are |
1548 | because they rely on inefficient but fork-safe C<select> or C<poll> |
2866 | because they rely on inefficient but fork-safe C<select> or C<poll> calls |
1549 | calls. Only L<EV> is fully fork-aware. |
2867 | - higher performance APIs such as BSD's kqueue or the dreaded Linux epoll |
|
|
2868 | are usually badly thought-out hacks that are incompatible with fork in |
|
|
2869 | one way or another. Only L<EV> is fully fork-aware and ensures that you |
|
|
2870 | continue event-processing in both parent and child (or both, if you know |
|
|
2871 | what you are doing). |
|
|
2872 | |
|
|
2873 | This means that, in general, you cannot fork and do event processing in |
|
|
2874 | the child if the event library was initialised before the fork (which |
|
|
2875 | usually happens when the first AnyEvent watcher is created, or the library |
|
|
2876 | is loaded). |
1550 | |
2877 | |
1551 | If you have to fork, you must either do so I<before> creating your first |
2878 | If you have to fork, you must either do so I<before> creating your first |
1552 | watcher OR you must not use AnyEvent at all in the child. |
2879 | watcher OR you must not use AnyEvent at all in the child OR you must do |
|
|
2880 | something completely out of the scope of AnyEvent. |
|
|
2881 | |
|
|
2882 | The problem of doing event processing in the parent I<and> the child |
|
|
2883 | is much more complicated: even for backends that I<are> fork-aware or |
|
|
2884 | fork-safe, their behaviour is not usually what you want: fork clones all |
|
|
2885 | watchers, that means all timers, I/O watchers etc. are active in both |
|
|
2886 | parent and child, which is almost never what you want. USing C<exec> |
|
|
2887 | to start worker children from some kind of manage rprocess is usually |
|
|
2888 | preferred, because it is much easier and cleaner, at the expense of having |
|
|
2889 | to have another binary. |
1553 | |
2890 | |
1554 | |
2891 | |
1555 | =head1 SECURITY CONSIDERATIONS |
2892 | =head1 SECURITY CONSIDERATIONS |
1556 | |
2893 | |
1557 | AnyEvent can be forced to load any event model via |
2894 | AnyEvent can be forced to load any event model via |
… | |
… | |
1562 | specified in the variable. |
2899 | specified in the variable. |
1563 | |
2900 | |
1564 | You can make AnyEvent completely ignore this variable by deleting it |
2901 | You can make AnyEvent completely ignore this variable by deleting it |
1565 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
2902 | before the first watcher gets created, e.g. with a C<BEGIN> block: |
1566 | |
2903 | |
1567 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
2904 | BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } |
1568 | |
2905 | |
1569 | use AnyEvent; |
2906 | use AnyEvent; |
1570 | |
2907 | |
1571 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
2908 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1572 | be used to probe what backend is used and gain other information (which is |
2909 | be used to probe what backend is used and gain other information (which is |
1573 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
2910 | probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and |
|
|
2911 | $ENV{PERL_ANYEVENT_STRICT}. |
|
|
2912 | |
|
|
2913 | Note that AnyEvent will remove I<all> environment variables starting with |
|
|
2914 | C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is |
|
|
2915 | enabled. |
|
|
2916 | |
|
|
2917 | |
|
|
2918 | =head1 BUGS |
|
|
2919 | |
|
|
2920 | Perl 5.8 has numerous memleaks that sometimes hit this module and are hard |
|
|
2921 | to work around. If you suffer from memleaks, first upgrade to Perl 5.10 |
|
|
2922 | and check wether the leaks still show up. (Perl 5.10.0 has other annoying |
|
|
2923 | memleaks, such as leaking on C<map> and C<grep> but it is usually not as |
|
|
2924 | pronounced). |
1574 | |
2925 | |
1575 | |
2926 | |
1576 | =head1 SEE ALSO |
2927 | =head1 SEE ALSO |
1577 | |
2928 | |
1578 | Utility functions: L<AnyEvent::Util>. |
2929 | Tutorial/Introduction: L<AnyEvent::Intro>. |
1579 | |
2930 | |
1580 | Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, |
2931 | FAQ: L<AnyEvent::FAQ>. |
1581 | L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. |
2932 | |
|
|
2933 | Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log> |
|
|
2934 | (simply logging). |
|
|
2935 | |
|
|
2936 | Development/Debugging: L<AnyEvent::Strict> (stricter checking), |
|
|
2937 | L<AnyEvent::Debug> (interactive shell, watcher tracing). |
|
|
2938 | |
|
|
2939 | Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>, |
|
|
2940 | L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>, |
|
|
2941 | L<Qt>, L<POE>, L<FLTK>. |
1582 | |
2942 | |
1583 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
2943 | Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, |
1584 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
2944 | L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, |
1585 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
2945 | L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, |
|
|
2946 | L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>, |
1586 | L<AnyEvent::Impl::POE>. |
2947 | L<AnyEvent::Impl::FLTK>. |
1587 | |
2948 | |
1588 | Non-blocking file handles, sockets, TCP clients and |
2949 | Non-blocking handles, pipes, stream sockets, TCP clients and |
1589 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. |
2950 | servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. |
1590 | |
2951 | |
1591 | Asynchronous DNS: L<AnyEvent::DNS>. |
2952 | Asynchronous DNS: L<AnyEvent::DNS>. |
1592 | |
2953 | |
1593 | Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, |
2954 | Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>. |
1594 | |
2955 | |
1595 | Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. |
2956 | Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>, |
|
|
2957 | L<AnyEvent::HTTP>. |
1596 | |
2958 | |
1597 | |
2959 | |
1598 | =head1 AUTHOR |
2960 | =head1 AUTHOR |
1599 | |
2961 | |
1600 | Marc Lehmann <schmorp@schmorp.de> |
2962 | Marc Lehmann <schmorp@schmorp.de> |
1601 | http://home.schmorp.de/ |
2963 | http://home.schmorp.de/ |
1602 | |
2964 | |
1603 | =cut |
2965 | =cut |
1604 | |
2966 | |
1605 | 1 |
2967 | 1 |
1606 | |
2968 | |