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2 | |
2 | |
3 | EV - perl interface to libev, a high performance full-featured event loop |
3 | EV - perl interface to libev, a high performance full-featured event loop |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use EV; |
7 | use EV; |
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8 | |
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9 | # TIMERS |
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10 | |
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11 | my $w = EV::timer 2, 0, sub { |
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12 | warn "is called after 2s"; |
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13 | }; |
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14 | |
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15 | my $w = EV::timer 2, 2, sub { |
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16 | warn "is called roughly every 2s (repeat = 2)"; |
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17 | }; |
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18 | |
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19 | undef $w; # destroy event watcher again |
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20 | |
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21 | my $w = EV::periodic 0, 60, 0, sub { |
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22 | warn "is called every minute, on the minute, exactly"; |
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23 | }; |
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24 | |
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25 | # IO |
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26 | |
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27 | my $w = EV::io *STDIN, EV::READ, sub { |
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28 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
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29 | warn "stdin is readable, you entered: ", <STDIN>; |
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30 | }; |
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31 | |
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32 | # SIGNALS |
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33 | |
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34 | my $w = EV::signal 'QUIT', sub { |
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35 | warn "sigquit received\n"; |
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36 | }; |
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37 | |
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38 | # CHILD/PID STATUS CHANGES |
8 | |
39 | |
9 | # TIMERS |
40 | my $w = EV::child 666, 0, sub { |
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41 | my ($w, $revents) = @_; |
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42 | my $status = $w->rstatus; |
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43 | }; |
10 | |
44 | |
11 | my $w = EV::timer 2, 0, sub { |
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12 | warn "is called after 2s"; |
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13 | }; |
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14 | |
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15 | my $w = EV::timer 2, 2, sub { |
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16 | warn "is called roughly every 2s (repeat = 2)"; |
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17 | }; |
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18 | |
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19 | undef $w; # destroy event watcher again |
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20 | |
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21 | my $w = EV::periodic 0, 60, 0, sub { |
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22 | warn "is called every minute, on the minute, exactly"; |
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23 | }; |
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24 | |
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25 | # IO |
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26 | |
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27 | my $w = EV::io *STDIN, EV::READ, sub { |
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28 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
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29 | warn "stdin is readable, you entered: ", <STDIN>; |
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30 | }; |
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31 | |
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32 | # SIGNALS |
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33 | |
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34 | my $w = EV::signal 'QUIT', sub { |
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35 | warn "sigquit received\n"; |
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36 | }; |
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37 | |
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38 | # CHILD/PID STATUS CHANGES |
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39 | |
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40 | my $w = EV::child 666, 0, sub { |
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41 | my ($w, $revents) = @_; |
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42 | my $status = $w->rstatus; |
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43 | }; |
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44 | |
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45 | # STAT CHANGES |
45 | # STAT CHANGES |
46 | my $w = EV::stat "/etc/passwd", 10, sub { |
46 | my $w = EV::stat "/etc/passwd", 10, sub { |
47 | my ($w, $revents) = @_; |
47 | my ($w, $revents) = @_; |
48 | warn $w->path, " has changed somehow.\n"; |
48 | warn $w->path, " has changed somehow.\n"; |
49 | }; |
49 | }; |
50 | |
50 | |
51 | # MAINLOOP |
51 | # MAINLOOP |
52 | EV::loop; # loop until EV::unloop is called or all watchers stop |
52 | EV::run; # loop until EV::unloop is called or all watchers stop |
53 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
53 | EV::run EV::RUN_ONCE; # block until at least one event could be handled |
54 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
54 | EV::run EV::RUN_NOWAIT; # try to handle same events, but do not block |
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55 | |
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56 | =head1 BEFORE YOU START USING THIS MODULE |
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57 | |
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58 | If you only need timer, I/O, signal, child and idle watchers and not the |
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59 | advanced functionality of this module, consider using L<AnyEvent> instead, |
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60 | specifically the simplified API described in L<AE>. |
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61 | |
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62 | When used with EV as backend, the L<AE> API is as fast as the native L<EV> |
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63 | API, but your programs/modules will still run with many other event loops. |
55 | |
64 | |
56 | =head1 DESCRIPTION |
65 | =head1 DESCRIPTION |
57 | |
66 | |
58 | This module provides an interface to libev |
67 | This module provides an interface to libev |
59 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
68 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
60 | below is comprehensive, one might also consult the documentation of libev |
69 | below is comprehensive, one might also consult the documentation of |
61 | itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more |
70 | libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or |
62 | subtle details on watcher semantics or some discussion on the available |
71 | F<perldoc EV::libev>) for more subtle details on watcher semantics or some |
63 | backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just |
72 | discussion on the available backends, or how to force a specific backend |
64 | about in any case because it has much more detailed information. |
73 | with C<LIBEV_FLAGS>, or just about in any case because it has much more |
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74 | detailed information. |
65 | |
75 | |
66 | This module is very fast and scalable. It is actually so fast that you |
76 | This module is very fast and scalable. It is actually so fast that you |
67 | can use it through the L<AnyEvent> module, stay portable to other event |
77 | can use it through the L<AnyEvent> module, stay portable to other event |
68 | loops (if you don't rely on any watcher types not available through it) |
78 | loops (if you don't rely on any watcher types not available through it) |
69 | and still be faster than with any other event loop currently supported in |
79 | and still be faster than with any other event loop currently supported in |
70 | Perl. |
80 | Perl. |
71 | |
81 | |
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82 | =head2 PORTING FROM EV 3.X to 4.X |
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83 | |
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84 | EV version 4 introduces a number of incompatible changes summarised |
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85 | here. According to the depreciation strategy used by libev, there is a |
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86 | compatibility layer in place so programs should continue to run unchanged |
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87 | (the XS interface lacks this layer, so programs using that one need to be |
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88 | updated). |
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89 | |
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90 | This compatibility layer will be switched off in some future release. |
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91 | |
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92 | All changes relevant to Perl are renames of symbols, functions and |
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93 | methods: |
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94 | |
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95 | EV::loop => EV::run |
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96 | EV::LOOP_NONBLOCK => EV::RUN_NOWAIT |
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97 | EV::LOOP_ONESHOT => EV::RUN_ONCE |
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98 | |
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99 | EV::unloop => EV::break |
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100 | EV::UNLOOP_CANCEL => EV::BREAK_CANCEL |
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101 | EV::UNLOOP_ONE => EV::BREAK_ONE |
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102 | EV::UNLOOP_ALL => EV::BREAK_ALL |
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103 | |
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104 | EV::TIMEOUT => EV::TIMER |
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105 | |
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106 | EV::loop_count => EV::iteration |
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107 | EV::loop_depth => EV::depth |
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108 | EV::loop_verify => EV::verify |
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109 | |
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110 | The loop object methods corresponding to the functions above have been |
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111 | similarly renamed. |
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112 | |
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113 | =head2 MODULE EXPORTS |
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114 | |
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115 | This module does not export any symbols. |
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116 | |
72 | =cut |
117 | =cut |
73 | |
118 | |
74 | package EV; |
119 | package EV; |
75 | |
120 | |
76 | use strict; |
121 | use common::sense; |
77 | |
122 | |
78 | BEGIN { |
123 | BEGIN { |
79 | our $VERSION = '3.33'; |
124 | our $VERSION = '4.11'; |
80 | use XSLoader; |
125 | use XSLoader; |
81 | XSLoader::load "EV", $VERSION; |
126 | XSLoader::load "EV", $VERSION; |
82 | } |
127 | } |
83 | |
128 | |
84 | @EV::IO::ISA = |
129 | @EV::IO::ISA = |
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111 | default loop as this is fastest (perl-wise), best supported by other |
156 | default loop as this is fastest (perl-wise), best supported by other |
112 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
157 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
113 | |
158 | |
114 | For specific programs you can create additional event loops dynamically. |
159 | For specific programs you can create additional event loops dynamically. |
115 | |
160 | |
116 | =over 4 |
161 | If you want to take advantage of kqueue (which often works properly for |
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162 | sockets only) even though the default loop doesn't enable it, you can |
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163 | I<embed> a kqueue loop into the default loop: running the default loop |
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164 | will then also service the kqueue loop to some extent. See the example in |
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165 | the section about embed watchers for an example on how to achieve that. |
117 | |
166 | |
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167 | =over 4 |
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168 | |
118 | =item $loop = new EV::loop [$flags] |
169 | =item $loop = new EV::Loop [$flags] |
119 | |
170 | |
120 | Create a new event loop as per the specified flags. Please refer to the |
171 | Create a new event loop as per the specified flags. Please refer to |
121 | C<ev_loop_new ()> function description in the libev documentation |
172 | the C<ev_loop_new ()> function description in the libev documentation |
122 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>) |
173 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>, |
123 | for more info. |
174 | or locally-installed as F<EV::libev> manpage) for more info. |
124 | |
175 | |
125 | The loop will automatically be destroyed when it is no longer referenced |
176 | The loop will automatically be destroyed when it is no longer referenced |
126 | by any watcher and the loop object goes out of scope. |
177 | by any watcher and the loop object goes out of scope. |
127 | |
178 | |
128 | Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop |
179 | If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK> |
129 | is protected by this module. |
180 | is recommended, as only the default event loop is protected by this |
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181 | module. If you I<are> embedding this loop in the default loop, this is not |
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182 | necessary, as C<EV::embed> automatically does the right thing on fork. |
130 | |
183 | |
131 | =item $loop->loop_fork |
184 | =item $loop->loop_fork |
132 | |
185 | |
133 | Must be called after a fork in the child, before entering or continuing |
186 | Must be called after a fork in the child, before entering or continuing |
134 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
187 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
135 | this fucntion automatically, at some performance loss (refer to the libev |
188 | this function automatically, at some performance loss (refer to the libev |
136 | documentation). |
189 | documentation). |
137 | |
190 | |
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191 | =item $loop->verify |
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192 | |
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193 | Calls C<ev_verify> to make internal consistency checks (for debugging |
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194 | libev) and abort the program if any data structures were found to be |
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195 | corrupted. |
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196 | |
138 | =item $loop = EV::default_loop [$flags] |
197 | =item $loop = EV::default_loop [$flags] |
139 | |
198 | |
140 | Return the default loop (which is a singleton object). |
199 | Return the default loop (which is a singleton object). Since this module |
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200 | already creates the default loop with default flags, specifying flags here |
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201 | will not have any effect unless you destroy the default loop first, which |
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202 | isn't supported. So in short: don't do it, and if you break it, you get to |
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203 | keep the pieces. |
141 | |
204 | |
142 | =back |
205 | =back |
143 | |
206 | |
144 | |
207 | |
145 | =head1 BASIC INTERFACE |
208 | =head1 BASIC INTERFACE |
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175 | =item $time = EV::now |
238 | =item $time = EV::now |
176 | |
239 | |
177 | =item $time = $loop->now |
240 | =item $time = $loop->now |
178 | |
241 | |
179 | Returns the time the last event loop iteration has been started. This |
242 | Returns the time the last event loop iteration has been started. This |
180 | is the time that (relative) timers are based on, and refering to it is |
243 | is the time that (relative) timers are based on, and referring to it is |
181 | usually faster then calling EV::time. |
244 | usually faster then calling EV::time. |
182 | |
245 | |
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246 | =item EV::now_update |
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247 | |
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248 | =item $loop->now_update |
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249 | |
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250 | Establishes the current time by querying the kernel, updating the time |
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251 | returned by C<EV::now> in the progress. This is a costly operation and |
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252 | is usually done automatically within C<EV::loop>. |
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253 | |
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254 | This function is rarely useful, but when some event callback runs for a |
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255 | very long time without entering the event loop, updating libev's idea of |
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256 | the current time is a good idea. |
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257 | |
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258 | =item EV::suspend |
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259 | |
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260 | =item $loop->suspend |
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261 | |
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262 | =item EV::resume |
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263 | |
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264 | =item $loop->resume |
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265 | |
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266 | These two functions suspend and resume a loop, for use when the loop is |
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267 | not used for a while and timeouts should not be processed. |
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268 | |
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269 | A typical use case would be an interactive program such as a game: When |
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270 | the user presses C<^Z> to suspend the game and resumes it an hour later it |
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271 | would be best to handle timeouts as if no time had actually passed while |
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272 | the program was suspended. This can be achieved by calling C<suspend> |
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273 | in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling |
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274 | C<resume> directly afterwards to resume timer processing. |
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275 | |
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276 | Effectively, all C<timer> watchers will be delayed by the time spend |
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277 | between C<suspend> and C<resume>, and all C<periodic> watchers |
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278 | will be rescheduled (that is, they will lose any events that would have |
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279 | occured while suspended). |
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280 | |
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281 | After calling C<suspend> you B<must not> call I<any> function on the given |
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282 | loop other than C<resume>, and you B<must not> call C<resume> |
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283 | without a previous call to C<suspend>. |
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284 | |
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285 | Calling C<suspend>/C<resume> has the side effect of updating the event |
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286 | loop time (see C<now_update>). |
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287 | |
183 | =item $backend = EV::backend |
288 | =item $backend = EV::backend |
184 | |
289 | |
185 | =item $backend = $loop->backend |
290 | =item $backend = $loop->backend |
186 | |
291 | |
187 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
292 | Returns an integer describing the backend used by libev (EV::BACKEND_SELECT |
188 | or EV::METHOD_EPOLL). |
293 | or EV::BACKEND_EPOLL). |
189 | |
294 | |
190 | =item EV::loop [$flags] |
295 | =item $active = EV::run [$flags] |
191 | |
296 | |
192 | =item $loop->loop ([$flags]) |
297 | =item $active = $loop->run ([$flags]) |
193 | |
298 | |
194 | Begin checking for events and calling callbacks. It returns when a |
299 | Begin checking for events and calling callbacks. It returns when a |
195 | callback calls EV::unloop. |
300 | callback calls EV::unloop or the flasg are nonzero (in which case the |
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301 | return value is true) or when there are no active watchers which reference |
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302 | the loop (keepalive is true), in which case the return value will be |
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303 | false. The returnv alue can generally be interpreted as "if true, there is |
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304 | more work left to do". |
196 | |
305 | |
197 | The $flags argument can be one of the following: |
306 | The $flags argument can be one of the following: |
198 | |
307 | |
199 | 0 as above |
308 | 0 as above |
200 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
309 | EV::RUN_ONCE block at most once (wait, but do not loop) |
201 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
310 | EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait) |
202 | |
311 | |
203 | =item EV::unloop [$how] |
312 | =item EV::break [$how] |
204 | |
313 | |
205 | =item $loop->unloop ([$how]) |
314 | =item $loop->break ([$how]) |
206 | |
315 | |
207 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
316 | When called with no arguments or an argument of EV::BREAK_ONE, makes the |
208 | innermost call to EV::loop return. |
317 | innermost call to EV::loop return. |
209 | |
318 | |
210 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
319 | When called with an argument of EV::BREAK_ALL, all calls to EV::loop will |
211 | fast as possible. |
320 | return as fast as possible. |
212 | |
321 | |
213 | =item $count = EV::loop_count |
322 | When called with an argument of EV::BREAK_CANCEL, any pending break will |
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323 | be cancelled. |
214 | |
324 | |
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325 | =item $count = EV::iteration |
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326 | |
215 | =item $count = $loop->loop_count |
327 | =item $count = $loop->iteration |
216 | |
328 | |
217 | Return the number of times the event loop has polled for new |
329 | Return the number of times the event loop has polled for new |
218 | events. Sometiems useful as a generation counter. |
330 | events. Sometimes useful as a generation counter. |
219 | |
331 | |
220 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
332 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
221 | |
333 | |
222 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
334 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
223 | |
335 | |
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234 | timeout. Otherwise a EV::timer with this value will be started. |
346 | timeout. Otherwise a EV::timer with this value will be started. |
235 | |
347 | |
236 | When an error occurs or either the timeout or I/O watcher triggers, then |
348 | When an error occurs or either the timeout or I/O watcher triggers, then |
237 | the callback will be called with the received event set (in general |
349 | the callback will be called with the received event set (in general |
238 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
350 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
239 | C<EV::WRITE> and C<EV::TIMEOUT>). |
351 | C<EV::WRITE> and C<EV::TIMER>). |
240 | |
352 | |
241 | EV::once doesn't return anything: the watchers stay active till either |
353 | EV::once doesn't return anything: the watchers stay active till either |
242 | of them triggers, then they will be stopped and freed, and the callback |
354 | of them triggers, then they will be stopped and freed, and the callback |
243 | invoked. |
355 | invoked. |
244 | |
356 | |
245 | =item EV::feed_fd_event ($fd, $revents) |
357 | =item EV::feed_fd_event $fd, $revents |
246 | |
358 | |
247 | =item $loop->feed_fd_event ($fd, $revents) |
359 | =item $loop->feed_fd_event ($fd, $revents) |
248 | |
360 | |
249 | Feed an event on a file descriptor into EV. EV will react to this call as |
361 | Feed an event on a file descriptor into EV. EV will react to this call as |
250 | if the readyness notifications specified by C<$revents> (a combination of |
362 | if the readyness notifications specified by C<$revents> (a combination of |
251 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
363 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
252 | |
364 | |
253 | =item EV::feed_signal_event ($signal) |
365 | =item EV::feed_signal_event $signal |
254 | |
366 | |
255 | Feed a signal event into EV. EV will react to this call as if the signal |
367 | Feed a signal event into the default loop. EV will react to this call as |
256 | specified by C<$signal> had occured. |
368 | if the signal specified by C<$signal> had occured. |
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369 | |
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370 | =item EV::feed_signal $signal |
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371 | |
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372 | Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works |
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373 | regardless of which loop has registered the signal, and is mainly useful |
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374 | fro custom signal implementations. |
257 | |
375 | |
258 | =item EV::set_io_collect_interval $time |
376 | =item EV::set_io_collect_interval $time |
259 | |
377 | |
260 | =item $loop->set_io_collect_interval ($time) |
378 | =item $loop->set_io_collect_interval ($time) |
261 | |
379 | |
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263 | |
381 | |
264 | =item $loop->set_timeout_collect_interval ($time) |
382 | =item $loop->set_timeout_collect_interval ($time) |
265 | |
383 | |
266 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
384 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
267 | wait interval for timer events. See the libev documentation at |
385 | wait interval for timer events. See the libev documentation at |
268 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for |
386 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> |
269 | a more detailed discussion. |
387 | (locally installed as F<EV::libev>) for a more detailed discussion. |
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388 | |
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389 | =item $count = EV::pending_count |
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390 | |
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391 | =item $count = $loop->pending_count |
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392 | |
|
|
393 | Returns the number of currently pending watchers. |
|
|
394 | |
|
|
395 | =item EV::invoke_pending |
|
|
396 | |
|
|
397 | =item $loop->invoke_pending |
|
|
398 | |
|
|
399 | Invoke all currently pending watchers. |
270 | |
400 | |
271 | =back |
401 | =back |
272 | |
402 | |
273 | |
403 | |
274 | =head1 WATCHER OBJECTS |
404 | =head1 WATCHER OBJECTS |
275 | |
405 | |
276 | A watcher is an object that gets created to record your interest in some |
406 | A watcher is an object that gets created to record your interest in some |
277 | event. For instance, if you want to wait for STDIN to become readable, you |
407 | event. For instance, if you want to wait for STDIN to become readable, you |
278 | would create an EV::io watcher for that: |
408 | would create an EV::io watcher for that: |
279 | |
409 | |
280 | my $watcher = EV::io *STDIN, EV::READ, sub { |
410 | my $watcher = EV::io *STDIN, EV::READ, sub { |
281 | my ($watcher, $revents) = @_; |
411 | my ($watcher, $revents) = @_; |
282 | warn "yeah, STDIN should now be readable without blocking!\n" |
412 | warn "yeah, STDIN should now be readable without blocking!\n" |
283 | }; |
413 | }; |
284 | |
414 | |
285 | All watchers can be active (waiting for events) or inactive (paused). Only |
415 | All watchers can be active (waiting for events) or inactive (paused). Only |
286 | active watchers will have their callbacks invoked. All callbacks will be |
416 | active watchers will have their callbacks invoked. All callbacks will be |
287 | called with at least two arguments: the watcher and a bitmask of received |
417 | called with at least two arguments: the watcher and a bitmask of received |
288 | events. |
418 | events. |
289 | |
419 | |
290 | Each watcher type has its associated bit in revents, so you can use the |
420 | Each watcher type has its associated bit in revents, so you can use the |
291 | same callback for multiple watchers. The event mask is named after the |
421 | same callback for multiple watchers. The event mask is named after the |
292 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
422 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
293 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
423 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
294 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
424 | (which can set both EV::READ and EV::WRITE bits). |
295 | uses EV::TIMEOUT). |
|
|
296 | |
425 | |
297 | In the rare case where one wants to create a watcher but not start it at |
426 | In the rare case where one wants to create a watcher but not start it at |
298 | the same time, each constructor has a variant with a trailing C<_ns> in |
427 | the same time, each constructor has a variant with a trailing C<_ns> in |
299 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
428 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
300 | |
429 | |
… | |
… | |
379 | |
508 | |
380 | =item $previous_state = $w->keepalive ($bool) |
509 | =item $previous_state = $w->keepalive ($bool) |
381 | |
510 | |
382 | Normally, C<EV::loop> will return when there are no active watchers |
511 | Normally, C<EV::loop> will return when there are no active watchers |
383 | (which is a "deadlock" because no progress can be made anymore). This is |
512 | (which is a "deadlock" because no progress can be made anymore). This is |
384 | convinient because it allows you to start your watchers (and your jobs), |
513 | convenient because it allows you to start your watchers (and your jobs), |
385 | call C<EV::loop> once and when it returns you know that all your jobs are |
514 | call C<EV::loop> once and when it returns you know that all your jobs are |
386 | finished (or they forgot to register some watchers for their task :). |
515 | finished (or they forgot to register some watchers for their task :). |
387 | |
516 | |
388 | Sometimes, however, this gets in your way, for example when the module |
517 | Sometimes, however, this gets in your way, for example when the module |
389 | that calls C<EV::loop> (usually the main program) is not the same module |
518 | that calls C<EV::loop> (usually the main program) is not the same module |
… | |
… | |
393 | because you happen to have this long-running UDP port watcher. |
522 | because you happen to have this long-running UDP port watcher. |
394 | |
523 | |
395 | In this case you can clear the keepalive status, which means that even |
524 | In this case you can clear the keepalive status, which means that even |
396 | though your watcher is active, it won't keep C<EV::loop> from returning. |
525 | though your watcher is active, it won't keep C<EV::loop> from returning. |
397 | |
526 | |
398 | The initial value for keepalive is true (enabled), and you cna change it |
527 | The initial value for keepalive is true (enabled), and you can change it |
399 | any time. |
528 | any time. |
400 | |
529 | |
401 | Example: Register an I/O watcher for some UDP socket but do not keep the |
530 | Example: Register an I/O watcher for some UDP socket but do not keep the |
402 | event loop from running just because of that watcher. |
531 | event loop from running just because of that watcher. |
403 | |
532 | |
404 | my $udp_socket = ... |
533 | my $udp_socket = ... |
405 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
534 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
406 | $1000udp_watcher->keepalive (0); |
535 | $udp_watcher->keepalive (0); |
407 | |
536 | |
408 | =item $loop = $w->loop |
537 | =item $loop = $w->loop |
409 | |
538 | |
410 | Return the loop that this watcher is attached to. |
539 | Return the loop that this watcher is attached to. |
411 | |
540 | |
… | |
… | |
568 | time the periodic watcher gets scheduled, the reschedule callback |
697 | time the periodic watcher gets scheduled, the reschedule callback |
569 | ($reschedule_cb) will be called with the watcher as first, and the current |
698 | ($reschedule_cb) will be called with the watcher as first, and the current |
570 | time as second argument. |
699 | time as second argument. |
571 | |
700 | |
572 | I<This callback MUST NOT stop or destroy this or any other periodic |
701 | I<This callback MUST NOT stop or destroy this or any other periodic |
573 | watcher, ever>. If you need to stop it, return 1e30 and stop it |
702 | watcher, ever, and MUST NOT call any event loop functions or methods>. If |
574 | afterwards. |
703 | you need to stop it, return 1e30 and stop it afterwards. You may create |
|
|
704 | and start a C<EV::prepare> watcher for this task. |
575 | |
705 | |
576 | It must return the next time to trigger, based on the passed time value |
706 | It must return the next time to trigger, based on the passed time value |
577 | (that is, the lowest time value larger than to the second argument). It |
707 | (that is, the lowest time value larger than or equal to to the second |
578 | will usually be called just before the callback will be triggered, but |
708 | argument). It will usually be called just before the callback will be |
579 | might be called at other times, too. |
709 | triggered, but might be called at other times, too. |
580 | |
710 | |
581 | This can be used to create very complex timers, such as a timer that |
711 | This can be used to create very complex timers, such as a timer that |
582 | triggers on each midnight, local time (actually 24 hours after the last |
712 | triggers on each midnight, local time (actually 24 hours after the last |
583 | midnight, to keep the example simple. If you know a way to do it correctly |
713 | midnight, to keep the example simple. If you know a way to do it correctly |
584 | in about the same space (without requiring elaborate modules), drop me a |
714 | in about the same space (without requiring elaborate modules), drop me a |
… | |
… | |
620 | |
750 | |
621 | =item $w = EV::signal $signal, $callback |
751 | =item $w = EV::signal $signal, $callback |
622 | |
752 | |
623 | =item $w = EV::signal_ns $signal, $callback |
753 | =item $w = EV::signal_ns $signal, $callback |
624 | |
754 | |
|
|
755 | =item $w = $loop->signal ($signal, $callback) |
|
|
756 | |
|
|
757 | =item $w = $loop->signal_ns ($signal, $callback) |
|
|
758 | |
625 | Call the callback when $signal is received (the signal can be specified by |
759 | Call the callback when $signal is received (the signal can be specified by |
626 | number or by name, just as with C<kill> or C<%SIG>). |
760 | number or by name, just as with C<kill> or C<%SIG>). |
|
|
761 | |
|
|
762 | Only one event loop can grab a given signal - attempting to grab the same |
|
|
763 | signal from two EV loops will crash the program immediately or cause data |
|
|
764 | corruption. |
627 | |
765 | |
628 | EV will grab the signal for the process (the kernel only allows one |
766 | EV will grab the signal for the process (the kernel only allows one |
629 | component to receive a signal at a time) when you start a signal watcher, |
767 | component to receive a signal at a time) when you start a signal watcher, |
630 | and removes it again when you stop it. Perl does the same when you |
768 | and removes it again when you stop it. Perl does the same when you |
631 | add/remove callbacks to C<%SIG>, so watch out. |
769 | add/remove callbacks to C<%SIG>, so watch out. |
… | |
… | |
856 | =item $w = $loop->check_ns ($callback) |
994 | =item $w = $loop->check_ns ($callback) |
857 | |
995 | |
858 | Call the callback just after the process wakes up again (after it has |
996 | Call the callback just after the process wakes up again (after it has |
859 | gathered events), but before any other callbacks have been invoked. |
997 | gathered events), but before any other callbacks have been invoked. |
860 | |
998 | |
861 | This is used to integrate other event-based software into the EV |
999 | This can be used to integrate other event-based software into the EV |
862 | mainloop: You register a prepare callback and in there, you create io and |
1000 | mainloop: You register a prepare callback and in there, you create io and |
863 | timer watchers as required by the other software. Here is a real-world |
1001 | timer watchers as required by the other software. Here is a real-world |
864 | example of integrating Net::SNMP (with some details left out): |
1002 | example of integrating Net::SNMP (with some details left out): |
865 | |
1003 | |
866 | our @snmp_watcher; |
1004 | our @snmp_watcher; |
… | |
… | |
896 | # make the dispatcher handle any new stuff |
1034 | # make the dispatcher handle any new stuff |
897 | ... not shown |
1035 | ... not shown |
898 | }; |
1036 | }; |
899 | |
1037 | |
900 | The callbacks of the created watchers will not be called as the watchers |
1038 | The callbacks of the created watchers will not be called as the watchers |
901 | are destroyed before this cna happen (remember EV::check gets called |
1039 | are destroyed before this can happen (remember EV::check gets called |
902 | first). |
1040 | first). |
903 | |
1041 | |
904 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
1042 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
|
|
1043 | |
|
|
1044 | =item EV::CHECK constant issues |
|
|
1045 | |
|
|
1046 | Like all other watcher types, there is a bitmask constant for use in |
|
|
1047 | C<$revents> and other places. The C<EV::CHECK> is special as it has |
|
|
1048 | the same name as the C<CHECK> sub called by Perl. This doesn't cause |
|
|
1049 | big issues on newer perls (beginning with 5.8.9), but it means thatthe |
|
|
1050 | constant must be I<inlined>, i.e. runtime calls will not work. That means |
|
|
1051 | that as long as you always C<use EV> and then C<EV::CHECK> you are on the |
|
|
1052 | safe side. |
905 | |
1053 | |
906 | =back |
1054 | =back |
907 | |
1055 | |
908 | |
1056 | |
909 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
1057 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
… | |
… | |
937 | loop, other types of watchers might be handled in a delayed or incorrect |
1085 | loop, other types of watchers might be handled in a delayed or incorrect |
938 | fashion and must not be used). |
1086 | fashion and must not be used). |
939 | |
1087 | |
940 | See the libev documentation at |
1088 | See the libev documentation at |
941 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> |
1089 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> |
942 | for more details. |
1090 | (locally installed as F<EV::libev>) for more details. |
943 | |
1091 | |
944 | In short, this watcher is most useful on BSD systems without working |
1092 | In short, this watcher is most useful on BSD systems without working |
945 | kqueue to still be able to handle a large number of sockets: |
1093 | kqueue to still be able to handle a large number of sockets: |
946 | |
1094 | |
947 | my $socket_loop; |
1095 | my $socket_loop; |
948 | |
1096 | |
949 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
1097 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
950 | if ( |
1098 | if ( |
951 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
1099 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
952 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
1100 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
953 | ) { |
1101 | ) { |
954 | # use kqueue for sockets |
1102 | # use kqueue for sockets |
955 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
1103 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
956 | } |
1104 | } |
957 | |
1105 | |
958 | # use the default loop otherwise |
1106 | # use the default loop otherwise |
959 | $socket_loop ||= EV::default_loop; |
1107 | $socket_loop ||= EV::default_loop; |
960 | |
1108 | |
961 | =over 4 |
1109 | =over 4 |
962 | |
1110 | |
963 | =item $w = EV::embed $otherloop, $callback |
1111 | =item $w = EV::embed $otherloop[, $callback] |
964 | |
1112 | |
965 | =item $w = EV::embed_ns $otherloop, $callback |
1113 | =item $w = EV::embed_ns $otherloop[, $callback] |
966 | |
1114 | |
967 | =item $w = $loop->embed ($otherloop, $callback) |
1115 | =item $w = $loop->embed ($otherloop[, $callback]) |
968 | |
1116 | |
969 | =item $w = $loop->embed_ns ($otherloop, $callback) |
1117 | =item $w = $loop->embed_ns ($otherloop[, $callback]) |
970 | |
1118 | |
971 | Call the callback when the embedded event loop (C<$otherloop>) has any |
1119 | Call the callback when the embedded event loop (C<$otherloop>) has any |
972 | I/O activity. The C<$callback> should alwas be specified as C<undef> in |
1120 | I/O activity. The C<$callback> is optional: if it is missing, then the |
973 | this version of EV, which means the embedded event loop will be managed |
1121 | embedded event loop will be managed automatically (which is recommended), |
974 | automatically. |
1122 | otherwise you have to invoke C<sweep> yourself. |
975 | |
1123 | |
976 | The C<embed_ns> variant doesn't start (activate) the newly created watcher. |
1124 | The C<embed_ns> variant doesn't start (activate) the newly created watcher. |
977 | |
1125 | |
978 | =back |
1126 | =back |
979 | |
1127 | |
980 | =head3 ASYNC WATCHERS - how to wake up another event loop |
1128 | =head3 ASYNC WATCHERS - how to wake up another event loop |
981 | |
1129 | |
982 | Async watchers are provided by EV, but have little use in perl directly, as perl |
1130 | Async watchers are provided by EV, but have little use in perl directly, |
983 | neither supports threads nor direct access to signal handlers or other |
1131 | as perl neither supports threads running in parallel nor direct access to |
984 | contexts where they could be of value. |
1132 | signal handlers or other contexts where they could be of value. |
985 | |
1133 | |
986 | It is, however, possible to use them from the XS level. |
1134 | It is, however, possible to use them from the XS level. |
987 | |
1135 | |
988 | Please see the libev documentation for further details. |
1136 | Please see the libev documentation for further details. |
989 | |
1137 | |
… | |
… | |
991 | |
1139 | |
992 | =item $w = EV::async $callback |
1140 | =item $w = EV::async $callback |
993 | |
1141 | |
994 | =item $w = EV::async_ns $callback |
1142 | =item $w = EV::async_ns $callback |
995 | |
1143 | |
|
|
1144 | =item $w = $loop->async ($callback) |
|
|
1145 | |
|
|
1146 | =item $w = $loop->async_ns ($callback) |
|
|
1147 | |
996 | =item $w->send |
1148 | =item $w->send |
997 | |
1149 | |
998 | =item $bool = $w->async_pending |
1150 | =item $bool = $w->async_pending |
999 | |
1151 | |
1000 | =back |
1152 | =back |
|
|
1153 | |
|
|
1154 | =head3 CLEANUP WATCHERS - how to clean up when the event loop goes away |
|
|
1155 | |
|
|
1156 | Cleanup watchers are not supported on the Perl level, they can only be |
|
|
1157 | used via XS currently. |
1001 | |
1158 | |
1002 | |
1159 | |
1003 | =head1 PERL SIGNALS |
1160 | =head1 PERL SIGNALS |
1004 | |
1161 | |
1005 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
1162 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
… | |
… | |
1017 | my $async_check = EV::check sub { }; |
1174 | my $async_check = EV::check sub { }; |
1018 | |
1175 | |
1019 | This ensures that perl gets into control for a short time to handle any |
1176 | This ensures that perl gets into control for a short time to handle any |
1020 | pending signals, and also ensures (slightly) slower overall operation. |
1177 | pending signals, and also ensures (slightly) slower overall operation. |
1021 | |
1178 | |
1022 | =head1 THREADS |
1179 | =head1 ITHREADS |
1023 | |
1180 | |
1024 | Threads are not supported by this module in any way. Perl pseudo-threads |
1181 | Ithreads are not supported by this module in any way. Perl pseudo-threads |
1025 | is evil stuff and must die. As soon as Perl gains real threads I will work |
1182 | is evil stuff and must die. Real threads as provided by Coro are fully |
1026 | on thread support for it. |
1183 | supported (and enhanced support is available via L<Coro::EV>). |
1027 | |
1184 | |
1028 | =head1 FORK |
1185 | =head1 FORK |
1029 | |
1186 | |
1030 | Most of the "improved" event delivering mechanisms of modern operating |
1187 | Most of the "improved" event delivering mechanisms of modern operating |
1031 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
1188 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
… | |
… | |
1053 | |
1210 | |
1054 | 1; |
1211 | 1; |
1055 | |
1212 | |
1056 | =head1 SEE ALSO |
1213 | =head1 SEE ALSO |
1057 | |
1214 | |
|
|
1215 | L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS> |
1058 | L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as |
1216 | (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event |
1059 | event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient |
1217 | loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread |
1060 | coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for |
1218 | integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for |
1061 | event-loop agnostic and portable event driven programming. |
1219 | event-loop agnostic and portable event driven programming. |
1062 | |
1220 | |
1063 | =head1 AUTHOR |
1221 | =head1 AUTHOR |
1064 | |
1222 | |
1065 | Marc Lehmann <schmorp@schmorp.de> |
1223 | Marc Lehmann <schmorp@schmorp.de> |
1066 | http://home.schmorp.de/ |
1224 | http://home.schmorp.de/ |
1067 | |
1225 | |
1068 | =cut |
1226 | =cut |
1069 | |
1227 | |