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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::loop; # 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::loop EV::LOOP_ONESHOT; # 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::loop EV::LOOP_NONBLOCK; # 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://cvs.schmorp.de/libev/ev.html>) for more subtle details on |
70 | libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or |
62 | watcher semantics or some discussion on the available backends, or how to |
71 | F<perldoc EV::libev>) for more subtle details on watcher semantics or some |
63 | force a specific backend with C<LIBEV_FLAGS>, or just about in any case |
72 | discussion on the available backends, or how to force a specific backend |
64 | 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. |
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75 | |
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76 | This module is very fast and scalable. It is actually so fast that you |
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77 | can use it through the L<AnyEvent> module, stay portable to other event |
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78 | loops (if you don't rely on any watcher types not available through it) |
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79 | and still be faster than with any other event loop currently supported in |
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80 | Perl. |
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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. |
65 | |
116 | |
66 | =cut |
117 | =cut |
67 | |
118 | |
68 | package EV; |
119 | package EV; |
69 | |
120 | |
70 | use strict; |
121 | use common::sense; |
71 | |
122 | |
72 | BEGIN { |
123 | BEGIN { |
73 | our $VERSION = '3.2'; |
124 | our $VERSION = '4.02'; |
74 | use XSLoader; |
125 | use XSLoader; |
75 | XSLoader::load "EV", $VERSION; |
126 | XSLoader::load "EV", $VERSION; |
76 | } |
127 | } |
77 | |
128 | |
78 | @EV::IO::ISA = |
129 | @EV::IO::ISA = |
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105 | 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 |
106 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
157 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
107 | |
158 | |
108 | For specific programs you can create additional event loops dynamically. |
159 | For specific programs you can create additional event loops dynamically. |
109 | |
160 | |
110 | =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. |
111 | |
166 | |
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167 | =over 4 |
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168 | |
112 | =item $loop = new EV::loop [$flags] |
169 | =item $loop = new EV::Loop [$flags] |
113 | |
170 | |
114 | 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 |
115 | C<ev_loop_new ()> function description in the libev documentation |
172 | the C<ev_loop_new ()> function description in the libev documentation |
116 | (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>, |
117 | for more info. |
174 | or locally-installed as F<EV::libev> manpage) for more info. |
118 | |
175 | |
119 | 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 |
120 | by any watcher and the loop object goes out of scope. |
177 | by any watcher and the loop object goes out of scope. |
121 | |
178 | |
122 | 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> |
123 | 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. |
124 | |
183 | |
125 | =item $loop->loop_fork |
184 | =item $loop->loop_fork |
126 | |
185 | |
127 | 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 |
128 | 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 |
129 | this fucntion automatically, at some performance loss (refer to the libev |
188 | this function automatically, at some performance loss (refer to the libev |
130 | documentation). |
189 | documentation). |
131 | |
190 | |
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191 | =item $loop->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 | |
132 | =item $loop = EV::default_loop [$flags] |
197 | =item $loop = EV::default_loop [$flags] |
133 | |
198 | |
134 | 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. |
135 | |
204 | |
136 | =back |
205 | =back |
137 | |
206 | |
138 | |
207 | |
139 | =head1 BASIC INTERFACE |
208 | =head1 BASIC INTERFACE |
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169 | =item $time = EV::now |
238 | =item $time = EV::now |
170 | |
239 | |
171 | =item $time = $loop->now |
240 | =item $time = $loop->now |
172 | |
241 | |
173 | 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 |
174 | 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 |
175 | usually faster then calling EV::time. |
244 | usually faster then calling EV::time. |
176 | |
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 | |
177 | =item $backend = EV::backend |
288 | =item $backend = EV::backend |
178 | |
289 | |
179 | =item $backend = $loop->backend |
290 | =item $backend = $loop->backend |
180 | |
291 | |
181 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
292 | Returns an integer describing the backend used by libev (EV::BACKEND_SELECT |
182 | or EV::METHOD_EPOLL). |
293 | or EV::BACKEND_EPOLL). |
183 | |
294 | |
184 | =item EV::loop [$flags] |
295 | =item EV::loop [$flags] |
185 | |
296 | |
186 | =item $loop->loop ([$flags]) |
297 | =item $loop->loop ([$flags]) |
187 | |
298 | |
188 | Begin checking for events and calling callbacks. It returns when a |
299 | Begin checking for events and calling callbacks. It returns when a |
189 | callback calls EV::unloop. |
300 | callback calls EV::unloop. |
190 | |
301 | |
191 | The $flags argument can be one of the following: |
302 | The $flags argument can be one of the following: |
192 | |
303 | |
193 | 0 as above |
304 | 0 as above |
194 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
305 | EV::LOOP_ONCE block at most once (wait, but do not loop) |
195 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
306 | EV::LOOP_NOWAIT do not block at all (fetch/handle events but do not wait) |
196 | |
307 | |
197 | =item EV::unloop [$how] |
308 | =item EV::break [$how] |
198 | |
309 | |
199 | =item $loop->unloop ([$how]) |
310 | =item $loop->break ([$how]) |
200 | |
311 | |
201 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
312 | When called with no arguments or an argument of EV::BREAK_ONE, makes the |
202 | innermost call to EV::loop return. |
313 | innermost call to EV::loop return. |
203 | |
314 | |
204 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
315 | When called with an argument of EV::BREAK_ALL, all calls to EV::loop will |
205 | fast as possible. |
316 | return as fast as possible. |
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317 | |
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318 | When called with an argument of EV::BREAK_CANCEL, any pending break will |
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319 | be cancelled. |
206 | |
320 | |
207 | =item $count = EV::loop_count |
321 | =item $count = EV::loop_count |
208 | |
322 | |
209 | =item $count = $loop->loop_count |
323 | =item $count = $loop->loop_count |
210 | |
324 | |
211 | Return the number of times the event loop has polled for new |
325 | Return the number of times the event loop has polled for new |
212 | events. Sometiems useful as a generation counter. |
326 | events. Sometimes useful as a generation counter. |
213 | |
327 | |
214 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
328 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
215 | |
329 | |
216 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
330 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
217 | |
331 | |
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228 | timeout. Otherwise a EV::timer with this value will be started. |
342 | timeout. Otherwise a EV::timer with this value will be started. |
229 | |
343 | |
230 | When an error occurs or either the timeout or I/O watcher triggers, then |
344 | When an error occurs or either the timeout or I/O watcher triggers, then |
231 | the callback will be called with the received event set (in general |
345 | the callback will be called with the received event set (in general |
232 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
346 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
233 | C<EV::WRITE> and C<EV::TIMEOUT>). |
347 | C<EV::WRITE> and C<EV::TIMER>). |
234 | |
348 | |
235 | EV::once doesn't return anything: the watchers stay active till either |
349 | EV::once doesn't return anything: the watchers stay active till either |
236 | of them triggers, then they will be stopped and freed, and the callback |
350 | of them triggers, then they will be stopped and freed, and the callback |
237 | invoked. |
351 | invoked. |
238 | |
352 | |
239 | =item EV::feed_fd_event ($fd, $revents) |
353 | =item EV::feed_fd_event $fd, $revents |
240 | |
354 | |
241 | =item $loop->feed_fd_event ($fd, $revents) |
355 | =item $loop->feed_fd_event ($fd, $revents) |
242 | |
356 | |
243 | Feed an event on a file descriptor into EV. EV will react to this call as |
357 | Feed an event on a file descriptor into EV. EV will react to this call as |
244 | if the readyness notifications specified by C<$revents> (a combination of |
358 | if the readyness notifications specified by C<$revents> (a combination of |
245 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
359 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
246 | |
360 | |
247 | =item EV::feed_signal_event ($signal) |
361 | =item EV::feed_signal_event $signal |
248 | |
362 | |
249 | Feed a signal event into EV. EV will react to this call as if the signal |
363 | Feed a signal event into the default loop. EV will react to this call as |
250 | specified by C<$signal> had occured. |
364 | if the signal specified by C<$signal> had occured. |
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365 | |
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366 | =item EV::feed_signal $signal |
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367 | |
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368 | Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works |
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369 | regardless of which loop has registered the signal, and is mainly useful |
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370 | fro custom signal implementations. |
251 | |
371 | |
252 | =item EV::set_io_collect_interval $time |
372 | =item EV::set_io_collect_interval $time |
253 | |
373 | |
254 | =item $loop->set_io_collect_interval ($time) |
374 | =item $loop->set_io_collect_interval ($time) |
255 | |
375 | |
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257 | |
377 | |
258 | =item $loop->set_timeout_collect_interval ($time) |
378 | =item $loop->set_timeout_collect_interval ($time) |
259 | |
379 | |
260 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
380 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
261 | wait interval for timer events. See the libev documentation at |
381 | wait interval for timer events. See the libev documentation at |
262 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for |
382 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> |
263 | a more detailed discussion. |
383 | (locally installed as F<EV::libev>) for a more detailed discussion. |
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384 | |
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385 | =item $count = EV::pending_count |
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386 | |
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387 | =item $count = $loop->pending_count |
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388 | |
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389 | Returns the number of currently pending watchers. |
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390 | |
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391 | =item EV::invoke_pending |
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392 | |
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393 | =item $loop->invoke_pending |
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394 | |
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395 | Invoke all currently pending watchers. |
264 | |
396 | |
265 | =back |
397 | =back |
266 | |
398 | |
267 | |
399 | |
268 | =head1 WATCHER OBJECTS |
400 | =head1 WATCHER OBJECTS |
269 | |
401 | |
270 | A watcher is an object that gets created to record your interest in some |
402 | A watcher is an object that gets created to record your interest in some |
271 | event. For instance, if you want to wait for STDIN to become readable, you |
403 | event. For instance, if you want to wait for STDIN to become readable, you |
272 | would create an EV::io watcher for that: |
404 | would create an EV::io watcher for that: |
273 | |
405 | |
274 | my $watcher = EV::io *STDIN, EV::READ, sub { |
406 | my $watcher = EV::io *STDIN, EV::READ, sub { |
275 | my ($watcher, $revents) = @_; |
407 | my ($watcher, $revents) = @_; |
276 | warn "yeah, STDIN should now be readable without blocking!\n" |
408 | warn "yeah, STDIN should now be readable without blocking!\n" |
277 | }; |
409 | }; |
278 | |
410 | |
279 | All watchers can be active (waiting for events) or inactive (paused). Only |
411 | All watchers can be active (waiting for events) or inactive (paused). Only |
280 | active watchers will have their callbacks invoked. All callbacks will be |
412 | active watchers will have their callbacks invoked. All callbacks will be |
281 | called with at least two arguments: the watcher and a bitmask of received |
413 | called with at least two arguments: the watcher and a bitmask of received |
282 | events. |
414 | events. |
283 | |
415 | |
284 | Each watcher type has its associated bit in revents, so you can use the |
416 | Each watcher type has its associated bit in revents, so you can use the |
285 | same callback for multiple watchers. The event mask is named after the |
417 | same callback for multiple watchers. The event mask is named after the |
286 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
418 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
287 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
419 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
288 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
420 | (which can set both EV::READ and EV::WRITE bits). |
289 | uses EV::TIMEOUT). |
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|
290 | |
421 | |
291 | In the rare case where one wants to create a watcher but not start it at |
422 | In the rare case where one wants to create a watcher but not start it at |
292 | the same time, each constructor has a variant with a trailing C<_ns> in |
423 | the same time, each constructor has a variant with a trailing C<_ns> in |
293 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
424 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
294 | |
425 | |
… | |
… | |
373 | |
504 | |
374 | =item $previous_state = $w->keepalive ($bool) |
505 | =item $previous_state = $w->keepalive ($bool) |
375 | |
506 | |
376 | Normally, C<EV::loop> will return when there are no active watchers |
507 | Normally, C<EV::loop> will return when there are no active watchers |
377 | (which is a "deadlock" because no progress can be made anymore). This is |
508 | (which is a "deadlock" because no progress can be made anymore). This is |
378 | convinient because it allows you to start your watchers (and your jobs), |
509 | convenient because it allows you to start your watchers (and your jobs), |
379 | call C<EV::loop> once and when it returns you know that all your jobs are |
510 | call C<EV::loop> once and when it returns you know that all your jobs are |
380 | finished (or they forgot to register some watchers for their task :). |
511 | finished (or they forgot to register some watchers for their task :). |
381 | |
512 | |
382 | Sometimes, however, this gets in your way, for example when the module |
513 | Sometimes, however, this gets in your way, for example when the module |
383 | that calls C<EV::loop> (usually the main program) is not the same module |
514 | that calls C<EV::loop> (usually the main program) is not the same module |
… | |
… | |
387 | because you happen to have this long-running UDP port watcher. |
518 | because you happen to have this long-running UDP port watcher. |
388 | |
519 | |
389 | In this case you can clear the keepalive status, which means that even |
520 | In this case you can clear the keepalive status, which means that even |
390 | though your watcher is active, it won't keep C<EV::loop> from returning. |
521 | though your watcher is active, it won't keep C<EV::loop> from returning. |
391 | |
522 | |
392 | The initial value for keepalive is true (enabled), and you cna change it |
523 | The initial value for keepalive is true (enabled), and you can change it |
393 | any time. |
524 | any time. |
394 | |
525 | |
395 | Example: Register an I/O watcher for some UDP socket but do not keep the |
526 | Example: Register an I/O watcher for some UDP socket but do not keep the |
396 | event loop from running just because of that watcher. |
527 | event loop from running just because of that watcher. |
397 | |
528 | |
398 | my $udp_socket = ... |
529 | my $udp_socket = ... |
399 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
530 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
400 | $1000udp_watcher->keepalive (0); |
531 | $udp_watcher->keepalive (0); |
401 | |
532 | |
402 | =item $loop = $w->loop |
533 | =item $loop = $w->loop |
403 | |
534 | |
404 | Return the loop that this watcher is attached to. |
535 | Return the loop that this watcher is attached to. |
405 | |
536 | |
… | |
… | |
562 | time the periodic watcher gets scheduled, the reschedule callback |
693 | time the periodic watcher gets scheduled, the reschedule callback |
563 | ($reschedule_cb) will be called with the watcher as first, and the current |
694 | ($reschedule_cb) will be called with the watcher as first, and the current |
564 | time as second argument. |
695 | time as second argument. |
565 | |
696 | |
566 | I<This callback MUST NOT stop or destroy this or any other periodic |
697 | I<This callback MUST NOT stop or destroy this or any other periodic |
567 | watcher, ever>. If you need to stop it, return 1e30 and stop it |
698 | watcher, ever, and MUST NOT call any event loop functions or methods>. If |
568 | afterwards. |
699 | you need to stop it, return 1e30 and stop it afterwards. You may create |
|
|
700 | and start a C<EV::prepare> watcher for this task. |
569 | |
701 | |
570 | It must return the next time to trigger, based on the passed time value |
702 | It must return the next time to trigger, based on the passed time value |
571 | (that is, the lowest time value larger than to the second argument). It |
703 | (that is, the lowest time value larger than or equal to to the second |
572 | will usually be called just before the callback will be triggered, but |
704 | argument). It will usually be called just before the callback will be |
573 | might be called at other times, too. |
705 | triggered, but might be called at other times, too. |
574 | |
706 | |
575 | This can be used to create very complex timers, such as a timer that |
707 | This can be used to create very complex timers, such as a timer that |
576 | triggers on each midnight, local time (actually 24 hours after the last |
708 | triggers on each midnight, local time (actually 24 hours after the last |
577 | midnight, to keep the example simple. If you know a way to do it correctly |
709 | midnight, to keep the example simple. If you know a way to do it correctly |
578 | in about the same space (without requiring elaborate modules), drop me a |
710 | in about the same space (without requiring elaborate modules), drop me a |
… | |
… | |
614 | |
746 | |
615 | =item $w = EV::signal $signal, $callback |
747 | =item $w = EV::signal $signal, $callback |
616 | |
748 | |
617 | =item $w = EV::signal_ns $signal, $callback |
749 | =item $w = EV::signal_ns $signal, $callback |
618 | |
750 | |
|
|
751 | =item $w = $loop->signal ($signal, $callback) |
|
|
752 | |
|
|
753 | =item $w = $loop->signal_ns ($signal, $callback) |
|
|
754 | |
619 | Call the callback when $signal is received (the signal can be specified by |
755 | Call the callback when $signal is received (the signal can be specified by |
620 | number or by name, just as with C<kill> or C<%SIG>). |
756 | number or by name, just as with C<kill> or C<%SIG>). |
|
|
757 | |
|
|
758 | Only one event loop can grab a given signal - attempting to grab the same |
|
|
759 | signal from two EV loops will crash the program immediately or cause data |
|
|
760 | corruption. |
621 | |
761 | |
622 | EV will grab the signal for the process (the kernel only allows one |
762 | EV will grab the signal for the process (the kernel only allows one |
623 | component to receive a signal at a time) when you start a signal watcher, |
763 | component to receive a signal at a time) when you start a signal watcher, |
624 | and removes it again when you stop it. Perl does the same when you |
764 | and removes it again when you stop it. Perl does the same when you |
625 | add/remove callbacks to C<%SIG>, so watch out. |
765 | add/remove callbacks to C<%SIG>, so watch out. |
… | |
… | |
850 | =item $w = $loop->check_ns ($callback) |
990 | =item $w = $loop->check_ns ($callback) |
851 | |
991 | |
852 | Call the callback just after the process wakes up again (after it has |
992 | Call the callback just after the process wakes up again (after it has |
853 | gathered events), but before any other callbacks have been invoked. |
993 | gathered events), but before any other callbacks have been invoked. |
854 | |
994 | |
855 | This is used to integrate other event-based software into the EV |
995 | This can be used to integrate other event-based software into the EV |
856 | mainloop: You register a prepare callback and in there, you create io and |
996 | mainloop: You register a prepare callback and in there, you create io and |
857 | timer watchers as required by the other software. Here is a real-world |
997 | timer watchers as required by the other software. Here is a real-world |
858 | example of integrating Net::SNMP (with some details left out): |
998 | example of integrating Net::SNMP (with some details left out): |
859 | |
999 | |
860 | our @snmp_watcher; |
1000 | our @snmp_watcher; |
… | |
… | |
890 | # make the dispatcher handle any new stuff |
1030 | # make the dispatcher handle any new stuff |
891 | ... not shown |
1031 | ... not shown |
892 | }; |
1032 | }; |
893 | |
1033 | |
894 | The callbacks of the created watchers will not be called as the watchers |
1034 | The callbacks of the created watchers will not be called as the watchers |
895 | are destroyed before this cna happen (remember EV::check gets called |
1035 | are destroyed before this can happen (remember EV::check gets called |
896 | first). |
1036 | first). |
897 | |
1037 | |
898 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
1038 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
|
|
1039 | |
|
|
1040 | =item EV::CHECK constant issues |
|
|
1041 | |
|
|
1042 | Like all other watcher types, there is a bitmask constant for use in |
|
|
1043 | C<$revents> and other places. The C<EV::CHECK> is special as it has |
|
|
1044 | the same name as the C<CHECK> sub called by Perl. This doesn't cause |
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|
1045 | big issues on newer perls (beginning with 5.8.9), but it means thatthe |
|
|
1046 | constant must be I<inlined>, i.e. runtime calls will not work. That means |
|
|
1047 | that as long as you always C<use EV> and then C<EV::CHECK> you are on the |
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|
1048 | safe side. |
899 | |
1049 | |
900 | =back |
1050 | =back |
901 | |
1051 | |
902 | |
1052 | |
903 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
1053 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
… | |
… | |
931 | loop, other types of watchers might be handled in a delayed or incorrect |
1081 | loop, other types of watchers might be handled in a delayed or incorrect |
932 | fashion and must not be used). |
1082 | fashion and must not be used). |
933 | |
1083 | |
934 | See the libev documentation at |
1084 | See the libev documentation at |
935 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> |
1085 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> |
936 | for more details. |
1086 | (locally installed as F<EV::libev>) for more details. |
937 | |
1087 | |
938 | In short, this watcher is most useful on BSD systems without working |
1088 | In short, this watcher is most useful on BSD systems without working |
939 | kqueue to still be able to handle a large number of sockets: |
1089 | kqueue to still be able to handle a large number of sockets: |
940 | |
1090 | |
941 | my $socket_loop; |
1091 | my $socket_loop; |
942 | |
1092 | |
943 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
1093 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
944 | if ( |
1094 | if ( |
945 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
1095 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
946 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
1096 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
947 | ) { |
1097 | ) { |
948 | # use kqueue for sockets |
1098 | # use kqueue for sockets |
949 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
1099 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
950 | } |
1100 | } |
951 | |
1101 | |
952 | # use the default loop otherwise |
1102 | # use the default loop otherwise |
953 | $socket_loop ||= EV::default_loop; |
1103 | $socket_loop ||= EV::default_loop; |
954 | |
1104 | |
955 | =over 4 |
1105 | =over 4 |
956 | |
1106 | |
957 | =item $w = EV::embed $otherloop, $callback |
1107 | =item $w = EV::embed $otherloop[, $callback] |
958 | |
1108 | |
959 | =item $w = EV::embed_ns $otherloop, $callback |
1109 | =item $w = EV::embed_ns $otherloop[, $callback] |
960 | |
1110 | |
961 | =item $w = $loop->embed ($otherloop, $callback) |
1111 | =item $w = $loop->embed ($otherloop[, $callback]) |
962 | |
1112 | |
963 | =item $w = $loop->embed_ns ($otherloop, $callback) |
1113 | =item $w = $loop->embed_ns ($otherloop[, $callback]) |
964 | |
1114 | |
965 | Call the callback when the embedded event loop (C<$otherloop>) has any |
1115 | Call the callback when the embedded event loop (C<$otherloop>) has any |
966 | I/O activity. The C<$callback> should alwas be specified as C<undef> in |
1116 | I/O activity. The C<$callback> is optional: if it is missing, then the |
967 | this version of EV, which means the embedded event loop will be managed |
1117 | embedded event loop will be managed automatically (which is recommended), |
968 | automatically. |
1118 | otherwise you have to invoke C<sweep> yourself. |
969 | |
1119 | |
970 | The C<embed_ns> variant doesn't start (activate) the newly created watcher. |
1120 | The C<embed_ns> variant doesn't start (activate) the newly created watcher. |
971 | |
1121 | |
972 | =back |
1122 | =back |
973 | |
1123 | |
974 | =head3 ASYNC WATCHERS - how to wake up another event loop |
1124 | =head3 ASYNC WATCHERS - how to wake up another event loop |
975 | |
1125 | |
976 | Async watchers are provided by EV, but have little use in perl directly, as perl |
1126 | Async watchers are provided by EV, but have little use in perl directly, |
977 | neither supports threads nor direct access to signal handlers or other |
1127 | as perl neither supports threads running in parallel nor direct access to |
978 | contexts where they could be of value. |
1128 | signal handlers or other contexts where they could be of value. |
979 | |
1129 | |
980 | It is, however, possible to use them from the XS level. |
1130 | It is, however, possible to use them from the XS level. |
981 | |
1131 | |
982 | Please see the libev documentation for further details. |
1132 | Please see the libev documentation for further details. |
983 | |
1133 | |
… | |
… | |
1011 | my $async_check = EV::check sub { }; |
1161 | my $async_check = EV::check sub { }; |
1012 | |
1162 | |
1013 | This ensures that perl gets into control for a short time to handle any |
1163 | This ensures that perl gets into control for a short time to handle any |
1014 | pending signals, and also ensures (slightly) slower overall operation. |
1164 | pending signals, and also ensures (slightly) slower overall operation. |
1015 | |
1165 | |
1016 | =head1 THREADS |
1166 | =head1 ITHREADS |
1017 | |
1167 | |
1018 | Threads are not supported by this module in any way. Perl pseudo-threads |
1168 | Ithreads are not supported by this module in any way. Perl pseudo-threads |
1019 | is evil stuff and must die. As soon as Perl gains real threads I will work |
1169 | is evil stuff and must die. Real threads as provided by Coro are fully |
1020 | on thread support for it. |
1170 | supported (and enhanced support is available via L<Coro::EV>). |
1021 | |
1171 | |
1022 | =head1 FORK |
1172 | =head1 FORK |
1023 | |
1173 | |
1024 | Most of the "improved" event delivering mechanisms of modern operating |
1174 | Most of the "improved" event delivering mechanisms of modern operating |
1025 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
1175 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
… | |
… | |
1047 | |
1197 | |
1048 | 1; |
1198 | 1; |
1049 | |
1199 | |
1050 | =head1 SEE ALSO |
1200 | =head1 SEE ALSO |
1051 | |
1201 | |
|
|
1202 | L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS> |
1052 | L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as |
1203 | (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event |
1053 | event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient |
1204 | loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread |
1054 | coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). |
1205 | integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for |
|
|
1206 | event-loop agnostic and portable event driven programming. |
1055 | |
1207 | |
1056 | =head1 AUTHOR |
1208 | =head1 AUTHOR |
1057 | |
1209 | |
1058 | Marc Lehmann <schmorp@schmorp.de> |
1210 | Marc Lehmann <schmorp@schmorp.de> |
1059 | http://home.schmorp.de/ |
1211 | http://home.schmorp.de/ |
1060 | |
1212 | |
1061 | =cut |
1213 | =cut |
1062 | |
1214 | |