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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 $w = EV::child 666, sub { |
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41 | my ($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::break 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://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 = '2.0'; |
124 | our $VERSION = '4.32'; |
74 | use XSLoader; |
125 | use XSLoader; |
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126 | local $^W = 0; # avoid spurious warning |
75 | XSLoader::load "EV", $VERSION; |
127 | XSLoader::load "EV", $VERSION; |
76 | } |
128 | } |
77 | |
129 | |
78 | @EV::IO::ISA = |
130 | @EV::IO::ISA = |
79 | @EV::Timer::ISA = |
131 | @EV::Timer::ISA = |
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84 | @EV::Idle::ISA = |
136 | @EV::Idle::ISA = |
85 | @EV::Prepare::ISA = |
137 | @EV::Prepare::ISA = |
86 | @EV::Check::ISA = |
138 | @EV::Check::ISA = |
87 | @EV::Embed::ISA = |
139 | @EV::Embed::ISA = |
88 | @EV::Fork::ISA = |
140 | @EV::Fork::ISA = |
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141 | @EV::Async::ISA = |
89 | "EV::Watcher"; |
142 | "EV::Watcher"; |
90 | |
143 | |
91 | @EV::Loop::Default::ISA = "EV::Loop"; |
144 | @EV::Loop::Default::ISA = "EV::Loop"; |
92 | |
145 | |
93 | =head1 EVENT LOOPS |
146 | =head1 EVENT LOOPS |
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102 | selecting a working backend (which for example rules out kqueue on most |
155 | selecting a working backend (which for example rules out kqueue on most |
103 | BSDs). Modules should, unless they have "special needs" always use the |
156 | BSDs). Modules should, unless they have "special needs" always use the |
104 | default loop as this is fastest (perl-wise), best supported by other |
157 | default loop as this is fastest (perl-wise), best supported by other |
105 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
158 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
106 | |
159 | |
107 | For specific programs you cna create additional event loops dynamically. |
160 | For specific programs you can create additional event loops dynamically. |
108 | |
161 | |
109 | =over 4 |
162 | If you want to take advantage of kqueue (which often works properly for |
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163 | sockets only) even though the default loop doesn't enable it, you can |
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164 | I<embed> a kqueue loop into the default loop: running the default loop |
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165 | will then also service the kqueue loop to some extent. See the example in |
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166 | the section about embed watchers for an example on how to achieve that. |
110 | |
167 | |
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168 | =over 4 |
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169 | |
111 | =item $loop = new EV::loop [$flags] |
170 | =item $loop = new EV::Loop [$flags] |
112 | |
171 | |
113 | Create a new event loop as per the specified flags. Please refer to the |
172 | Create a new event loop as per the specified flags. Please refer to |
114 | C<ev_loop_new ()> function description in the libev documentation |
173 | the C<ev_loop_new ()> function description in the libev documentation |
115 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>) |
174 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>, |
116 | for more info. |
175 | or locally-installed as F<EV::libev> manpage) for more info. |
117 | |
176 | |
118 | The loop will automatically be destroyed when it is no longer referenced |
177 | The loop will automatically be destroyed when it is no longer referenced |
119 | by any watcher and the loop object goes out of scope. |
178 | by any watcher and the loop object goes out of scope. |
120 | |
179 | |
121 | Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop |
180 | If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK> |
122 | is protected by this module. |
181 | is recommended, as only the default event loop is protected by this |
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182 | module. If you I<are> embedding this loop in the default loop, this is not |
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183 | necessary, as C<EV::embed> automatically does the right thing on fork. |
123 | |
184 | |
124 | =item $loop->loop_fork |
185 | =item $loop->loop_fork |
125 | |
186 | |
126 | Must be called after a fork in the child, before entering or continuing |
187 | Must be called after a fork in the child, before entering or continuing |
127 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
188 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
128 | this fucntion automatically, at some performance loss (refer to the libev |
189 | this function automatically, at some performance loss (refer to the libev |
129 | documentation). |
190 | documentation). |
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191 | |
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192 | =item $loop->verify |
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193 | |
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194 | Calls C<ev_verify> to make internal consistency checks (for debugging |
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195 | libev) and abort the program if any data structures were found to be |
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196 | corrupted. |
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197 | |
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198 | =item $loop = EV::default_loop [$flags] |
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199 | |
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200 | Return the default loop (which is a singleton object). Since this module |
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201 | already creates the default loop with default flags, specifying flags here |
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202 | will not have any effect unless you destroy the default loop first, which |
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203 | isn't supported. So in short: don't do it, and if you break it, you get to |
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204 | keep the pieces. |
130 | |
205 | |
131 | =back |
206 | =back |
132 | |
207 | |
133 | |
208 | |
134 | =head1 BASIC INTERFACE |
209 | =head1 BASIC INTERFACE |
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141 | throws an exception (with $@ containing the error). The default prints an |
216 | throws an exception (with $@ containing the error). The default prints an |
142 | informative message and continues. |
217 | informative message and continues. |
143 | |
218 | |
144 | If this callback throws an exception it will be silently ignored. |
219 | If this callback throws an exception it will be silently ignored. |
145 | |
220 | |
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221 | =item $flags = EV::supported_backends |
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222 | |
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223 | =item $flags = EV::recommended_backends |
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224 | |
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225 | =item $flags = EV::embeddable_backends |
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226 | |
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227 | Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this |
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228 | instance of EV, the set of recommended backends (supposed to be good) for |
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229 | this platform and the set of embeddable backends (see EMBED WATCHERS). |
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230 | |
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231 | =item EV::sleep $seconds |
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232 | |
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233 | Block the process for the given number of (fractional) seconds. |
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234 | |
146 | =item $time = EV::time |
235 | =item $time = EV::time |
147 | |
236 | |
148 | Returns the current time in (fractional) seconds since the epoch. |
237 | Returns the current time in (fractional) seconds since the epoch. |
149 | |
238 | |
150 | =item $time = EV::now |
239 | =item $time = EV::now |
151 | |
240 | |
152 | =item $time = $loop->now |
241 | =item $time = $loop->now |
153 | |
242 | |
154 | Returns the time the last event loop iteration has been started. This |
243 | Returns the time the last event loop iteration has been started. This |
155 | is the time that (relative) timers are based on, and refering to it is |
244 | is the time that (relative) timers are based on, and referring to it is |
156 | usually faster then calling EV::time. |
245 | usually faster then calling EV::time. |
157 | |
246 | |
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247 | =item EV::now_update |
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248 | |
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249 | =item $loop->now_update |
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250 | |
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251 | Establishes the current time by querying the kernel, updating the time |
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252 | returned by C<EV::now> in the progress. This is a costly operation and |
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253 | is usually done automatically within C<EV::run>. |
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254 | |
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255 | This function is rarely useful, but when some event callback runs for a |
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256 | very long time without entering the event loop, updating libev's idea of |
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257 | the current time is a good idea. |
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258 | |
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259 | =item EV::suspend |
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260 | |
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261 | =item $loop->suspend |
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262 | |
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263 | =item EV::resume |
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264 | |
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265 | =item $loop->resume |
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266 | |
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267 | These two functions suspend and resume a loop, for use when the loop is |
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268 | not used for a while and timeouts should not be processed. |
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269 | |
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270 | A typical use case would be an interactive program such as a game: When |
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271 | the user presses C<^Z> to suspend the game and resumes it an hour later it |
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272 | would be best to handle timeouts as if no time had actually passed while |
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273 | the program was suspended. This can be achieved by calling C<suspend> |
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274 | in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling |
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275 | C<resume> directly afterwards to resume timer processing. |
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276 | |
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277 | Effectively, all C<timer> watchers will be delayed by the time spend |
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278 | between C<suspend> and C<resume>, and all C<periodic> watchers |
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279 | will be rescheduled (that is, they will lose any events that would have |
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280 | occured while suspended). |
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281 | |
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282 | After calling C<suspend> you B<must not> call I<any> function on the given |
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283 | loop other than C<resume>, and you B<must not> call C<resume> |
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284 | without a previous call to C<suspend>. |
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285 | |
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286 | Calling C<suspend>/C<resume> has the side effect of updating the event |
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287 | loop time (see C<now_update>). |
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288 | |
158 | =item $backend = EV::backend |
289 | =item $backend = EV::backend |
159 | |
290 | |
160 | =item $backend = $loop->backend |
291 | =item $backend = $loop->backend |
161 | |
292 | |
162 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
293 | Returns an integer describing the backend used by libev (EV::BACKEND_SELECT |
163 | or EV::METHOD_EPOLL). |
294 | or EV::BACKEND_EPOLL). |
164 | |
295 | |
165 | =item EV::loop [$flags] |
296 | =item $active = EV::run [$flags] |
166 | |
297 | |
167 | =item $loop->loop ([$flags]) |
298 | =item $active = $loop->run ([$flags]) |
168 | |
299 | |
169 | Begin checking for events and calling callbacks. It returns when a |
300 | Begin checking for events and calling callbacks. It returns when a |
170 | callback calls EV::unloop. |
301 | callback calls EV::break or the flags are nonzero (in which case the |
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302 | return value is true) or when there are no active watchers which reference |
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303 | the loop (keepalive is true), in which case the return value will be |
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304 | false. The return value can generally be interpreted as "if true, there is |
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305 | more work left to do". |
171 | |
306 | |
172 | The $flags argument can be one of the following: |
307 | The $flags argument can be one of the following: |
173 | |
308 | |
174 | 0 as above |
309 | 0 as above |
175 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
310 | EV::RUN_ONCE block at most once (wait, but do not loop) |
176 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
311 | EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait) |
177 | |
312 | |
178 | =item EV::unloop [$how] |
313 | =item EV::break [$how] |
179 | |
314 | |
180 | =item $loop->unloop ([$how]) |
315 | =item $loop->break ([$how]) |
181 | |
316 | |
182 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
317 | When called with no arguments or an argument of EV::BREAK_ONE, makes the |
183 | innermost call to EV::loop return. |
318 | innermost call to EV::run return. |
184 | |
319 | |
185 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
320 | When called with an argument of EV::BREAK_ALL, all calls to EV::run will |
186 | fast as possible. |
321 | return as fast as possible. |
187 | |
322 | |
188 | =item $count = EV::loop_count |
323 | When called with an argument of EV::BREAK_CANCEL, any pending break will |
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324 | be cancelled. |
189 | |
325 | |
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326 | =item $count = EV::iteration |
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327 | |
190 | =item $count = $loop->loop_count |
328 | =item $count = $loop->iteration |
191 | |
329 | |
192 | Return the number of times the event loop has polled for new |
330 | Return the number of times the event loop has polled for new |
193 | events. Sometiems useful as a generation counter. |
331 | events. Sometimes useful as a generation counter. |
194 | |
332 | |
195 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
333 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
196 | |
334 | |
197 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
335 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
198 | |
336 | |
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204 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
342 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
205 | you do not want to wait for some I/O event, specify C<undef> for |
343 | you do not want to wait for some I/O event, specify C<undef> for |
206 | C<$fh_or_undef> and C<0> for C<$events>). |
344 | C<$fh_or_undef> and C<0> for C<$events>). |
207 | |
345 | |
208 | If timeout is C<undef> or negative, then there will be no |
346 | If timeout is C<undef> or negative, then there will be no |
209 | timeout. Otherwise a EV::timer with this value will be started. |
347 | timeout. Otherwise an C<EV::timer> with this value will be started. |
210 | |
348 | |
211 | When an error occurs or either the timeout or I/O watcher triggers, then |
349 | When an error occurs or either the timeout or I/O watcher triggers, then |
212 | the callback will be called with the received event set (in general |
350 | the callback will be called with the received event set (in general |
213 | you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, |
351 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
214 | C<EV::WRITE> and C<EV::TIMEOUT>). |
352 | C<EV::WRITE> and C<EV::TIMER>). |
215 | |
353 | |
216 | EV::once doesn't return anything: the watchers stay active till either |
354 | EV::once doesn't return anything: the watchers stay active till either |
217 | of them triggers, then they will be stopped and freed, and the callback |
355 | of them triggers, then they will be stopped and freed, and the callback |
218 | invoked. |
356 | invoked. |
219 | |
357 | |
220 | =item EV::feed_fd_event ($fd, $revents) |
358 | =item EV::feed_fd_event $fd, $revents |
221 | |
359 | |
222 | =item $loop->feed_fd_event ($fd, $revents) |
360 | =item $loop->feed_fd_event ($fd, $revents) |
223 | |
361 | |
224 | Feed an event on a file descriptor into EV. EV will react to this call as |
362 | Feed an event on a file descriptor into EV. EV will react to this call as |
225 | if the readyness notifications specified by C<$revents> (a combination of |
363 | if the readyness notifications specified by C<$revents> (a combination of |
226 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
364 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
227 | |
365 | |
228 | =item EV::feed_signal_event ($signal) |
366 | =item EV::feed_signal_event $signal |
229 | |
367 | |
230 | Feed a signal event into EV. EV will react to this call as if the signal |
368 | Feed a signal event into the default loop. EV will react to this call as |
231 | specified by C<$signal> had occured. |
369 | if the signal specified by C<$signal> had occured. |
|
|
370 | |
|
|
371 | =item EV::feed_signal $signal |
|
|
372 | |
|
|
373 | Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works |
|
|
374 | regardless of which loop has registered the signal, and is mainly useful |
|
|
375 | for custom signal implementations. |
|
|
376 | |
|
|
377 | =item EV::set_io_collect_interval $time |
|
|
378 | |
|
|
379 | =item $loop->set_io_collect_interval ($time) |
|
|
380 | |
|
|
381 | =item EV::set_timeout_collect_interval $time |
|
|
382 | |
|
|
383 | =item $loop->set_timeout_collect_interval ($time) |
|
|
384 | |
|
|
385 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
|
|
386 | wait interval for timer events. See the libev documentation at |
|
|
387 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> |
|
|
388 | (locally installed as F<EV::libev>) for a more detailed discussion. |
|
|
389 | |
|
|
390 | =item $count = EV::pending_count |
|
|
391 | |
|
|
392 | =item $count = $loop->pending_count |
|
|
393 | |
|
|
394 | Returns the number of currently pending watchers. |
|
|
395 | |
|
|
396 | =item EV::invoke_pending |
|
|
397 | |
|
|
398 | =item $loop->invoke_pending |
|
|
399 | |
|
|
400 | Invoke all currently pending watchers. |
232 | |
401 | |
233 | =back |
402 | =back |
234 | |
403 | |
235 | |
404 | |
236 | =head1 WATCHER OBJECTS |
405 | =head1 WATCHER OBJECTS |
237 | |
406 | |
238 | A watcher is an object that gets created to record your interest in some |
407 | A watcher is an object that gets created to record your interest in some |
239 | event. For instance, if you want to wait for STDIN to become readable, you |
408 | event. For instance, if you want to wait for STDIN to become readable, you |
240 | would create an EV::io watcher for that: |
409 | would create an EV::io watcher for that: |
241 | |
410 | |
242 | my $watcher = EV::io *STDIN, EV::READ, sub { |
411 | my $watcher = EV::io *STDIN, EV::READ, sub { |
243 | my ($watcher, $revents) = @_; |
412 | my ($watcher, $revents) = @_; |
244 | warn "yeah, STDIN should not be readable without blocking!\n" |
413 | warn "yeah, STDIN should now be readable without blocking!\n" |
245 | }; |
414 | }; |
246 | |
415 | |
247 | All watchers can be active (waiting for events) or inactive (paused). Only |
416 | All watchers can be active (waiting for events) or inactive (paused). Only |
248 | active watchers will have their callbacks invoked. All callbacks will be |
417 | active watchers will have their callbacks invoked. All callbacks will be |
249 | called with at least two arguments: the watcher and a bitmask of received |
418 | called with at least two arguments: the watcher and a bitmask of received |
250 | events. |
419 | events. |
251 | |
420 | |
252 | Each watcher type has its associated bit in revents, so you can use the |
421 | Each watcher type has its associated bit in revents, so you can use the |
253 | same callback for multiple watchers. The event mask is named after the |
422 | same callback for multiple watchers. The event mask is named after the |
254 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
423 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
255 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
424 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
256 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
425 | (which can set both EV::READ and EV::WRITE bits). |
257 | uses EV::TIMEOUT). |
|
|
258 | |
426 | |
259 | In the rare case where one wants to create a watcher but not start it at |
427 | In the rare case where one wants to create a watcher but not start it at |
260 | the same time, each constructor has a variant with a trailing C<_ns> in |
428 | the same time, each constructor has a variant with a trailing C<_ns> in |
261 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
429 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
262 | |
430 | |
… | |
… | |
333 | Feed some events on this watcher into EV. EV will react to this call as if |
501 | Feed some events on this watcher into EV. EV will react to this call as if |
334 | the watcher had received the given C<$revents> mask. |
502 | the watcher had received the given C<$revents> mask. |
335 | |
503 | |
336 | =item $revents = $w->clear_pending |
504 | =item $revents = $w->clear_pending |
337 | |
505 | |
338 | If the watcher is pending, this function returns clears its pending status |
506 | If the watcher is pending, this function clears its pending status and |
339 | and returns its C<$revents> bitset (as if its callback was invoked). If the |
507 | returns its C<$revents> bitset (as if its callback was invoked). If the |
340 | watcher isn't pending it does nothing and returns C<0>. |
508 | watcher isn't pending it does nothing and returns C<0>. |
341 | |
509 | |
342 | =item $previous_state = $w->keepalive ($bool) |
510 | =item $previous_state = $w->keepalive ($bool) |
343 | |
511 | |
344 | Normally, C<EV::loop> will return when there are no active watchers |
512 | Normally, C<EV::run> will return when there are no active watchers |
345 | (which is a "deadlock" because no progress can be made anymore). This is |
513 | (which is a "deadlock" because no progress can be made anymore). This is |
346 | convinient because it allows you to start your watchers (and your jobs), |
514 | convenient because it allows you to start your watchers (and your jobs), |
347 | call C<EV::loop> once and when it returns you know that all your jobs are |
515 | call C<EV::run> once and when it returns you know that all your jobs are |
348 | finished (or they forgot to register some watchers for their task :). |
516 | finished (or they forgot to register some watchers for their task :). |
349 | |
517 | |
350 | Sometimes, however, this gets in your way, for example when you the module |
518 | Sometimes, however, this gets in your way, for example when the module |
351 | that calls C<EV::loop> (usually the main program) is not the same module |
519 | that calls C<EV::run> (usually the main program) is not the same module |
352 | as a long-living watcher (for example a DNS client module written by |
520 | as a long-living watcher (for example a DNS client module written by |
353 | somebody else even). Then you might want any outstanding requests to be |
521 | somebody else even). Then you might want any outstanding requests to be |
354 | handled, but you would not want to keep C<EV::loop> from returning just |
522 | handled, but you would not want to keep C<EV::run> from returning just |
355 | because you happen to have this long-running UDP port watcher. |
523 | because you happen to have this long-running UDP port watcher. |
356 | |
524 | |
357 | In this case you can clear the keepalive status, which means that even |
525 | In this case you can clear the keepalive status, which means that even |
358 | though your watcher is active, it won't keep C<EV::loop> from returning. |
526 | though your watcher is active, it won't keep C<EV::run> from returning. |
359 | |
527 | |
360 | The initial value for keepalive is true (enabled), and you cna change it |
528 | The initial value for keepalive is true (enabled), and you can change it |
361 | any time. |
529 | any time. |
362 | |
530 | |
363 | Example: Register an I/O watcher for some UDP socket but do not keep the |
531 | Example: Register an I/O watcher for some UDP socket but do not keep the |
364 | event loop from running just because of that watcher. |
532 | event loop from running just because of that watcher. |
365 | |
533 | |
366 | my $udp_socket = ... |
534 | my $udp_socket = ... |
367 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
535 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
368 | $udp_watcher->keepalive (0); |
536 | $udp_watcher->keepalive (0); |
369 | |
537 | |
|
|
538 | =item $loop = $w->loop |
|
|
539 | |
|
|
540 | Return the loop that this watcher is attached to. |
|
|
541 | |
370 | =back |
542 | =back |
371 | |
543 | |
372 | |
544 | |
373 | =head1 WATCHER TYPES |
545 | =head1 WATCHER TYPES |
374 | |
546 | |
… | |
… | |
380 | |
552 | |
381 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
553 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
382 | |
554 | |
383 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
555 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
384 | |
556 | |
385 | =item $w = $loop->io 8$fileno_or_fh, $eventmask, $callback) |
557 | =item $w = $loop->io ($fileno_or_fh, $eventmask, $callback) |
386 | |
558 | |
387 | =item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
559 | =item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
388 | |
560 | |
389 | As long as the returned watcher object is alive, call the C<$callback> |
561 | As long as the returned watcher object is alive, call the C<$callback> |
390 | when at least one of events specified in C<$eventmask> occurs. |
562 | when at least one of events specified in C<$eventmask> occurs. |
… | |
… | |
426 | |
598 | |
427 | =item $w = $loop->timer ($after, $repeat, $callback) |
599 | =item $w = $loop->timer ($after, $repeat, $callback) |
428 | |
600 | |
429 | =item $w = $loop->timer_ns ($after, $repeat, $callback) |
601 | =item $w = $loop->timer_ns ($after, $repeat, $callback) |
430 | |
602 | |
431 | Calls the callback after C<$after> seconds (which may be fractional). If |
603 | Calls the callback after C<$after> seconds (which may be fractional or |
432 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
604 | negative). If C<$repeat> is non-zero, the timer will be restarted (with |
433 | value as $after) after the callback returns. |
605 | the $repeat value as $after) after the callback returns. |
434 | |
606 | |
435 | This means that the callback would be called roughly after C<$after> |
607 | This means that the callback would be called roughly after C<$after> |
436 | seconds, and then every C<$repeat> seconds. The timer does his best not |
608 | seconds, and then every C<$repeat> seconds. The timer does his best not |
437 | to drift, but it will not invoke the timer more often then once per event |
609 | to drift, but it will not invoke the timer more often then once per event |
438 | loop iteration, and might drift in other cases. If that isn't acceptable, |
610 | loop iteration, and might drift in other cases. If that isn't acceptable, |
… | |
… | |
442 | in front of the machine while the timer is running and changes the system |
614 | in front of the machine while the timer is running and changes the system |
443 | clock, the timer will nevertheless run (roughly) the same time. |
615 | clock, the timer will nevertheless run (roughly) the same time. |
444 | |
616 | |
445 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
617 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
446 | |
618 | |
447 | =item $w->set ($after, $repeat) |
619 | =item $w->set ($after, $repeat = 0) |
448 | |
620 | |
449 | Reconfigures the watcher, see the constructor above for details. Can be called at |
621 | Reconfigures the watcher, see the constructor above for details. Can be called at |
450 | any time. |
622 | any time. |
451 | |
623 | |
452 | =item $w->again |
624 | =item $w->again |
|
|
625 | |
|
|
626 | =item $w->again ($repeat) |
453 | |
627 | |
454 | Similar to the C<start> method, but has special semantics for repeating timers: |
628 | Similar to the C<start> method, but has special semantics for repeating timers: |
455 | |
629 | |
456 | If the timer is active and non-repeating, it will be stopped. |
630 | If the timer is active and non-repeating, it will be stopped. |
457 | |
631 | |
… | |
… | |
464 | |
638 | |
465 | This behaviour is useful when you have a timeout for some IO |
639 | This behaviour is useful when you have a timeout for some IO |
466 | operation. You create a timer object with the same value for C<$after> and |
640 | operation. You create a timer object with the same value for C<$after> and |
467 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
641 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
468 | on the timeout. |
642 | on the timeout. |
|
|
643 | |
|
|
644 | If called with a C<$repeat> argument, then it uses this a timer repeat |
|
|
645 | value. |
|
|
646 | |
|
|
647 | =item $after = $w->remaining |
|
|
648 | |
|
|
649 | Calculates and returns the remaining time till the timer will fire. |
|
|
650 | |
|
|
651 | =item $repeat = $w->repeat |
|
|
652 | |
|
|
653 | =item $old_repeat = $w->repeat ($new_repeat) |
|
|
654 | |
|
|
655 | Returns the current value of the repeat attribute and optionally sets a |
|
|
656 | new one. Setting the new one will not restart the watcher - if the watcher |
|
|
657 | is active, the new repeat value is used whenever it expires next. |
469 | |
658 | |
470 | =back |
659 | =back |
471 | |
660 | |
472 | |
661 | |
473 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
662 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
… | |
… | |
498 | This time simply fires at the wallclock time C<$at> and doesn't repeat. It |
687 | This time simply fires at the wallclock time C<$at> and doesn't repeat. It |
499 | will not adjust when a time jump occurs, that is, if it is to be run |
688 | will not adjust when a time jump occurs, that is, if it is to be run |
500 | at January 1st 2011 then it will run when the system time reaches or |
689 | at January 1st 2011 then it will run when the system time reaches or |
501 | surpasses this time. |
690 | surpasses this time. |
502 | |
691 | |
503 | =item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
692 | =item * repeating interval timer ($interval > 0, $reschedule_cb = 0) |
504 | |
693 | |
505 | In this mode the watcher will always be scheduled to time out at the |
694 | In this mode the watcher will always be scheduled to time out at the |
506 | next C<$at + N * $interval> time (for some integer N) and then repeat, |
695 | next C<$at + N * $interval> time (for the lowest integer N) and then repeat, |
507 | regardless of any time jumps. |
696 | regardless of any time jumps. Note that, since C<N> can be negative, the |
|
|
697 | first trigger can happen before C<$at>. |
508 | |
698 | |
509 | This can be used to create timers that do not drift with respect to system |
699 | This can be used to create timers that do not drift with respect to system |
510 | time: |
700 | time: |
511 | |
701 | |
512 | my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; |
702 | my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; |
513 | |
703 | |
514 | That doesn't mean there will always be 3600 seconds in between triggers, |
704 | That doesn't mean there will always be 3600 seconds in between triggers, |
515 | but only that the the clalback will be called when the system time shows a |
705 | but only that the the callback will be called when the system time shows a |
516 | full hour (UTC). |
706 | full hour (UTC). |
517 | |
707 | |
518 | Another way to think about it (for the mathematically inclined) is that |
708 | Another way to think about it (for the mathematically inclined) is that |
519 | EV::periodic will try to run the callback in this mode at the next |
709 | EV::periodic will try to run the callback in this mode at the next |
520 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
710 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
… | |
… | |
526 | time the periodic watcher gets scheduled, the reschedule callback |
716 | time the periodic watcher gets scheduled, the reschedule callback |
527 | ($reschedule_cb) will be called with the watcher as first, and the current |
717 | ($reschedule_cb) will be called with the watcher as first, and the current |
528 | time as second argument. |
718 | time as second argument. |
529 | |
719 | |
530 | I<This callback MUST NOT stop or destroy this or any other periodic |
720 | I<This callback MUST NOT stop or destroy this or any other periodic |
531 | watcher, ever>. If you need to stop it, return 1e30 and stop it |
721 | watcher, ever, and MUST NOT call any event loop functions or methods>. If |
532 | afterwards. |
722 | you need to stop it, return 1e30 and stop it afterwards. You may create |
|
|
723 | and start an C<EV::prepare> watcher for this task. |
533 | |
724 | |
534 | It must return the next time to trigger, based on the passed time value |
725 | It must return the next time to trigger, based on the passed time value |
535 | (that is, the lowest time value larger than to the second argument). It |
726 | (that is, the lowest time value larger than or equal to to the second |
536 | will usually be called just before the callback will be triggered, but |
727 | argument). It will usually be called just before the callback will be |
537 | might be called at other times, too. |
728 | triggered, but might be called at other times, too. |
538 | |
729 | |
539 | This can be used to create very complex timers, such as a timer that |
730 | This can be used to create very complex timers, such as a timer that |
540 | triggers on each midnight, local time (actually 24 hours after the last |
731 | triggers on each midnight, local time (actually one day after the last |
541 | midnight, to keep the example simple. If you know a way to do it correctly |
732 | midnight, to keep the example simple): |
542 | in about the same space (without requiring elaborate modules), drop me a |
|
|
543 | note :): |
|
|
544 | |
733 | |
545 | my $daily = EV::periodic 0, 0, sub { |
734 | my $daily = EV::periodic 0, 0, sub { |
546 | my ($w, $now) = @_; |
735 | my ($w, $now) = @_; |
547 | |
736 | |
548 | use Time::Local (); |
737 | use Time::Local (); |
549 | my (undef, undef, undef, $d, $m, $y) = localtime $now; |
738 | my (undef, undef, undef, $d, $m, $y) = localtime $now; |
550 | 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y |
739 | Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y |
551 | }, sub { |
740 | }, sub { |
552 | print "it's midnight or likely shortly after, now\n"; |
741 | print "it's midnight or likely shortly after, now\n"; |
553 | }; |
742 | }; |
554 | |
743 | |
555 | =back |
744 | =back |
… | |
… | |
567 | |
756 | |
568 | =item $time = $w->at |
757 | =item $time = $w->at |
569 | |
758 | |
570 | Return the time that the watcher is expected to trigger next. |
759 | Return the time that the watcher is expected to trigger next. |
571 | |
760 | |
|
|
761 | =item $offset = $w->offset |
|
|
762 | |
|
|
763 | =item $old_offset = $w->offset ($new_offset) |
|
|
764 | |
|
|
765 | Returns the current value of the offset attribute and optionally sets a |
|
|
766 | new one. Setting the new one will not restart the watcher - if the watcher |
|
|
767 | is active, the new offset value is used whenever it expires next. |
|
|
768 | |
|
|
769 | =item $interval = $w->interval |
|
|
770 | |
|
|
771 | =item $old_interval = $w->interval ($new_interval) |
|
|
772 | |
|
|
773 | See above, for the interval attribute. |
|
|
774 | |
|
|
775 | =item $reschedule_cb = $w->reschedule_cb |
|
|
776 | |
|
|
777 | =item $old_reschedule_cb = $w->reschedule_cb ($new_reschedule_cb) |
|
|
778 | |
|
|
779 | See above, for the reschedule callback. |
|
|
780 | |
572 | =back |
781 | =back |
573 | |
782 | |
574 | |
783 | |
575 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
784 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
576 | |
785 | |
577 | =over 4 |
786 | =over 4 |
578 | |
787 | |
579 | =item $w = EV::signal $signal, $callback |
788 | =item $w = EV::signal $signal, $callback |
580 | |
789 | |
581 | =item $w = EV::signal_ns $signal, $callback |
790 | =item $w = EV::signal_ns $signal, $callback |
|
|
791 | |
|
|
792 | =item $w = $loop->signal ($signal, $callback) |
|
|
793 | |
|
|
794 | =item $w = $loop->signal_ns ($signal, $callback) |
582 | |
795 | |
583 | Call the callback when $signal is received (the signal can be specified by |
796 | Call the callback when $signal is received (the signal can be specified by |
584 | number or by name, just as with C<kill> or C<%SIG>). |
797 | number or by name, just as with C<kill> or C<%SIG>). |
|
|
798 | |
|
|
799 | Only one event loop can grab a given signal - attempting to grab the same |
|
|
800 | signal from two EV loops will crash the program immediately or cause data |
|
|
801 | corruption. |
585 | |
802 | |
586 | EV will grab the signal for the process (the kernel only allows one |
803 | EV will grab the signal for the process (the kernel only allows one |
587 | component to receive a signal at a time) when you start a signal watcher, |
804 | component to receive a signal at a time) when you start a signal watcher, |
588 | and removes it again when you stop it. Perl does the same when you |
805 | and removes it again when you stop it. Perl does the same when you |
589 | add/remove callbacks to C<%SIG>, so watch out. |
806 | add/remove callbacks to C<%SIG>, so watch out. |
… | |
… | |
609 | |
826 | |
610 | =head3 CHILD WATCHERS - watch out for process status changes |
827 | =head3 CHILD WATCHERS - watch out for process status changes |
611 | |
828 | |
612 | =over 4 |
829 | =over 4 |
613 | |
830 | |
614 | =item $w = EV::child $pid, $callback |
831 | =item $w = EV::child $pid, $trace, $callback |
615 | |
832 | |
616 | =item $w = EV::child_ns $pid, $callback |
833 | =item $w = EV::child_ns $pid, $trace, $callback |
617 | |
834 | |
618 | =item $w = $loop->child ($pid, $callback) |
835 | =item $w = $loop->child ($pid, $trace, $callback) |
619 | |
836 | |
620 | =item $w = $loop->child_ns ($pid, $callback) |
837 | =item $w = $loop->child_ns ($pid, $trace, $callback) |
621 | |
838 | |
622 | Call the callback when a status change for pid C<$pid> (or any pid if |
839 | Call the callback when a status change for pid C<$pid> (or any pid |
623 | C<$pid> is 0) has been received. More precisely: when the process receives |
840 | if C<$pid> is 0) has been received (a status change happens when the |
|
|
841 | process terminates or is killed, or, when trace is true, additionally when |
|
|
842 | it is stopped or continued). More precisely: when the process receives |
624 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
843 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
625 | changed/zombie children and call the callback. |
844 | changed/zombie children and call the callback. |
626 | |
845 | |
627 | It is valid (and fully supported) to install a child watcher after a child |
846 | It is valid (and fully supported) to install a child watcher after a child |
628 | has exited but before the event loop has started its next iteration (for |
847 | has exited but before the event loop has started its next iteration (for |
… | |
… | |
635 | You can have as many pid watchers per pid as you want, they will all be |
854 | You can have as many pid watchers per pid as you want, they will all be |
636 | called. |
855 | called. |
637 | |
856 | |
638 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
857 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
639 | |
858 | |
640 | =item $w->set ($pid) |
859 | =item $w->set ($pid, $trace) |
641 | |
860 | |
642 | Reconfigures the watcher, see the constructor above for details. Can be called at |
861 | Reconfigures the watcher, see the constructor above for details. Can be called at |
643 | any time. |
862 | any time. |
644 | |
863 | |
645 | =item $current_pid = $w->pid |
864 | =item $current_pid = $w->pid |
646 | |
|
|
647 | =item $old_pid = $w->pid ($new_pid) |
|
|
648 | |
865 | |
649 | Returns the previously set process id and optionally set a new one. |
866 | Returns the previously set process id and optionally set a new one. |
650 | |
867 | |
651 | =item $exit_status = $w->rstatus |
868 | =item $exit_status = $w->rstatus |
652 | |
869 | |
… | |
… | |
787 | |
1004 | |
788 | =item $w = EV::prepare_ns $callback |
1005 | =item $w = EV::prepare_ns $callback |
789 | |
1006 | |
790 | =item $w = $loop->prepare ($callback) |
1007 | =item $w = $loop->prepare ($callback) |
791 | |
1008 | |
792 | =item $w = $loop->prepare_ns 8$callback) |
1009 | =item $w = $loop->prepare_ns ($callback) |
793 | |
1010 | |
794 | Call the callback just before the process would block. You can still |
1011 | Call the callback just before the process would block. You can still |
795 | create/modify any watchers at this point. |
1012 | create/modify any watchers at this point. |
796 | |
1013 | |
797 | See the EV::check watcher, below, for explanations and an example. |
1014 | See the EV::check watcher, below, for explanations and an example. |
… | |
… | |
814 | =item $w = $loop->check_ns ($callback) |
1031 | =item $w = $loop->check_ns ($callback) |
815 | |
1032 | |
816 | Call the callback just after the process wakes up again (after it has |
1033 | Call the callback just after the process wakes up again (after it has |
817 | gathered events), but before any other callbacks have been invoked. |
1034 | gathered events), but before any other callbacks have been invoked. |
818 | |
1035 | |
819 | This is used to integrate other event-based software into the EV |
1036 | This can be used to integrate other event-based software into the EV |
820 | mainloop: You register a prepare callback and in there, you create io and |
1037 | mainloop: You register a prepare callback and in there, you create io and |
821 | timer watchers as required by the other software. Here is a real-world |
1038 | timer watchers as required by the other software. Here is a real-world |
822 | example of integrating Net::SNMP (with some details left out): |
1039 | example of integrating Net::SNMP (with some details left out): |
823 | |
1040 | |
824 | our @snmp_watcher; |
1041 | our @snmp_watcher; |
… | |
… | |
854 | # make the dispatcher handle any new stuff |
1071 | # make the dispatcher handle any new stuff |
855 | ... not shown |
1072 | ... not shown |
856 | }; |
1073 | }; |
857 | |
1074 | |
858 | The callbacks of the created watchers will not be called as the watchers |
1075 | The callbacks of the created watchers will not be called as the watchers |
859 | are destroyed before this cna happen (remember EV::check gets called |
1076 | are destroyed before this can happen (remember EV::check gets called |
860 | first). |
1077 | first). |
861 | |
1078 | |
862 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
1079 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
|
|
1080 | |
|
|
1081 | =item EV::CHECK constant issues |
|
|
1082 | |
|
|
1083 | Like all other watcher types, there is a bitmask constant for use in |
|
|
1084 | C<$revents> and other places. The C<EV::CHECK> is special as it has |
|
|
1085 | the same name as the C<CHECK> sub called by Perl. This doesn't cause |
|
|
1086 | big issues on newer perls (beginning with 5.8.9), but it means thatthe |
|
|
1087 | constant must be I<inlined>, i.e. runtime calls will not work. That means |
|
|
1088 | that as long as you always C<use EV> and then C<EV::CHECK> you are on the |
|
|
1089 | safe side. |
863 | |
1090 | |
864 | =back |
1091 | =back |
865 | |
1092 | |
866 | |
1093 | |
867 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
1094 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
… | |
… | |
884 | after a fork. |
1111 | after a fork. |
885 | |
1112 | |
886 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
1113 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
887 | |
1114 | |
888 | =back |
1115 | =back |
|
|
1116 | |
|
|
1117 | |
|
|
1118 | =head3 EMBED WATCHERS - when one backend isn't enough... |
|
|
1119 | |
|
|
1120 | This is a rather advanced watcher type that lets you embed one event loop |
|
|
1121 | into another (currently only IO events are supported in the embedded |
|
|
1122 | loop, other types of watchers might be handled in a delayed or incorrect |
|
|
1123 | fashion and must not be used). |
|
|
1124 | |
|
|
1125 | See the libev documentation at |
|
|
1126 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> |
|
|
1127 | (locally installed as F<EV::libev>) for more details. |
|
|
1128 | |
|
|
1129 | In short, this watcher is most useful on BSD systems without working |
|
|
1130 | kqueue to still be able to handle a large number of sockets: |
|
|
1131 | |
|
|
1132 | my $socket_loop; |
|
|
1133 | |
|
|
1134 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
|
|
1135 | if ( |
|
|
1136 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
|
|
1137 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
|
|
1138 | ) { |
|
|
1139 | # use kqueue for sockets |
|
|
1140 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
|
|
1141 | } |
|
|
1142 | |
|
|
1143 | # use the default loop otherwise |
|
|
1144 | $socket_loop ||= EV::default_loop; |
|
|
1145 | |
|
|
1146 | =over 4 |
|
|
1147 | |
|
|
1148 | =item $w = EV::embed $otherloop[, $callback] |
|
|
1149 | |
|
|
1150 | =item $w = EV::embed_ns $otherloop[, $callback] |
|
|
1151 | |
|
|
1152 | =item $w = $loop->embed ($otherloop[, $callback]) |
|
|
1153 | |
|
|
1154 | =item $w = $loop->embed_ns ($otherloop[, $callback]) |
|
|
1155 | |
|
|
1156 | Call the callback when the embedded event loop (C<$otherloop>) has any |
|
|
1157 | I/O activity. The C<$callback> is optional: if it is missing, then the |
|
|
1158 | embedded event loop will be managed automatically (which is recommended), |
|
|
1159 | otherwise you have to invoke C<sweep> yourself. |
|
|
1160 | |
|
|
1161 | The C<embed_ns> variant doesn't start (activate) the newly created watcher. |
|
|
1162 | |
|
|
1163 | =back |
|
|
1164 | |
|
|
1165 | =head3 ASYNC WATCHERS - how to wake up another event loop |
|
|
1166 | |
|
|
1167 | Async watchers are provided by EV, but have little use in perl directly, |
|
|
1168 | as perl neither supports threads running in parallel nor direct access to |
|
|
1169 | signal handlers or other contexts where they could be of value. |
|
|
1170 | |
|
|
1171 | It is, however, possible to use them from the XS level. |
|
|
1172 | |
|
|
1173 | Please see the libev documentation for further details. |
|
|
1174 | |
|
|
1175 | =over 4 |
|
|
1176 | |
|
|
1177 | =item $w = EV::async $callback |
|
|
1178 | |
|
|
1179 | =item $w = EV::async_ns $callback |
|
|
1180 | |
|
|
1181 | =item $w = $loop->async ($callback) |
|
|
1182 | |
|
|
1183 | =item $w = $loop->async_ns ($callback) |
|
|
1184 | |
|
|
1185 | =item $w->send |
|
|
1186 | |
|
|
1187 | =item $bool = $w->async_pending |
|
|
1188 | |
|
|
1189 | =back |
|
|
1190 | |
|
|
1191 | =head3 CLEANUP WATCHERS - how to clean up when the event loop goes away |
|
|
1192 | |
|
|
1193 | Cleanup watchers are not supported on the Perl level, they can only be |
|
|
1194 | used via XS currently. |
889 | |
1195 | |
890 | |
1196 | |
891 | =head1 PERL SIGNALS |
1197 | =head1 PERL SIGNALS |
892 | |
1198 | |
893 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
1199 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
… | |
… | |
902 | to be called on every event loop iteration by installing a C<EV::check> |
1208 | to be called on every event loop iteration by installing a C<EV::check> |
903 | watcher: |
1209 | watcher: |
904 | |
1210 | |
905 | my $async_check = EV::check sub { }; |
1211 | my $async_check = EV::check sub { }; |
906 | |
1212 | |
907 | This ensures that perl shortly gets into control for a short time, and |
1213 | This ensures that perl gets into control for a short time to handle any |
908 | also ensures slower overall operation. |
1214 | pending signals, and also ensures (slightly) slower overall operation. |
909 | |
1215 | |
910 | =head1 THREADS |
1216 | =head1 ITHREADS |
911 | |
1217 | |
912 | Threads are not supported by this module in any way. Perl pseudo-threads |
1218 | Ithreads are not supported by this module in any way. Perl pseudo-threads |
913 | is evil stuff and must die. As soon as Perl gains real threads I will work |
1219 | is evil stuff and must die. Real threads as provided by Coro are fully |
914 | on thread support for it. |
1220 | supported (and enhanced support is available via L<Coro::EV>). |
915 | |
1221 | |
916 | =head1 FORK |
1222 | =head1 FORK |
917 | |
1223 | |
918 | Most of the "improved" event delivering mechanisms of modern operating |
1224 | Most of the "improved" event delivering mechanisms of modern operating |
919 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
1225 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
… | |
… | |
941 | |
1247 | |
942 | 1; |
1248 | 1; |
943 | |
1249 | |
944 | =head1 SEE ALSO |
1250 | =head1 SEE ALSO |
945 | |
1251 | |
|
|
1252 | L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS> |
946 | L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as |
1253 | (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event |
947 | event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient |
1254 | loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread |
948 | coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). |
1255 | integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for |
|
|
1256 | event-loop agnostic and portable event driven programming. |
949 | |
1257 | |
950 | =head1 AUTHOR |
1258 | =head1 AUTHOR |
951 | |
1259 | |
952 | Marc Lehmann <schmorp@schmorp.de> |
1260 | Marc Lehmann <schmorp@schmorp.de> |
953 | http://home.schmorp.de/ |
1261 | http://home.schmorp.de/ |
954 | |
1262 | |
955 | =cut |
1263 | =cut |
956 | |
1264 | |