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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::unloop is called or all watchers stop |
53 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
53 | EV::run EV::RUN_ONCE; # block until at least one event could be handled |
54 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
54 | EV::run EV::RUN_NOWAIT; # try to handle same events, but do not block |
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55 | |
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56 | =head1 BEFORE YOU START USING THIS MODULE |
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57 | |
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58 | If you only need timer, I/O, signal, child and idle watchers and not the |
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59 | advanced functionality of this module, consider using L<AnyEvent> instead, |
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60 | specifically the simplified API described in L<AE>. |
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61 | |
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62 | When used with EV as backend, the L<AE> API is as fast as the native L<EV> |
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63 | API, but your programs/modules will still run with many other event loops. |
55 | |
64 | |
56 | =head1 DESCRIPTION |
65 | =head1 DESCRIPTION |
57 | |
66 | |
58 | This module provides an interface to libev |
67 | This module provides an interface to libev |
59 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
68 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
60 | below is comprehensive, one might also consult the documentation of libev |
69 | below is comprehensive, one might also consult the documentation of |
61 | itself (L<http://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>. |
72 | discussion on the available backends, or how to force a specific backend |
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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. |
64 | |
116 | |
65 | =cut |
117 | =cut |
66 | |
118 | |
67 | package EV; |
119 | package EV; |
68 | |
120 | |
69 | use strict; |
121 | use common::sense; |
70 | |
122 | |
71 | BEGIN { |
123 | BEGIN { |
72 | our $VERSION = '1.5'; |
124 | our $VERSION = '4.10'; |
73 | use XSLoader; |
125 | use XSLoader; |
74 | XSLoader::load "EV", $VERSION; |
126 | XSLoader::load "EV", $VERSION; |
75 | } |
127 | } |
76 | |
128 | |
77 | @EV::IO::ISA = |
129 | @EV::IO::ISA = |
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83 | @EV::Idle::ISA = |
135 | @EV::Idle::ISA = |
84 | @EV::Prepare::ISA = |
136 | @EV::Prepare::ISA = |
85 | @EV::Check::ISA = |
137 | @EV::Check::ISA = |
86 | @EV::Embed::ISA = |
138 | @EV::Embed::ISA = |
87 | @EV::Fork::ISA = |
139 | @EV::Fork::ISA = |
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140 | @EV::Async::ISA = |
88 | "EV::Watcher"; |
141 | "EV::Watcher"; |
89 | |
142 | |
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143 | @EV::Loop::Default::ISA = "EV::Loop"; |
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144 | |
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145 | =head1 EVENT LOOPS |
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146 | |
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147 | EV supports multiple event loops: There is a single "default event loop" |
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148 | that can handle everything including signals and child watchers, and any |
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149 | number of "dynamic event loops" that can use different backends (with |
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150 | various limitations), but no child and signal watchers. |
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151 | |
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152 | You do not have to do anything to create the default event loop: When |
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153 | the module is loaded a suitable backend is selected on the premise of |
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154 | selecting a working backend (which for example rules out kqueue on most |
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155 | BSDs). Modules should, unless they have "special needs" always use the |
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156 | default loop as this is fastest (perl-wise), best supported by other |
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157 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
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158 | |
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159 | For specific programs you can create additional event loops dynamically. |
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160 | |
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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. |
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166 | |
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167 | =over 4 |
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168 | |
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169 | =item $loop = new EV::Loop [$flags] |
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170 | |
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171 | Create a new event loop as per the specified flags. Please refer to |
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172 | the C<ev_loop_new ()> function description in the libev documentation |
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173 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>, |
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174 | or locally-installed as F<EV::libev> manpage) for more info. |
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175 | |
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176 | The loop will automatically be destroyed when it is no longer referenced |
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177 | by any watcher and the loop object goes out of scope. |
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178 | |
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179 | If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK> |
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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. |
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183 | |
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184 | =item $loop->loop_fork |
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185 | |
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186 | Must be called after a fork in the child, before entering or continuing |
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187 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
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188 | this function automatically, at some performance loss (refer to the libev |
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189 | documentation). |
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190 | |
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191 | =item $loop->verify |
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192 | |
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193 | Calls C<ev_verify> to make internal consistency checks (for debugging |
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194 | libev) and abort the program if any data structures were found to be |
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195 | corrupted. |
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196 | |
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197 | =item $loop = EV::default_loop [$flags] |
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198 | |
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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. |
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204 | |
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205 | =back |
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206 | |
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207 | |
90 | =head1 BASIC INTERFACE |
208 | =head1 BASIC INTERFACE |
91 | |
209 | |
92 | =over 4 |
210 | =over 4 |
93 | |
211 | |
94 | =item $EV::DIED |
212 | =item $EV::DIED |
95 | |
213 | |
96 | Must contain a reference to a function that is called when a callback |
214 | Must contain a reference to a function that is called when a callback |
97 | throws an exception (with $@ containing thr error). The default prints an |
215 | throws an exception (with $@ containing the error). The default prints an |
98 | informative message and continues. |
216 | informative message and continues. |
99 | |
217 | |
100 | If this callback throws an exception it will be silently ignored. |
218 | If this callback throws an exception it will be silently ignored. |
101 | |
219 | |
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220 | =item $flags = EV::supported_backends |
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221 | |
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222 | =item $flags = EV::recommended_backends |
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223 | |
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224 | =item $flags = EV::embeddable_backends |
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225 | |
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226 | Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this |
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227 | instance of EV, the set of recommended backends (supposed to be good) for |
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228 | this platform and the set of embeddable backends (see EMBED WATCHERS). |
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229 | |
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230 | =item EV::sleep $seconds |
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231 | |
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232 | Block the process for the given number of (fractional) seconds. |
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233 | |
102 | =item $time = EV::time |
234 | =item $time = EV::time |
103 | |
235 | |
104 | Returns the current time in (fractional) seconds since the epoch. |
236 | Returns the current time in (fractional) seconds since the epoch. |
105 | |
237 | |
106 | =item $time = EV::now |
238 | =item $time = EV::now |
107 | |
239 | |
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240 | =item $time = $loop->now |
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241 | |
108 | 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 |
109 | 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 |
110 | usually faster then calling EV::time. |
244 | usually faster then calling EV::time. |
111 | |
245 | |
112 | =item $method = EV::method |
246 | =item EV::now_update |
113 | |
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 | |
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288 | =item $backend = EV::backend |
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289 | |
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290 | =item $backend = $loop->backend |
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291 | |
114 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
292 | Returns an integer describing the backend used by libev (EV::BACKEND_SELECT |
115 | or EV::METHOD_EPOLL). |
293 | or EV::BACKEND_EPOLL). |
116 | |
294 | |
117 | =item EV::loop [$flags] |
295 | =item EV::run [$flags] |
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296 | |
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297 | =item $loop->run ([$flags]) |
118 | |
298 | |
119 | Begin checking for events and calling callbacks. It returns when a |
299 | Begin checking for events and calling callbacks. It returns when a |
120 | callback calls EV::unloop. |
300 | callback calls EV::unloop. |
121 | |
301 | |
122 | The $flags argument can be one of the following: |
302 | The $flags argument can be one of the following: |
123 | |
303 | |
124 | 0 as above |
304 | 0 as above |
125 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
305 | EV::RUN_ONCE block at most once (wait, but do not loop) |
126 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
306 | EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait) |
127 | |
307 | |
128 | =item EV::unloop [$how] |
308 | =item EV::break [$how] |
129 | |
309 | |
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310 | =item $loop->break ([$how]) |
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311 | |
130 | 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 |
131 | innermost call to EV::loop return. |
313 | innermost call to EV::loop return. |
132 | |
314 | |
133 | 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 |
134 | 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. |
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320 | |
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321 | =item $count = EV::iteration |
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322 | |
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323 | =item $count = $loop->iteration |
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324 | |
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325 | Return the number of times the event loop has polled for new |
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326 | events. Sometimes useful as a generation counter. |
135 | |
327 | |
136 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
328 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
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329 | |
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330 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
137 | |
331 | |
138 | This function rolls together an I/O and a timer watcher for a single |
332 | This function rolls together an I/O and a timer watcher for a single |
139 | one-shot event without the need for managing a watcher object. |
333 | one-shot event without the need for managing a watcher object. |
140 | |
334 | |
141 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
335 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
… | |
… | |
147 | If timeout is C<undef> or negative, then there will be no |
341 | If timeout is C<undef> or negative, then there will be no |
148 | timeout. Otherwise a EV::timer with this value will be started. |
342 | timeout. Otherwise a EV::timer with this value will be started. |
149 | |
343 | |
150 | 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 |
151 | 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 |
152 | 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>, |
153 | C<EV::WRITE> and C<EV::TIMEOUT>). |
347 | C<EV::WRITE> and C<EV::TIMER>). |
154 | |
348 | |
155 | 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 |
156 | 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 |
157 | invoked. |
351 | invoked. |
158 | |
352 | |
159 | =back |
353 | =item EV::feed_fd_event $fd, $revents |
160 | |
354 | |
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355 | =item $loop->feed_fd_event ($fd, $revents) |
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356 | |
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357 | Feed an event on a file descriptor into EV. EV will react to this call as |
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358 | if the readyness notifications specified by C<$revents> (a combination of |
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359 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
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360 | |
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361 | =item EV::feed_signal_event $signal |
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362 | |
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363 | Feed a signal event into the default loop. EV will react to this call as |
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364 | if the signal specified by C<$signal> had occured. |
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365 | |
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366 | =item EV::feed_signal $signal |
|
|
367 | |
|
|
368 | Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works |
|
|
369 | regardless of which loop has registered the signal, and is mainly useful |
|
|
370 | fro custom signal implementations. |
|
|
371 | |
|
|
372 | =item EV::set_io_collect_interval $time |
|
|
373 | |
|
|
374 | =item $loop->set_io_collect_interval ($time) |
|
|
375 | |
|
|
376 | =item EV::set_timeout_collect_interval $time |
|
|
377 | |
|
|
378 | =item $loop->set_timeout_collect_interval ($time) |
|
|
379 | |
|
|
380 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
|
|
381 | wait interval for timer events. See the libev documentation at |
|
|
382 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> |
|
|
383 | (locally installed as F<EV::libev>) for a more detailed discussion. |
|
|
384 | |
|
|
385 | =item $count = EV::pending_count |
|
|
386 | |
|
|
387 | =item $count = $loop->pending_count |
|
|
388 | |
|
|
389 | Returns the number of currently pending watchers. |
|
|
390 | |
|
|
391 | =item EV::invoke_pending |
|
|
392 | |
|
|
393 | =item $loop->invoke_pending |
|
|
394 | |
|
|
395 | Invoke all currently pending watchers. |
|
|
396 | |
|
|
397 | =back |
|
|
398 | |
|
|
399 | |
161 | =head2 WATCHER OBJECTS |
400 | =head1 WATCHER OBJECTS |
162 | |
401 | |
163 | 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 |
164 | 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 |
165 | would create an EV::io watcher for that: |
404 | would create an EV::io watcher for that: |
166 | |
405 | |
167 | my $watcher = EV::io *STDIN, EV::READ, sub { |
406 | my $watcher = EV::io *STDIN, EV::READ, sub { |
168 | my ($watcher, $revents) = @_; |
407 | my ($watcher, $revents) = @_; |
169 | warn "yeah, STDIN should not be readable without blocking!\n" |
408 | warn "yeah, STDIN should now be readable without blocking!\n" |
170 | }; |
409 | }; |
171 | |
410 | |
172 | 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 |
173 | active watchers will have their callbacks invoked. All callbacks will be |
412 | active watchers will have their callbacks invoked. All callbacks will be |
174 | 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 |
175 | events. |
414 | events. |
176 | |
415 | |
177 | 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 |
178 | 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 |
179 | 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, |
180 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
419 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
181 | (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). |
182 | uses EV::TIMEOUT). |
|
|
183 | |
421 | |
184 | 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 |
185 | 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 |
186 | 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. |
187 | |
425 | |
… | |
… | |
207 | |
445 | |
208 | =item $w->stop |
446 | =item $w->stop |
209 | |
447 | |
210 | Stop a watcher if it is active. Also clear any pending events (events that |
448 | Stop a watcher if it is active. Also clear any pending events (events that |
211 | have been received but that didn't yet result in a callback invocation), |
449 | have been received but that didn't yet result in a callback invocation), |
212 | regardless of wether the watcher was active or not. |
450 | regardless of whether the watcher was active or not. |
213 | |
451 | |
214 | =item $bool = $w->is_active |
452 | =item $bool = $w->is_active |
215 | |
453 | |
216 | Returns true if the watcher is active, false otherwise. |
454 | Returns true if the watcher is active, false otherwise. |
217 | |
455 | |
… | |
… | |
247 | The default priority of any newly-created watcher is 0. |
485 | The default priority of any newly-created watcher is 0. |
248 | |
486 | |
249 | Note that the priority semantics have not yet been fleshed out and are |
487 | Note that the priority semantics have not yet been fleshed out and are |
250 | subject to almost certain change. |
488 | subject to almost certain change. |
251 | |
489 | |
252 | =item $w->trigger ($revents) |
490 | =item $w->invoke ($revents) |
253 | |
491 | |
254 | Call the callback *now* with the given event mask. |
492 | Call the callback *now* with the given event mask. |
|
|
493 | |
|
|
494 | =item $w->feed_event ($revents) |
|
|
495 | |
|
|
496 | Feed some events on this watcher into EV. EV will react to this call as if |
|
|
497 | the watcher had received the given C<$revents> mask. |
|
|
498 | |
|
|
499 | =item $revents = $w->clear_pending |
|
|
500 | |
|
|
501 | If the watcher is pending, this function clears its pending status and |
|
|
502 | returns its C<$revents> bitset (as if its callback was invoked). If the |
|
|
503 | watcher isn't pending it does nothing and returns C<0>. |
255 | |
504 | |
256 | =item $previous_state = $w->keepalive ($bool) |
505 | =item $previous_state = $w->keepalive ($bool) |
257 | |
506 | |
258 | 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 |
259 | (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 |
260 | 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), |
261 | 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 |
262 | finished (or they forgot to register some watchers for their task :). |
511 | finished (or they forgot to register some watchers for their task :). |
263 | |
512 | |
264 | Sometimes, however, this gets in your way, for example when you the module |
513 | Sometimes, however, this gets in your way, for example when the module |
265 | 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 |
266 | as a long-living watcher (for example a DNS client module written by |
515 | as a long-living watcher (for example a DNS client module written by |
267 | somebody else even). Then you might want any outstanding requests to be |
516 | somebody else even). Then you might want any outstanding requests to be |
268 | handled, but you would not want to keep C<EV::loop> from returning just |
517 | handled, but you would not want to keep C<EV::loop> from returning just |
269 | because you happen to have this long-running UDP port watcher. |
518 | because you happen to have this long-running UDP port watcher. |
270 | |
519 | |
271 | 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 |
272 | 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. |
273 | |
522 | |
274 | 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 |
275 | any time. |
524 | any time. |
276 | |
525 | |
277 | Example: Register an IO 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 |
278 | event loop from running just because of that watcher. |
527 | event loop from running just because of that watcher. |
279 | |
528 | |
280 | my $udp_socket = ... |
529 | my $udp_socket = ... |
281 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
530 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
282 | $udp_watcher->keepalive (0); |
531 | $udp_watcher->keepalive (0); |
283 | |
532 | |
284 | =back |
533 | =item $loop = $w->loop |
285 | |
534 | |
|
|
535 | Return the loop that this watcher is attached to. |
286 | |
536 | |
|
|
537 | =back |
|
|
538 | |
|
|
539 | |
287 | =head2 WATCHER TYPES |
540 | =head1 WATCHER TYPES |
288 | |
541 | |
289 | Each of the following subsections describes a single watcher type. |
542 | Each of the following subsections describes a single watcher type. |
290 | |
543 | |
291 | =head3 IO WATCHERS - is this file descriptor readable or writable? |
544 | =head3 I/O WATCHERS - is this file descriptor readable or writable? |
292 | |
545 | |
293 | =over 4 |
546 | =over 4 |
294 | |
547 | |
295 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
548 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
296 | |
549 | |
297 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
550 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
|
|
551 | |
|
|
552 | =item $w = $loop->io ($fileno_or_fh, $eventmask, $callback) |
|
|
553 | |
|
|
554 | =item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
298 | |
555 | |
299 | As long as the returned watcher object is alive, call the C<$callback> |
556 | As long as the returned watcher object is alive, call the C<$callback> |
300 | when at least one of events specified in C<$eventmask> occurs. |
557 | when at least one of events specified in C<$eventmask> occurs. |
301 | |
558 | |
302 | The $eventmask can be one or more of these constants ORed together: |
559 | The $eventmask can be one or more of these constants ORed together: |
… | |
… | |
331 | =over 4 |
588 | =over 4 |
332 | |
589 | |
333 | =item $w = EV::timer $after, $repeat, $callback |
590 | =item $w = EV::timer $after, $repeat, $callback |
334 | |
591 | |
335 | =item $w = EV::timer_ns $after, $repeat, $callback |
592 | =item $w = EV::timer_ns $after, $repeat, $callback |
|
|
593 | |
|
|
594 | =item $w = $loop->timer ($after, $repeat, $callback) |
|
|
595 | |
|
|
596 | =item $w = $loop->timer_ns ($after, $repeat, $callback) |
336 | |
597 | |
337 | Calls the callback after C<$after> seconds (which may be fractional). If |
598 | Calls the callback after C<$after> seconds (which may be fractional). If |
338 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
599 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
339 | value as $after) after the callback returns. |
600 | value as $after) after the callback returns. |
340 | |
601 | |
… | |
… | |
381 | =over 4 |
642 | =over 4 |
382 | |
643 | |
383 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
644 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
384 | |
645 | |
385 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
646 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
|
|
647 | |
|
|
648 | =item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
|
|
649 | |
|
|
650 | =item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback) |
386 | |
651 | |
387 | Similar to EV::timer, but is not based on relative timeouts but on |
652 | Similar to EV::timer, but is not based on relative timeouts but on |
388 | absolute times. Apart from creating "simple" timers that trigger "at" the |
653 | absolute times. Apart from creating "simple" timers that trigger "at" the |
389 | specified time, it can also be used for non-drifting absolute timers and |
654 | specified time, it can also be used for non-drifting absolute timers and |
390 | more complex, cron-like, setups that are not adversely affected by time |
655 | more complex, cron-like, setups that are not adversely affected by time |
… | |
… | |
400 | This time simply fires at the wallclock time C<$at> and doesn't repeat. It |
665 | This time simply fires at the wallclock time C<$at> and doesn't repeat. It |
401 | will not adjust when a time jump occurs, that is, if it is to be run |
666 | will not adjust when a time jump occurs, that is, if it is to be run |
402 | at January 1st 2011 then it will run when the system time reaches or |
667 | at January 1st 2011 then it will run when the system time reaches or |
403 | surpasses this time. |
668 | surpasses this time. |
404 | |
669 | |
405 | =item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
670 | =item * repeating interval timer ($interval > 0, $reschedule_cb = 0) |
406 | |
671 | |
407 | In this mode the watcher will always be scheduled to time out at the |
672 | In this mode the watcher will always be scheduled to time out at the |
408 | next C<$at + N * $interval> time (for some integer N) and then repeat, |
673 | next C<$at + N * $interval> time (for some integer N) and then repeat, |
409 | regardless of any time jumps. |
674 | regardless of any time jumps. |
410 | |
675 | |
… | |
… | |
428 | time the periodic watcher gets scheduled, the reschedule callback |
693 | time the periodic watcher gets scheduled, the reschedule callback |
429 | ($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 |
430 | time as second argument. |
695 | time as second argument. |
431 | |
696 | |
432 | 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 |
433 | 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 |
434 | 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. |
435 | |
701 | |
436 | 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 |
437 | (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 |
438 | 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 |
439 | might be called at other times, too. |
705 | triggered, but might be called at other times, too. |
440 | |
706 | |
441 | 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 |
442 | 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 |
443 | 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 |
444 | 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 |
… | |
… | |
465 | |
731 | |
466 | =item $w->again |
732 | =item $w->again |
467 | |
733 | |
468 | Simply stops and starts the watcher again. |
734 | Simply stops and starts the watcher again. |
469 | |
735 | |
|
|
736 | =item $time = $w->at |
|
|
737 | |
|
|
738 | Return the time that the watcher is expected to trigger next. |
|
|
739 | |
470 | =back |
740 | =back |
471 | |
741 | |
472 | |
742 | |
473 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
743 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
474 | |
744 | |
475 | =over 4 |
745 | =over 4 |
476 | |
746 | |
477 | =item $w = EV::signal $signal, $callback |
747 | =item $w = EV::signal $signal, $callback |
478 | |
748 | |
479 | =item $w = EV::signal_ns $signal, $callback |
749 | =item $w = EV::signal_ns $signal, $callback |
|
|
750 | |
|
|
751 | =item $w = $loop->signal ($signal, $callback) |
|
|
752 | |
|
|
753 | =item $w = $loop->signal_ns ($signal, $callback) |
480 | |
754 | |
481 | 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 |
482 | 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. |
483 | |
761 | |
484 | 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 |
485 | 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, |
486 | 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 |
487 | add/remove callbacks to C<%SIG>, so watch out. |
765 | add/remove callbacks to C<%SIG>, so watch out. |
… | |
… | |
507 | |
785 | |
508 | =head3 CHILD WATCHERS - watch out for process status changes |
786 | =head3 CHILD WATCHERS - watch out for process status changes |
509 | |
787 | |
510 | =over 4 |
788 | =over 4 |
511 | |
789 | |
512 | =item $w = EV::child $pid, $callback |
790 | =item $w = EV::child $pid, $trace, $callback |
513 | |
791 | |
514 | =item $w = EV::child_ns $pid, $callback |
792 | =item $w = EV::child_ns $pid, $trace, $callback |
515 | |
793 | |
|
|
794 | =item $w = $loop->child ($pid, $trace, $callback) |
|
|
795 | |
|
|
796 | =item $w = $loop->child_ns ($pid, $trace, $callback) |
|
|
797 | |
516 | Call the callback when a status change for pid C<$pid> (or any pid if |
798 | Call the callback when a status change for pid C<$pid> (or any pid |
517 | C<$pid> is 0) has been received. More precisely: when the process receives |
799 | if C<$pid> is 0) has been received (a status change happens when the |
|
|
800 | process terminates or is killed, or, when trace is true, additionally when |
|
|
801 | it is stopped or continued). More precisely: when the process receives |
518 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
802 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
519 | changed/zombie children and call the callback. |
803 | changed/zombie children and call the callback. |
520 | |
804 | |
521 | It is valid (and fully supported) to install a child watcher after a child |
805 | It is valid (and fully supported) to install a child watcher after a child |
522 | has exited but before the event loop has started its next iteration (for |
806 | has exited but before the event loop has started its next iteration (for |
… | |
… | |
529 | You can have as many pid watchers per pid as you want, they will all be |
813 | You can have as many pid watchers per pid as you want, they will all be |
530 | called. |
814 | called. |
531 | |
815 | |
532 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
816 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
533 | |
817 | |
534 | =item $w->set ($pid) |
818 | =item $w->set ($pid, $trace) |
535 | |
819 | |
536 | Reconfigures the watcher, see the constructor above for details. Can be called at |
820 | Reconfigures the watcher, see the constructor above for details. Can be called at |
537 | any time. |
821 | any time. |
538 | |
822 | |
539 | =item $current_pid = $w->pid |
823 | =item $current_pid = $w->pid |
540 | |
824 | |
541 | =item $old_pid = $w->pid ($new_pid) |
|
|
542 | |
|
|
543 | Returns the previously set process id and optionally set a new one. |
825 | Returns the previously set process id and optionally set a new one. |
544 | |
826 | |
545 | =item $exit_status = $w->rstatus |
827 | =item $exit_status = $w->rstatus |
546 | |
828 | |
547 | Return the exit/wait status (as returned by waitpid, see the waitpid entry |
829 | Return the exit/wait status (as returned by waitpid, see the waitpid entry |
… | |
… | |
560 | =over 4 |
842 | =over 4 |
561 | |
843 | |
562 | =item $w = EV::stat $path, $interval, $callback |
844 | =item $w = EV::stat $path, $interval, $callback |
563 | |
845 | |
564 | =item $w = EV::stat_ns $path, $interval, $callback |
846 | =item $w = EV::stat_ns $path, $interval, $callback |
|
|
847 | |
|
|
848 | =item $w = $loop->stat ($path, $interval, $callback) |
|
|
849 | |
|
|
850 | =item $w = $loop->stat_ns ($path, $interval, $callback) |
565 | |
851 | |
566 | Call the callback when a file status change has been detected on |
852 | Call the callback when a file status change has been detected on |
567 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
853 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
568 | to "path does not exist" is a status change like any other. |
854 | to "path does not exist" is a status change like any other. |
569 | |
855 | |
… | |
… | |
640 | |
926 | |
641 | =item $w = EV::idle $callback |
927 | =item $w = EV::idle $callback |
642 | |
928 | |
643 | =item $w = EV::idle_ns $callback |
929 | =item $w = EV::idle_ns $callback |
644 | |
930 | |
645 | Call the callback when there are no pending io, timer/periodic, signal or |
931 | =item $w = $loop->idle ($callback) |
646 | child events, i.e. when the process is idle. |
932 | |
|
|
933 | =item $w = $loop->idle_ns ($callback) |
|
|
934 | |
|
|
935 | Call the callback when there are no other pending watchers of the same or |
|
|
936 | higher priority (excluding check, prepare and other idle watchers of the |
|
|
937 | same or lower priority, of course). They are called idle watchers because |
|
|
938 | when the watcher is the highest priority pending event in the process, the |
|
|
939 | process is considered to be idle at that priority. |
|
|
940 | |
|
|
941 | If you want a watcher that is only ever called when I<no> other events are |
|
|
942 | outstanding you have to set the priority to C<EV::MINPRI>. |
647 | |
943 | |
648 | The process will not block as long as any idle watchers are active, and |
944 | The process will not block as long as any idle watchers are active, and |
649 | they will be called repeatedly until stopped. |
945 | they will be called repeatedly until stopped. |
650 | |
946 | |
|
|
947 | For example, if you have idle watchers at priority C<0> and C<1>, and |
|
|
948 | an I/O watcher at priority C<0>, then the idle watcher at priority C<1> |
|
|
949 | and the I/O watcher will always run when ready. Only when the idle watcher |
|
|
950 | at priority C<1> is stopped and the I/O watcher at priority C<0> is not |
|
|
951 | pending with the C<0>-priority idle watcher be invoked. |
|
|
952 | |
651 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
953 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
652 | |
954 | |
653 | =back |
955 | =back |
654 | |
956 | |
655 | |
957 | |
… | |
… | |
658 | =over 4 |
960 | =over 4 |
659 | |
961 | |
660 | =item $w = EV::prepare $callback |
962 | =item $w = EV::prepare $callback |
661 | |
963 | |
662 | =item $w = EV::prepare_ns $callback |
964 | =item $w = EV::prepare_ns $callback |
|
|
965 | |
|
|
966 | =item $w = $loop->prepare ($callback) |
|
|
967 | |
|
|
968 | =item $w = $loop->prepare_ns ($callback) |
663 | |
969 | |
664 | Call the callback just before the process would block. You can still |
970 | Call the callback just before the process would block. You can still |
665 | create/modify any watchers at this point. |
971 | create/modify any watchers at this point. |
666 | |
972 | |
667 | See the EV::check watcher, below, for explanations and an example. |
973 | See the EV::check watcher, below, for explanations and an example. |
… | |
… | |
677 | |
983 | |
678 | =item $w = EV::check $callback |
984 | =item $w = EV::check $callback |
679 | |
985 | |
680 | =item $w = EV::check_ns $callback |
986 | =item $w = EV::check_ns $callback |
681 | |
987 | |
|
|
988 | =item $w = $loop->check ($callback) |
|
|
989 | |
|
|
990 | =item $w = $loop->check_ns ($callback) |
|
|
991 | |
682 | 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 |
683 | gathered events), but before any other callbacks have been invoked. |
993 | gathered events), but before any other callbacks have been invoked. |
684 | |
994 | |
685 | 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 |
686 | 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 |
687 | 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 |
688 | example of integrating Net::SNMP (with some details left out): |
998 | example of integrating Net::SNMP (with some details left out): |
689 | |
999 | |
690 | our @snmp_watcher; |
1000 | our @snmp_watcher; |
… | |
… | |
695 | or return; |
1005 | or return; |
696 | |
1006 | |
697 | # make the dispatcher handle any outstanding stuff |
1007 | # make the dispatcher handle any outstanding stuff |
698 | ... not shown |
1008 | ... not shown |
699 | |
1009 | |
700 | # create an IO watcher for each and every socket |
1010 | # create an I/O watcher for each and every socket |
701 | @snmp_watcher = ( |
1011 | @snmp_watcher = ( |
702 | (map { EV::io $_, EV::READ, sub { } } |
1012 | (map { EV::io $_, EV::READ, sub { } } |
703 | keys %{ $dispatcher->{_descriptors} }), |
1013 | keys %{ $dispatcher->{_descriptors} }), |
704 | |
1014 | |
705 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
1015 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
… | |
… | |
720 | # make the dispatcher handle any new stuff |
1030 | # make the dispatcher handle any new stuff |
721 | ... not shown |
1031 | ... not shown |
722 | }; |
1032 | }; |
723 | |
1033 | |
724 | The callbacks of the created watchers will not be called as the watchers |
1034 | The callbacks of the created watchers will not be called as the watchers |
725 | are destroyed before this cna happen (remember EV::check gets called |
1035 | are destroyed before this can happen (remember EV::check gets called |
726 | first). |
1036 | first). |
727 | |
1037 | |
728 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
1038 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
|
|
1039 | |
|
|
1040 | =item EV::CHECK constant issues |
|
|
1041 | |
|
|
1042 | Like all other watcher types, there is a bitmask constant for use in |
|
|
1043 | C<$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 |
|
|
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 |
|
|
1048 | safe side. |
729 | |
1049 | |
730 | =back |
1050 | =back |
731 | |
1051 | |
732 | |
1052 | |
733 | =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 |
… | |
… | |
740 | |
1060 | |
741 | =item $w = EV::fork $callback |
1061 | =item $w = EV::fork $callback |
742 | |
1062 | |
743 | =item $w = EV::fork_ns $callback |
1063 | =item $w = EV::fork_ns $callback |
744 | |
1064 | |
|
|
1065 | =item $w = $loop->fork ($callback) |
|
|
1066 | |
|
|
1067 | =item $w = $loop->fork_ns ($callback) |
|
|
1068 | |
745 | Call the callback before the event loop is resumed in the child process |
1069 | Call the callback before the event loop is resumed in the child process |
746 | after a fork. |
1070 | after a fork. |
747 | |
1071 | |
748 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
1072 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
749 | |
1073 | |
750 | =back |
1074 | =back |
751 | |
1075 | |
752 | |
1076 | |
|
|
1077 | =head3 EMBED WATCHERS - when one backend isn't enough... |
|
|
1078 | |
|
|
1079 | This is a rather advanced watcher type that lets you embed one event loop |
|
|
1080 | into another (currently only IO events are supported in the embedded |
|
|
1081 | loop, other types of watchers might be handled in a delayed or incorrect |
|
|
1082 | fashion and must not be used). |
|
|
1083 | |
|
|
1084 | See the libev documentation at |
|
|
1085 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> |
|
|
1086 | (locally installed as F<EV::libev>) for more details. |
|
|
1087 | |
|
|
1088 | In short, this watcher is most useful on BSD systems without working |
|
|
1089 | kqueue to still be able to handle a large number of sockets: |
|
|
1090 | |
|
|
1091 | my $socket_loop; |
|
|
1092 | |
|
|
1093 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
|
|
1094 | if ( |
|
|
1095 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
|
|
1096 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
|
|
1097 | ) { |
|
|
1098 | # use kqueue for sockets |
|
|
1099 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
|
|
1100 | } |
|
|
1101 | |
|
|
1102 | # use the default loop otherwise |
|
|
1103 | $socket_loop ||= EV::default_loop; |
|
|
1104 | |
|
|
1105 | =over 4 |
|
|
1106 | |
|
|
1107 | =item $w = EV::embed $otherloop[, $callback] |
|
|
1108 | |
|
|
1109 | =item $w = EV::embed_ns $otherloop[, $callback] |
|
|
1110 | |
|
|
1111 | =item $w = $loop->embed ($otherloop[, $callback]) |
|
|
1112 | |
|
|
1113 | =item $w = $loop->embed_ns ($otherloop[, $callback]) |
|
|
1114 | |
|
|
1115 | Call the callback when the embedded event loop (C<$otherloop>) has any |
|
|
1116 | I/O activity. The C<$callback> is optional: if it is missing, then the |
|
|
1117 | embedded event loop will be managed automatically (which is recommended), |
|
|
1118 | otherwise you have to invoke C<sweep> yourself. |
|
|
1119 | |
|
|
1120 | The C<embed_ns> variant doesn't start (activate) the newly created watcher. |
|
|
1121 | |
|
|
1122 | =back |
|
|
1123 | |
|
|
1124 | =head3 ASYNC WATCHERS - how to wake up another event loop |
|
|
1125 | |
|
|
1126 | Async watchers are provided by EV, but have little use in perl directly, |
|
|
1127 | as perl neither supports threads running in parallel nor direct access to |
|
|
1128 | signal handlers or other contexts where they could be of value. |
|
|
1129 | |
|
|
1130 | It is, however, possible to use them from the XS level. |
|
|
1131 | |
|
|
1132 | Please see the libev documentation for further details. |
|
|
1133 | |
|
|
1134 | =over 4 |
|
|
1135 | |
|
|
1136 | =item $w = EV::async $callback |
|
|
1137 | |
|
|
1138 | =item $w = EV::async_ns $callback |
|
|
1139 | |
|
|
1140 | =item $w->send |
|
|
1141 | |
|
|
1142 | =item $bool = $w->async_pending |
|
|
1143 | |
|
|
1144 | =back |
|
|
1145 | |
|
|
1146 | |
|
|
1147 | =head1 PERL SIGNALS |
|
|
1148 | |
|
|
1149 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
|
|
1150 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
1151 | handled when Perl runs, which means your signal handler might be invoked |
|
|
1152 | only the next time an event callback is invoked. |
|
|
1153 | |
|
|
1154 | The solution is to use EV signal watchers (see C<EV::signal>), which will |
|
|
1155 | ensure proper operations with regards to other event watchers. |
|
|
1156 | |
|
|
1157 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
1158 | to be called on every event loop iteration by installing a C<EV::check> |
|
|
1159 | watcher: |
|
|
1160 | |
|
|
1161 | my $async_check = EV::check sub { }; |
|
|
1162 | |
|
|
1163 | This ensures that perl gets into control for a short time to handle any |
|
|
1164 | pending signals, and also ensures (slightly) slower overall operation. |
|
|
1165 | |
753 | =head1 THREADS |
1166 | =head1 ITHREADS |
754 | |
1167 | |
755 | 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 |
756 | 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 |
757 | on thread support for it. |
1170 | supported (and enhanced support is available via L<Coro::EV>). |
758 | |
1171 | |
759 | =head1 FORK |
1172 | =head1 FORK |
760 | |
1173 | |
761 | Most of the "improved" event delivering mechanisms of modern operating |
1174 | Most of the "improved" event delivering mechanisms of modern operating |
762 | 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 |
… | |
… | |
778 | our $DIED = sub { |
1191 | our $DIED = sub { |
779 | warn "EV: error in callback (ignoring): $@"; |
1192 | warn "EV: error in callback (ignoring): $@"; |
780 | }; |
1193 | }; |
781 | |
1194 | |
782 | default_loop |
1195 | default_loop |
783 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; |
1196 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?'; |
784 | |
1197 | |
785 | 1; |
1198 | 1; |
786 | |
1199 | |
787 | =head1 SEE ALSO |
1200 | =head1 SEE ALSO |
788 | |
1201 | |
|
|
1202 | L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS> |
789 | 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 |
790 | event loop), L<Coro::EV> (efficient coroutines with EV). |
1204 | loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread |
|
|
1205 | integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for |
|
|
1206 | event-loop agnostic and portable event driven programming. |
791 | |
1207 | |
792 | =head1 AUTHOR |
1208 | =head1 AUTHOR |
793 | |
1209 | |
794 | Marc Lehmann <schmorp@schmorp.de> |
1210 | Marc Lehmann <schmorp@schmorp.de> |
795 | http://home.schmorp.de/ |
1211 | http://home.schmorp.de/ |
796 | |
1212 | |
797 | =cut |
1213 | =cut |
798 | |
1214 | |