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| 2 | |
2 | |
| 3 | EV - perl interface to libevent, monkey.org/~provos/libevent/ |
3 | EV - perl interface to libevent, monkey.org/~provos/libevent/ |
| 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 | # TIMER |
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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, 1, sub { |
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16 | warn "is called roughly every 2s (repeat = 1)"; |
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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::timer_abs 0, 60, 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 $w = EV::io \*STDIN, EV::READ | EV::PERSIST, sub { |
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28 | my ($w, $events) = @_; # all callbacks get the watcher object and event mask |
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29 | if ($events & EV::TIMEOUT) { |
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30 | warn "nothing received on stdin for 10 seconds, retrying"; |
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31 | } else { |
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32 | warn "stdin is readable, you entered: ", <STDIN>; |
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33 | } |
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34 | }; |
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35 | $w->timeout (10); |
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36 | |
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37 | my $w = EV::timed_io \*STDIN, EV::READ, 30, sub { |
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38 | my ($w, $events) = @_; |
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39 | if ($_[1] & EV::TIMEOUT) { |
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40 | warn "nothing entered within 30 seconds, bye bye.\n"; |
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41 | $w->stop; |
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42 | } else { |
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43 | my $line = <STDIN>; |
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44 | warn "you entered something, you again have 30 seconds.\n"; |
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45 | } |
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46 | }; |
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47 | |
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48 | # SIGNALS |
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49 | |
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50 | my $w = EV::signal 'QUIT', sub { |
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51 | warn "sigquit received\n"; |
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52 | }; |
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53 | |
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54 | my $w = EV::signal 3, sub { |
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55 | warn "sigquit received (this is GNU/Linux, right?)\n"; |
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56 | }; |
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57 | |
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58 | # MAINLOOP |
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59 | EV::dispatch; # loop as long as watchers are active |
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60 | EV::loop; # the same thing |
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61 | EV::loop EV::LOOP_ONCE; # block until some events could be handles |
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62 | EV::loop EV::LOOP_NONBLOCK; # check and handle some events, but do not wait |
| 8 | |
63 | |
| 9 | =head1 DESCRIPTION |
64 | =head1 DESCRIPTION |
| 10 | |
65 | |
| 11 | This module provides an interface to libevent |
66 | This module provides an interface to libevent |
| 12 | (L<http://monkey.org/~provos/libevent/>). |
67 | (L<http://monkey.org/~provos/libevent/>). You probably should acquaint |
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68 | yourself with its documentation and source code to be able to use this |
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69 | module fully. |
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70 | |
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71 | Please note thta this module disables the libevent EPOLL method by |
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72 | default, see BUGS, below, if you need to enable it. |
| 13 | |
73 | |
| 14 | =cut |
74 | =cut |
| 15 | |
75 | |
| 16 | package EV; |
76 | package EV; |
| 17 | |
77 | |
| 18 | use strict; |
78 | use strict; |
| 19 | |
79 | |
| 20 | BEGIN { |
80 | BEGIN { |
| 21 | our $VERSION = '0.01'; |
81 | our $VERSION = '0.03'; |
| 22 | use XSLoader; |
82 | use XSLoader; |
| 23 | XSLoader::load "EV", $VERSION; |
83 | XSLoader::load "EV", $VERSION; |
| 24 | } |
84 | } |
| 25 | |
85 | |
| 26 | =head1 FUNCTIONAL INTERFACE |
86 | @EV::Io::ISA = "EV::Watcher"; |
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87 | @EV::Time::ISA = "EV::Watcher"; |
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88 | @EV::Timer::ISA = "EV::Time"; |
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89 | @EV::Periodic::ISA = "EV::Time"; |
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90 | @EV::Signal::ISA = "EV::Watcher"; |
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91 | @EV::Idle::ISA = "EV::Watcher"; |
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92 | @EV::Prepare::ISA = "EV::Watcher"; |
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93 | @EV::Check::ISA = "EV::Watcher"; |
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94 | |
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95 | =head1 BASIC INTERFACE |
| 27 | |
96 | |
| 28 | =over 4 |
97 | =over 4 |
| 29 | |
98 | |
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99 | =item $EV::NPRI |
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100 | |
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101 | How many priority levels are available. |
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102 | |
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103 | =item $EV::DIED |
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104 | |
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105 | Must contain a reference to a function that is called when a callback |
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106 | throws an exception (with $@ containing thr error). The default prints an |
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107 | informative message and continues. |
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108 | |
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109 | If this callback throws an exception it will be silently ignored. |
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110 | |
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111 | =item $time = EV::now |
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112 | |
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113 | Returns the time in (fractional) seconds since the epoch. |
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114 | |
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115 | =item $version = EV::version |
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116 | |
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117 | =item $method = EV::method |
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118 | |
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119 | Return version string and event polling method used. |
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120 | |
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121 | =item EV::loop $flags # EV::LOOP_ONCE, EV::LOOP_ONESHOT |
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122 | |
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123 | =item EV::loopexit $after |
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124 | |
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125 | Exit any active loop or dispatch after C<$after> seconds or immediately if |
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126 | C<$after> is missing or zero. |
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127 | |
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128 | =item EV::dispatch |
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129 | |
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130 | Same as C<EV::loop 0>. |
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131 | |
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132 | =item EV::event $callback |
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133 | |
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134 | Creates a new event watcher waiting for nothing, calling the given callback. |
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135 | |
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136 | =item my $w = EV::io $fileno_or_fh, $eventmask, $callback |
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137 | |
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138 | =item my $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
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139 | |
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140 | As long as the returned watcher object is alive, call the C<$callback> |
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141 | when the events specified in C<$eventmask> happen. Initially, the timeout |
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142 | is disabled. |
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143 | |
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144 | You can additionall set a timeout to occur on the watcher, but note that |
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145 | this timeout will not be reset when you get an I/O event in the EV::PERSIST |
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146 | case, and reaching a timeout will always stop the watcher even in the |
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147 | EV::PERSIST case. |
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148 | |
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149 | If you want a timeout to occur only after a specific time of inactivity, set |
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150 | a repeating timeout and do NOT use EV::PERSIST. |
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151 | |
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152 | Eventmask can be one or more of these constants ORed together: |
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153 | |
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154 | EV::READ wait until read() wouldn't block anymore |
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155 | EV::WRITE wait until write() wouldn't block anymore |
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156 | EV::PERSIST stay active after a (non-timeout) event occured |
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157 | |
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158 | The C<io_ns> variant doesn't add/start the newly created watcher. |
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159 | |
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160 | =item my $w = EV::timed_io $fileno_or_fh, $eventmask, $timeout, $callback |
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161 | |
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162 | =item my $w = EV::timed_io_ns $fileno_or_fh, $eventmask, $timeout, $callback |
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163 | |
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164 | Same as C<io> and C<io_ns>, but also specifies a timeout (as if there was |
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165 | a call to C<< $w->timeout ($timout, 1) >>. The persist flag is not allowed |
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166 | and will automatically be cleared. The watcher will be restarted after each event. |
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167 | |
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168 | If the timeout is zero or undef, no timeout will be set, and a normal |
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169 | watcher (with the persist flag set!) will be created. |
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170 | |
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171 | This has the effect of timing out after the specified period of inactivity |
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172 | has happened. |
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173 | |
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174 | Due to the design of libevent, this is also relatively inefficient, having |
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175 | one or two io watchers and a separate timeout watcher that you reset on |
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176 | activity (by calling its C<start> method) is usually more efficient. |
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177 | |
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178 | =item my $w = EV::timer $after, $repeat, $callback |
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179 | |
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180 | =item my $w = EV::timer_ns $after, $repeat, $callback |
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181 | |
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182 | Calls the callback after C<$after> seconds. If C<$repeat> is true, the |
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183 | timer will be restarted after the callback returns. This means that the |
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184 | callback would be called roughly every C<$after> seconds, prolonged by the |
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185 | time the callback takes. |
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186 | |
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187 | The C<timer_ns> variant doesn't add/start the newly created watcher. |
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188 | |
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189 | =item my $w = EV::timer_abs $at, $interval, $callback |
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190 | |
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191 | =item my $w = EV::timer_abs_ns $at, $interval, $callback |
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192 | |
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193 | Similar to EV::timer, but the time is given as an absolute point in time |
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194 | (C<$at>), plus an optional C<$interval>. |
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195 | |
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196 | If the C<$interval> is zero, then the callback will be called at the time |
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197 | C<$at> if that is in the future, or as soon as possible if its in the |
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198 | past. It will not automatically repeat. |
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199 | |
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200 | If the C<$interval> is nonzero, then the watcher will always be scheduled |
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201 | to time out at the next C<$at + integer * $interval> time. |
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202 | |
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203 | This can be used to schedule a callback to run at very regular intervals, |
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204 | as long as the processing time is less then the interval (otherwise |
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205 | obviously events will be skipped). |
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206 | |
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207 | Another way to think about it (for the mathematically inclined) is that |
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208 | C<timer_abs> will try to tun the callback at the next possible time where |
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209 | C<$time = $at (mod $interval)>, regardless of any time jumps. |
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210 | |
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211 | The C<timer_abs_ns> variant doesn't add/start the newly created watcher. |
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212 | |
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213 | =item my $w = EV::signal $signal, $callback |
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214 | |
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215 | =item my $w = EV::signal_ns $signal, $callback |
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216 | |
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217 | Call the callback when $signal is received (the signal can be specified |
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218 | by number or by name, just as with kill or %SIG). Signal watchers are |
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219 | persistent no natter what. |
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220 | |
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221 | EV will grab the signal for the process (the kernel only allows one |
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222 | component to receive signals) when you start a signal watcher, and |
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223 | removes it again when you stop it. Pelr does the same when you add/remove |
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224 | callbacks to %SIG, so watch out. |
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225 | |
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226 | Unfortunately, only one handler can be registered per signal. Screw |
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227 | libevent. |
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228 | |
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229 | The C<signal_ns> variant doesn't add/start the newly created watcher. |
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230 | |
| 30 | =back |
231 | =back |
| 31 | |
232 | |
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233 | =head1 THE EV::Event CLASS |
| 32 | |
234 | |
| 33 | =head1 OBJECT-ORIENTED INTERFACE |
235 | All EV functions creating an event watcher (designated by C<my $w => |
| 34 | |
236 | above) support the following methods on the returned watcher object: |
| 35 | The object oriented interface lets you configure your own encoding or |
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| 36 | decoding style, within the limits of supported formats. |
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| 37 | |
237 | |
| 38 | =over 4 |
238 | =over 4 |
| 39 | |
239 | |
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240 | =item $w->add ($timeout) |
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241 | |
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242 | Stops and (re-)starts the event watcher, setting the optional timeout to |
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243 | the given value, or clearing the timeout if none is given. |
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244 | |
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245 | =item $w->start |
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246 | |
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247 | Stops and (re-)starts the event watcher without touching the timeout. |
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248 | |
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249 | =item $w->del |
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250 | |
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251 | =item $w->stop |
|
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252 | |
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253 | Stop the event watcher if it was started. |
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254 | |
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255 | =item $current_callback = $w->cb |
|
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256 | |
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257 | =item $old_callback = $w->cb ($new_callback) |
|
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258 | |
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259 | Return the previously set callback and optionally set a new one. |
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260 | |
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261 | =item $current_fh = $w->fh |
|
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262 | |
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263 | =item $old_fh = $w->fh ($new_fh) |
|
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264 | |
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265 | Returns the previously set filehandle and optionally set a new one (also |
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266 | clears the EV::SIGNAL flag when setting a filehandle). |
|
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267 | |
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268 | =item $current_signal = $w->signal |
|
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269 | |
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270 | =item $old_signal = $w->signal ($new_signal) |
|
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271 | |
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272 | Returns the previously set signal number and optionally set a new one (also sets |
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273 | the EV::SIGNAL flag when setting a signal). |
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274 | |
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275 | =item $current_eventmask = $w->events |
|
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276 | |
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277 | =item $old_eventmask = $w->events ($new_eventmask) |
|
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278 | |
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279 | Returns the previously set event mask and optionally set a new one. |
|
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280 | |
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281 | =item $w->timeout ($after, $repeat) |
|
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282 | |
|
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283 | Resets the timeout (see C<EV::timer> for details). |
|
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284 | |
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285 | =item $w->timeout_abs ($at, $interval) |
|
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286 | |
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287 | Resets the timeout (see C<EV::timer_abs> for details). |
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288 | |
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289 | =item $w->priority_set ($priority) |
|
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290 | |
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291 | Set the priority of the watcher to C<$priority> (0 <= $priority < $EV::NPRI). |
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292 | |
| 40 | =back |
293 | =back |
| 41 | |
294 | |
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295 | =head1 THREADS |
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296 | |
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297 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
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298 | and must die. |
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299 | |
| 42 | =head1 BUGS |
300 | =head1 BUGS |
| 43 | |
301 | |
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302 | Lots. Libevent itself isn't well tested and rather buggy, and this module |
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303 | is quite new at the moment. |
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304 | |
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305 | Please note that the epoll method is not, in general, reliable in programs |
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306 | that use fork (even if no libveent calls are being made in the forked |
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307 | process). If your program behaves erratically, try setting the environment |
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308 | variable C<EVENT_NOEPOLL> first when running the program. |
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309 | |
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310 | In general, if you fork, then you can only use the EV module in one of the |
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311 | children. |
|
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312 | |
| 44 | =cut |
313 | =cut |
| 45 | |
314 | |
| 46 | our $NPRI = 4; |
315 | our $DIED = sub { |
| 47 | our $BASE = init; |
316 | warn "EV: error in callback (ignoring): $@"; |
| 48 | priority_init $NPRI; |
317 | }; |
|
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318 | |
|
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319 | init; |
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320 | |
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321 | push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"]; |
| 49 | |
322 | |
| 50 | 1; |
323 | 1; |
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324 | |
|
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325 | =head1 SEE ALSO |
|
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326 | |
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327 | L<EV::DNS>, L<event(3)>, L<event.h>, L<evdns.h>. |
|
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328 | L<EV::AnyEvent>. |
| 51 | |
329 | |
| 52 | =head1 AUTHOR |
330 | =head1 AUTHOR |
| 53 | |
331 | |
| 54 | Marc Lehmann <schmorp@schmorp.de> |
332 | Marc Lehmann <schmorp@schmorp.de> |
| 55 | http://home.schmorp.de/ |
333 | http://home.schmorp.de/ |
