1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | EV - perl interface to libevent, monkey.org/~provos/libevent/ |
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; |
8 | |
8 | |
9 | # TIMER |
9 | # TIMERS |
10 | |
10 | |
11 | my $w = EV::timer 2, 0, sub { |
11 | my $w = EV::timer 2, 0, sub { |
12 | warn "is called after 2s"; |
12 | warn "is called after 2s"; |
13 | }; |
13 | }; |
14 | |
14 | |
15 | my $w = EV::timer 2, 1, sub { |
15 | my $w = EV::timer 2, 2, sub { |
16 | warn "is called roughly every 2s (repeat = 1)"; |
16 | warn "is called roughly every 2s (repeat = 2)"; |
17 | }; |
17 | }; |
18 | |
18 | |
19 | undef $w; # destroy event watcher again |
19 | undef $w; # destroy event watcher again |
20 | |
20 | |
21 | my $w = EV::timer_abs 0, 60, sub { |
21 | my $w = EV::periodic 0, 60, 0, sub { |
22 | warn "is called every minute, on the minute, exactly"; |
22 | warn "is called every minute, on the minute, exactly"; |
23 | }; |
23 | }; |
24 | |
24 | |
25 | # IO |
25 | # IO |
26 | |
26 | |
27 | my $w = EV::io \*STDIN, EV::READ | EV::PERSIST, sub { |
27 | my $w = EV::io *STDIN, EV::READ, sub { |
28 | my ($w, $revents) = @_; # all callbacks get the watcher object and event mask |
28 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
29 | if ($revents & 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>; |
29 | warn "stdin is readable, you entered: ", <STDIN>; |
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, $revents) = @_; |
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39 | if ($revents & 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 | }; |
30 | }; |
47 | |
31 | |
48 | # SIGNALS |
32 | # SIGNALS |
49 | |
33 | |
50 | my $w = EV::signal 'QUIT', sub { |
34 | my $w = EV::signal 'QUIT', sub { |
51 | warn "sigquit received\n"; |
35 | warn "sigquit received\n"; |
52 | }; |
36 | }; |
53 | |
37 | |
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 | # CHILD/PID STATUS CHANGES |
38 | # CHILD/PID STATUS CHANGES |
59 | |
39 | |
60 | my $w = EV::child 666, sub { |
40 | my $w = EV::child 666, sub { |
61 | my ($w, $revents, $status) = @_; |
41 | my ($w, $revents) = @_; |
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42 | my $status = $w->rstatus; |
62 | }; |
43 | }; |
63 | |
44 | |
64 | # MAINLOOP |
45 | # MAINLOOP |
65 | EV::dispatch; # loop as long as watchers are active |
46 | EV::loop; # loop until EV::unloop is called or all watchers stop |
66 | EV::loop; # the same thing |
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67 | EV::loop EV::LOOP_ONESHOT; # block until some events could be handles |
47 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
68 | EV::loop EV::LOOP_NONBLOCK; # check and handle some events, but do not wait |
48 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
69 | |
49 | |
70 | =head1 DESCRIPTION |
50 | =head1 DESCRIPTION |
71 | |
51 | |
72 | This module provides an interface to libev |
52 | This module provides an interface to libev |
73 | (L<http://software.schmorp.de/pkg/libev.html>). You probably should |
53 | (L<http://software.schmorp.de/pkg/libev.html>). |
74 | acquaint yourself with its documentation and source code to be able to use |
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75 | this module fully. |
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76 | |
54 | |
77 | =cut |
55 | =cut |
78 | |
56 | |
79 | package EV; |
57 | package EV; |
80 | |
58 | |
81 | use strict; |
59 | use strict; |
82 | |
60 | |
83 | BEGIN { |
61 | BEGIN { |
84 | our $VERSION = '0.03'; |
62 | our $VERSION = '0.9'; |
85 | use XSLoader; |
63 | use XSLoader; |
86 | XSLoader::load "EV", $VERSION; |
64 | XSLoader::load "EV", $VERSION; |
87 | } |
65 | } |
88 | |
66 | |
89 | @EV::Io::ISA = "EV::Watcher"; |
67 | @EV::Io::ISA = |
90 | @EV::Time::ISA = "EV::Watcher"; |
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91 | @EV::Timer::ISA = "EV::Time"; |
68 | @EV::Timer::ISA = |
92 | @EV::Periodic::ISA = "EV::Time"; |
69 | @EV::Periodic::ISA = |
93 | @EV::Signal::ISA = "EV::Watcher"; |
70 | @EV::Signal::ISA = |
94 | @EV::Idle::ISA = "EV::Watcher"; |
71 | @EV::Idle::ISA = |
95 | @EV::Prepare::ISA = "EV::Watcher"; |
72 | @EV::Prepare::ISA = |
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73 | @EV::Check::ISA = |
96 | @EV::Check::ISA = "EV::Watcher"; |
74 | @EV::Child::ISA = "EV::Watcher"; |
97 | |
75 | |
98 | =head1 BASIC INTERFACE |
76 | =head1 BASIC INTERFACE |
99 | |
77 | |
100 | =over 4 |
78 | =over 4 |
101 | |
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102 | =item $EV::NPRI |
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103 | |
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104 | How many priority levels are available. |
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105 | |
79 | |
106 | =item $EV::DIED |
80 | =item $EV::DIED |
107 | |
81 | |
108 | Must contain a reference to a function that is called when a callback |
82 | Must contain a reference to a function that is called when a callback |
109 | throws an exception (with $@ containing thr error). The default prints an |
83 | throws an exception (with $@ containing thr error). The default prints an |
110 | informative message and continues. |
84 | informative message and continues. |
111 | |
85 | |
112 | If this callback throws an exception it will be silently ignored. |
86 | If this callback throws an exception it will be silently ignored. |
113 | |
87 | |
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88 | =item $time = EV::time |
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89 | |
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90 | Returns the current time in (fractional) seconds since the epoch. |
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91 | |
114 | =item $time = EV::now |
92 | =item $time = EV::now |
115 | |
93 | |
116 | Returns the time in (fractional) seconds since the epoch. |
94 | Returns the time the last event loop iteration has been started. This |
117 | |
95 | is the time that (relative) timers are based on, and refering to it is |
118 | =item $version = EV::version |
96 | usually faster then calling EV::time. |
119 | |
97 | |
120 | =item $method = EV::method |
98 | =item $method = EV::method |
121 | |
99 | |
122 | Return version string and event polling method used. |
100 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
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101 | or EV::METHOD_EPOLL). |
123 | |
102 | |
124 | =item EV::loop $flags # EV::LOOP_ONCE, EV::LOOP_ONESHOT |
103 | =item EV::loop [$flags] |
125 | |
104 | |
126 | =item EV::loopexit $after |
105 | Begin checking for events and calling callbacks. It returns when a |
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106 | callback calls EV::unloop. |
127 | |
107 | |
128 | Exit any active loop or dispatch after C<$after> seconds or immediately if |
108 | The $flags argument can be one of the following: |
129 | C<$after> is missing or zero. |
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130 | |
109 | |
131 | =item EV::dispatch |
110 | 0 as above |
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111 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
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112 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
132 | |
113 | |
133 | Same as C<EV::loop 0>. |
114 | =item EV::unloop [$how] |
134 | |
115 | |
135 | =item EV::event $callback |
116 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
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117 | innermost call to EV::loop return. |
136 | |
118 | |
137 | Creates a new event watcher waiting for nothing, calling the given callback. |
119 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
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120 | fast as possible. |
138 | |
121 | |
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122 | =back |
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123 | |
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124 | =head2 WATCHER |
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125 | |
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126 | A watcher is an object that gets created to record your interest in some |
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127 | event. For instance, if you want to wait for STDIN to become readable, you |
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128 | would create an EV::io watcher for that: |
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129 | |
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130 | my $watcher = EV::io *STDIN, EV::READ, sub { |
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131 | my ($watcher, $revents) = @_; |
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132 | warn "yeah, STDIN should not be readable without blocking!\n" |
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133 | }; |
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134 | |
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135 | All watchers can be active (waiting for events) or inactive (paused). Only |
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136 | active watchers will have their callbacks invoked. All callbacks will be |
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137 | called with at least two arguments: the watcher and a bitmask of received |
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138 | events. |
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139 | |
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140 | Each watcher type has its associated bit in revents, so you can use the |
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141 | same callback for multiple watchers. The event mask is named after the |
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142 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
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143 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
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144 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
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145 | uses EV::TIMEOUT). |
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146 | |
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147 | In the rare case where one wants to create a watcher but not start it at |
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148 | the same time, each constructor has a variant with a trailing C<_ns> in |
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149 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
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150 | |
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151 | Please note that a watcher will automatically be stopped when the watcher |
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152 | object is destroyed, so you I<need> to keep the watcher objects returned by |
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153 | the constructors. |
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154 | |
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155 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
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156 | ->fh and so on) automatically stop and start it again if it is active, |
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157 | which means pending events get lost. |
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158 | |
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159 | =head2 WATCHER TYPES |
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160 | |
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161 | Now lets move to the existing watcher types and asociated methods. |
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162 | |
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163 | The following methods are available for all watchers. Then followes a |
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164 | description of each watcher constructor (EV::io, EV::timer, EV::periodic, |
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165 | EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by |
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166 | any type-specific methods (if any). |
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167 | |
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168 | =over 4 |
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169 | |
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170 | =item $w->start |
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171 | |
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172 | Starts a watcher if it isn't active already. Does nothing to an already |
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173 | active watcher. By default, all watchers start out in the active state |
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174 | (see the description of the C<_ns> variants if you need stopped watchers). |
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175 | |
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176 | =item $w->stop |
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177 | |
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178 | Stop a watcher if it is active. Also clear any pending events (events that |
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179 | have been received but that didn't yet result in a callback invocation), |
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180 | regardless of wether the watcher was active or not. |
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181 | |
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182 | =item $bool = $w->is_active |
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183 | |
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184 | Returns true if the watcher is active, false otherwise. |
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185 | |
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186 | =item $current_data = $w->data |
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187 | |
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188 | =item $old_data = $w->data ($new_data) |
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189 | |
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190 | Queries a freely usable data scalar on the watcher and optionally changes |
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191 | it. This is a way to associate custom data with a watcher: |
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192 | |
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193 | my $w = EV::timer 60, 0, sub { |
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194 | warn $_[0]->data; |
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195 | }; |
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196 | $w->data ("print me!"); |
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197 | |
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198 | =item $current_cb = $w->cb |
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199 | |
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200 | =item $old_cb = $w->cb ($new_cb) |
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201 | |
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202 | Queries the callback on the watcher and optionally changes it. You can do |
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203 | this at any time without the watcher restarting. |
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204 | |
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205 | =item $current_priority = $w->priority |
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206 | |
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207 | =item $old_priority = $w->priority ($new_priority) |
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208 | |
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209 | Queries the priority on the watcher and optionally changes it. Pending |
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210 | watchers with higher priority will be invoked first. The valid range of |
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211 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
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212 | -2). If the priority is outside this range it will automatically be |
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213 | normalised to the nearest valid priority. |
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214 | |
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215 | The default priority of any newly-created weatcher is 0. |
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216 | |
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217 | =item $w->trigger ($revents) |
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218 | |
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219 | Call the callback *now* with the given event mask. |
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220 | |
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221 | |
139 | =item my $w = EV::io $fileno_or_fh, $eventmask, $callback |
222 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
140 | |
223 | |
141 | =item my $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
224 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
142 | |
225 | |
143 | As long as the returned watcher object is alive, call the C<$callback> |
226 | As long as the returned watcher object is alive, call the C<$callback> |
144 | when the events specified in C<$eventmask> happen. Initially, the timeout |
227 | when the events specified in C<$eventmask>. |
145 | is disabled. |
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146 | |
228 | |
147 | You can additionall set a timeout to occur on the watcher, but note that |
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148 | this timeout will not be reset when you get an I/O event in the EV::PERSIST |
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149 | case, and reaching a timeout will always stop the watcher even in the |
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150 | EV::PERSIST case. |
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151 | |
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152 | If you want a timeout to occur only after a specific time of inactivity, set |
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153 | a repeating timeout and do NOT use EV::PERSIST. |
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154 | |
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155 | Eventmask can be one or more of these constants ORed together: |
229 | The $eventmask can be one or more of these constants ORed together: |
156 | |
230 | |
157 | EV::READ wait until read() wouldn't block anymore |
231 | EV::READ wait until read() wouldn't block anymore |
158 | EV::WRITE wait until write() wouldn't block anymore |
232 | EV::WRITE wait until write() wouldn't block anymore |
159 | EV::PERSIST stay active after a (non-timeout) event occured |
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160 | |
233 | |
161 | The C<io_ns> variant doesn't add/start the newly created watcher. |
234 | The C<io_ns> variant doesn't start (activate) the newly created watcher. |
162 | |
235 | |
163 | =item my $w = EV::timed_io $fileno_or_fh, $eventmask, $timeout, $callback |
236 | =item $w->set ($fileno_or_fh, $eventmask) |
164 | |
237 | |
165 | =item my $w = EV::timed_io_ns $fileno_or_fh, $eventmask, $timeout, $callback |
238 | Reconfigures the watcher, see the constructor above for details. Can be |
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239 | called at any time. |
166 | |
240 | |
167 | Same as C<io> and C<io_ns>, but also specifies a timeout (as if there was |
241 | =item $current_fh = $w->fh |
168 | a call to C<< $w->timeout ($timout, 1) >>. The persist flag is not allowed |
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169 | and will automatically be cleared. The watcher will be restarted after each event. |
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170 | |
242 | |
171 | If the timeout is zero or undef, no timeout will be set, and a normal |
243 | =item $old_fh = $w->fh ($new_fh) |
172 | watcher (with the persist flag set!) will be created. |
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173 | |
244 | |
174 | This has the effect of timing out after the specified period of inactivity |
245 | Returns the previously set filehandle and optionally set a new one. |
175 | has happened. |
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176 | |
246 | |
177 | Due to the design of libevent, this is also relatively inefficient, having |
247 | =item $current_eventmask = $w->events |
178 | one or two io watchers and a separate timeout watcher that you reset on |
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179 | activity (by calling its C<start> method) is usually more efficient. |
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180 | |
248 | |
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249 | =item $old_eventmask = $w->events ($new_eventmask) |
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250 | |
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251 | Returns the previously set event mask and optionally set a new one. |
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252 | |
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253 | |
181 | =item my $w = EV::timer $after, $repeat, $callback |
254 | =item $w = EV::timer $after, $repeat, $callback |
182 | |
255 | |
183 | =item my $w = EV::timer_ns $after, $repeat, $callback |
256 | =item $w = EV::timer_ns $after, $repeat, $callback |
184 | |
257 | |
185 | Calls the callback after C<$after> seconds. If C<$repeat> is true, the |
258 | Calls the callback after C<$after> seconds. If C<$repeat> is non-zero, |
186 | timer will be restarted after the callback returns. This means that the |
259 | the timer will be restarted (with the $repeat value as $after) after the |
187 | callback would be called roughly every C<$after> seconds, prolonged by the |
260 | callback returns. |
188 | time the callback takes. |
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189 | |
261 | |
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262 | This means that the callback would be called roughly after C<$after> |
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263 | seconds, and then every C<$repeat> seconds. The timer does his best not |
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264 | to drift, but it will not invoke the timer more often then once per event |
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265 | loop iteration, and might drift in other cases. If that isn't acceptable, |
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266 | look at EV::periodic, which can provide long-term stable timers. |
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267 | |
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268 | The timer is based on a monotonic clock, that is, if somebody is sitting |
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269 | in front of the machine while the timer is running and changes the system |
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270 | clock, the timer will nevertheless run (roughly) the same time. |
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271 | |
190 | The C<timer_ns> variant doesn't add/start the newly created watcher. |
272 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
191 | |
273 | |
192 | =item my $w = EV::timer_abs $at, $interval, $callback |
274 | =item $w->set ($after, $repeat) |
193 | |
275 | |
194 | =item my $w = EV::timer_abs_ns $at, $interval, $callback |
276 | Reconfigures the watcher, see the constructor above for details. Can be at |
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277 | any time. |
195 | |
278 | |
196 | Similar to EV::timer, but the time is given as an absolute point in time |
279 | =item $w->again |
197 | (C<$at>), plus an optional C<$interval>. |
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198 | |
280 | |
199 | If the C<$interval> is zero, then the callback will be called at the time |
281 | Similar to the C<start> method, but has special semantics for repeating timers: |
200 | C<$at> if that is in the future, or as soon as possible if its in the |
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201 | past. It will not automatically repeat. |
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202 | |
282 | |
203 | If the C<$interval> is nonzero, then the watcher will always be scheduled |
283 | If the timer is active and non-repeating, it will be stopped. |
204 | to time out at the next C<$at + integer * $interval> time. |
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205 | |
284 | |
206 | This can be used to schedule a callback to run at very regular intervals, |
285 | If the timer is active and repeating, reset the timeout to occur |
207 | as long as the processing time is less then the interval (otherwise |
286 | C<$repeat> seconds after now. |
208 | obviously events will be skipped). |
287 | |
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288 | If the timer is inactive and repeating, start it using the repeat value. |
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289 | |
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290 | Otherwise do nothing. |
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291 | |
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292 | This behaviour is useful when you have a timeout for some IO |
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293 | operation. You create a timer object with the same value for C<$after> and |
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294 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
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295 | on the timeout. |
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296 | |
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297 | |
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298 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
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299 | |
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300 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
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301 | |
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302 | Similar to EV::timer, but is not based on relative timeouts but on |
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303 | absolute times. Apart from creating "simple" timers that trigger "at" the |
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304 | specified time, it can also be used for non-drifting absolute timers and |
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305 | more complex, cron-like, setups that are not adversely affected by time |
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306 | jumps (i.e. when the system clock is changed by explicit date -s or other |
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307 | means such as ntpd). It is also the most complex watcher type in EV. |
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308 | |
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309 | It has three distinct "modes": |
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310 | |
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311 | =over 4 |
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312 | |
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313 | =item * absolute timer ($interval = $reschedule_cb = 0) |
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314 | |
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315 | This time simply fires at the wallclock time C<$at> and doesn't repeat. It |
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316 | will not adjust when a time jump occurs, that is, if it is to be run |
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317 | at January 1st 2011 then it will run when the system time reaches or |
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318 | surpasses this time. |
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319 | |
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320 | =item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
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321 | |
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322 | In this mode the watcher will always be scheduled to time out at the |
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323 | next C<$at + N * $interval> time (for some integer N) and then repeat, |
|
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324 | regardless of any time jumps. |
|
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325 | |
|
|
326 | This can be used to create timers that do not drift with respect to system |
|
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327 | time: |
|
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328 | |
|
|
329 | my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; |
|
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330 | |
|
|
331 | That doesn't mean there will always be 3600 seconds in between triggers, |
|
|
332 | but only that the the clalback will be called when the system time shows a |
|
|
333 | full hour (UTC). |
209 | |
334 | |
210 | Another way to think about it (for the mathematically inclined) is that |
335 | Another way to think about it (for the mathematically inclined) is that |
211 | C<timer_abs> will try to tun the callback at the next possible time where |
336 | EV::periodic will try to run the callback in this mode at the next |
212 | C<$time = $at (mod $interval)>, regardless of any time jumps. |
337 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
|
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338 | jumps. |
213 | |
339 | |
|
|
340 | =item * manual reschedule mode ($reschedule_cb = coderef) |
|
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341 | |
|
|
342 | In this mode $interval and $at are both being ignored. Instead, each |
|
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343 | time the periodic watcher gets scheduled, the reschedule callback |
|
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344 | ($reschedule_cb) will be called with the watcher as first, and the current |
|
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345 | time as second argument. |
|
|
346 | |
|
|
347 | I<This callback MUST NOT stop or destroy this or any other periodic |
|
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348 | watcher, ever>. If you need to stop it, return 1e30 and stop it |
|
|
349 | afterwards. |
|
|
350 | |
|
|
351 | It must return the next time to trigger, based on the passed time value |
|
|
352 | (that is, the lowest time value larger than to the second argument). It |
|
|
353 | will usually be called just before the callback will be triggered, but |
|
|
354 | might be called at other times, too. |
|
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355 | |
|
|
356 | This can be used to create very complex timers, such as a timer that |
|
|
357 | triggers on each midnight, local time (actually 24 hours after the last |
|
|
358 | midnight, to keep the example simple. If you know a way to do it correctly |
|
|
359 | in about the same space (without requiring elaborate modules), drop me a |
|
|
360 | note :): |
|
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361 | |
|
|
362 | my $daily = EV::periodic 0, 0, sub { |
|
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363 | my ($w, $now) = @_; |
|
|
364 | |
|
|
365 | use Time::Local (); |
|
|
366 | my (undef, undef, undef, $d, $m, $y) = localtime $now; |
|
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367 | 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y |
|
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368 | }, sub { |
|
|
369 | print "it's midnight or likely shortly after, now\n"; |
|
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370 | }; |
|
|
371 | |
|
|
372 | =back |
|
|
373 | |
214 | The C<timer_abs_ns> variant doesn't add/start the newly created watcher. |
374 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
215 | |
375 | |
|
|
376 | =item $w->set ($at, $interval, $reschedule_cb) |
|
|
377 | |
|
|
378 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
379 | any time. |
|
|
380 | |
|
|
381 | =item $w->again |
|
|
382 | |
|
|
383 | Simply stops and starts the watcher again. |
|
|
384 | |
|
|
385 | |
216 | =item my $w = EV::signal $signal, $callback |
386 | =item $w = EV::signal $signal, $callback |
217 | |
387 | |
218 | =item my $w = EV::signal_ns $signal, $callback |
388 | =item $w = EV::signal_ns $signal, $callback |
219 | |
389 | |
220 | Call the callback when $signal is received (the signal can be specified |
390 | Call the callback when $signal is received (the signal can be specified |
221 | by number or by name, just as with kill or %SIG). Signal watchers are |
391 | by number or by name, just as with kill or %SIG). |
222 | persistent no natter what. |
|
|
223 | |
392 | |
224 | EV will grab the signal for the process (the kernel only allows one |
393 | EV will grab the signal for the process (the kernel only allows one |
225 | component to receive signals) when you start a signal watcher, and |
394 | component to receive a signal at a time) when you start a signal watcher, |
226 | removes it again when you stop it. Pelr does the same when you add/remove |
395 | and removes it again when you stop it. Perl does the same when you |
227 | callbacks to %SIG, so watch out. |
396 | add/remove callbacks to %SIG, so watch out. |
228 | |
397 | |
229 | Unfortunately, only one handler can be registered per signal. Screw |
398 | You can have as many signal watchers per signal as you want. |
230 | libevent. |
|
|
231 | |
399 | |
232 | The C<signal_ns> variant doesn't add/start the newly created watcher. |
400 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
|
|
401 | |
|
|
402 | =item $w->set ($signal) |
|
|
403 | |
|
|
404 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
405 | any time. |
|
|
406 | |
|
|
407 | =item $current_signum = $w->signal |
|
|
408 | |
|
|
409 | =item $old_signum = $w->signal ($new_signal) |
|
|
410 | |
|
|
411 | Returns the previously set signal (always as a number not name) and |
|
|
412 | optionally set a new one. |
|
|
413 | |
|
|
414 | |
|
|
415 | =item $w = EV::child $pid, $callback |
|
|
416 | |
|
|
417 | =item $w = EV::child_ns $pid, $callback |
|
|
418 | |
|
|
419 | Call the callback when a status change for pid C<$pid> (or any pid |
|
|
420 | if C<$pid> is 0) has been received. More precisely: when the process |
|
|
421 | receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all |
|
|
422 | changed/zombie children and call the callback. |
|
|
423 | |
|
|
424 | You can access both status and pid by using the C<rstatus> and C<rpid> |
|
|
425 | methods on the watcher object. |
|
|
426 | |
|
|
427 | You can have as many pid watchers per pid as you want. |
|
|
428 | |
|
|
429 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
|
|
430 | |
|
|
431 | =item $w->set ($pid) |
|
|
432 | |
|
|
433 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
434 | any time. |
|
|
435 | |
|
|
436 | =item $current_pid = $w->pid |
|
|
437 | |
|
|
438 | =item $old_pid = $w->pid ($new_pid) |
|
|
439 | |
|
|
440 | Returns the previously set process id and optionally set a new one. |
|
|
441 | |
|
|
442 | =item $exit_status = $w->rstatus |
|
|
443 | |
|
|
444 | Return the exit/wait status (as returned by waitpid, see the waitpid entry |
|
|
445 | in perlfunc). |
|
|
446 | |
|
|
447 | =item $pid = $w->rpid |
|
|
448 | |
|
|
449 | Return the pid of the awaited child (useful when you have installed a |
|
|
450 | watcher for all pids). |
|
|
451 | |
|
|
452 | |
|
|
453 | =item $w = EV::idle $callback |
|
|
454 | |
|
|
455 | =item $w = EV::idle_ns $callback |
|
|
456 | |
|
|
457 | Call the callback when there are no pending io, timer/periodic, signal or |
|
|
458 | child events, i.e. when the process is idle. |
|
|
459 | |
|
|
460 | The process will not block as long as any idle watchers are active, and |
|
|
461 | they will be called repeatedly until stopped. |
|
|
462 | |
|
|
463 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
|
|
464 | |
|
|
465 | |
|
|
466 | =item $w = EV::prepare $callback |
|
|
467 | |
|
|
468 | =item $w = EV::prepare_ns $callback |
|
|
469 | |
|
|
470 | Call the callback just before the process would block. You can still |
|
|
471 | create/modify any watchers at this point. |
|
|
472 | |
|
|
473 | See the EV::check watcher, below, for explanations and an example. |
|
|
474 | |
|
|
475 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
|
|
476 | |
|
|
477 | |
|
|
478 | =item $w = EV::check $callback |
|
|
479 | |
|
|
480 | =item $w = EV::check_ns $callback |
|
|
481 | |
|
|
482 | Call the callback just after the process wakes up again (after it has |
|
|
483 | gathered events), but before any other callbacks have been invoked. |
|
|
484 | |
|
|
485 | This is used to integrate other event-based software into the EV |
|
|
486 | mainloop: You register a prepare callback and in there, you create io and |
|
|
487 | timer watchers as required by the other software. Here is a real-world |
|
|
488 | example of integrating Net::SNMP (with some details left out): |
|
|
489 | |
|
|
490 | our @snmp_watcher; |
|
|
491 | |
|
|
492 | our $snmp_prepare = EV::prepare sub { |
|
|
493 | # do nothing unless active |
|
|
494 | $dispatcher->{_event_queue_h} |
|
|
495 | or return; |
|
|
496 | |
|
|
497 | # make the dispatcher handle any outstanding stuff |
|
|
498 | |
|
|
499 | # create an IO watcher for each and every socket |
|
|
500 | @snmp_watcher = ( |
|
|
501 | (map { EV::io $_, EV::READ, sub { } } |
|
|
502 | keys %{ $dispatcher->{_descriptors} }), |
|
|
503 | ); |
|
|
504 | |
|
|
505 | # if there are any timeouts, also create a timer |
|
|
506 | push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { } |
|
|
507 | if $event->[Net::SNMP::Dispatcher::_ACTIVE]; |
|
|
508 | }; |
|
|
509 | |
|
|
510 | The callbacks are irrelevant, the only purpose of those watchers is |
|
|
511 | to wake up the process as soon as one of those events occurs (socket |
|
|
512 | readable, or timer timed out). The corresponding EV::check watcher will then |
|
|
513 | clean up: |
|
|
514 | |
|
|
515 | our $snmp_check = EV::check sub { |
|
|
516 | # destroy all watchers |
|
|
517 | @snmp_watcher = (); |
|
|
518 | |
|
|
519 | # make the dispatcher handle any new stuff |
|
|
520 | }; |
|
|
521 | |
|
|
522 | The callbacks of the created watchers will not be called as the watchers |
|
|
523 | are destroyed before this cna happen (remember EV::check gets called |
|
|
524 | first). |
|
|
525 | |
|
|
526 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
233 | |
527 | |
234 | =back |
528 | =back |
235 | |
529 | |
236 | =head1 THE EV::Event CLASS |
|
|
237 | |
|
|
238 | All EV functions creating an event watcher (designated by C<my $w => |
|
|
239 | above) support the following methods on the returned watcher object: |
|
|
240 | |
|
|
241 | =over 4 |
|
|
242 | |
|
|
243 | =item $w->add ($timeout) |
|
|
244 | |
|
|
245 | Stops and (re-)starts the event watcher, setting the optional timeout to |
|
|
246 | the given value, or clearing the timeout if none is given. |
|
|
247 | |
|
|
248 | =item $w->start |
|
|
249 | |
|
|
250 | Stops and (re-)starts the event watcher without touching the timeout. |
|
|
251 | |
|
|
252 | =item $w->del |
|
|
253 | |
|
|
254 | =item $w->stop |
|
|
255 | |
|
|
256 | Stop the event watcher if it was started. |
|
|
257 | |
|
|
258 | =item $current_callback = $w->cb |
|
|
259 | |
|
|
260 | =item $old_callback = $w->cb ($new_callback) |
|
|
261 | |
|
|
262 | Return the previously set callback and optionally set a new one. |
|
|
263 | |
|
|
264 | =item $current_fh = $w->fh |
|
|
265 | |
|
|
266 | =item $old_fh = $w->fh ($new_fh) |
|
|
267 | |
|
|
268 | Returns the previously set filehandle and optionally set a new one (also |
|
|
269 | clears the EV::SIGNAL flag when setting a filehandle). |
|
|
270 | |
|
|
271 | =item $current_signal = $w->signal |
|
|
272 | |
|
|
273 | =item $old_signal = $w->signal ($new_signal) |
|
|
274 | |
|
|
275 | Returns the previously set signal number and optionally set a new one (also sets |
|
|
276 | the EV::SIGNAL flag when setting a signal). |
|
|
277 | |
|
|
278 | =item $current_eventmask = $w->events |
|
|
279 | |
|
|
280 | =item $old_eventmask = $w->events ($new_eventmask) |
|
|
281 | |
|
|
282 | Returns the previously set event mask and optionally set a new one. |
|
|
283 | |
|
|
284 | =item $w->timeout ($after, $repeat) |
|
|
285 | |
|
|
286 | Resets the timeout (see C<EV::timer> for details). |
|
|
287 | |
|
|
288 | =item $w->timeout_abs ($at, $interval) |
|
|
289 | |
|
|
290 | Resets the timeout (see C<EV::timer_abs> for details). |
|
|
291 | |
|
|
292 | =item $w->priority_set ($priority) |
|
|
293 | |
|
|
294 | Set the priority of the watcher to C<$priority> (0 <= $priority < $EV::NPRI). |
|
|
295 | |
|
|
296 | =back |
|
|
297 | |
|
|
298 | =head1 THREADS |
530 | =head1 THREADS |
299 | |
531 | |
300 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
532 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
301 | and must die. |
533 | stuff and must die. |
302 | |
|
|
303 | =head1 BUGS |
|
|
304 | |
|
|
305 | Lots. Libevent itself isn't well tested and rather buggy, and this module |
|
|
306 | is quite new at the moment. |
|
|
307 | |
|
|
308 | Please note that the epoll method is not, in general, reliable in programs |
|
|
309 | that use fork (even if no libveent calls are being made in the forked |
|
|
310 | process). If your program behaves erratically, try setting the environment |
|
|
311 | variable C<EVENT_NOEPOLL> first when running the program. |
|
|
312 | |
|
|
313 | In general, if you fork, then you can only use the EV module in one of the |
|
|
314 | children. |
|
|
315 | |
534 | |
316 | =cut |
535 | =cut |
317 | |
536 | |
318 | our $DIED = sub { |
537 | our $DIED = sub { |
319 | warn "EV: error in callback (ignoring): $@"; |
538 | warn "EV: error in callback (ignoring): $@"; |
320 | }; |
539 | }; |
321 | |
540 | |
322 | init; |
541 | default_loop |
323 | |
542 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; |
324 | push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"]; |
|
|
325 | |
543 | |
326 | 1; |
544 | 1; |
327 | |
545 | |
328 | =head1 SEE ALSO |
546 | =head1 SEE ALSO |
329 | |
547 | |
330 | L<EV::DNS>, L<event(3)>, L<event.h>, L<evdns.h>. |
548 | L<EV::DNS>. |
331 | L<EV::AnyEvent>. |
|
|
332 | |
549 | |
333 | =head1 AUTHOR |
550 | =head1 AUTHOR |
334 | |
551 | |
335 | Marc Lehmann <schmorp@schmorp.de> |
552 | Marc Lehmann <schmorp@schmorp.de> |
336 | http://home.schmorp.de/ |
553 | http://home.schmorp.de/ |