… | |
… | |
39 | |
39 | |
40 | my $w = EV::child 666, sub { |
40 | my $w = EV::child 666, sub { |
41 | my ($w, $revents) = @_; |
41 | my ($w, $revents) = @_; |
42 | my $status = $w->rstatus; |
42 | my $status = $w->rstatus; |
43 | }; |
43 | }; |
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44 | |
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45 | # STAT CHANGES |
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46 | my $w = EV::stat "/etc/passwd", 10, sub { |
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47 | my ($w, $revents) = @_; |
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48 | warn $w->path, " has changed somehow.\n"; |
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49 | }; |
44 | |
50 | |
45 | # MAINLOOP |
51 | # MAINLOOP |
46 | EV::loop; # loop until EV::unloop is called or all watchers stop |
52 | EV::loop; # loop until EV::unloop is called or all watchers stop |
47 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
53 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
48 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
54 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
49 | |
55 | |
50 | =head1 DESCRIPTION |
56 | =head1 DESCRIPTION |
51 | |
57 | |
52 | This module provides an interface to libev |
58 | This module provides an interface to libev |
53 | (L<http://software.schmorp.de/pkg/libev.html>). |
59 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
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60 | below is comprehensive, one might also consult the documentation of libev |
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61 | itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on |
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62 | watcher semantics or some discussion on the available backends, or how to |
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63 | force a specific backend with C<LIBEV_FLAGS>, or just about in any case |
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64 | because it has much more detailed information. |
54 | |
65 | |
55 | =cut |
66 | =cut |
56 | |
67 | |
57 | package EV; |
68 | package EV; |
58 | |
69 | |
59 | use strict; |
70 | use strict; |
60 | |
71 | |
61 | BEGIN { |
72 | BEGIN { |
62 | our $VERSION = '1.2'; |
73 | our $VERSION = '2.0'; |
63 | use XSLoader; |
74 | use XSLoader; |
64 | XSLoader::load "EV", $VERSION; |
75 | XSLoader::load "EV", $VERSION; |
65 | } |
76 | } |
66 | |
77 | |
67 | @EV::Io::ISA = |
78 | @EV::IO::ISA = |
68 | @EV::Timer::ISA = |
79 | @EV::Timer::ISA = |
69 | @EV::Periodic::ISA = |
80 | @EV::Periodic::ISA = |
70 | @EV::Signal::ISA = |
81 | @EV::Signal::ISA = |
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82 | @EV::Child::ISA = |
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83 | @EV::Stat::ISA = |
71 | @EV::Idle::ISA = |
84 | @EV::Idle::ISA = |
72 | @EV::Prepare::ISA = |
85 | @EV::Prepare::ISA = |
73 | @EV::Check::ISA = |
86 | @EV::Check::ISA = |
74 | @EV::Child::ISA = "EV::Watcher"; |
87 | @EV::Embed::ISA = |
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88 | @EV::Fork::ISA = |
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89 | "EV::Watcher"; |
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90 | |
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91 | @EV::Loop::Default::ISA = "EV::Loop"; |
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92 | |
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93 | =head1 EVENT LOOPS |
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94 | |
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95 | EV supports multiple event loops: There is a single "default event loop" |
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96 | that can handle everything including signals and child watchers, and any |
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97 | number of "dynamic event loops" that can use different backends (with |
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98 | various limitations), but no child and signal watchers. |
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99 | |
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100 | You do not have to do anything to create the default event loop: When |
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101 | the module is loaded a suitable backend is selected on the premise of |
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102 | selecting a working backend (which for example rules out kqueue on most |
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103 | BSDs). Modules should, unless they have "special needs" always use the |
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104 | default loop as this is fastest (perl-wise), best supported by other |
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105 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
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106 | |
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107 | For specific programs you cna create additional event loops dynamically. |
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108 | |
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109 | =over 4 |
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110 | |
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111 | =item $loop = new EV::loop [$flags] |
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112 | |
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113 | Create a new event loop as per the specified flags. Please refer to the |
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114 | C<ev_loop_new ()> function description in the libev documentation |
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115 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>) |
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116 | for more info. |
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117 | |
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118 | The loop will automatically be destroyed when it is no longer referenced |
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119 | by any watcher and the loop object goes out of scope. |
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120 | |
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121 | Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop |
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122 | is protected by this module. |
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123 | |
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124 | =item $loop->loop_fork |
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125 | |
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126 | Must be called after a fork in the child, before entering or continuing |
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127 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
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128 | this fucntion automatically, at some performance loss (refer to the libev |
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129 | documentation). |
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130 | |
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131 | =back |
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132 | |
75 | |
133 | |
76 | =head1 BASIC INTERFACE |
134 | =head1 BASIC INTERFACE |
77 | |
135 | |
78 | =over 4 |
136 | =over 4 |
79 | |
137 | |
80 | =item $EV::DIED |
138 | =item $EV::DIED |
81 | |
139 | |
82 | Must contain a reference to a function that is called when a callback |
140 | Must contain a reference to a function that is called when a callback |
83 | throws an exception (with $@ containing thr error). The default prints an |
141 | throws an exception (with $@ containing the error). The default prints an |
84 | informative message and continues. |
142 | informative message and continues. |
85 | |
143 | |
86 | If this callback throws an exception it will be silently ignored. |
144 | If this callback throws an exception it will be silently ignored. |
87 | |
145 | |
88 | =item $time = EV::time |
146 | =item $time = EV::time |
89 | |
147 | |
90 | Returns the current time in (fractional) seconds since the epoch. |
148 | Returns the current time in (fractional) seconds since the epoch. |
91 | |
149 | |
92 | =item $time = EV::now |
150 | =item $time = EV::now |
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151 | |
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152 | =item $time = $loop->now |
93 | |
153 | |
94 | Returns the time the last event loop iteration has been started. This |
154 | Returns the time the last event loop iteration has been started. This |
95 | is the time that (relative) timers are based on, and refering to it is |
155 | is the time that (relative) timers are based on, and refering to it is |
96 | usually faster then calling EV::time. |
156 | usually faster then calling EV::time. |
97 | |
157 | |
98 | =item $method = EV::method |
158 | =item $backend = EV::backend |
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159 | |
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160 | =item $backend = $loop->backend |
99 | |
161 | |
100 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
162 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
101 | or EV::METHOD_EPOLL). |
163 | or EV::METHOD_EPOLL). |
102 | |
164 | |
103 | =item EV::loop [$flags] |
165 | =item EV::loop [$flags] |
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166 | |
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167 | =item $loop->loop ([$flags]) |
104 | |
168 | |
105 | Begin checking for events and calling callbacks. It returns when a |
169 | Begin checking for events and calling callbacks. It returns when a |
106 | callback calls EV::unloop. |
170 | callback calls EV::unloop. |
107 | |
171 | |
108 | The $flags argument can be one of the following: |
172 | The $flags argument can be one of the following: |
… | |
… | |
111 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
175 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
112 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
176 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
113 | |
177 | |
114 | =item EV::unloop [$how] |
178 | =item EV::unloop [$how] |
115 | |
179 | |
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180 | =item $loop->unloop ([$how]) |
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181 | |
116 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
182 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
117 | innermost call to EV::loop return. |
183 | innermost call to EV::loop return. |
118 | |
184 | |
119 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
185 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
120 | fast as possible. |
186 | fast as possible. |
121 | |
187 | |
122 | =back |
188 | =item $count = EV::loop_count |
123 | |
189 | |
124 | =head2 WATCHER |
190 | =item $count = $loop->loop_count |
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191 | |
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192 | Return the number of times the event loop has polled for new |
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193 | events. Sometiems useful as a generation counter. |
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194 | |
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195 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
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196 | |
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197 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
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198 | |
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199 | This function rolls together an I/O and a timer watcher for a single |
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200 | one-shot event without the need for managing a watcher object. |
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201 | |
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202 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
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203 | must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ |
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204 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
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205 | you do not want to wait for some I/O event, specify C<undef> for |
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206 | C<$fh_or_undef> and C<0> for C<$events>). |
|
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207 | |
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208 | If timeout is C<undef> or negative, then there will be no |
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209 | timeout. Otherwise a EV::timer with this value will be started. |
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210 | |
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211 | When an error occurs or either the timeout or I/O watcher triggers, then |
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212 | the callback will be called with the received event set (in general |
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213 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
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214 | C<EV::WRITE> and C<EV::TIMEOUT>). |
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215 | |
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216 | EV::once doesn't return anything: the watchers stay active till either |
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217 | of them triggers, then they will be stopped and freed, and the callback |
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218 | invoked. |
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219 | |
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220 | =item EV::feed_fd_event ($fd, $revents) |
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221 | |
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222 | =item $loop->feed_fd_event ($fd, $revents) |
|
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223 | |
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224 | Feed an event on a file descriptor into EV. EV will react to this call as |
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225 | if the readyness notifications specified by C<$revents> (a combination of |
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226 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
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227 | |
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228 | =item EV::feed_signal_event ($signal) |
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229 | |
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230 | Feed a signal event into EV. EV will react to this call as if the signal |
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231 | specified by C<$signal> had occured. |
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232 | |
|
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233 | =back |
|
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234 | |
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235 | |
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236 | =head1 WATCHER OBJECTS |
125 | |
237 | |
126 | A watcher is an object that gets created to record your interest in some |
238 | A watcher is an object that gets created to record your interest in some |
127 | event. For instance, if you want to wait for STDIN to become readable, you |
239 | event. For instance, if you want to wait for STDIN to become readable, you |
128 | would create an EV::io watcher for that: |
240 | would create an EV::io watcher for that: |
129 | |
241 | |
130 | my $watcher = EV::io *STDIN, EV::READ, sub { |
242 | my $watcher = EV::io *STDIN, EV::READ, sub { |
131 | my ($watcher, $revents) = @_; |
243 | my ($watcher, $revents) = @_; |
132 | warn "yeah, STDIN should not be readable without blocking!\n" |
244 | warn "yeah, STDIN should now be readable without blocking!\n" |
133 | }; |
245 | }; |
134 | |
246 | |
135 | All watchers can be active (waiting for events) or inactive (paused). Only |
247 | All watchers can be active (waiting for events) or inactive (paused). Only |
136 | active watchers will have their callbacks invoked. All callbacks will be |
248 | active watchers will have their callbacks invoked. All callbacks will be |
137 | called with at least two arguments: the watcher and a bitmask of received |
249 | called with at least two arguments: the watcher and a bitmask of received |
138 | events. |
250 | events. |
139 | |
251 | |
140 | Each watcher type has its associated bit in revents, so you can use the |
252 | Each watcher type has its associated bit in revents, so you can use the |
141 | same callback for multiple watchers. The event mask is named after the |
253 | same callback for multiple watchers. The event mask is named after the |
142 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
254 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
143 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
255 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
144 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
256 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
145 | uses EV::TIMEOUT). |
257 | uses EV::TIMEOUT). |
146 | |
258 | |
147 | In the rare case where one wants to create a watcher but not start it at |
259 | In the rare case where one wants to create a watcher but not start it at |
148 | the same time, each constructor has a variant with a trailing C<_ns> in |
260 | the same time, each constructor has a variant with a trailing C<_ns> in |
… | |
… | |
154 | |
266 | |
155 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
267 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
156 | ->fh and so on) automatically stop and start it again if it is active, |
268 | ->fh and so on) automatically stop and start it again if it is active, |
157 | which means pending events get lost. |
269 | which means pending events get lost. |
158 | |
270 | |
159 | =head2 WATCHER TYPES |
271 | =head2 COMMON WATCHER METHODS |
160 | |
272 | |
161 | Now lets move to the existing watcher types and asociated methods. |
273 | This section lists methods common to all watchers. |
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 | |
274 | |
168 | =over 4 |
275 | =over 4 |
169 | |
276 | |
170 | =item $w->start |
277 | =item $w->start |
171 | |
278 | |
… | |
… | |
175 | |
282 | |
176 | =item $w->stop |
283 | =item $w->stop |
177 | |
284 | |
178 | Stop a watcher if it is active. Also clear any pending events (events that |
285 | Stop a watcher if it is active. Also clear any pending events (events that |
179 | have been received but that didn't yet result in a callback invocation), |
286 | have been received but that didn't yet result in a callback invocation), |
180 | regardless of wether the watcher was active or not. |
287 | regardless of whether the watcher was active or not. |
181 | |
288 | |
182 | =item $bool = $w->is_active |
289 | =item $bool = $w->is_active |
183 | |
290 | |
184 | Returns true if the watcher is active, false otherwise. |
291 | Returns true if the watcher is active, false otherwise. |
185 | |
292 | |
… | |
… | |
210 | watchers with higher priority will be invoked first. The valid range of |
317 | watchers with higher priority will be invoked first. The valid range of |
211 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
318 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
212 | -2). If the priority is outside this range it will automatically be |
319 | -2). If the priority is outside this range it will automatically be |
213 | normalised to the nearest valid priority. |
320 | normalised to the nearest valid priority. |
214 | |
321 | |
215 | The default priority of any newly-created weatcher is 0. |
322 | The default priority of any newly-created watcher is 0. |
216 | |
323 | |
|
|
324 | Note that the priority semantics have not yet been fleshed out and are |
|
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325 | subject to almost certain change. |
|
|
326 | |
217 | =item $w->trigger ($revents) |
327 | =item $w->invoke ($revents) |
218 | |
328 | |
219 | Call the callback *now* with the given event mask. |
329 | Call the callback *now* with the given event mask. |
220 | |
330 | |
|
|
331 | =item $w->feed_event ($revents) |
|
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332 | |
|
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333 | Feed some events on this watcher into EV. EV will react to this call as if |
|
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334 | the watcher had received the given C<$revents> mask. |
|
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335 | |
|
|
336 | =item $revents = $w->clear_pending |
|
|
337 | |
|
|
338 | If the watcher is pending, this function clears its pending status and |
|
|
339 | returns its C<$revents> bitset (as if its callback was invoked). If the |
|
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340 | watcher isn't pending it does nothing and returns C<0>. |
|
|
341 | |
|
|
342 | =item $previous_state = $w->keepalive ($bool) |
|
|
343 | |
|
|
344 | Normally, C<EV::loop> will return when there are no active watchers |
|
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345 | (which is a "deadlock" because no progress can be made anymore). This is |
|
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346 | convinient because it allows you to start your watchers (and your jobs), |
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347 | call C<EV::loop> once and when it returns you know that all your jobs are |
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348 | finished (or they forgot to register some watchers for their task :). |
|
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349 | |
|
|
350 | Sometimes, however, this gets in your way, for example when the module |
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351 | that calls C<EV::loop> (usually the main program) is not the same module |
|
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352 | as a long-living watcher (for example a DNS client module written by |
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353 | somebody else even). Then you might want any outstanding requests to be |
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354 | handled, but you would not want to keep C<EV::loop> from returning just |
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355 | because you happen to have this long-running UDP port watcher. |
|
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356 | |
|
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357 | In this case you can clear the keepalive status, which means that even |
|
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358 | though your watcher is active, it won't keep C<EV::loop> from returning. |
|
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359 | |
|
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360 | The initial value for keepalive is true (enabled), and you cna change it |
|
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361 | any time. |
|
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362 | |
|
|
363 | Example: Register an I/O watcher for some UDP socket but do not keep the |
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364 | event loop from running just because of that watcher. |
|
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365 | |
|
|
366 | my $udp_socket = ... |
|
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367 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
|
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368 | $1000udp_watcher->keepalive (0); |
|
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369 | |
|
|
370 | =item $loop = $w->loop |
|
|
371 | |
|
|
372 | Return the loop that this watcher is attached to. |
|
|
373 | |
|
|
374 | =back |
|
|
375 | |
|
|
376 | |
|
|
377 | =head1 WATCHER TYPES |
|
|
378 | |
|
|
379 | Each of the following subsections describes a single watcher type. |
|
|
380 | |
|
|
381 | =head3 I/O WATCHERS - is this file descriptor readable or writable? |
|
|
382 | |
|
|
383 | =over 4 |
221 | |
384 | |
222 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
385 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
223 | |
386 | |
224 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
387 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
225 | |
388 | |
|
|
389 | =item $w = $loop->io ($fileno_or_fh, $eventmask, $callback) |
|
|
390 | |
|
|
391 | =item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
|
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392 | |
226 | As long as the returned watcher object is alive, call the C<$callback> |
393 | As long as the returned watcher object is alive, call the C<$callback> |
227 | when the events specified in C<$eventmask>. |
394 | when at least one of events specified in C<$eventmask> occurs. |
228 | |
395 | |
229 | The $eventmask can be one or more of these constants ORed together: |
396 | The $eventmask can be one or more of these constants ORed together: |
230 | |
397 | |
231 | EV::READ wait until read() wouldn't block anymore |
398 | EV::READ wait until read() wouldn't block anymore |
232 | EV::WRITE wait until write() wouldn't block anymore |
399 | EV::WRITE wait until write() wouldn't block anymore |
… | |
… | |
248 | |
415 | |
249 | =item $old_eventmask = $w->events ($new_eventmask) |
416 | =item $old_eventmask = $w->events ($new_eventmask) |
250 | |
417 | |
251 | Returns the previously set event mask and optionally set a new one. |
418 | Returns the previously set event mask and optionally set a new one. |
252 | |
419 | |
|
|
420 | =back |
|
|
421 | |
|
|
422 | |
|
|
423 | =head3 TIMER WATCHERS - relative and optionally repeating timeouts |
|
|
424 | |
|
|
425 | =over 4 |
253 | |
426 | |
254 | =item $w = EV::timer $after, $repeat, $callback |
427 | =item $w = EV::timer $after, $repeat, $callback |
255 | |
428 | |
256 | =item $w = EV::timer_ns $after, $repeat, $callback |
429 | =item $w = EV::timer_ns $after, $repeat, $callback |
257 | |
430 | |
258 | Calls the callback after C<$after> seconds. If C<$repeat> is non-zero, |
431 | =item $w = $loop->timer ($after, $repeat, $callback) |
259 | the timer will be restarted (with the $repeat value as $after) after the |
432 | |
260 | callback returns. |
433 | =item $w = $loop->timer_ns ($after, $repeat, $callback) |
|
|
434 | |
|
|
435 | Calls the callback after C<$after> seconds (which may be fractional). If |
|
|
436 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
|
|
437 | value as $after) after the callback returns. |
261 | |
438 | |
262 | This means that the callback would be called roughly after C<$after> |
439 | This means that the callback would be called roughly after C<$after> |
263 | seconds, and then every C<$repeat> seconds. The timer does his best not |
440 | seconds, and then every C<$repeat> seconds. The timer does his best not |
264 | to drift, but it will not invoke the timer more often then once per event |
441 | to drift, but it will not invoke the timer more often then once per event |
265 | loop iteration, and might drift in other cases. If that isn't acceptable, |
442 | loop iteration, and might drift in other cases. If that isn't acceptable, |
… | |
… | |
271 | |
448 | |
272 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
449 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
273 | |
450 | |
274 | =item $w->set ($after, $repeat) |
451 | =item $w->set ($after, $repeat) |
275 | |
452 | |
276 | Reconfigures the watcher, see the constructor above for details. Can be at |
453 | Reconfigures the watcher, see the constructor above for details. Can be called at |
277 | any time. |
454 | any time. |
278 | |
455 | |
279 | =item $w->again |
456 | =item $w->again |
280 | |
457 | |
281 | Similar to the C<start> method, but has special semantics for repeating timers: |
458 | Similar to the C<start> method, but has special semantics for repeating timers: |
… | |
… | |
292 | This behaviour is useful when you have a timeout for some IO |
469 | This behaviour is useful when you have a timeout for some IO |
293 | operation. You create a timer object with the same value for C<$after> and |
470 | operation. You create a timer object with the same value for C<$after> and |
294 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
471 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
295 | on the timeout. |
472 | on the timeout. |
296 | |
473 | |
|
|
474 | =back |
|
|
475 | |
|
|
476 | |
|
|
477 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
|
|
478 | |
|
|
479 | =over 4 |
297 | |
480 | |
298 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
481 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
299 | |
482 | |
300 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
483 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
|
|
484 | |
|
|
485 | =item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
|
|
486 | |
|
|
487 | =item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback) |
301 | |
488 | |
302 | Similar to EV::timer, but is not based on relative timeouts but on |
489 | Similar to EV::timer, but is not based on relative timeouts but on |
303 | absolute times. Apart from creating "simple" timers that trigger "at" the |
490 | absolute times. Apart from creating "simple" timers that trigger "at" the |
304 | specified time, it can also be used for non-drifting absolute timers and |
491 | specified time, it can also be used for non-drifting absolute timers and |
305 | more complex, cron-like, setups that are not adversely affected by time |
492 | more complex, cron-like, setups that are not adversely affected by time |
… | |
… | |
373 | |
560 | |
374 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
561 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
375 | |
562 | |
376 | =item $w->set ($at, $interval, $reschedule_cb) |
563 | =item $w->set ($at, $interval, $reschedule_cb) |
377 | |
564 | |
378 | Reconfigures the watcher, see the constructor above for details. Can be at |
565 | Reconfigures the watcher, see the constructor above for details. Can be called at |
379 | any time. |
566 | any time. |
380 | |
567 | |
381 | =item $w->again |
568 | =item $w->again |
382 | |
569 | |
383 | Simply stops and starts the watcher again. |
570 | Simply stops and starts the watcher again. |
384 | |
571 | |
|
|
572 | =item $time = $w->at |
|
|
573 | |
|
|
574 | Return the time that the watcher is expected to trigger next. |
|
|
575 | |
|
|
576 | =back |
|
|
577 | |
|
|
578 | |
|
|
579 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
|
|
580 | |
|
|
581 | =over 4 |
385 | |
582 | |
386 | =item $w = EV::signal $signal, $callback |
583 | =item $w = EV::signal $signal, $callback |
387 | |
584 | |
388 | =item $w = EV::signal_ns $signal, $callback |
585 | =item $w = EV::signal_ns $signal, $callback |
389 | |
586 | |
390 | Call the callback when $signal is received (the signal can be specified |
587 | Call the callback when $signal is received (the signal can be specified by |
391 | by number or by name, just as with kill or %SIG). |
588 | number or by name, just as with C<kill> or C<%SIG>). |
392 | |
589 | |
393 | EV will grab the signal for the process (the kernel only allows one |
590 | EV will grab the signal for the process (the kernel only allows one |
394 | component to receive a signal at a time) when you start a signal watcher, |
591 | component to receive a signal at a time) when you start a signal watcher, |
395 | and removes it again when you stop it. Perl does the same when you |
592 | and removes it again when you stop it. Perl does the same when you |
396 | add/remove callbacks to %SIG, so watch out. |
593 | add/remove callbacks to C<%SIG>, so watch out. |
397 | |
594 | |
398 | You can have as many signal watchers per signal as you want. |
595 | You can have as many signal watchers per signal as you want. |
399 | |
596 | |
400 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
597 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
401 | |
598 | |
402 | =item $w->set ($signal) |
599 | =item $w->set ($signal) |
403 | |
600 | |
404 | Reconfigures the watcher, see the constructor above for details. Can be at |
601 | Reconfigures the watcher, see the constructor above for details. Can be |
405 | any time. |
602 | called at any time. |
406 | |
603 | |
407 | =item $current_signum = $w->signal |
604 | =item $current_signum = $w->signal |
408 | |
605 | |
409 | =item $old_signum = $w->signal ($new_signal) |
606 | =item $old_signum = $w->signal ($new_signal) |
410 | |
607 | |
411 | Returns the previously set signal (always as a number not name) and |
608 | Returns the previously set signal (always as a number not name) and |
412 | optionally set a new one. |
609 | optionally set a new one. |
413 | |
610 | |
|
|
611 | =back |
|
|
612 | |
|
|
613 | |
|
|
614 | =head3 CHILD WATCHERS - watch out for process status changes |
|
|
615 | |
|
|
616 | =over 4 |
414 | |
617 | |
415 | =item $w = EV::child $pid, $callback |
618 | =item $w = EV::child $pid, $callback |
416 | |
619 | |
417 | =item $w = EV::child_ns $pid, $callback |
620 | =item $w = EV::child_ns $pid, $callback |
418 | |
621 | |
|
|
622 | =item $w = $loop->child ($pid, $callback) |
|
|
623 | |
|
|
624 | =item $w = $loop->child_ns ($pid, $callback) |
|
|
625 | |
419 | Call the callback when a status change for pid C<$pid> (or any pid |
626 | Call the callback when a status change for pid C<$pid> (or any pid if |
420 | if C<$pid> is 0) has been received. More precisely: when the process |
627 | C<$pid> is 0) has been received. More precisely: when the process receives |
421 | receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all |
628 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
422 | changed/zombie children and call the callback. |
629 | changed/zombie children and call the callback. |
423 | |
630 | |
424 | You can access both status and pid by using the C<rstatus> and C<rpid> |
631 | It is valid (and fully supported) to install a child watcher after a child |
425 | methods on the watcher object. |
632 | has exited but before the event loop has started its next iteration (for |
|
|
633 | example, first you C<fork>, then the new child process might exit, and |
|
|
634 | only then do you install a child watcher in the parent for the new pid). |
426 | |
635 | |
|
|
636 | You can access both exit (or tracing) status and pid by using the |
|
|
637 | C<rstatus> and C<rpid> methods on the watcher object. |
|
|
638 | |
427 | You can have as many pid watchers per pid as you want. |
639 | You can have as many pid watchers per pid as you want, they will all be |
|
|
640 | called. |
428 | |
641 | |
429 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
642 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
430 | |
643 | |
431 | =item $w->set ($pid) |
644 | =item $w->set ($pid) |
432 | |
645 | |
433 | Reconfigures the watcher, see the constructor above for details. Can be at |
646 | Reconfigures the watcher, see the constructor above for details. Can be called at |
434 | any time. |
647 | any time. |
435 | |
648 | |
436 | =item $current_pid = $w->pid |
649 | =item $current_pid = $w->pid |
437 | |
650 | |
438 | =item $old_pid = $w->pid ($new_pid) |
651 | =item $old_pid = $w->pid ($new_pid) |
… | |
… | |
447 | =item $pid = $w->rpid |
660 | =item $pid = $w->rpid |
448 | |
661 | |
449 | Return the pid of the awaited child (useful when you have installed a |
662 | Return the pid of the awaited child (useful when you have installed a |
450 | watcher for all pids). |
663 | watcher for all pids). |
451 | |
664 | |
|
|
665 | =back |
|
|
666 | |
|
|
667 | |
|
|
668 | =head3 STAT WATCHERS - did the file attributes just change? |
|
|
669 | |
|
|
670 | =over 4 |
|
|
671 | |
|
|
672 | =item $w = EV::stat $path, $interval, $callback |
|
|
673 | |
|
|
674 | =item $w = EV::stat_ns $path, $interval, $callback |
|
|
675 | |
|
|
676 | =item $w = $loop->stat ($path, $interval, $callback) |
|
|
677 | |
|
|
678 | =item $w = $loop->stat_ns ($path, $interval, $callback) |
|
|
679 | |
|
|
680 | Call the callback when a file status change has been detected on |
|
|
681 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
|
|
682 | to "path does not exist" is a status change like any other. |
|
|
683 | |
|
|
684 | The C<$interval> is a recommended polling interval for systems where |
|
|
685 | OS-supported change notifications don't exist or are not supported. If |
|
|
686 | you use C<0> then an unspecified default is used (which is highly |
|
|
687 | recommended!), which is to be expected to be around five seconds usually. |
|
|
688 | |
|
|
689 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
690 | as even with OS-supported change notifications, this can be |
|
|
691 | resource-intensive. |
|
|
692 | |
|
|
693 | The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
|
|
694 | |
|
|
695 | =item ... = $w->stat |
|
|
696 | |
|
|
697 | This call is very similar to the perl C<stat> built-in: It stats (using |
|
|
698 | C<lstat>) the path specified in the watcher and sets perls stat cache (as |
|
|
699 | well as EV's idea of the current stat values) to the values found. |
|
|
700 | |
|
|
701 | In scalar context, a boolean is return indicating success or failure of |
|
|
702 | the stat. In list context, the same 13-value list as with stat is returned |
|
|
703 | (except that the blksize and blocks fields are not reliable). |
|
|
704 | |
|
|
705 | In the case of an error, errno is set to C<ENOENT> (regardless of the |
|
|
706 | actual error value) and the C<nlink> value is forced to zero (if the stat |
|
|
707 | was successful then nlink is guaranteed to be non-zero). |
|
|
708 | |
|
|
709 | See also the next two entries for more info. |
|
|
710 | |
|
|
711 | =item ... = $w->attr |
|
|
712 | |
|
|
713 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
714 | the values most recently detected by EV. See the next entry for more info. |
|
|
715 | |
|
|
716 | =item ... = $w->prev |
|
|
717 | |
|
|
718 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
719 | the previous set of values, before the change. |
|
|
720 | |
|
|
721 | That is, when the watcher callback is invoked, C<< $w->prev >> will be set |
|
|
722 | to the values found I<before> a change was detected, while C<< $w->attr >> |
|
|
723 | returns the values found leading to the change detection. The difference (if any) |
|
|
724 | between C<prev> and C<attr> is what triggered the callback. |
|
|
725 | |
|
|
726 | If you did something to the filesystem object and do not want to trigger |
|
|
727 | yet another change, you can call C<stat> to update EV's idea of what the |
|
|
728 | current attributes are. |
|
|
729 | |
|
|
730 | =item $w->set ($path, $interval) |
|
|
731 | |
|
|
732 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
733 | called at any time. |
|
|
734 | |
|
|
735 | =item $current_path = $w->path |
|
|
736 | |
|
|
737 | =item $old_path = $w->path ($new_path) |
|
|
738 | |
|
|
739 | Returns the previously set path and optionally set a new one. |
|
|
740 | |
|
|
741 | =item $current_interval = $w->interval |
|
|
742 | |
|
|
743 | =item $old_interval = $w->interval ($new_interval) |
|
|
744 | |
|
|
745 | Returns the previously set interval and optionally set a new one. Can be |
|
|
746 | used to query the actual interval used. |
|
|
747 | |
|
|
748 | =back |
|
|
749 | |
|
|
750 | |
|
|
751 | =head3 IDLE WATCHERS - when you've got nothing better to do... |
|
|
752 | |
|
|
753 | =over 4 |
452 | |
754 | |
453 | =item $w = EV::idle $callback |
755 | =item $w = EV::idle $callback |
454 | |
756 | |
455 | =item $w = EV::idle_ns $callback |
757 | =item $w = EV::idle_ns $callback |
456 | |
758 | |
457 | Call the callback when there are no pending io, timer/periodic, signal or |
759 | =item $w = $loop->idle ($callback) |
458 | child events, i.e. when the process is idle. |
760 | |
|
|
761 | =item $w = $loop->idle_ns ($callback) |
|
|
762 | |
|
|
763 | Call the callback when there are no other pending watchers of the same or |
|
|
764 | higher priority (excluding check, prepare and other idle watchers of the |
|
|
765 | same or lower priority, of course). They are called idle watchers because |
|
|
766 | when the watcher is the highest priority pending event in the process, the |
|
|
767 | process is considered to be idle at that priority. |
|
|
768 | |
|
|
769 | If you want a watcher that is only ever called when I<no> other events are |
|
|
770 | outstanding you have to set the priority to C<EV::MINPRI>. |
459 | |
771 | |
460 | The process will not block as long as any idle watchers are active, and |
772 | The process will not block as long as any idle watchers are active, and |
461 | they will be called repeatedly until stopped. |
773 | they will be called repeatedly until stopped. |
462 | |
774 | |
|
|
775 | For example, if you have idle watchers at priority C<0> and C<1>, and |
|
|
776 | an I/O watcher at priority C<0>, then the idle watcher at priority C<1> |
|
|
777 | and the I/O watcher will always run when ready. Only when the idle watcher |
|
|
778 | at priority C<1> is stopped and the I/O watcher at priority C<0> is not |
|
|
779 | pending with the C<0>-priority idle watcher be invoked. |
|
|
780 | |
463 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
781 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
464 | |
782 | |
|
|
783 | =back |
|
|
784 | |
|
|
785 | |
|
|
786 | =head3 PREPARE WATCHERS - customise your event loop! |
|
|
787 | |
|
|
788 | =over 4 |
465 | |
789 | |
466 | =item $w = EV::prepare $callback |
790 | =item $w = EV::prepare $callback |
467 | |
791 | |
468 | =item $w = EV::prepare_ns $callback |
792 | =item $w = EV::prepare_ns $callback |
|
|
793 | |
|
|
794 | =item $w = $loop->prepare ($callback) |
|
|
795 | |
|
|
796 | =item $w = $loop->prepare_ns ($callback) |
469 | |
797 | |
470 | Call the callback just before the process would block. You can still |
798 | Call the callback just before the process would block. You can still |
471 | create/modify any watchers at this point. |
799 | create/modify any watchers at this point. |
472 | |
800 | |
473 | See the EV::check watcher, below, for explanations and an example. |
801 | See the EV::check watcher, below, for explanations and an example. |
474 | |
802 | |
475 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
803 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
476 | |
804 | |
|
|
805 | =back |
|
|
806 | |
|
|
807 | |
|
|
808 | =head3 CHECK WATCHERS - customise your event loop even more! |
|
|
809 | |
|
|
810 | =over 4 |
477 | |
811 | |
478 | =item $w = EV::check $callback |
812 | =item $w = EV::check $callback |
479 | |
813 | |
480 | =item $w = EV::check_ns $callback |
814 | =item $w = EV::check_ns $callback |
|
|
815 | |
|
|
816 | =item $w = $loop->check ($callback) |
|
|
817 | |
|
|
818 | =item $w = $loop->check_ns ($callback) |
481 | |
819 | |
482 | Call the callback just after the process wakes up again (after it has |
820 | Call the callback just after the process wakes up again (after it has |
483 | gathered events), but before any other callbacks have been invoked. |
821 | gathered events), but before any other callbacks have been invoked. |
484 | |
822 | |
485 | This is used to integrate other event-based software into the EV |
823 | This is used to integrate other event-based software into the EV |
… | |
… | |
493 | # do nothing unless active |
831 | # do nothing unless active |
494 | $dispatcher->{_event_queue_h} |
832 | $dispatcher->{_event_queue_h} |
495 | or return; |
833 | or return; |
496 | |
834 | |
497 | # make the dispatcher handle any outstanding stuff |
835 | # make the dispatcher handle any outstanding stuff |
|
|
836 | ... not shown |
498 | |
837 | |
499 | # create an IO watcher for each and every socket |
838 | # create an I/O watcher for each and every socket |
500 | @snmp_watcher = ( |
839 | @snmp_watcher = ( |
501 | (map { EV::io $_, EV::READ, sub { } } |
840 | (map { EV::io $_, EV::READ, sub { } } |
502 | keys %{ $dispatcher->{_descriptors} }), |
841 | keys %{ $dispatcher->{_descriptors} }), |
|
|
842 | |
|
|
843 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
|
|
844 | ? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0), |
|
|
845 | 0, sub { }, |
503 | ); |
846 | ); |
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 | }; |
847 | }; |
509 | |
848 | |
510 | The callbacks are irrelevant, the only purpose of those watchers is |
849 | The callbacks are irrelevant (and are not even being called), the |
511 | to wake up the process as soon as one of those events occurs (socket |
850 | only purpose of those watchers is to wake up the process as soon as |
512 | readable, or timer timed out). The corresponding EV::check watcher will then |
851 | one of those events occurs (socket readable, or timer timed out). The |
513 | clean up: |
852 | corresponding EV::check watcher will then clean up: |
514 | |
853 | |
515 | our $snmp_check = EV::check sub { |
854 | our $snmp_check = EV::check sub { |
516 | # destroy all watchers |
855 | # destroy all watchers |
517 | @snmp_watcher = (); |
856 | @snmp_watcher = (); |
518 | |
857 | |
519 | # make the dispatcher handle any new stuff |
858 | # make the dispatcher handle any new stuff |
|
|
859 | ... not shown |
520 | }; |
860 | }; |
521 | |
861 | |
522 | The callbacks of the created watchers will not be called as the watchers |
862 | 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 |
863 | are destroyed before this cna happen (remember EV::check gets called |
524 | first). |
864 | first). |
525 | |
865 | |
526 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
866 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
527 | |
867 | |
528 | =back |
868 | =back |
529 | |
869 | |
|
|
870 | |
|
|
871 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
|
|
872 | |
|
|
873 | Fork watchers are called when a C<fork ()> was detected. The invocation |
|
|
874 | is done before the event loop blocks next and before C<check> watchers |
|
|
875 | are being called, and only in the child after the fork. |
|
|
876 | |
|
|
877 | =over 4 |
|
|
878 | |
|
|
879 | =item $w = EV::fork $callback |
|
|
880 | |
|
|
881 | =item $w = EV::fork_ns $callback |
|
|
882 | |
|
|
883 | =item $w = $loop->fork ($callback) |
|
|
884 | |
|
|
885 | =item $w = $loop->fork_ns ($callback) |
|
|
886 | |
|
|
887 | Call the callback before the event loop is resumed in the child process |
|
|
888 | after a fork. |
|
|
889 | |
|
|
890 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
|
|
891 | |
|
|
892 | =back |
|
|
893 | |
|
|
894 | |
|
|
895 | =head1 PERL SIGNALS |
|
|
896 | |
|
|
897 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
|
|
898 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
899 | handled when Perl runs, which means your signal handler might be invoked |
|
|
900 | only the next time an event callback is invoked. |
|
|
901 | |
|
|
902 | The solution is to use EV signal watchers (see C<EV::signal>), which will |
|
|
903 | ensure proper operations with regards to other event watchers. |
|
|
904 | |
|
|
905 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
906 | to be called on every event loop iteration by installing a C<EV::check> |
|
|
907 | watcher: |
|
|
908 | |
|
|
909 | my $async_check = EV::check sub { }; |
|
|
910 | |
|
|
911 | This ensures that perl gets into control for a short time to handle any |
|
|
912 | pending signals, and also ensures (slightly) slower overall operation. |
|
|
913 | |
530 | =head1 THREADS |
914 | =head1 THREADS |
531 | |
915 | |
532 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
916 | Threads are not supported by this module in any way. Perl pseudo-threads |
533 | stuff and must die. |
917 | is evil stuff and must die. As soon as Perl gains real threads I will work |
|
|
918 | on thread support for it. |
|
|
919 | |
|
|
920 | =head1 FORK |
|
|
921 | |
|
|
922 | Most of the "improved" event delivering mechanisms of modern operating |
|
|
923 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
|
|
924 | not supported and usually destructive). Libev makes it possible to work |
|
|
925 | around this by having a function that recreates the kernel state after |
|
|
926 | fork in the child. |
|
|
927 | |
|
|
928 | On non-win32 platforms, this module requires the pthread_atfork |
|
|
929 | functionality to do this automatically for you. This function is quite |
|
|
930 | buggy on most BSDs, though, so YMMV. The overhead for this is quite |
|
|
931 | negligible, because everything the function currently does is set a flag |
|
|
932 | that is checked only when the event loop gets used the next time, so when |
|
|
933 | you do fork but not use EV, the overhead is minimal. |
|
|
934 | |
|
|
935 | On win32, there is no notion of fork so all this doesn't apply, of course. |
534 | |
936 | |
535 | =cut |
937 | =cut |
536 | |
938 | |
537 | our $DIED = sub { |
939 | our $DIED = sub { |
538 | warn "EV: error in callback (ignoring): $@"; |
940 | warn "EV: error in callback (ignoring): $@"; |
539 | }; |
941 | }; |
540 | |
942 | |
541 | default_loop |
943 | default_loop |
542 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; |
944 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?'; |
543 | |
945 | |
544 | 1; |
946 | 1; |
545 | |
947 | |
546 | =head1 SEE ALSO |
948 | =head1 SEE ALSO |
547 | |
949 | |
548 | L<EV::DNS>. |
950 | L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as |
|
|
951 | event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient |
|
|
952 | coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). |
549 | |
953 | |
550 | =head1 AUTHOR |
954 | =head1 AUTHOR |
551 | |
955 | |
552 | Marc Lehmann <schmorp@schmorp.de> |
956 | Marc Lehmann <schmorp@schmorp.de> |
553 | http://home.schmorp.de/ |
957 | http://home.schmorp.de/ |