… | |
… | |
58 | This module provides an interface to libev |
58 | This module provides an interface to libev |
59 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
59 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
60 | below is comprehensive, one might also consult the documentation of libev |
60 | below is comprehensive, one might also consult the documentation of libev |
61 | itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on |
61 | itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on |
62 | watcher semantics or some discussion on the available backends, or how to |
62 | watcher semantics or some discussion on the available backends, or how to |
63 | force a specific backend with C<LIBEV_FLAGS>. |
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. |
64 | |
65 | |
65 | =cut |
66 | =cut |
66 | |
67 | |
67 | package EV; |
68 | package EV; |
68 | |
69 | |
69 | use strict; |
70 | use strict; |
70 | |
71 | |
71 | BEGIN { |
72 | BEGIN { |
72 | our $VERSION = '1.4'; |
73 | our $VERSION = '2.0'; |
73 | use XSLoader; |
74 | use XSLoader; |
74 | XSLoader::load "EV", $VERSION; |
75 | XSLoader::load "EV", $VERSION; |
75 | } |
76 | } |
76 | |
77 | |
77 | @EV::IO::ISA = |
78 | @EV::IO::ISA = |
78 | @EV::Timer::ISA = |
79 | @EV::Timer::ISA = |
79 | @EV::Periodic::ISA = |
80 | @EV::Periodic::ISA = |
80 | @EV::Signal::ISA = |
81 | @EV::Signal::ISA = |
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82 | @EV::Child::ISA = |
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83 | @EV::Stat::ISA = |
81 | @EV::Idle::ISA = |
84 | @EV::Idle::ISA = |
82 | @EV::Prepare::ISA = |
85 | @EV::Prepare::ISA = |
83 | @EV::Check::ISA = |
86 | @EV::Check::ISA = |
84 | @EV::Child::ISA = |
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85 | @EV::Embed::ISA = |
87 | @EV::Embed::ISA = |
86 | @EV::Stat::ISA = "EV::Watcher"; |
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 can 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 | =item $loop = EV::default_loop [$flags] |
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132 | |
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133 | Return the default loop (which is a singleton object). |
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134 | |
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135 | =back |
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136 | |
87 | |
137 | |
88 | =head1 BASIC INTERFACE |
138 | =head1 BASIC INTERFACE |
89 | |
139 | |
90 | =over 4 |
140 | =over 4 |
91 | |
141 | |
92 | =item $EV::DIED |
142 | =item $EV::DIED |
93 | |
143 | |
94 | Must contain a reference to a function that is called when a callback |
144 | Must contain a reference to a function that is called when a callback |
95 | throws an exception (with $@ containing thr error). The default prints an |
145 | throws an exception (with $@ containing the error). The default prints an |
96 | informative message and continues. |
146 | informative message and continues. |
97 | |
147 | |
98 | If this callback throws an exception it will be silently ignored. |
148 | If this callback throws an exception it will be silently ignored. |
99 | |
149 | |
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150 | =item $flags = EV::supported_backends |
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151 | |
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152 | =item $flags = EV::recommended_backends |
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153 | |
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154 | =item $flags = EV::embeddable_backends |
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155 | |
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156 | Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this |
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157 | instance of EV, the set of recommended backends (supposed to be good) for |
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158 | this platform and the set of embeddable backends (see EMBED WATCHERS). |
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159 | |
100 | =item $time = EV::time |
160 | =item $time = EV::time |
101 | |
161 | |
102 | Returns the current time in (fractional) seconds since the epoch. |
162 | Returns the current time in (fractional) seconds since the epoch. |
103 | |
163 | |
104 | =item $time = EV::now |
164 | =item $time = EV::now |
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165 | |
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166 | =item $time = $loop->now |
105 | |
167 | |
106 | Returns the time the last event loop iteration has been started. This |
168 | Returns the time the last event loop iteration has been started. This |
107 | is the time that (relative) timers are based on, and refering to it is |
169 | is the time that (relative) timers are based on, and refering to it is |
108 | usually faster then calling EV::time. |
170 | usually faster then calling EV::time. |
109 | |
171 | |
110 | =item $method = EV::method |
172 | =item $backend = EV::backend |
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173 | |
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174 | =item $backend = $loop->backend |
111 | |
175 | |
112 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
176 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
113 | or EV::METHOD_EPOLL). |
177 | or EV::METHOD_EPOLL). |
114 | |
178 | |
115 | =item EV::loop [$flags] |
179 | =item EV::loop [$flags] |
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180 | |
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181 | =item $loop->loop ([$flags]) |
116 | |
182 | |
117 | Begin checking for events and calling callbacks. It returns when a |
183 | Begin checking for events and calling callbacks. It returns when a |
118 | callback calls EV::unloop. |
184 | callback calls EV::unloop. |
119 | |
185 | |
120 | The $flags argument can be one of the following: |
186 | The $flags argument can be one of the following: |
… | |
… | |
123 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
189 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
124 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
190 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
125 | |
191 | |
126 | =item EV::unloop [$how] |
192 | =item EV::unloop [$how] |
127 | |
193 | |
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194 | =item $loop->unloop ([$how]) |
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195 | |
128 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
196 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
129 | innermost call to EV::loop return. |
197 | innermost call to EV::loop return. |
130 | |
198 | |
131 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
199 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
132 | fast as possible. |
200 | fast as possible. |
133 | |
201 | |
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202 | =item $count = EV::loop_count |
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203 | |
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204 | =item $count = $loop->loop_count |
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205 | |
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206 | Return the number of times the event loop has polled for new |
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207 | events. Sometiems useful as a generation counter. |
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208 | |
134 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
209 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
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210 | |
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211 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
135 | |
212 | |
136 | This function rolls together an I/O and a timer watcher for a single |
213 | This function rolls together an I/O and a timer watcher for a single |
137 | one-shot event without the need for managing a watcher object. |
214 | one-shot event without the need for managing a watcher object. |
138 | |
215 | |
139 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
216 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
… | |
… | |
145 | If timeout is C<undef> or negative, then there will be no |
222 | If timeout is C<undef> or negative, then there will be no |
146 | timeout. Otherwise a EV::timer with this value will be started. |
223 | timeout. Otherwise a EV::timer with this value will be started. |
147 | |
224 | |
148 | When an error occurs or either the timeout or I/O watcher triggers, then |
225 | When an error occurs or either the timeout or I/O watcher triggers, then |
149 | the callback will be called with the received event set (in general |
226 | the callback will be called with the received event set (in general |
150 | you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, |
227 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
151 | C<EV::WRITE> and C<EV::TIMEOUT>). |
228 | C<EV::WRITE> and C<EV::TIMEOUT>). |
152 | |
229 | |
153 | EV::once doesn't return anything: the watchers stay active till either |
230 | EV::once doesn't return anything: the watchers stay active till either |
154 | of them triggers, then they will be stopped and freed, and the callback |
231 | of them triggers, then they will be stopped and freed, and the callback |
155 | invoked. |
232 | invoked. |
156 | |
233 | |
157 | =back |
234 | =item EV::feed_fd_event ($fd, $revents) |
158 | |
235 | |
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236 | =item $loop->feed_fd_event ($fd, $revents) |
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237 | |
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238 | Feed an event on a file descriptor into EV. EV will react to this call as |
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239 | if the readyness notifications specified by C<$revents> (a combination of |
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240 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
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241 | |
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242 | =item EV::feed_signal_event ($signal) |
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243 | |
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244 | Feed a signal event into EV. EV will react to this call as if the signal |
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245 | specified by C<$signal> had occured. |
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246 | |
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247 | =item EV::set_io_collect_interval $time |
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248 | |
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249 | =item $loop->set_io_collect_interval ($time) |
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250 | |
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251 | =item EV::set_timeout_collect_interval $time |
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252 | |
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253 | =item $loop->set_timeout_collect_interval ($time) |
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254 | |
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255 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
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256 | wait interval for timer events. See the libev documentation at |
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257 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for |
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258 | a more detailed discussion. |
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259 | |
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260 | =back |
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261 | |
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262 | |
159 | =head2 WATCHER OBJECTS |
263 | =head1 WATCHER OBJECTS |
160 | |
264 | |
161 | A watcher is an object that gets created to record your interest in some |
265 | A watcher is an object that gets created to record your interest in some |
162 | event. For instance, if you want to wait for STDIN to become readable, you |
266 | event. For instance, if you want to wait for STDIN to become readable, you |
163 | would create an EV::io watcher for that: |
267 | would create an EV::io watcher for that: |
164 | |
268 | |
165 | my $watcher = EV::io *STDIN, EV::READ, sub { |
269 | my $watcher = EV::io *STDIN, EV::READ, sub { |
166 | my ($watcher, $revents) = @_; |
270 | my ($watcher, $revents) = @_; |
167 | warn "yeah, STDIN should not be readable without blocking!\n" |
271 | warn "yeah, STDIN should now be readable without blocking!\n" |
168 | }; |
272 | }; |
169 | |
273 | |
170 | All watchers can be active (waiting for events) or inactive (paused). Only |
274 | All watchers can be active (waiting for events) or inactive (paused). Only |
171 | active watchers will have their callbacks invoked. All callbacks will be |
275 | active watchers will have their callbacks invoked. All callbacks will be |
172 | called with at least two arguments: the watcher and a bitmask of received |
276 | called with at least two arguments: the watcher and a bitmask of received |
173 | events. |
277 | events. |
174 | |
278 | |
175 | Each watcher type has its associated bit in revents, so you can use the |
279 | Each watcher type has its associated bit in revents, so you can use the |
176 | same callback for multiple watchers. The event mask is named after the |
280 | same callback for multiple watchers. The event mask is named after the |
177 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
281 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
178 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
282 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
179 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
283 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
180 | uses EV::TIMEOUT). |
284 | uses EV::TIMEOUT). |
181 | |
285 | |
182 | In the rare case where one wants to create a watcher but not start it at |
286 | In the rare case where one wants to create a watcher but not start it at |
183 | the same time, each constructor has a variant with a trailing C<_ns> in |
287 | the same time, each constructor has a variant with a trailing C<_ns> in |
… | |
… | |
205 | |
309 | |
206 | =item $w->stop |
310 | =item $w->stop |
207 | |
311 | |
208 | Stop a watcher if it is active. Also clear any pending events (events that |
312 | Stop a watcher if it is active. Also clear any pending events (events that |
209 | have been received but that didn't yet result in a callback invocation), |
313 | have been received but that didn't yet result in a callback invocation), |
210 | regardless of wether the watcher was active or not. |
314 | regardless of whether the watcher was active or not. |
211 | |
315 | |
212 | =item $bool = $w->is_active |
316 | =item $bool = $w->is_active |
213 | |
317 | |
214 | Returns true if the watcher is active, false otherwise. |
318 | Returns true if the watcher is active, false otherwise. |
215 | |
319 | |
… | |
… | |
245 | The default priority of any newly-created watcher is 0. |
349 | The default priority of any newly-created watcher is 0. |
246 | |
350 | |
247 | Note that the priority semantics have not yet been fleshed out and are |
351 | Note that the priority semantics have not yet been fleshed out and are |
248 | subject to almost certain change. |
352 | subject to almost certain change. |
249 | |
353 | |
250 | =item $w->trigger ($revents) |
354 | =item $w->invoke ($revents) |
251 | |
355 | |
252 | Call the callback *now* with the given event mask. |
356 | Call the callback *now* with the given event mask. |
|
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357 | |
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358 | =item $w->feed_event ($revents) |
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359 | |
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360 | Feed some events on this watcher into EV. EV will react to this call as if |
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361 | the watcher had received the given C<$revents> mask. |
|
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362 | |
|
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363 | =item $revents = $w->clear_pending |
|
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364 | |
|
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365 | If the watcher is pending, this function clears its pending status and |
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366 | returns its C<$revents> bitset (as if its callback was invoked). If the |
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367 | watcher isn't pending it does nothing and returns C<0>. |
253 | |
368 | |
254 | =item $previous_state = $w->keepalive ($bool) |
369 | =item $previous_state = $w->keepalive ($bool) |
255 | |
370 | |
256 | Normally, C<EV::loop> will return when there are no active watchers |
371 | Normally, C<EV::loop> will return when there are no active watchers |
257 | (which is a "deadlock" because no progress can be made anymore). This is |
372 | (which is a "deadlock" because no progress can be made anymore). This is |
258 | convinient because it allows you to start your watchers (and your jobs), |
373 | convinient because it allows you to start your watchers (and your jobs), |
259 | call C<EV::loop> once and when it returns you know that all your jobs are |
374 | call C<EV::loop> once and when it returns you know that all your jobs are |
260 | finished (or they forgot to register some watchers for their task :). |
375 | finished (or they forgot to register some watchers for their task :). |
261 | |
376 | |
262 | Sometimes, however, this gets in your way, for example when you the module |
377 | Sometimes, however, this gets in your way, for example when the module |
263 | that calls C<EV::loop> (usually the main program) is not the same module |
378 | that calls C<EV::loop> (usually the main program) is not the same module |
264 | as a long-living watcher (for example a DNS client module written by |
379 | as a long-living watcher (for example a DNS client module written by |
265 | somebody else even). Then you might want any outstanding requests to be |
380 | somebody else even). Then you might want any outstanding requests to be |
266 | handled, but you would not want to keep C<EV::loop> from returning just |
381 | handled, but you would not want to keep C<EV::loop> from returning just |
267 | because you happen to have this long-running UDP port watcher. |
382 | because you happen to have this long-running UDP port watcher. |
… | |
… | |
270 | though your watcher is active, it won't keep C<EV::loop> from returning. |
385 | though your watcher is active, it won't keep C<EV::loop> from returning. |
271 | |
386 | |
272 | The initial value for keepalive is true (enabled), and you cna change it |
387 | The initial value for keepalive is true (enabled), and you cna change it |
273 | any time. |
388 | any time. |
274 | |
389 | |
275 | Example: Register an IO watcher for some UDP socket but do not keep the |
390 | Example: Register an I/O watcher for some UDP socket but do not keep the |
276 | event loop from running just because of that watcher. |
391 | event loop from running just because of that watcher. |
277 | |
392 | |
278 | my $udp_socket = ... |
393 | my $udp_socket = ... |
279 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
394 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
280 | $udp_watcher->keepalive (0); |
395 | $1000udp_watcher->keepalive (0); |
281 | |
396 | |
282 | =back |
397 | =item $loop = $w->loop |
283 | |
398 | |
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399 | Return the loop that this watcher is attached to. |
284 | |
400 | |
|
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401 | =back |
|
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402 | |
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403 | |
285 | =head2 WATCHER TYPES |
404 | =head1 WATCHER TYPES |
286 | |
405 | |
287 | Each of the following subsections describes a single watcher type. |
406 | Each of the following subsections describes a single watcher type. |
288 | |
407 | |
289 | =head3 IO WATCHERS - is this file descriptor readable or writable? |
408 | =head3 I/O WATCHERS - is this file descriptor readable or writable? |
290 | |
409 | |
291 | =over 4 |
410 | =over 4 |
292 | |
411 | |
293 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
412 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
294 | |
413 | |
295 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
414 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
|
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415 | |
|
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416 | =item $w = $loop->io ($fileno_or_fh, $eventmask, $callback) |
|
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417 | |
|
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418 | =item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
296 | |
419 | |
297 | As long as the returned watcher object is alive, call the C<$callback> |
420 | As long as the returned watcher object is alive, call the C<$callback> |
298 | when at least one of events specified in C<$eventmask> occurs. |
421 | when at least one of events specified in C<$eventmask> occurs. |
299 | |
422 | |
300 | The $eventmask can be one or more of these constants ORed together: |
423 | The $eventmask can be one or more of these constants ORed together: |
… | |
… | |
329 | =over 4 |
452 | =over 4 |
330 | |
453 | |
331 | =item $w = EV::timer $after, $repeat, $callback |
454 | =item $w = EV::timer $after, $repeat, $callback |
332 | |
455 | |
333 | =item $w = EV::timer_ns $after, $repeat, $callback |
456 | =item $w = EV::timer_ns $after, $repeat, $callback |
|
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457 | |
|
|
458 | =item $w = $loop->timer ($after, $repeat, $callback) |
|
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459 | |
|
|
460 | =item $w = $loop->timer_ns ($after, $repeat, $callback) |
334 | |
461 | |
335 | Calls the callback after C<$after> seconds (which may be fractional). If |
462 | Calls the callback after C<$after> seconds (which may be fractional). If |
336 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
463 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
337 | value as $after) after the callback returns. |
464 | value as $after) after the callback returns. |
338 | |
465 | |
… | |
… | |
379 | =over 4 |
506 | =over 4 |
380 | |
507 | |
381 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
508 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
382 | |
509 | |
383 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
510 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
|
|
511 | |
|
|
512 | =item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
|
|
513 | |
|
|
514 | =item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback) |
384 | |
515 | |
385 | Similar to EV::timer, but is not based on relative timeouts but on |
516 | Similar to EV::timer, but is not based on relative timeouts but on |
386 | absolute times. Apart from creating "simple" timers that trigger "at" the |
517 | absolute times. Apart from creating "simple" timers that trigger "at" the |
387 | specified time, it can also be used for non-drifting absolute timers and |
518 | specified time, it can also be used for non-drifting absolute timers and |
388 | more complex, cron-like, setups that are not adversely affected by time |
519 | more complex, cron-like, setups that are not adversely affected by time |
… | |
… | |
463 | |
594 | |
464 | =item $w->again |
595 | =item $w->again |
465 | |
596 | |
466 | Simply stops and starts the watcher again. |
597 | Simply stops and starts the watcher again. |
467 | |
598 | |
|
|
599 | =item $time = $w->at |
|
|
600 | |
|
|
601 | Return the time that the watcher is expected to trigger next. |
|
|
602 | |
468 | =back |
603 | =back |
469 | |
604 | |
470 | |
605 | |
471 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
606 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
472 | |
607 | |
… | |
… | |
509 | |
644 | |
510 | =item $w = EV::child $pid, $callback |
645 | =item $w = EV::child $pid, $callback |
511 | |
646 | |
512 | =item $w = EV::child_ns $pid, $callback |
647 | =item $w = EV::child_ns $pid, $callback |
513 | |
648 | |
|
|
649 | =item $w = $loop->child ($pid, $callback) |
|
|
650 | |
|
|
651 | =item $w = $loop->child_ns ($pid, $callback) |
|
|
652 | |
514 | Call the callback when a status change for pid C<$pid> (or any pid if |
653 | Call the callback when a status change for pid C<$pid> (or any pid if |
515 | C<$pid> is 0) has been received. More precisely: when the process receives |
654 | C<$pid> is 0) has been received. More precisely: when the process receives |
516 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
655 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
517 | changed/zombie children and call the callback. |
656 | changed/zombie children and call the callback. |
518 | |
657 | |
… | |
… | |
551 | watcher for all pids). |
690 | watcher for all pids). |
552 | |
691 | |
553 | =back |
692 | =back |
554 | |
693 | |
555 | |
694 | |
|
|
695 | =head3 STAT WATCHERS - did the file attributes just change? |
|
|
696 | |
|
|
697 | =over 4 |
|
|
698 | |
|
|
699 | =item $w = EV::stat $path, $interval, $callback |
|
|
700 | |
|
|
701 | =item $w = EV::stat_ns $path, $interval, $callback |
|
|
702 | |
|
|
703 | =item $w = $loop->stat ($path, $interval, $callback) |
|
|
704 | |
|
|
705 | =item $w = $loop->stat_ns ($path, $interval, $callback) |
|
|
706 | |
|
|
707 | Call the callback when a file status change has been detected on |
|
|
708 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
|
|
709 | to "path does not exist" is a status change like any other. |
|
|
710 | |
|
|
711 | The C<$interval> is a recommended polling interval for systems where |
|
|
712 | OS-supported change notifications don't exist or are not supported. If |
|
|
713 | you use C<0> then an unspecified default is used (which is highly |
|
|
714 | recommended!), which is to be expected to be around five seconds usually. |
|
|
715 | |
|
|
716 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
717 | as even with OS-supported change notifications, this can be |
|
|
718 | resource-intensive. |
|
|
719 | |
|
|
720 | The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
|
|
721 | |
|
|
722 | =item ... = $w->stat |
|
|
723 | |
|
|
724 | This call is very similar to the perl C<stat> built-in: It stats (using |
|
|
725 | C<lstat>) the path specified in the watcher and sets perls stat cache (as |
|
|
726 | well as EV's idea of the current stat values) to the values found. |
|
|
727 | |
|
|
728 | In scalar context, a boolean is return indicating success or failure of |
|
|
729 | the stat. In list context, the same 13-value list as with stat is returned |
|
|
730 | (except that the blksize and blocks fields are not reliable). |
|
|
731 | |
|
|
732 | In the case of an error, errno is set to C<ENOENT> (regardless of the |
|
|
733 | actual error value) and the C<nlink> value is forced to zero (if the stat |
|
|
734 | was successful then nlink is guaranteed to be non-zero). |
|
|
735 | |
|
|
736 | See also the next two entries for more info. |
|
|
737 | |
|
|
738 | =item ... = $w->attr |
|
|
739 | |
|
|
740 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
741 | the values most recently detected by EV. See the next entry for more info. |
|
|
742 | |
|
|
743 | =item ... = $w->prev |
|
|
744 | |
|
|
745 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
746 | the previous set of values, before the change. |
|
|
747 | |
|
|
748 | That is, when the watcher callback is invoked, C<< $w->prev >> will be set |
|
|
749 | to the values found I<before> a change was detected, while C<< $w->attr >> |
|
|
750 | returns the values found leading to the change detection. The difference (if any) |
|
|
751 | between C<prev> and C<attr> is what triggered the callback. |
|
|
752 | |
|
|
753 | If you did something to the filesystem object and do not want to trigger |
|
|
754 | yet another change, you can call C<stat> to update EV's idea of what the |
|
|
755 | current attributes are. |
|
|
756 | |
|
|
757 | =item $w->set ($path, $interval) |
|
|
758 | |
|
|
759 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
760 | called at any time. |
|
|
761 | |
|
|
762 | =item $current_path = $w->path |
|
|
763 | |
|
|
764 | =item $old_path = $w->path ($new_path) |
|
|
765 | |
|
|
766 | Returns the previously set path and optionally set a new one. |
|
|
767 | |
|
|
768 | =item $current_interval = $w->interval |
|
|
769 | |
|
|
770 | =item $old_interval = $w->interval ($new_interval) |
|
|
771 | |
|
|
772 | Returns the previously set interval and optionally set a new one. Can be |
|
|
773 | used to query the actual interval used. |
|
|
774 | |
|
|
775 | =back |
|
|
776 | |
|
|
777 | |
556 | =head3 IDLE WATCHERS - when you've got nothing better to do... |
778 | =head3 IDLE WATCHERS - when you've got nothing better to do... |
557 | |
779 | |
558 | =over 4 |
780 | =over 4 |
559 | |
781 | |
560 | =item $w = EV::idle $callback |
782 | =item $w = EV::idle $callback |
561 | |
783 | |
562 | =item $w = EV::idle_ns $callback |
784 | =item $w = EV::idle_ns $callback |
563 | |
785 | |
564 | Call the callback when there are no pending io, timer/periodic, signal or |
786 | =item $w = $loop->idle ($callback) |
565 | child events, i.e. when the process is idle. |
787 | |
|
|
788 | =item $w = $loop->idle_ns ($callback) |
|
|
789 | |
|
|
790 | Call the callback when there are no other pending watchers of the same or |
|
|
791 | higher priority (excluding check, prepare and other idle watchers of the |
|
|
792 | same or lower priority, of course). They are called idle watchers because |
|
|
793 | when the watcher is the highest priority pending event in the process, the |
|
|
794 | process is considered to be idle at that priority. |
|
|
795 | |
|
|
796 | If you want a watcher that is only ever called when I<no> other events are |
|
|
797 | outstanding you have to set the priority to C<EV::MINPRI>. |
566 | |
798 | |
567 | The process will not block as long as any idle watchers are active, and |
799 | The process will not block as long as any idle watchers are active, and |
568 | they will be called repeatedly until stopped. |
800 | they will be called repeatedly until stopped. |
569 | |
801 | |
|
|
802 | For example, if you have idle watchers at priority C<0> and C<1>, and |
|
|
803 | an I/O watcher at priority C<0>, then the idle watcher at priority C<1> |
|
|
804 | and the I/O watcher will always run when ready. Only when the idle watcher |
|
|
805 | at priority C<1> is stopped and the I/O watcher at priority C<0> is not |
|
|
806 | pending with the C<0>-priority idle watcher be invoked. |
|
|
807 | |
570 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
808 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
571 | |
809 | |
572 | =back |
810 | =back |
573 | |
811 | |
574 | |
812 | |
… | |
… | |
577 | =over 4 |
815 | =over 4 |
578 | |
816 | |
579 | =item $w = EV::prepare $callback |
817 | =item $w = EV::prepare $callback |
580 | |
818 | |
581 | =item $w = EV::prepare_ns $callback |
819 | =item $w = EV::prepare_ns $callback |
|
|
820 | |
|
|
821 | =item $w = $loop->prepare ($callback) |
|
|
822 | |
|
|
823 | =item $w = $loop->prepare_ns ($callback) |
582 | |
824 | |
583 | Call the callback just before the process would block. You can still |
825 | Call the callback just before the process would block. You can still |
584 | create/modify any watchers at this point. |
826 | create/modify any watchers at this point. |
585 | |
827 | |
586 | See the EV::check watcher, below, for explanations and an example. |
828 | See the EV::check watcher, below, for explanations and an example. |
… | |
… | |
595 | =over 4 |
837 | =over 4 |
596 | |
838 | |
597 | =item $w = EV::check $callback |
839 | =item $w = EV::check $callback |
598 | |
840 | |
599 | =item $w = EV::check_ns $callback |
841 | =item $w = EV::check_ns $callback |
|
|
842 | |
|
|
843 | =item $w = $loop->check ($callback) |
|
|
844 | |
|
|
845 | =item $w = $loop->check_ns ($callback) |
600 | |
846 | |
601 | Call the callback just after the process wakes up again (after it has |
847 | Call the callback just after the process wakes up again (after it has |
602 | gathered events), but before any other callbacks have been invoked. |
848 | gathered events), but before any other callbacks have been invoked. |
603 | |
849 | |
604 | This is used to integrate other event-based software into the EV |
850 | This is used to integrate other event-based software into the EV |
… | |
… | |
614 | or return; |
860 | or return; |
615 | |
861 | |
616 | # make the dispatcher handle any outstanding stuff |
862 | # make the dispatcher handle any outstanding stuff |
617 | ... not shown |
863 | ... not shown |
618 | |
864 | |
619 | # create an IO watcher for each and every socket |
865 | # create an I/O watcher for each and every socket |
620 | @snmp_watcher = ( |
866 | @snmp_watcher = ( |
621 | (map { EV::io $_, EV::READ, sub { } } |
867 | (map { EV::io $_, EV::READ, sub { } } |
622 | keys %{ $dispatcher->{_descriptors} }), |
868 | keys %{ $dispatcher->{_descriptors} }), |
623 | |
869 | |
624 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
870 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
… | |
… | |
646 | |
892 | |
647 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
893 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
648 | |
894 | |
649 | =back |
895 | =back |
650 | |
896 | |
651 | =head3 STAT WATCHERS - did the file attributes just change? |
|
|
652 | |
897 | |
653 | =over 4 |
898 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
654 | |
899 | |
655 | =item $w = EV::stat $path, $interval, $callback |
900 | Fork watchers are called when a C<fork ()> was detected. The invocation |
|
|
901 | is done before the event loop blocks next and before C<check> watchers |
|
|
902 | are being called, and only in the child after the fork. |
656 | |
903 | |
657 | =item $w = EV::stat_ns $path, $interval, $callback |
904 | =over 4 |
658 | |
905 | |
659 | Call the callback when a file status change has been detected on |
906 | =item $w = EV::fork $callback |
660 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
|
|
661 | to "path does not exist" is a status change like any other. |
|
|
662 | |
907 | |
663 | The C<$interval> is a recommended polling interval for systems where |
908 | =item $w = EV::fork_ns $callback |
664 | OS-supported change notifications don't exist or are not supported. If |
|
|
665 | you use C<0> then an unspecified default is used (which is highly |
|
|
666 | recommended!), which is to be expected to be around five seconds usually. |
|
|
667 | |
909 | |
668 | This watcher type is not meant for massive numbers of stat watchers, |
910 | =item $w = $loop->fork ($callback) |
669 | as even with OS-supported change notifications, this can be |
|
|
670 | resource-intensive. |
|
|
671 | |
911 | |
|
|
912 | =item $w = $loop->fork_ns ($callback) |
|
|
913 | |
|
|
914 | Call the callback before the event loop is resumed in the child process |
|
|
915 | after a fork. |
|
|
916 | |
672 | The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
917 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
673 | |
918 | |
674 | =item $w->set ($path, $interval) |
|
|
675 | |
|
|
676 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
677 | called at any time. |
|
|
678 | |
|
|
679 | =item $current_path = $w->path |
|
|
680 | |
|
|
681 | =item $old_path = $w->path ($new_path) |
|
|
682 | |
|
|
683 | Returns the previously set path and optionally set a new one. |
|
|
684 | |
|
|
685 | =item $current_interval = $w->interval |
|
|
686 | |
|
|
687 | =item $old_interval = $w->interval ($new_interval) |
|
|
688 | |
|
|
689 | Returns the previously set interval and optionally set a new one. Can be |
|
|
690 | used to query the actual interval used. |
|
|
691 | |
|
|
692 | =back |
919 | =back |
693 | |
920 | |
|
|
921 | |
|
|
922 | =head3 EMBED WATCHERS - when one backend isn't enough... |
|
|
923 | |
|
|
924 | This is a rather advanced watcher type that lets you embed one event loop |
|
|
925 | into another (currently only IO events are supported in the embedded |
|
|
926 | loop, other types of watchers might be handled in a delayed or incorrect |
|
|
927 | fashion and must not be used). |
|
|
928 | |
|
|
929 | See the libev documentation at |
|
|
930 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> |
|
|
931 | for more details. |
|
|
932 | |
|
|
933 | In short, this watcher is most useful on BSD systems without working |
|
|
934 | kqueue to still be able to handle a large number of sockets: |
|
|
935 | |
|
|
936 | my $socket_loop; |
|
|
937 | |
|
|
938 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
|
|
939 | if ( |
|
|
940 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
|
|
941 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
|
|
942 | ) { |
|
|
943 | # use kqueue for sockets |
|
|
944 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
|
|
945 | } |
|
|
946 | |
|
|
947 | # use the default loop otherwise |
|
|
948 | $socket_loop ||= EV::default_loop; |
|
|
949 | |
|
|
950 | =over 4 |
|
|
951 | |
|
|
952 | =item $w = EV::embed $otherloop, $callback |
|
|
953 | |
|
|
954 | =item $w = EV::embed_ns $otherloop, $callback |
|
|
955 | |
|
|
956 | =item $w = $loop->embed ($otherloop, $callback) |
|
|
957 | |
|
|
958 | =item $w = $loop->embed_ns ($otherloop, $callback) |
|
|
959 | |
|
|
960 | Call the callback when the embedded event loop (C<$otherloop>) has any |
|
|
961 | I/O activity. The C<$callback> should alwas be specified as C<undef> in |
|
|
962 | this version of EV, which means the embedded event loop will be managed |
|
|
963 | automatically. |
|
|
964 | |
|
|
965 | The C<embed_ns> variant doesn't start (activate) the newly created watcher. |
|
|
966 | |
|
|
967 | =back |
|
|
968 | |
|
|
969 | |
|
|
970 | =head1 PERL SIGNALS |
|
|
971 | |
|
|
972 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
|
|
973 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
974 | handled when Perl runs, which means your signal handler might be invoked |
|
|
975 | only the next time an event callback is invoked. |
|
|
976 | |
|
|
977 | The solution is to use EV signal watchers (see C<EV::signal>), which will |
|
|
978 | ensure proper operations with regards to other event watchers. |
|
|
979 | |
|
|
980 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
981 | to be called on every event loop iteration by installing a C<EV::check> |
|
|
982 | watcher: |
|
|
983 | |
|
|
984 | my $async_check = EV::check sub { }; |
|
|
985 | |
|
|
986 | This ensures that perl gets into control for a short time to handle any |
|
|
987 | pending signals, and also ensures (slightly) slower overall operation. |
694 | |
988 | |
695 | =head1 THREADS |
989 | =head1 THREADS |
696 | |
990 | |
697 | Threads are not supported by this module in any way. Perl pseudo-threads |
991 | Threads are not supported by this module in any way. Perl pseudo-threads |
698 | is evil stuff and must die. As soon as Perl gains real threads I will work |
992 | is evil stuff and must die. As soon as Perl gains real threads I will work |
… | |
… | |
720 | our $DIED = sub { |
1014 | our $DIED = sub { |
721 | warn "EV: error in callback (ignoring): $@"; |
1015 | warn "EV: error in callback (ignoring): $@"; |
722 | }; |
1016 | }; |
723 | |
1017 | |
724 | default_loop |
1018 | default_loop |
725 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; |
1019 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?'; |
726 | |
1020 | |
727 | 1; |
1021 | 1; |
728 | |
1022 | |
729 | =head1 SEE ALSO |
1023 | =head1 SEE ALSO |
730 | |
1024 | |
731 | L<EV::DNS>. |
1025 | L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as |
|
|
1026 | event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient |
|
|
1027 | coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). |
732 | |
1028 | |
733 | =head1 AUTHOR |
1029 | =head1 AUTHOR |
734 | |
1030 | |
735 | Marc Lehmann <schmorp@schmorp.de> |
1031 | Marc Lehmann <schmorp@schmorp.de> |
736 | http://home.schmorp.de/ |
1032 | http://home.schmorp.de/ |