… | |
… | |
10 | |
10 | |
11 | my $w = EV::timer 2, 0, sub { |
11 | my $w = EV::timer 2, 0, sub { |
12 | warn "is called after 2s"; |
12 | warn "is called after 2s"; |
13 | }; |
13 | }; |
14 | |
14 | |
15 | my $w = EV::timer 2, 1, sub { |
15 | my $w = EV::timer 2, 2, sub { |
16 | warn "is called roughly every 2s (repeat = 1)"; |
16 | warn "is called roughly every 2s (repeat = 2)"; |
17 | }; |
17 | }; |
18 | |
18 | |
19 | undef $w; # destroy event watcher again |
19 | undef $w; # destroy event watcher again |
20 | |
20 | |
21 | my $w = EV::periodic 0, 60, 0, sub { |
21 | my $w = EV::periodic 0, 60, 0, sub { |
… | |
… | |
23 | }; |
23 | }; |
24 | |
24 | |
25 | # IO |
25 | # IO |
26 | |
26 | |
27 | my $w = EV::io *STDIN, EV::READ, sub { |
27 | my $w = EV::io *STDIN, EV::READ, sub { |
28 | my ($w, $revents) = @_; # all callbacks get the watcher object and event mask |
28 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
29 | warn "stdin is readable, you entered: ", <STDIN>; |
29 | warn "stdin is readable, you entered: ", <STDIN>; |
30 | }; |
30 | }; |
31 | |
31 | |
32 | # SIGNALS |
32 | # SIGNALS |
33 | |
33 | |
34 | my $w = EV::signal 'QUIT', sub { |
34 | my $w = EV::signal 'QUIT', sub { |
35 | warn "sigquit received\n"; |
35 | warn "sigquit received\n"; |
36 | }; |
36 | }; |
37 | |
37 | |
38 | my $w = EV::signal 3, sub { |
|
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39 | warn "sigquit received (this is GNU/Linux, right?)\n"; |
|
|
40 | }; |
|
|
41 | |
|
|
42 | # CHILD/PID STATUS CHANGES |
38 | # CHILD/PID STATUS CHANGES |
43 | |
39 | |
44 | my $w = EV::child 666, sub { |
40 | my $w = EV::child 666, sub { |
45 | my ($w, $revents) = @_; |
41 | my ($w, $revents) = @_; |
46 | # my $pid = $w->rpid; |
|
|
47 | my $status = $w->rstatus; |
42 | my $status = $w->rstatus; |
48 | }; |
43 | }; |
|
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44 | |
|
|
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 | }; |
49 | |
50 | |
50 | # MAINLOOP |
51 | # MAINLOOP |
51 | EV::loop; # loop until EV::loop_done is called |
52 | EV::loop; # loop until EV::unloop is called or all watchers stop |
52 | 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 |
53 | 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 |
54 | |
55 | |
55 | =head1 DESCRIPTION |
56 | =head1 DESCRIPTION |
56 | |
57 | |
57 | This module provides an interface to libev |
58 | This module provides an interface to libev |
58 | (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. |
59 | |
65 | |
60 | =cut |
66 | =cut |
61 | |
67 | |
62 | package EV; |
68 | package EV; |
63 | |
69 | |
64 | use strict; |
70 | use strict; |
65 | |
71 | |
66 | BEGIN { |
72 | BEGIN { |
67 | our $VERSION = '0.7'; |
73 | our $VERSION = '1.72'; |
68 | use XSLoader; |
74 | use XSLoader; |
69 | XSLoader::load "EV", $VERSION; |
75 | XSLoader::load "EV", $VERSION; |
70 | } |
76 | } |
71 | |
77 | |
72 | @EV::Io::ISA = |
78 | @EV::IO::ISA = |
73 | @EV::Timer::ISA = |
79 | @EV::Timer::ISA = |
74 | @EV::Periodic::ISA = |
80 | @EV::Periodic::ISA = |
75 | @EV::Signal::ISA = |
81 | @EV::Signal::ISA = |
|
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82 | @EV::Child::ISA = |
|
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83 | @EV::Stat::ISA = |
76 | @EV::Idle::ISA = |
84 | @EV::Idle::ISA = |
77 | @EV::Prepare::ISA = |
85 | @EV::Prepare::ISA = |
78 | @EV::Check::ISA = |
86 | @EV::Check::ISA = |
79 | @EV::Child::ISA = "EV::Watcher"; |
87 | @EV::Embed::ISA = |
|
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88 | @EV::Fork::ISA = |
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89 | "EV::Watcher"; |
80 | |
90 | |
81 | =head1 BASIC INTERFACE |
91 | =head1 BASIC INTERFACE |
82 | |
92 | |
83 | =over 4 |
93 | =over 4 |
84 | |
94 | |
85 | =item $EV::DIED |
95 | =item $EV::DIED |
86 | |
96 | |
87 | Must contain a reference to a function that is called when a callback |
97 | Must contain a reference to a function that is called when a callback |
88 | throws an exception (with $@ containing thr error). The default prints an |
98 | throws an exception (with $@ containing the error). The default prints an |
89 | informative message and continues. |
99 | informative message and continues. |
90 | |
100 | |
91 | If this callback throws an exception it will be silently ignored. |
101 | If this callback throws an exception it will be silently ignored. |
92 | |
102 | |
93 | =item $time = EV::time |
103 | =item $time = EV::time |
… | |
… | |
98 | |
108 | |
99 | Returns the time the last event loop iteration has been started. This |
109 | Returns the time the last event loop iteration has been started. This |
100 | is the time that (relative) timers are based on, and refering to it is |
110 | is the time that (relative) timers are based on, and refering to it is |
101 | usually faster then calling EV::time. |
111 | usually faster then calling EV::time. |
102 | |
112 | |
103 | =item $method = EV::ev_method |
113 | =item $method = EV::method |
104 | |
114 | |
105 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
115 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
106 | or EV::METHOD_EPOLL). |
116 | or EV::METHOD_EPOLL). |
107 | |
117 | |
108 | =item EV::loop [$flags] |
118 | =item EV::loop [$flags] |
109 | |
119 | |
110 | Begin checking for events and calling callbacks. It returns when a |
120 | Begin checking for events and calling callbacks. It returns when a |
111 | callback calls EV::loop_done. |
121 | callback calls EV::unloop. |
112 | |
122 | |
113 | The $flags argument can be one of the following: |
123 | The $flags argument can be one of the following: |
114 | |
124 | |
115 | 0 as above |
125 | 0 as above |
116 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
126 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
117 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
127 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
118 | |
128 | |
119 | =item EV::loop_done [$how] |
129 | =item EV::unloop [$how] |
120 | |
130 | |
121 | When called with no arguments or an argument of 1, makes the innermost |
131 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
122 | call to EV::loop return. |
132 | innermost call to EV::loop return. |
123 | |
133 | |
124 | When called with an agrument of 2, all calls to EV::loop will return as |
134 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
125 | fast as possible. |
135 | fast as possible. |
126 | |
136 | |
127 | =back |
137 | =item $count = EV::loop_count |
128 | |
138 | |
|
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139 | Return the number of times the event loop has polled for new |
|
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140 | events. Sometiems useful as a generation counter. |
|
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141 | |
|
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142 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
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143 | |
|
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144 | This function rolls together an I/O and a timer watcher for a single |
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145 | one-shot event without the need for managing a watcher object. |
|
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146 | |
|
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147 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
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148 | must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ |
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149 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
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150 | you do not want to wait for some I/O event, specify C<undef> for |
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151 | C<$fh_or_undef> and C<0> for C<$events>). |
|
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152 | |
|
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153 | If timeout is C<undef> or negative, then there will be no |
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154 | timeout. Otherwise a EV::timer with this value will be started. |
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155 | |
|
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156 | When an error occurs or either the timeout or I/O watcher triggers, then |
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157 | the callback will be called with the received event set (in general |
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158 | you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, |
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159 | C<EV::WRITE> and C<EV::TIMEOUT>). |
|
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160 | |
|
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161 | EV::once doesn't return anything: the watchers stay active till either |
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162 | of them triggers, then they will be stopped and freed, and the callback |
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163 | invoked. |
|
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164 | |
|
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165 | =item EV::feed_fd_event ($fd, $revents) |
|
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166 | |
|
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167 | Feed an event on a file descriptor into EV. EV will react to this call as |
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168 | if the readyness notifications specified by C<$revents> (a combination of |
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169 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
|
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170 | |
|
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171 | =item EV::feed_signal_event ($signal) |
|
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172 | |
|
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173 | Feed a signal event into EV. EV will react to this call as if the signal |
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174 | specified by C<$signal> had occured. |
|
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175 | |
|
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176 | =back |
|
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177 | |
|
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178 | |
129 | =head2 WATCHER |
179 | =head2 WATCHER OBJECTS |
130 | |
180 | |
131 | A watcher is an object that gets created to record your interest in some |
181 | A watcher is an object that gets created to record your interest in some |
132 | event. For instance, if you want to wait for STDIN to become readable, you |
182 | event. For instance, if you want to wait for STDIN to become readable, you |
133 | would create an EV::io watcher for that: |
183 | would create an EV::io watcher for that: |
134 | |
184 | |
… | |
… | |
143 | events. |
193 | events. |
144 | |
194 | |
145 | Each watcher type has its associated bit in revents, so you can use the |
195 | Each watcher type has its associated bit in revents, so you can use the |
146 | same callback for multiple watchers. The event mask is named after the |
196 | same callback for multiple watchers. The event mask is named after the |
147 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
197 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
148 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
198 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
149 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
199 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
150 | uses EV::TIMEOUT). |
200 | uses EV::TIMEOUT). |
151 | |
201 | |
152 | In the rare case where one wants to create a watcher but not start it at |
202 | In the rare case where one wants to create a watcher but not start it at |
153 | the same time, each constructor has a variant with a trailing C<_ns> in |
203 | the same time, each constructor has a variant with a trailing C<_ns> in |
… | |
… | |
159 | |
209 | |
160 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
210 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
161 | ->fh and so on) automatically stop and start it again if it is active, |
211 | ->fh and so on) automatically stop and start it again if it is active, |
162 | which means pending events get lost. |
212 | which means pending events get lost. |
163 | |
213 | |
164 | =head2 WATCHER TYPES |
214 | =head2 COMMON WATCHER METHODS |
165 | |
215 | |
166 | Now lets move to the existing watcher types and asociated methods. |
216 | This section lists methods common to all watchers. |
167 | |
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168 | The following methods are available for all watchers. Then followes a |
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169 | description of each watcher constructor (EV::io, EV::timer, EV::periodic, |
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170 | EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by |
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171 | any type-specific methods (if any). |
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172 | |
217 | |
173 | =over 4 |
218 | =over 4 |
174 | |
219 | |
175 | =item $w->start |
220 | =item $w->start |
176 | |
221 | |
… | |
… | |
180 | |
225 | |
181 | =item $w->stop |
226 | =item $w->stop |
182 | |
227 | |
183 | Stop a watcher if it is active. Also clear any pending events (events that |
228 | Stop a watcher if it is active. Also clear any pending events (events that |
184 | have been received but that didn't yet result in a callback invocation), |
229 | have been received but that didn't yet result in a callback invocation), |
185 | regardless of wether the watcher was active or not. |
230 | regardless of whether the watcher was active or not. |
186 | |
231 | |
187 | =item $bool = $w->is_active |
232 | =item $bool = $w->is_active |
188 | |
233 | |
189 | Returns true if the watcher is active, false otherwise. |
234 | Returns true if the watcher is active, false otherwise. |
190 | |
235 | |
… | |
… | |
215 | watchers with higher priority will be invoked first. The valid range of |
260 | watchers with higher priority will be invoked first. The valid range of |
216 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
261 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
217 | -2). If the priority is outside this range it will automatically be |
262 | -2). If the priority is outside this range it will automatically be |
218 | normalised to the nearest valid priority. |
263 | normalised to the nearest valid priority. |
219 | |
264 | |
220 | The default priority of any newly-created weatcher is 0. |
265 | The default priority of any newly-created watcher is 0. |
221 | |
266 | |
|
|
267 | Note that the priority semantics have not yet been fleshed out and are |
|
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268 | subject to almost certain change. |
|
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269 | |
222 | =item $w->trigger ($revents) |
270 | =item $w->invoke ($revents) |
223 | |
271 | |
224 | Call the callback *now* with the given event mask. |
272 | Call the callback *now* with the given event mask. |
225 | |
273 | |
|
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274 | =item $w->feed_event ($revents) |
|
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275 | |
|
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276 | Feed some events on this watcher into EV. EV will react to this call as if |
|
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277 | the watcher had received the given C<$revents> mask. |
|
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278 | |
|
|
279 | =item $revents = $w->clear_pending |
|
|
280 | |
|
|
281 | If the watcher is pending, this function returns clears its pending status |
|
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282 | and returns its C<$revents> bitset (as if its callback was invoked). If the |
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283 | watcher isn't pending it does nothing and returns C<0>. |
|
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284 | |
|
|
285 | =item $previous_state = $w->keepalive ($bool) |
|
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286 | |
|
|
287 | Normally, C<EV::loop> will return when there are no active watchers |
|
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288 | (which is a "deadlock" because no progress can be made anymore). This is |
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289 | convinient because it allows you to start your watchers (and your jobs), |
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290 | call C<EV::loop> once and when it returns you know that all your jobs are |
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291 | finished (or they forgot to register some watchers for their task :). |
|
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292 | |
|
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293 | Sometimes, however, this gets in your way, for example when you the module |
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294 | that calls C<EV::loop> (usually the main program) is not the same module |
|
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295 | as a long-living watcher (for example a DNS client module written by |
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296 | somebody else even). Then you might want any outstanding requests to be |
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297 | handled, but you would not want to keep C<EV::loop> from returning just |
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298 | because you happen to have this long-running UDP port watcher. |
|
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299 | |
|
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300 | In this case you can clear the keepalive status, which means that even |
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301 | though your watcher is active, it won't keep C<EV::loop> from returning. |
|
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302 | |
|
|
303 | The initial value for keepalive is true (enabled), and you cna change it |
|
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304 | any time. |
|
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305 | |
|
|
306 | Example: Register an I/O watcher for some UDP socket but do not keep the |
|
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307 | event loop from running just because of that watcher. |
|
|
308 | |
|
|
309 | my $udp_socket = ... |
|
|
310 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
|
|
311 | $udp_watcher->keepalive (0); |
|
|
312 | |
|
|
313 | =back |
|
|
314 | |
|
|
315 | |
|
|
316 | =head2 WATCHER TYPES |
|
|
317 | |
|
|
318 | Each of the following subsections describes a single watcher type. |
|
|
319 | |
|
|
320 | =head3 I/O WATCHERS - is this file descriptor readable or writable? |
|
|
321 | |
|
|
322 | =over 4 |
226 | |
323 | |
227 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
324 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
228 | |
325 | |
229 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
326 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
230 | |
327 | |
231 | As long as the returned watcher object is alive, call the C<$callback> |
328 | As long as the returned watcher object is alive, call the C<$callback> |
232 | when the events specified in C<$eventmask>. |
329 | when at least one of events specified in C<$eventmask> occurs. |
233 | |
330 | |
234 | The $eventmask can be one or more of these constants ORed together: |
331 | The $eventmask can be one or more of these constants ORed together: |
235 | |
332 | |
236 | EV::READ wait until read() wouldn't block anymore |
333 | EV::READ wait until read() wouldn't block anymore |
237 | EV::WRITE wait until write() wouldn't block anymore |
334 | EV::WRITE wait until write() wouldn't block anymore |
… | |
… | |
253 | |
350 | |
254 | =item $old_eventmask = $w->events ($new_eventmask) |
351 | =item $old_eventmask = $w->events ($new_eventmask) |
255 | |
352 | |
256 | Returns the previously set event mask and optionally set a new one. |
353 | Returns the previously set event mask and optionally set a new one. |
257 | |
354 | |
|
|
355 | =back |
|
|
356 | |
|
|
357 | |
|
|
358 | =head3 TIMER WATCHERS - relative and optionally repeating timeouts |
|
|
359 | |
|
|
360 | =over 4 |
258 | |
361 | |
259 | =item $w = EV::timer $after, $repeat, $callback |
362 | =item $w = EV::timer $after, $repeat, $callback |
260 | |
363 | |
261 | =item $w = EV::timer_ns $after, $repeat, $callback |
364 | =item $w = EV::timer_ns $after, $repeat, $callback |
262 | |
365 | |
263 | Calls the callback after C<$after> seconds. If C<$repeat> is non-zero, |
366 | Calls the callback after C<$after> seconds (which may be fractional). If |
264 | the timer will be restarted (with the $repeat value as $after) after the |
367 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
265 | callback returns. |
368 | value as $after) after the callback returns. |
266 | |
369 | |
267 | This means that the callback would be called roughly after C<$after> |
370 | This means that the callback would be called roughly after C<$after> |
268 | seconds, and then every C<$repeat> seconds. "Roughly" because the time of |
371 | seconds, and then every C<$repeat> seconds. The timer does his best not |
269 | callback processing is not taken into account, so the timer will slowly |
372 | to drift, but it will not invoke the timer more often then once per event |
270 | drift. If that isn't acceptable, look at EV::periodic. |
373 | loop iteration, and might drift in other cases. If that isn't acceptable, |
|
|
374 | look at EV::periodic, which can provide long-term stable timers. |
271 | |
375 | |
272 | The timer is based on a monotonic clock, that is if somebody is sitting |
376 | The timer is based on a monotonic clock, that is, if somebody is sitting |
273 | in front of the machine while the timer is running and changes the system |
377 | in front of the machine while the timer is running and changes the system |
274 | clock, the timer will nevertheless run (roughly) the same time. |
378 | clock, the timer will nevertheless run (roughly) the same time. |
275 | |
379 | |
276 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
380 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
277 | |
381 | |
278 | =item $w->set ($after, $repeat) |
382 | =item $w->set ($after, $repeat) |
279 | |
383 | |
280 | Reconfigures the watcher, see the constructor above for details. Can be at |
384 | Reconfigures the watcher, see the constructor above for details. Can be called at |
281 | any time. |
385 | any time. |
282 | |
386 | |
283 | =item $w->again |
387 | =item $w->again |
284 | |
388 | |
285 | Similar to the C<start> method, but has special semantics for repeating timers: |
389 | Similar to the C<start> method, but has special semantics for repeating timers: |
|
|
390 | |
|
|
391 | If the timer is active and non-repeating, it will be stopped. |
286 | |
392 | |
287 | If the timer is active and repeating, reset the timeout to occur |
393 | If the timer is active and repeating, reset the timeout to occur |
288 | C<$repeat> seconds after now. |
394 | C<$repeat> seconds after now. |
289 | |
395 | |
290 | If the timer is active and non-repeating, it will be stopped. |
|
|
291 | |
|
|
292 | If the timer is in active and repeating, start it. |
396 | If the timer is inactive and repeating, start it using the repeat value. |
293 | |
397 | |
294 | Otherwise do nothing. |
398 | Otherwise do nothing. |
295 | |
399 | |
296 | This behaviour is useful when you have a timeout for some IO |
400 | This behaviour is useful when you have a timeout for some IO |
297 | operation. You create a timer object with the same value for C<$after> and |
401 | operation. You create a timer object with the same value for C<$after> and |
298 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
402 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
299 | on the timeout. |
403 | on the timeout. |
300 | |
404 | |
|
|
405 | =back |
|
|
406 | |
|
|
407 | |
|
|
408 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
|
|
409 | |
|
|
410 | =over 4 |
301 | |
411 | |
302 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
412 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
303 | |
413 | |
304 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
414 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
305 | |
415 | |
… | |
… | |
341 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
451 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
342 | jumps. |
452 | jumps. |
343 | |
453 | |
344 | =item * manual reschedule mode ($reschedule_cb = coderef) |
454 | =item * manual reschedule mode ($reschedule_cb = coderef) |
345 | |
455 | |
346 | In this mode $interval and $at are both being ignored. Instead, each time |
456 | In this mode $interval and $at are both being ignored. Instead, each |
347 | the periodic watcher gets scheduled, the first callback ($reschedule_cb) |
457 | time the periodic watcher gets scheduled, the reschedule callback |
348 | will be called with the watcher as first, and the current time as second |
458 | ($reschedule_cb) will be called with the watcher as first, and the current |
349 | argument. |
459 | time as second argument. |
350 | |
460 | |
351 | I<This callback MUST NOT stop or destroy this or any other periodic |
461 | I<This callback MUST NOT stop or destroy this or any other periodic |
352 | watcher, ever>. If you need to stop it, return 1e30 and stop it |
462 | watcher, ever>. If you need to stop it, return 1e30 and stop it |
353 | afterwards. |
463 | afterwards. |
354 | |
464 | |
… | |
… | |
377 | |
487 | |
378 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
488 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
379 | |
489 | |
380 | =item $w->set ($at, $interval, $reschedule_cb) |
490 | =item $w->set ($at, $interval, $reschedule_cb) |
381 | |
491 | |
382 | Reconfigures the watcher, see the constructor above for details. Can be at |
492 | Reconfigures the watcher, see the constructor above for details. Can be called at |
383 | any time. |
493 | any time. |
384 | |
494 | |
385 | =item $w->again |
495 | =item $w->again |
386 | |
496 | |
387 | Simply stops and starts the watcher again. |
497 | Simply stops and starts the watcher again. |
388 | |
498 | |
|
|
499 | =back |
|
|
500 | |
|
|
501 | |
|
|
502 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
|
|
503 | |
|
|
504 | =over 4 |
389 | |
505 | |
390 | =item $w = EV::signal $signal, $callback |
506 | =item $w = EV::signal $signal, $callback |
391 | |
507 | |
392 | =item $w = EV::signal_ns $signal, $callback |
508 | =item $w = EV::signal_ns $signal, $callback |
393 | |
509 | |
394 | Call the callback when $signal is received (the signal can be specified |
510 | Call the callback when $signal is received (the signal can be specified by |
395 | by number or by name, just as with kill or %SIG). |
511 | number or by name, just as with C<kill> or C<%SIG>). |
396 | |
512 | |
397 | EV will grab the signal for the process (the kernel only allows one |
513 | EV will grab the signal for the process (the kernel only allows one |
398 | component to receive a signal at a time) when you start a signal watcher, |
514 | component to receive a signal at a time) when you start a signal watcher, |
399 | and removes it again when you stop it. Perl does the same when you |
515 | and removes it again when you stop it. Perl does the same when you |
400 | add/remove callbacks to %SIG, so watch out. |
516 | add/remove callbacks to C<%SIG>, so watch out. |
401 | |
517 | |
402 | You can have as many signal watchers per signal as you want. |
518 | You can have as many signal watchers per signal as you want. |
403 | |
519 | |
404 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
520 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
405 | |
521 | |
406 | =item $w->set ($signal) |
522 | =item $w->set ($signal) |
407 | |
523 | |
408 | Reconfigures the watcher, see the constructor above for details. Can be at |
524 | Reconfigures the watcher, see the constructor above for details. Can be |
409 | any time. |
525 | called at any time. |
410 | |
526 | |
411 | =item $current_signum = $w->signal |
527 | =item $current_signum = $w->signal |
412 | |
528 | |
413 | =item $old_signum = $w->signal ($new_signal) |
529 | =item $old_signum = $w->signal ($new_signal) |
414 | |
530 | |
415 | Returns the previously set signal (always as a number not name) and |
531 | Returns the previously set signal (always as a number not name) and |
416 | optionally set a new one. |
532 | optionally set a new one. |
417 | |
533 | |
|
|
534 | =back |
|
|
535 | |
|
|
536 | |
|
|
537 | =head3 CHILD WATCHERS - watch out for process status changes |
|
|
538 | |
|
|
539 | =over 4 |
418 | |
540 | |
419 | =item $w = EV::child $pid, $callback |
541 | =item $w = EV::child $pid, $callback |
420 | |
542 | |
421 | =item $w = EV::child_ns $pid, $callback |
543 | =item $w = EV::child_ns $pid, $callback |
422 | |
544 | |
423 | Call the callback when a status change for pid C<$pid> (or any pid |
545 | Call the callback when a status change for pid C<$pid> (or any pid if |
424 | if C<$pid> is 0) has been received. More precisely: when the process |
546 | C<$pid> is 0) has been received. More precisely: when the process receives |
425 | receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all |
547 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
426 | changed/zombie children and call the callback. |
548 | changed/zombie children and call the callback. |
427 | |
549 | |
428 | You can access both status and pid by using the C<rstatus> and C<rpid> |
550 | It is valid (and fully supported) to install a child watcher after a child |
429 | methods on the watcher object. |
551 | has exited but before the event loop has started its next iteration (for |
|
|
552 | example, first you C<fork>, then the new child process might exit, and |
|
|
553 | only then do you install a child watcher in the parent for the new pid). |
430 | |
554 | |
|
|
555 | You can access both exit (or tracing) status and pid by using the |
|
|
556 | C<rstatus> and C<rpid> methods on the watcher object. |
|
|
557 | |
431 | You can have as many pid watchers per pid as you want. |
558 | You can have as many pid watchers per pid as you want, they will all be |
|
|
559 | called. |
432 | |
560 | |
433 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
561 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
434 | |
562 | |
435 | =item $w->set ($pid) |
563 | =item $w->set ($pid) |
436 | |
564 | |
437 | 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 |
438 | any time. |
566 | any time. |
439 | |
567 | |
440 | =item $current_pid = $w->pid |
568 | =item $current_pid = $w->pid |
441 | |
569 | |
442 | =item $old_pid = $w->pid ($new_pid) |
570 | =item $old_pid = $w->pid ($new_pid) |
… | |
… | |
451 | =item $pid = $w->rpid |
579 | =item $pid = $w->rpid |
452 | |
580 | |
453 | Return the pid of the awaited child (useful when you have installed a |
581 | Return the pid of the awaited child (useful when you have installed a |
454 | watcher for all pids). |
582 | watcher for all pids). |
455 | |
583 | |
|
|
584 | =back |
|
|
585 | |
|
|
586 | |
|
|
587 | =head3 STAT WATCHERS - did the file attributes just change? |
|
|
588 | |
|
|
589 | =over 4 |
|
|
590 | |
|
|
591 | =item $w = EV::stat $path, $interval, $callback |
|
|
592 | |
|
|
593 | =item $w = EV::stat_ns $path, $interval, $callback |
|
|
594 | |
|
|
595 | Call the callback when a file status change has been detected on |
|
|
596 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
|
|
597 | to "path does not exist" is a status change like any other. |
|
|
598 | |
|
|
599 | The C<$interval> is a recommended polling interval for systems where |
|
|
600 | OS-supported change notifications don't exist or are not supported. If |
|
|
601 | you use C<0> then an unspecified default is used (which is highly |
|
|
602 | recommended!), which is to be expected to be around five seconds usually. |
|
|
603 | |
|
|
604 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
605 | as even with OS-supported change notifications, this can be |
|
|
606 | resource-intensive. |
|
|
607 | |
|
|
608 | The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
|
|
609 | |
|
|
610 | =item ... = $w->stat |
|
|
611 | |
|
|
612 | This call is very similar to the perl C<stat> built-in: It stats (using |
|
|
613 | C<lstat>) the path specified in the watcher and sets perls stat cache (as |
|
|
614 | well as EV's idea of the current stat values) to the values found. |
|
|
615 | |
|
|
616 | In scalar context, a boolean is return indicating success or failure of |
|
|
617 | the stat. In list context, the same 13-value list as with stat is returned |
|
|
618 | (except that the blksize and blocks fields are not reliable). |
|
|
619 | |
|
|
620 | In the case of an error, errno is set to C<ENOENT> (regardless of the |
|
|
621 | actual error value) and the C<nlink> value is forced to zero (if the stat |
|
|
622 | was successful then nlink is guaranteed to be non-zero). |
|
|
623 | |
|
|
624 | See also the next two entries for more info. |
|
|
625 | |
|
|
626 | =item ... = $w->attr |
|
|
627 | |
|
|
628 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
629 | the values most recently detected by EV. See the next entry for more info. |
|
|
630 | |
|
|
631 | =item ... = $w->prev |
|
|
632 | |
|
|
633 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
634 | the previous set of values, before the change. |
|
|
635 | |
|
|
636 | That is, when the watcher callback is invoked, C<< $w->prev >> will be set |
|
|
637 | to the values found I<before> a change was detected, while C<< $w->attr >> |
|
|
638 | returns the values found leading to the change detection. The difference (if any) |
|
|
639 | between C<prev> and C<attr> is what triggered the callback. |
|
|
640 | |
|
|
641 | If you did something to the filesystem object and do not want to trigger |
|
|
642 | yet another change, you can call C<stat> to update EV's idea of what the |
|
|
643 | current attributes are. |
|
|
644 | |
|
|
645 | =item $w->set ($path, $interval) |
|
|
646 | |
|
|
647 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
648 | called at any time. |
|
|
649 | |
|
|
650 | =item $current_path = $w->path |
|
|
651 | |
|
|
652 | =item $old_path = $w->path ($new_path) |
|
|
653 | |
|
|
654 | Returns the previously set path and optionally set a new one. |
|
|
655 | |
|
|
656 | =item $current_interval = $w->interval |
|
|
657 | |
|
|
658 | =item $old_interval = $w->interval ($new_interval) |
|
|
659 | |
|
|
660 | Returns the previously set interval and optionally set a new one. Can be |
|
|
661 | used to query the actual interval used. |
|
|
662 | |
|
|
663 | =back |
|
|
664 | |
|
|
665 | |
|
|
666 | =head3 IDLE WATCHERS - when you've got nothing better to do... |
|
|
667 | |
|
|
668 | =over 4 |
456 | |
669 | |
457 | =item $w = EV::idle $callback |
670 | =item $w = EV::idle $callback |
458 | |
671 | |
459 | =item $w = EV::idle_ns $callback |
672 | =item $w = EV::idle_ns $callback |
460 | |
673 | |
461 | Call the callback when there are no pending io, timer/periodic, signal or |
674 | Call the callback when there are no other pending watchers of the same or |
462 | child events, i.e. when the process is idle. |
675 | higher priority (excluding check, prepare and other idle watchers of the |
|
|
676 | same or lower priority, of course). They are called idle watchers because |
|
|
677 | when the watcher is the highest priority pending event in the process, the |
|
|
678 | process is considered to be idle at that priority. |
|
|
679 | |
|
|
680 | If you want a watcher that is only ever called when I<no> other events are |
|
|
681 | outstanding you have to set the priority to C<EV::MINPRI>. |
463 | |
682 | |
464 | The process will not block as long as any idle watchers are active, and |
683 | The process will not block as long as any idle watchers are active, and |
465 | they will be called repeatedly until stopped. |
684 | they will be called repeatedly until stopped. |
466 | |
685 | |
|
|
686 | For example, if you have idle watchers at priority C<0> and C<1>, and |
|
|
687 | an I/O watcher at priority C<0>, then the idle watcher at priority C<1> |
|
|
688 | and the I/O watcher will always run when ready. Only when the idle watcher |
|
|
689 | at priority C<1> is stopped and the I/O watcher at priority C<0> is not |
|
|
690 | pending with the C<0>-priority idle watcher be invoked. |
|
|
691 | |
467 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
692 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
468 | |
693 | |
|
|
694 | =back |
|
|
695 | |
|
|
696 | |
|
|
697 | =head3 PREPARE WATCHERS - customise your event loop! |
|
|
698 | |
|
|
699 | =over 4 |
469 | |
700 | |
470 | =item $w = EV::prepare $callback |
701 | =item $w = EV::prepare $callback |
471 | |
702 | |
472 | =item $w = EV::prepare_ns $callback |
703 | =item $w = EV::prepare_ns $callback |
473 | |
704 | |
… | |
… | |
476 | |
707 | |
477 | See the EV::check watcher, below, for explanations and an example. |
708 | See the EV::check watcher, below, for explanations and an example. |
478 | |
709 | |
479 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
710 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
480 | |
711 | |
|
|
712 | =back |
|
|
713 | |
|
|
714 | |
|
|
715 | =head3 CHECK WATCHERS - customise your event loop even more! |
|
|
716 | |
|
|
717 | =over 4 |
481 | |
718 | |
482 | =item $w = EV::check $callback |
719 | =item $w = EV::check $callback |
483 | |
720 | |
484 | =item $w = EV::check_ns $callback |
721 | =item $w = EV::check_ns $callback |
485 | |
722 | |
… | |
… | |
497 | # do nothing unless active |
734 | # do nothing unless active |
498 | $dispatcher->{_event_queue_h} |
735 | $dispatcher->{_event_queue_h} |
499 | or return; |
736 | or return; |
500 | |
737 | |
501 | # make the dispatcher handle any outstanding stuff |
738 | # make the dispatcher handle any outstanding stuff |
|
|
739 | ... not shown |
502 | |
740 | |
503 | # create an IO watcher for each and every socket |
741 | # create an I/O watcher for each and every socket |
504 | @snmp_watcher = ( |
742 | @snmp_watcher = ( |
505 | (map { EV::io $_, EV::READ, sub { } } |
743 | (map { EV::io $_, EV::READ, sub { } } |
506 | keys %{ $dispatcher->{_descriptors} }), |
744 | keys %{ $dispatcher->{_descriptors} }), |
|
|
745 | |
|
|
746 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
|
|
747 | ? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0), |
|
|
748 | 0, sub { }, |
507 | ); |
749 | ); |
508 | |
|
|
509 | # if there are any timeouts, also create a timer |
|
|
510 | push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { } |
|
|
511 | if $event->[Net::SNMP::Dispatcher::_ACTIVE]; |
|
|
512 | }; |
750 | }; |
513 | |
751 | |
514 | The callbacks are irrelevant, the only purpose of those watchers is |
752 | The callbacks are irrelevant (and are not even being called), the |
515 | to wake up the process as soon as one of those events occurs (socket |
753 | only purpose of those watchers is to wake up the process as soon as |
516 | readable, or timer timed out). The corresponding EV::check watcher will then |
754 | one of those events occurs (socket readable, or timer timed out). The |
517 | clean up: |
755 | corresponding EV::check watcher will then clean up: |
518 | |
756 | |
519 | our $snmp_check = EV::check sub { |
757 | our $snmp_check = EV::check sub { |
520 | # destroy all watchers |
758 | # destroy all watchers |
521 | @snmp_watcher = (); |
759 | @snmp_watcher = (); |
522 | |
760 | |
523 | # make the dispatcher handle any new stuff |
761 | # make the dispatcher handle any new stuff |
|
|
762 | ... not shown |
524 | }; |
763 | }; |
525 | |
764 | |
526 | The callbacks of the created watchers will not be called as the watchers |
765 | The callbacks of the created watchers will not be called as the watchers |
527 | are destroyed before this cna happen (remember EV::check gets called |
766 | are destroyed before this cna happen (remember EV::check gets called |
528 | first). |
767 | first). |
529 | |
768 | |
530 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
769 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
531 | |
770 | |
532 | =back |
771 | =back |
533 | |
772 | |
|
|
773 | |
|
|
774 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
|
|
775 | |
|
|
776 | Fork watchers are called when a C<fork ()> was detected. The invocation |
|
|
777 | is done before the event loop blocks next and before C<check> watchers |
|
|
778 | are being called, and only in the child after the fork. |
|
|
779 | |
|
|
780 | =over 4 |
|
|
781 | |
|
|
782 | =item $w = EV::fork $callback |
|
|
783 | |
|
|
784 | =item $w = EV::fork_ns $callback |
|
|
785 | |
|
|
786 | Call the callback before the event loop is resumed in the child process |
|
|
787 | after a fork. |
|
|
788 | |
|
|
789 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
|
|
790 | |
|
|
791 | =back |
|
|
792 | |
|
|
793 | |
|
|
794 | =head1 PERL SIGNALS |
|
|
795 | |
|
|
796 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
|
|
797 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
798 | handled when Perl runs, which means your signal handler might be invoked |
|
|
799 | only the next time an event callback is invoked. |
|
|
800 | |
|
|
801 | The solution is to use EV signal watchers (see C<EV::signal>), which will |
|
|
802 | ensure proper operations with regards to other event watchers. |
|
|
803 | |
|
|
804 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
805 | to be called on every event loop iteration by installing a C<EV::check> |
|
|
806 | watcher: |
|
|
807 | |
|
|
808 | my $async_check = EV::check sub { }; |
|
|
809 | |
|
|
810 | This ensures that perl shortly gets into control for a short time, and |
|
|
811 | also ensures slower overall operation. |
|
|
812 | |
534 | =head1 THREADS |
813 | =head1 THREADS |
535 | |
814 | |
536 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
815 | Threads are not supported by this module in any way. Perl pseudo-threads |
537 | stuff and must die. |
816 | is evil stuff and must die. As soon as Perl gains real threads I will work |
|
|
817 | on thread support for it. |
|
|
818 | |
|
|
819 | =head1 FORK |
|
|
820 | |
|
|
821 | Most of the "improved" event delivering mechanisms of modern operating |
|
|
822 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
|
|
823 | not supported and usually destructive). Libev makes it possible to work |
|
|
824 | around this by having a function that recreates the kernel state after |
|
|
825 | fork in the child. |
|
|
826 | |
|
|
827 | On non-win32 platforms, this module requires the pthread_atfork |
|
|
828 | functionality to do this automatically for you. This function is quite |
|
|
829 | buggy on most BSDs, though, so YMMV. The overhead for this is quite |
|
|
830 | negligible, because everything the function currently does is set a flag |
|
|
831 | that is checked only when the event loop gets used the next time, so when |
|
|
832 | you do fork but not use EV, the overhead is minimal. |
|
|
833 | |
|
|
834 | On win32, there is no notion of fork so all this doesn't apply, of course. |
538 | |
835 | |
539 | =cut |
836 | =cut |
540 | |
837 | |
541 | our $DIED = sub { |
838 | our $DIED = sub { |
542 | warn "EV: error in callback (ignoring): $@"; |
839 | warn "EV: error in callback (ignoring): $@"; |
543 | }; |
840 | }; |
544 | |
841 | |
545 | default_loop |
842 | default_loop |
546 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; |
843 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?'; |
547 | |
844 | |
548 | 1; |
845 | 1; |
549 | |
846 | |
550 | =head1 SEE ALSO |
847 | =head1 SEE ALSO |
551 | |
848 | |
552 | L<EV::DNS>, L<EV::AnyEvent>. |
849 | L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as |
|
|
850 | event loop), L<Coro::EV> (efficient coroutines with EV). |
553 | |
851 | |
554 | =head1 AUTHOR |
852 | =head1 AUTHOR |
555 | |
853 | |
556 | Marc Lehmann <schmorp@schmorp.de> |
854 | Marc Lehmann <schmorp@schmorp.de> |
557 | http://home.schmorp.de/ |
855 | http://home.schmorp.de/ |