… | |
… | |
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 { |
|
|
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 | }; |
|
|
44 | |
|
|
45 | # STAT CHANGES |
|
|
46 | my $w = EV::stat "/etc/passwd", 10, sub { |
|
|
47 | my ($w, $revents) = @_; |
|
|
48 | warn $w->path, " has changed somehow.\n"; |
|
|
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 |
|
|
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 |
|
|
62 | watcher semantics or some discussion on the available backends, or how to |
|
|
63 | force a specific backend with C<LIBEV_FLAGS>. |
59 | |
64 | |
60 | =cut |
65 | =cut |
61 | |
66 | |
62 | package EV; |
67 | package EV; |
63 | |
68 | |
64 | use strict; |
69 | use strict; |
65 | |
70 | |
66 | BEGIN { |
71 | BEGIN { |
67 | our $VERSION = '0.6'; |
72 | our $VERSION = '1.6'; |
68 | use XSLoader; |
73 | use XSLoader; |
69 | XSLoader::load "EV", $VERSION; |
74 | XSLoader::load "EV", $VERSION; |
70 | } |
75 | } |
71 | |
76 | |
72 | @EV::Io::ISA = |
77 | @EV::IO::ISA = |
73 | @EV::Timer::ISA = |
78 | @EV::Timer::ISA = |
74 | @EV::Periodic::ISA = |
79 | @EV::Periodic::ISA = |
75 | @EV::Signal::ISA = |
80 | @EV::Signal::ISA = |
|
|
81 | @EV::Child::ISA = |
|
|
82 | @EV::Stat::ISA = |
76 | @EV::Idle::ISA = |
83 | @EV::Idle::ISA = |
77 | @EV::Prepare::ISA = |
84 | @EV::Prepare::ISA = |
78 | @EV::Check::ISA = |
85 | @EV::Check::ISA = |
79 | @EV::Child::ISA = "EV::Watcher"; |
86 | @EV::Embed::ISA = |
|
|
87 | @EV::Fork::ISA = |
|
|
88 | "EV::Watcher"; |
80 | |
89 | |
81 | =head1 BASIC INTERFACE |
90 | =head1 BASIC INTERFACE |
82 | |
91 | |
83 | =over 4 |
92 | =over 4 |
84 | |
93 | |
… | |
… | |
98 | |
107 | |
99 | Returns the time the last event loop iteration has been started. This |
108 | 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 |
109 | is the time that (relative) timers are based on, and refering to it is |
101 | usually faster then calling EV::time. |
110 | usually faster then calling EV::time. |
102 | |
111 | |
103 | =item $method = EV::ev_method |
112 | =item $method = EV::method |
104 | |
113 | |
105 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
114 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
106 | or EV::METHOD_EPOLL). |
115 | or EV::METHOD_EPOLL). |
107 | |
116 | |
108 | =item EV::loop [$flags] |
117 | =item EV::loop [$flags] |
109 | |
118 | |
110 | Begin checking for events and calling callbacks. It returns when a |
119 | Begin checking for events and calling callbacks. It returns when a |
111 | callback calls EV::loop_done. |
120 | callback calls EV::unloop. |
112 | |
121 | |
113 | The $flags argument can be one of the following: |
122 | The $flags argument can be one of the following: |
114 | |
123 | |
115 | 0 as above |
124 | 0 as above |
116 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
125 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
117 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
126 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
118 | |
127 | |
119 | =item EV::loop_done [$how] |
128 | =item EV::unloop [$how] |
120 | |
129 | |
121 | When called with no arguments or an argument of 1, makes the innermost |
130 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
122 | call to EV::loop return. |
131 | innermost call to EV::loop return. |
123 | |
132 | |
124 | When called with an agrument of 2, all calls to EV::loop will return as |
133 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
125 | fast as possible. |
134 | fast as possible. |
126 | |
135 | |
127 | =back |
136 | =item $count = EV::loop_count |
128 | |
137 | |
|
|
138 | Return the number of times the event loop has polled for new |
|
|
139 | events. Sometiems useful as a generation counter. |
|
|
140 | |
|
|
141 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
|
|
142 | |
|
|
143 | This function rolls together an I/O and a timer watcher for a single |
|
|
144 | one-shot event without the need for managing a watcher object. |
|
|
145 | |
|
|
146 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
|
|
147 | must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ |
|
|
148 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
|
|
149 | you do not want to wait for some I/O event, specify C<undef> for |
|
|
150 | C<$fh_or_undef> and C<0> for C<$events>). |
|
|
151 | |
|
|
152 | If timeout is C<undef> or negative, then there will be no |
|
|
153 | timeout. Otherwise a EV::timer with this value will be started. |
|
|
154 | |
|
|
155 | When an error occurs or either the timeout or I/O watcher triggers, then |
|
|
156 | the callback will be called with the received event set (in general |
|
|
157 | you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, |
|
|
158 | C<EV::WRITE> and C<EV::TIMEOUT>). |
|
|
159 | |
|
|
160 | EV::once doesn't return anything: the watchers stay active till either |
|
|
161 | of them triggers, then they will be stopped and freed, and the callback |
|
|
162 | invoked. |
|
|
163 | |
|
|
164 | =back |
|
|
165 | |
129 | =head2 WATCHER |
166 | =head2 WATCHER OBJECTS |
130 | |
167 | |
131 | A watcher is an object that gets created to record your interest in some |
168 | 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 |
169 | event. For instance, if you want to wait for STDIN to become readable, you |
133 | would create an EV::io watcher for that: |
170 | would create an EV::io watcher for that: |
134 | |
171 | |
… | |
… | |
159 | |
196 | |
160 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
197 | 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, |
198 | ->fh and so on) automatically stop and start it again if it is active, |
162 | which means pending events get lost. |
199 | which means pending events get lost. |
163 | |
200 | |
164 | =head2 WATCHER TYPES |
201 | =head2 COMMON WATCHER METHODS |
165 | |
202 | |
166 | Now lets move to the existing watcher types and asociated methods. |
203 | This section lists methods common to all watchers. |
167 | |
|
|
168 | The following methods are available for all watchers. Then followes a |
|
|
169 | description of each watcher constructor (EV::io, EV::timer, EV::periodic, |
|
|
170 | EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by |
|
|
171 | any type-specific methods (if any). |
|
|
172 | |
204 | |
173 | =over 4 |
205 | =over 4 |
174 | |
206 | |
175 | =item $w->start |
207 | =item $w->start |
176 | |
208 | |
… | |
… | |
215 | watchers with higher priority will be invoked first. The valid range of |
247 | watchers with higher priority will be invoked first. The valid range of |
216 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
248 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
217 | -2). If the priority is outside this range it will automatically be |
249 | -2). If the priority is outside this range it will automatically be |
218 | normalised to the nearest valid priority. |
250 | normalised to the nearest valid priority. |
219 | |
251 | |
220 | The default priority of any newly-created weatcher is 0. |
252 | The default priority of any newly-created watcher is 0. |
|
|
253 | |
|
|
254 | Note that the priority semantics have not yet been fleshed out and are |
|
|
255 | subject to almost certain change. |
221 | |
256 | |
222 | =item $w->trigger ($revents) |
257 | =item $w->trigger ($revents) |
223 | |
258 | |
224 | Call the callback *now* with the given event mask. |
259 | Call the callback *now* with the given event mask. |
225 | |
260 | |
|
|
261 | =item $previous_state = $w->keepalive ($bool) |
|
|
262 | |
|
|
263 | Normally, C<EV::loop> will return when there are no active watchers |
|
|
264 | (which is a "deadlock" because no progress can be made anymore). This is |
|
|
265 | convinient because it allows you to start your watchers (and your jobs), |
|
|
266 | call C<EV::loop> once and when it returns you know that all your jobs are |
|
|
267 | finished (or they forgot to register some watchers for their task :). |
|
|
268 | |
|
|
269 | Sometimes, however, this gets in your way, for example when you the module |
|
|
270 | that calls C<EV::loop> (usually the main program) is not the same module |
|
|
271 | as a long-living watcher (for example a DNS client module written by |
|
|
272 | somebody else even). Then you might want any outstanding requests to be |
|
|
273 | handled, but you would not want to keep C<EV::loop> from returning just |
|
|
274 | because you happen to have this long-running UDP port watcher. |
|
|
275 | |
|
|
276 | In this case you can clear the keepalive status, which means that even |
|
|
277 | though your watcher is active, it won't keep C<EV::loop> from returning. |
|
|
278 | |
|
|
279 | The initial value for keepalive is true (enabled), and you cna change it |
|
|
280 | any time. |
|
|
281 | |
|
|
282 | Example: Register an IO watcher for some UDP socket but do not keep the |
|
|
283 | event loop from running just because of that watcher. |
|
|
284 | |
|
|
285 | my $udp_socket = ... |
|
|
286 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
|
|
287 | $udp_watcher->keepalive (0); |
|
|
288 | |
|
|
289 | =back |
|
|
290 | |
|
|
291 | |
|
|
292 | =head2 WATCHER TYPES |
|
|
293 | |
|
|
294 | Each of the following subsections describes a single watcher type. |
|
|
295 | |
|
|
296 | =head3 IO WATCHERS - is this file descriptor readable or writable? |
|
|
297 | |
|
|
298 | =over 4 |
226 | |
299 | |
227 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
300 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
228 | |
301 | |
229 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
302 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
230 | |
303 | |
231 | As long as the returned watcher object is alive, call the C<$callback> |
304 | As long as the returned watcher object is alive, call the C<$callback> |
232 | when the events specified in C<$eventmask>. |
305 | when at least one of events specified in C<$eventmask> occurs. |
233 | |
306 | |
234 | The $eventmask can be one or more of these constants ORed together: |
307 | The $eventmask can be one or more of these constants ORed together: |
235 | |
308 | |
236 | EV::READ wait until read() wouldn't block anymore |
309 | EV::READ wait until read() wouldn't block anymore |
237 | EV::WRITE wait until write() wouldn't block anymore |
310 | EV::WRITE wait until write() wouldn't block anymore |
… | |
… | |
253 | |
326 | |
254 | =item $old_eventmask = $w->events ($new_eventmask) |
327 | =item $old_eventmask = $w->events ($new_eventmask) |
255 | |
328 | |
256 | Returns the previously set event mask and optionally set a new one. |
329 | Returns the previously set event mask and optionally set a new one. |
257 | |
330 | |
|
|
331 | =back |
|
|
332 | |
|
|
333 | |
|
|
334 | =head3 TIMER WATCHERS - relative and optionally repeating timeouts |
|
|
335 | |
|
|
336 | =over 4 |
258 | |
337 | |
259 | =item $w = EV::timer $after, $repeat, $callback |
338 | =item $w = EV::timer $after, $repeat, $callback |
260 | |
339 | |
261 | =item $w = EV::timer_ns $after, $repeat, $callback |
340 | =item $w = EV::timer_ns $after, $repeat, $callback |
262 | |
341 | |
263 | Calls the callback after C<$after> seconds. If C<$repeat> is non-zero, |
342 | Calls the callback after C<$after> seconds (which may be fractional). If |
264 | the timer will be restarted (with the $repeat value as $after) after the |
343 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
265 | callback returns. |
344 | value as $after) after the callback returns. |
266 | |
345 | |
267 | This means that the callback would be called roughly after C<$after> |
346 | 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 |
347 | 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 |
348 | 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. |
349 | loop iteration, and might drift in other cases. If that isn't acceptable, |
|
|
350 | look at EV::periodic, which can provide long-term stable timers. |
271 | |
351 | |
272 | The timer is based on a monotonic clock, that is if somebody is sitting |
352 | 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 |
353 | 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. |
354 | clock, the timer will nevertheless run (roughly) the same time. |
275 | |
355 | |
276 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
356 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
277 | |
357 | |
278 | =item $w->set ($after, $repeat) |
358 | =item $w->set ($after, $repeat) |
279 | |
359 | |
280 | Reconfigures the watcher, see the constructor above for details. Can be at |
360 | Reconfigures the watcher, see the constructor above for details. Can be called at |
281 | any time. |
361 | any time. |
282 | |
362 | |
283 | =item $w->again |
363 | =item $w->again |
284 | |
364 | |
285 | Similar to the C<start> method, but has special semantics for repeating timers: |
365 | Similar to the C<start> method, but has special semantics for repeating timers: |
|
|
366 | |
|
|
367 | If the timer is active and non-repeating, it will be stopped. |
286 | |
368 | |
287 | If the timer is active and repeating, reset the timeout to occur |
369 | If the timer is active and repeating, reset the timeout to occur |
288 | C<$repeat> seconds after now. |
370 | C<$repeat> seconds after now. |
289 | |
371 | |
290 | If the timer is active and non-repeating, it will be stopped. |
|
|
291 | |
|
|
292 | If the timer is in active and repeating, start it. |
372 | If the timer is inactive and repeating, start it using the repeat value. |
293 | |
373 | |
294 | Otherwise do nothing. |
374 | Otherwise do nothing. |
295 | |
375 | |
296 | This behaviour is useful when you have a timeout for some IO |
376 | This behaviour is useful when you have a timeout for some IO |
297 | operation. You create a timer object with the same value for C<$after> and |
377 | 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 |
378 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
299 | on the timeout. |
379 | on the timeout. |
300 | |
380 | |
|
|
381 | =back |
|
|
382 | |
|
|
383 | |
|
|
384 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
|
|
385 | |
|
|
386 | =over 4 |
301 | |
387 | |
302 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
388 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
303 | |
389 | |
304 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
390 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
305 | |
391 | |
… | |
… | |
341 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
427 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
342 | jumps. |
428 | jumps. |
343 | |
429 | |
344 | =item * manual reschedule mode ($reschedule_cb = coderef) |
430 | =item * manual reschedule mode ($reschedule_cb = coderef) |
345 | |
431 | |
346 | In this mode $interval and $at are both being ignored. Instead, each time |
432 | In this mode $interval and $at are both being ignored. Instead, each |
347 | the periodic watcher gets scheduled, the first callback ($reschedule_cb) |
433 | time the periodic watcher gets scheduled, the reschedule callback |
348 | will be called with the watcher as first, and the current time as second |
434 | ($reschedule_cb) will be called with the watcher as first, and the current |
349 | argument. |
435 | time as second argument. |
350 | |
436 | |
351 | I<This callback MUST NOT stop or destroy this or any other periodic |
437 | 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 |
438 | watcher, ever>. If you need to stop it, return 1e30 and stop it |
353 | afterwards. |
439 | afterwards. |
354 | |
440 | |
… | |
… | |
377 | |
463 | |
378 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
464 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
379 | |
465 | |
380 | =item $w->set ($at, $interval, $reschedule_cb) |
466 | =item $w->set ($at, $interval, $reschedule_cb) |
381 | |
467 | |
382 | Reconfigures the watcher, see the constructor above for details. Can be at |
468 | Reconfigures the watcher, see the constructor above for details. Can be called at |
383 | any time. |
469 | any time. |
384 | |
470 | |
385 | =item $w->again |
471 | =item $w->again |
386 | |
472 | |
387 | Simply stops and starts the watcher again. |
473 | Simply stops and starts the watcher again. |
388 | |
474 | |
|
|
475 | =back |
|
|
476 | |
|
|
477 | |
|
|
478 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
|
|
479 | |
|
|
480 | =over 4 |
389 | |
481 | |
390 | =item $w = EV::signal $signal, $callback |
482 | =item $w = EV::signal $signal, $callback |
391 | |
483 | |
392 | =item $w = EV::signal_ns $signal, $callback |
484 | =item $w = EV::signal_ns $signal, $callback |
393 | |
485 | |
394 | Call the callback when $signal is received (the signal can be specified |
486 | 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). |
487 | number or by name, just as with C<kill> or C<%SIG>). |
396 | |
488 | |
397 | EV will grab the signal for the process (the kernel only allows one |
489 | 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, |
490 | 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 |
491 | and removes it again when you stop it. Perl does the same when you |
400 | add/remove callbacks to %SIG, so watch out. |
492 | add/remove callbacks to C<%SIG>, so watch out. |
401 | |
493 | |
402 | You can have as many signal watchers per signal as you want. |
494 | You can have as many signal watchers per signal as you want. |
403 | |
495 | |
404 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
496 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
405 | |
497 | |
406 | =item $w->set ($signal) |
498 | =item $w->set ($signal) |
407 | |
499 | |
408 | Reconfigures the watcher, see the constructor above for details. Can be at |
500 | Reconfigures the watcher, see the constructor above for details. Can be |
409 | any time. |
501 | called at any time. |
410 | |
502 | |
411 | =item $current_signum = $w->signal |
503 | =item $current_signum = $w->signal |
412 | |
504 | |
413 | =item $old_signum = $w->signal ($new_signal) |
505 | =item $old_signum = $w->signal ($new_signal) |
414 | |
506 | |
415 | Returns the previously set signal (always as a number not name) and |
507 | Returns the previously set signal (always as a number not name) and |
416 | optionally set a new one. |
508 | optionally set a new one. |
417 | |
509 | |
|
|
510 | =back |
|
|
511 | |
|
|
512 | |
|
|
513 | =head3 CHILD WATCHERS - watch out for process status changes |
|
|
514 | |
|
|
515 | =over 4 |
418 | |
516 | |
419 | =item $w = EV::child $pid, $callback |
517 | =item $w = EV::child $pid, $callback |
420 | |
518 | |
421 | =item $w = EV::child_ns $pid, $callback |
519 | =item $w = EV::child_ns $pid, $callback |
422 | |
520 | |
423 | Call the callback when a status change for pid C<$pid> (or any pid |
521 | 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 |
522 | 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 |
523 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
426 | changed/zombie children and call the callback. |
524 | changed/zombie children and call the callback. |
427 | |
525 | |
428 | You can access both status and pid by using the C<rstatus> and C<rpid> |
526 | It is valid (and fully supported) to install a child watcher after a child |
429 | methods on the watcher object. |
527 | has exited but before the event loop has started its next iteration (for |
|
|
528 | example, first you C<fork>, then the new child process might exit, and |
|
|
529 | only then do you install a child watcher in the parent for the new pid). |
430 | |
530 | |
|
|
531 | You can access both exit (or tracing) status and pid by using the |
|
|
532 | C<rstatus> and C<rpid> methods on the watcher object. |
|
|
533 | |
431 | You can have as many pid watchers per pid as you want. |
534 | You can have as many pid watchers per pid as you want, they will all be |
|
|
535 | called. |
432 | |
536 | |
433 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
537 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
434 | |
538 | |
435 | =item $w->set ($pid) |
539 | =item $w->set ($pid) |
436 | |
540 | |
437 | Reconfigures the watcher, see the constructor above for details. Can be at |
541 | Reconfigures the watcher, see the constructor above for details. Can be called at |
438 | any time. |
542 | any time. |
439 | |
543 | |
440 | =item $current_pid = $w->pid |
544 | =item $current_pid = $w->pid |
441 | |
545 | |
442 | =item $old_pid = $w->pid ($new_pid) |
546 | =item $old_pid = $w->pid ($new_pid) |
… | |
… | |
451 | =item $pid = $w->rpid |
555 | =item $pid = $w->rpid |
452 | |
556 | |
453 | Return the pid of the awaited child (useful when you have installed a |
557 | Return the pid of the awaited child (useful when you have installed a |
454 | watcher for all pids). |
558 | watcher for all pids). |
455 | |
559 | |
|
|
560 | =back |
|
|
561 | |
|
|
562 | |
|
|
563 | =head3 STAT WATCHERS - did the file attributes just change? |
|
|
564 | |
|
|
565 | =over 4 |
|
|
566 | |
|
|
567 | =item $w = EV::stat $path, $interval, $callback |
|
|
568 | |
|
|
569 | =item $w = EV::stat_ns $path, $interval, $callback |
|
|
570 | |
|
|
571 | Call the callback when a file status change has been detected on |
|
|
572 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
|
|
573 | to "path does not exist" is a status change like any other. |
|
|
574 | |
|
|
575 | The C<$interval> is a recommended polling interval for systems where |
|
|
576 | OS-supported change notifications don't exist or are not supported. If |
|
|
577 | you use C<0> then an unspecified default is used (which is highly |
|
|
578 | recommended!), which is to be expected to be around five seconds usually. |
|
|
579 | |
|
|
580 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
581 | as even with OS-supported change notifications, this can be |
|
|
582 | resource-intensive. |
|
|
583 | |
|
|
584 | The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
|
|
585 | |
|
|
586 | =item ... = $w->stat |
|
|
587 | |
|
|
588 | This call is very similar to the perl C<stat> built-in: It stats (using |
|
|
589 | C<lstat>) the path specified in the watcher and sets perls stat cache (as |
|
|
590 | well as EV's idea of the current stat values) to the values found. |
|
|
591 | |
|
|
592 | In scalar context, a boolean is return indicating success or failure of |
|
|
593 | the stat. In list context, the same 13-value list as with stat is returned |
|
|
594 | (except that the blksize and blocks fields are not reliable). |
|
|
595 | |
|
|
596 | In the case of an error, errno is set to C<ENOENT> (regardless of the |
|
|
597 | actual error value) and the C<nlink> value is forced to zero (if the stat |
|
|
598 | was successful then nlink is guaranteed to be non-zero). |
|
|
599 | |
|
|
600 | See also the next two entries for more info. |
|
|
601 | |
|
|
602 | =item ... = $w->attr |
|
|
603 | |
|
|
604 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
605 | the values most recently detected by EV. See the next entry for more info. |
|
|
606 | |
|
|
607 | =item ... = $w->prev |
|
|
608 | |
|
|
609 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
610 | the previous set of values, before the change. |
|
|
611 | |
|
|
612 | That is, when the watcher callback is invoked, C<< $w->prev >> will be set |
|
|
613 | to the values found I<before> a change was detected, while C<< $w->attr >> |
|
|
614 | returns the values found leading to the change detection. The difference (if any) |
|
|
615 | between C<prev> and C<attr> is what triggered the callback. |
|
|
616 | |
|
|
617 | If you did something to the filesystem object and do not want to trigger |
|
|
618 | yet another change, you can call C<stat> to update EV's idea of what the |
|
|
619 | current attributes are. |
|
|
620 | |
|
|
621 | =item $w->set ($path, $interval) |
|
|
622 | |
|
|
623 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
624 | called at any time. |
|
|
625 | |
|
|
626 | =item $current_path = $w->path |
|
|
627 | |
|
|
628 | =item $old_path = $w->path ($new_path) |
|
|
629 | |
|
|
630 | Returns the previously set path and optionally set a new one. |
|
|
631 | |
|
|
632 | =item $current_interval = $w->interval |
|
|
633 | |
|
|
634 | =item $old_interval = $w->interval ($new_interval) |
|
|
635 | |
|
|
636 | Returns the previously set interval and optionally set a new one. Can be |
|
|
637 | used to query the actual interval used. |
|
|
638 | |
|
|
639 | =back |
|
|
640 | |
|
|
641 | |
|
|
642 | =head3 IDLE WATCHERS - when you've got nothing better to do... |
|
|
643 | |
|
|
644 | =over 4 |
456 | |
645 | |
457 | =item $w = EV::idle $callback |
646 | =item $w = EV::idle $callback |
458 | |
647 | |
459 | =item $w = EV::idle_ns $callback |
648 | =item $w = EV::idle_ns $callback |
460 | |
649 | |
… | |
… | |
464 | The process will not block as long as any idle watchers are active, and |
653 | The process will not block as long as any idle watchers are active, and |
465 | they will be called repeatedly until stopped. |
654 | they will be called repeatedly until stopped. |
466 | |
655 | |
467 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
656 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
468 | |
657 | |
|
|
658 | =back |
|
|
659 | |
|
|
660 | |
|
|
661 | =head3 PREPARE WATCHERS - customise your event loop! |
|
|
662 | |
|
|
663 | =over 4 |
469 | |
664 | |
470 | =item $w = EV::prepare $callback |
665 | =item $w = EV::prepare $callback |
471 | |
666 | |
472 | =item $w = EV::prepare_ns $callback |
667 | =item $w = EV::prepare_ns $callback |
473 | |
668 | |
… | |
… | |
476 | |
671 | |
477 | See the EV::check watcher, below, for explanations and an example. |
672 | See the EV::check watcher, below, for explanations and an example. |
478 | |
673 | |
479 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
674 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
480 | |
675 | |
|
|
676 | =back |
|
|
677 | |
|
|
678 | |
|
|
679 | =head3 CHECK WATCHERS - customise your event loop even more! |
|
|
680 | |
|
|
681 | =over 4 |
481 | |
682 | |
482 | =item $w = EV::check $callback |
683 | =item $w = EV::check $callback |
483 | |
684 | |
484 | =item $w = EV::check_ns $callback |
685 | =item $w = EV::check_ns $callback |
485 | |
686 | |
… | |
… | |
497 | # do nothing unless active |
698 | # do nothing unless active |
498 | $dispatcher->{_event_queue_h} |
699 | $dispatcher->{_event_queue_h} |
499 | or return; |
700 | or return; |
500 | |
701 | |
501 | # make the dispatcher handle any outstanding stuff |
702 | # make the dispatcher handle any outstanding stuff |
|
|
703 | ... not shown |
502 | |
704 | |
503 | # create an IO watcher for each and every socket |
705 | # create an IO watcher for each and every socket |
504 | @snmp_watcher = ( |
706 | @snmp_watcher = ( |
505 | (map { EV::io $_, EV::READ, sub { } } |
707 | (map { EV::io $_, EV::READ, sub { } } |
506 | keys %{ $dispatcher->{_descriptors} }), |
708 | keys %{ $dispatcher->{_descriptors} }), |
|
|
709 | |
|
|
710 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
|
|
711 | ? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0), |
|
|
712 | 0, sub { }, |
507 | ); |
713 | ); |
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 | }; |
714 | }; |
513 | |
715 | |
514 | The callbacks are irrelevant, the only purpose of those watchers is |
716 | 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 |
717 | 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 |
718 | one of those events occurs (socket readable, or timer timed out). The |
517 | clean up: |
719 | corresponding EV::check watcher will then clean up: |
518 | |
720 | |
519 | our $snmp_check = EV::check sub { |
721 | our $snmp_check = EV::check sub { |
520 | # destroy all watchers |
722 | # destroy all watchers |
521 | @snmp_watcher = (); |
723 | @snmp_watcher = (); |
522 | |
724 | |
523 | # make the dispatcher handle any new stuff |
725 | # make the dispatcher handle any new stuff |
|
|
726 | ... not shown |
524 | }; |
727 | }; |
525 | |
728 | |
526 | The callbacks of the created watchers will not be called as the watchers |
729 | 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 |
730 | are destroyed before this cna happen (remember EV::check gets called |
528 | first). |
731 | first). |
529 | |
732 | |
530 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
733 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
531 | |
734 | |
532 | =back |
735 | =back |
533 | |
736 | |
|
|
737 | |
|
|
738 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
|
|
739 | |
|
|
740 | Fork watchers are called when a C<fork ()> was detected. The invocation |
|
|
741 | is done before the event loop blocks next and before C<check> watchers |
|
|
742 | are being called, and only in the child after the fork. |
|
|
743 | |
|
|
744 | =over 4 |
|
|
745 | |
|
|
746 | =item $w = EV::fork $callback |
|
|
747 | |
|
|
748 | =item $w = EV::fork_ns $callback |
|
|
749 | |
|
|
750 | Call the callback before the event loop is resumed in the child process |
|
|
751 | after a fork. |
|
|
752 | |
|
|
753 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
|
|
754 | |
|
|
755 | =back |
|
|
756 | |
|
|
757 | |
|
|
758 | =head1 PERL SIGNALS |
|
|
759 | |
|
|
760 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
|
|
761 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
762 | handled when Perl runs, which means your signal handler might be invoked |
|
|
763 | only the next time an event callback is invoked. |
|
|
764 | |
|
|
765 | The solution is to use EV signal watchers (see C<EV::signal>), which will |
|
|
766 | ensure proper operations with regards to other event watchers. |
|
|
767 | |
|
|
768 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
769 | to be called on every event loop iteration by installing a C<EV::check> |
|
|
770 | watcher: |
|
|
771 | |
|
|
772 | my $async_check = EV::check sub { }; |
|
|
773 | |
|
|
774 | This ensures that perl shortly gets into control for a short time, and |
|
|
775 | also ensures slower overall operation. |
|
|
776 | |
534 | =head1 THREADS |
777 | =head1 THREADS |
535 | |
778 | |
536 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
779 | Threads are not supported by this module in any way. Perl pseudo-threads |
537 | stuff and must die. |
780 | is evil stuff and must die. As soon as Perl gains real threads I will work |
|
|
781 | on thread support for it. |
|
|
782 | |
|
|
783 | =head1 FORK |
|
|
784 | |
|
|
785 | Most of the "improved" event delivering mechanisms of modern operating |
|
|
786 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
|
|
787 | not supported and usually destructive). Libev makes it possible to work |
|
|
788 | around this by having a function that recreates the kernel state after |
|
|
789 | fork in the child. |
|
|
790 | |
|
|
791 | On non-win32 platforms, this module requires the pthread_atfork |
|
|
792 | functionality to do this automatically for you. This function is quite |
|
|
793 | buggy on most BSDs, though, so YMMV. The overhead for this is quite |
|
|
794 | negligible, because everything the function currently does is set a flag |
|
|
795 | that is checked only when the event loop gets used the next time, so when |
|
|
796 | you do fork but not use EV, the overhead is minimal. |
|
|
797 | |
|
|
798 | On win32, there is no notion of fork so all this doesn't apply, of course. |
538 | |
799 | |
539 | =cut |
800 | =cut |
540 | |
801 | |
541 | our $DIED = sub { |
802 | our $DIED = sub { |
542 | warn "EV: error in callback (ignoring): $@"; |
803 | warn "EV: error in callback (ignoring): $@"; |
… | |
… | |
547 | |
808 | |
548 | 1; |
809 | 1; |
549 | |
810 | |
550 | =head1 SEE ALSO |
811 | =head1 SEE ALSO |
551 | |
812 | |
552 | L<EV::DNS>, L<EV::AnyEvent>. |
813 | L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as |
|
|
814 | event loop), L<Coro::EV> (efficient coroutines with EV). |
553 | |
815 | |
554 | =head1 AUTHOR |
816 | =head1 AUTHOR |
555 | |
817 | |
556 | Marc Lehmann <schmorp@schmorp.de> |
818 | Marc Lehmann <schmorp@schmorp.de> |
557 | http://home.schmorp.de/ |
819 | http://home.schmorp.de/ |