… | |
… | |
39 | |
39 | |
40 | my $w = EV::child 666, sub { |
40 | my $w = EV::child 666, sub { |
41 | my ($w, $revents) = @_; |
41 | my ($w, $revents) = @_; |
42 | my $status = $w->rstatus; |
42 | my $status = $w->rstatus; |
43 | }; |
43 | }; |
|
|
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 | }; |
44 | |
50 | |
45 | # MAINLOOP |
51 | # MAINLOOP |
46 | EV::loop; # loop until EV::unloop is called or all watchers stop |
52 | EV::loop; # loop until EV::unloop is called or all watchers stop |
47 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
53 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
48 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
54 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
49 | |
55 | |
50 | =head1 DESCRIPTION |
56 | =head1 DESCRIPTION |
51 | |
57 | |
52 | This module provides an interface to libev |
58 | This module provides an interface to libev |
53 | (L<http://software.schmorp.de/pkg/libev.html>). |
59 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
|
|
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 |
|
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63 | force a specific backend with C<LIBEV_FLAGS>, or just about in any case |
|
|
64 | because it has much more detailed information. |
54 | |
65 | |
55 | =cut |
66 | =cut |
56 | |
67 | |
57 | package EV; |
68 | package EV; |
58 | |
69 | |
59 | use strict; |
70 | use strict; |
60 | |
71 | |
61 | BEGIN { |
72 | BEGIN { |
62 | our $VERSION = '1.2'; |
73 | our $VERSION = '1.72'; |
63 | use XSLoader; |
74 | use XSLoader; |
64 | XSLoader::load "EV", $VERSION; |
75 | XSLoader::load "EV", $VERSION; |
65 | } |
76 | } |
66 | |
77 | |
67 | @EV::IO::ISA = |
78 | @EV::IO::ISA = |
68 | @EV::Timer::ISA = |
79 | @EV::Timer::ISA = |
69 | @EV::Periodic::ISA = |
80 | @EV::Periodic::ISA = |
70 | @EV::Signal::ISA = |
81 | @EV::Signal::ISA = |
|
|
82 | @EV::Child::ISA = |
|
|
83 | @EV::Stat::ISA = |
71 | @EV::Idle::ISA = |
84 | @EV::Idle::ISA = |
72 | @EV::Prepare::ISA = |
85 | @EV::Prepare::ISA = |
73 | @EV::Check::ISA = |
86 | @EV::Check::ISA = |
74 | @EV::Child::ISA = "EV::Watcher"; |
87 | @EV::Embed::ISA = |
|
|
88 | @EV::Fork::ISA = |
|
|
89 | "EV::Watcher"; |
75 | |
90 | |
76 | =head1 BASIC INTERFACE |
91 | =head1 BASIC INTERFACE |
77 | |
92 | |
78 | =over 4 |
93 | =over 4 |
79 | |
94 | |
… | |
… | |
116 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
131 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
117 | innermost call to EV::loop return. |
132 | innermost call to EV::loop return. |
118 | |
133 | |
119 | When called with an argument of EV::UNLOOP_ALL, 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 |
120 | fast as possible. |
135 | fast as possible. |
|
|
136 | |
|
|
137 | =item $count = EV::loop_count |
|
|
138 | |
|
|
139 | Return the number of times the event loop has polled for new |
|
|
140 | events. Sometiems useful as a generation counter. |
121 | |
141 | |
122 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
142 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
123 | |
143 | |
124 | This function rolls together an I/O and a timer watcher for a single |
144 | This function rolls together an I/O and a timer watcher for a single |
125 | one-shot event without the need for managing a watcher object. |
145 | one-shot event without the need for managing a watcher object. |
… | |
… | |
140 | |
160 | |
141 | EV::once doesn't return anything: the watchers stay active till either |
161 | EV::once doesn't return anything: the watchers stay active till either |
142 | of them triggers, then they will be stopped and freed, and the callback |
162 | of them triggers, then they will be stopped and freed, and the callback |
143 | invoked. |
163 | invoked. |
144 | |
164 | |
145 | =back |
165 | =item EV::feed_fd_event ($fd, $revents) |
146 | |
166 | |
|
|
167 | Feed an event on a file descriptor into EV. EV will react to this call as |
|
|
168 | if the readyness notifications specified by C<$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 | |
|
|
176 | =back |
|
|
177 | |
|
|
178 | |
147 | =head2 WATCHER |
179 | =head2 WATCHER OBJECTS |
148 | |
180 | |
149 | 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 |
150 | 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 |
151 | would create an EV::io watcher for that: |
183 | would create an EV::io watcher for that: |
152 | |
184 | |
… | |
… | |
161 | events. |
193 | events. |
162 | |
194 | |
163 | 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 |
164 | 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 |
165 | 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, |
166 | 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 |
167 | (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 |
168 | uses EV::TIMEOUT). |
200 | uses EV::TIMEOUT). |
169 | |
201 | |
170 | 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 |
171 | 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 |
… | |
… | |
177 | |
209 | |
178 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
210 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
179 | ->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, |
180 | which means pending events get lost. |
212 | which means pending events get lost. |
181 | |
213 | |
182 | =head2 WATCHER TYPES |
214 | =head2 COMMON WATCHER METHODS |
183 | |
215 | |
184 | Now lets move to the existing watcher types and asociated methods. |
216 | This section lists methods common to all watchers. |
185 | |
|
|
186 | The following methods are available for all watchers. Then followes a |
|
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187 | description of each watcher constructor (EV::io, EV::timer, EV::periodic, |
|
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188 | EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by |
|
|
189 | any type-specific methods (if any). |
|
|
190 | |
217 | |
191 | =over 4 |
218 | =over 4 |
192 | |
219 | |
193 | =item $w->start |
220 | =item $w->start |
194 | |
221 | |
… | |
… | |
198 | |
225 | |
199 | =item $w->stop |
226 | =item $w->stop |
200 | |
227 | |
201 | 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 |
202 | 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), |
203 | regardless of wether the watcher was active or not. |
230 | regardless of whether the watcher was active or not. |
204 | |
231 | |
205 | =item $bool = $w->is_active |
232 | =item $bool = $w->is_active |
206 | |
233 | |
207 | Returns true if the watcher is active, false otherwise. |
234 | Returns true if the watcher is active, false otherwise. |
208 | |
235 | |
… | |
… | |
238 | The default priority of any newly-created watcher is 0. |
265 | The default priority of any newly-created watcher is 0. |
239 | |
266 | |
240 | Note that the priority semantics have not yet been fleshed out and are |
267 | Note that the priority semantics have not yet been fleshed out and are |
241 | subject to almost certain change. |
268 | subject to almost certain change. |
242 | |
269 | |
243 | =item $w->trigger ($revents) |
270 | =item $w->invoke ($revents) |
244 | |
271 | |
245 | Call the callback *now* with the given event mask. |
272 | Call the callback *now* with the given event mask. |
|
|
273 | |
|
|
274 | =item $w->feed_event ($revents) |
|
|
275 | |
|
|
276 | Feed some events on this watcher into EV. EV will react to this call as if |
|
|
277 | the watcher had received the given C<$revents> mask. |
|
|
278 | |
|
|
279 | =item $revents = $w->clear_pending |
|
|
280 | |
|
|
281 | If the watcher is pending, this function returns clears its pending status |
|
|
282 | and returns its C<$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>. |
246 | |
284 | |
247 | =item $previous_state = $w->keepalive ($bool) |
285 | =item $previous_state = $w->keepalive ($bool) |
248 | |
286 | |
249 | Normally, C<EV::loop> will return when there are no active watchers |
287 | Normally, C<EV::loop> will return when there are no active watchers |
250 | (which is a "deadlock" because no progress can be made anymore). This is |
288 | (which is a "deadlock" because no progress can be made anymore). This is |
… | |
… | |
263 | though your watcher is active, it won't keep C<EV::loop> from returning. |
301 | though your watcher is active, it won't keep C<EV::loop> from returning. |
264 | |
302 | |
265 | The initial value for keepalive is true (enabled), and you cna change it |
303 | The initial value for keepalive is true (enabled), and you cna change it |
266 | any time. |
304 | any time. |
267 | |
305 | |
268 | Example: Register an IO watcher for some UDP socket but do not keep the |
306 | Example: Register an I/O watcher for some UDP socket but do not keep the |
269 | event loop from running just because of that watcher. |
307 | event loop from running just because of that watcher. |
270 | |
308 | |
271 | my $udp_socket = ... |
309 | my $udp_socket = ... |
272 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
310 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
273 | $udp_watcher->keepalive (0); |
311 | $udp_watcher->keepalive (0); |
274 | |
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 |
|
|
323 | |
275 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
324 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
276 | |
325 | |
277 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
326 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
278 | |
327 | |
279 | As long as the returned watcher object is alive, call the C<$callback> |
328 | As long as the returned watcher object is alive, call the C<$callback> |
280 | when the events specified in C<$eventmask>. |
329 | when at least one of events specified in C<$eventmask> occurs. |
281 | |
330 | |
282 | 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: |
283 | |
332 | |
284 | EV::READ wait until read() wouldn't block anymore |
333 | EV::READ wait until read() wouldn't block anymore |
285 | EV::WRITE wait until write() wouldn't block anymore |
334 | EV::WRITE wait until write() wouldn't block anymore |
… | |
… | |
301 | |
350 | |
302 | =item $old_eventmask = $w->events ($new_eventmask) |
351 | =item $old_eventmask = $w->events ($new_eventmask) |
303 | |
352 | |
304 | 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. |
305 | |
354 | |
|
|
355 | =back |
|
|
356 | |
|
|
357 | |
|
|
358 | =head3 TIMER WATCHERS - relative and optionally repeating timeouts |
|
|
359 | |
|
|
360 | =over 4 |
306 | |
361 | |
307 | =item $w = EV::timer $after, $repeat, $callback |
362 | =item $w = EV::timer $after, $repeat, $callback |
308 | |
363 | |
309 | =item $w = EV::timer_ns $after, $repeat, $callback |
364 | =item $w = EV::timer_ns $after, $repeat, $callback |
310 | |
365 | |
311 | Calls the callback after C<$after> seconds. If C<$repeat> is non-zero, |
366 | Calls the callback after C<$after> seconds (which may be fractional). If |
312 | 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 |
313 | callback returns. |
368 | value as $after) after the callback returns. |
314 | |
369 | |
315 | This means that the callback would be called roughly after C<$after> |
370 | This means that the callback would be called roughly after C<$after> |
316 | seconds, and then every C<$repeat> seconds. The timer does his best not |
371 | seconds, and then every C<$repeat> seconds. The timer does his best not |
317 | to drift, but it will not invoke the timer more often then once per event |
372 | to drift, but it will not invoke the timer more often then once per event |
318 | loop iteration, and might drift in other cases. If that isn't acceptable, |
373 | loop iteration, and might drift in other cases. If that isn't acceptable, |
… | |
… | |
324 | |
379 | |
325 | 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. |
326 | |
381 | |
327 | =item $w->set ($after, $repeat) |
382 | =item $w->set ($after, $repeat) |
328 | |
383 | |
329 | 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 |
330 | any time. |
385 | any time. |
331 | |
386 | |
332 | =item $w->again |
387 | =item $w->again |
333 | |
388 | |
334 | Similar to the C<start> method, but has special semantics for repeating timers: |
389 | Similar to the C<start> method, but has special semantics for repeating timers: |
… | |
… | |
345 | This behaviour is useful when you have a timeout for some IO |
400 | This behaviour is useful when you have a timeout for some IO |
346 | operation. You create a timer object with the same value for C<$after> and |
401 | operation. You create a timer object with the same value for C<$after> and |
347 | C<$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 |
348 | on the timeout. |
403 | on the timeout. |
349 | |
404 | |
|
|
405 | =back |
|
|
406 | |
|
|
407 | |
|
|
408 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
|
|
409 | |
|
|
410 | =over 4 |
350 | |
411 | |
351 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
412 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
352 | |
413 | |
353 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
414 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
354 | |
415 | |
… | |
… | |
426 | |
487 | |
427 | 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. |
428 | |
489 | |
429 | =item $w->set ($at, $interval, $reschedule_cb) |
490 | =item $w->set ($at, $interval, $reschedule_cb) |
430 | |
491 | |
431 | 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 |
432 | any time. |
493 | any time. |
433 | |
494 | |
434 | =item $w->again |
495 | =item $w->again |
435 | |
496 | |
436 | Simply stops and starts the watcher again. |
497 | Simply stops and starts the watcher again. |
437 | |
498 | |
|
|
499 | =back |
|
|
500 | |
|
|
501 | |
|
|
502 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
|
|
503 | |
|
|
504 | =over 4 |
438 | |
505 | |
439 | =item $w = EV::signal $signal, $callback |
506 | =item $w = EV::signal $signal, $callback |
440 | |
507 | |
441 | =item $w = EV::signal_ns $signal, $callback |
508 | =item $w = EV::signal_ns $signal, $callback |
442 | |
509 | |
443 | 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 |
444 | by number or by name, just as with kill or %SIG). |
511 | number or by name, just as with C<kill> or C<%SIG>). |
445 | |
512 | |
446 | 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 |
447 | 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, |
448 | 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 |
449 | add/remove callbacks to %SIG, so watch out. |
516 | add/remove callbacks to C<%SIG>, so watch out. |
450 | |
517 | |
451 | 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. |
452 | |
519 | |
453 | 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. |
454 | |
521 | |
455 | =item $w->set ($signal) |
522 | =item $w->set ($signal) |
456 | |
523 | |
457 | Reconfigures the watcher, see the constructor above for details. Can be at |
524 | Reconfigures the watcher, see the constructor above for details. Can be |
458 | any time. |
525 | called at any time. |
459 | |
526 | |
460 | =item $current_signum = $w->signal |
527 | =item $current_signum = $w->signal |
461 | |
528 | |
462 | =item $old_signum = $w->signal ($new_signal) |
529 | =item $old_signum = $w->signal ($new_signal) |
463 | |
530 | |
464 | 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 |
465 | optionally set a new one. |
532 | optionally set a new one. |
466 | |
533 | |
|
|
534 | =back |
|
|
535 | |
|
|
536 | |
|
|
537 | =head3 CHILD WATCHERS - watch out for process status changes |
|
|
538 | |
|
|
539 | =over 4 |
467 | |
540 | |
468 | =item $w = EV::child $pid, $callback |
541 | =item $w = EV::child $pid, $callback |
469 | |
542 | |
470 | =item $w = EV::child_ns $pid, $callback |
543 | =item $w = EV::child_ns $pid, $callback |
471 | |
544 | |
472 | Call the callback when a status change for pid C<$pid> (or any pid |
545 | Call the callback when a status change for pid C<$pid> (or any pid if |
473 | if C<$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 |
474 | 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 |
475 | changed/zombie children and call the callback. |
548 | changed/zombie children and call the callback. |
476 | |
549 | |
477 | 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 |
478 | 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). |
479 | |
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 | |
480 | 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. |
481 | |
560 | |
482 | 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. |
483 | |
562 | |
484 | =item $w->set ($pid) |
563 | =item $w->set ($pid) |
485 | |
564 | |
486 | 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 |
487 | any time. |
566 | any time. |
488 | |
567 | |
489 | =item $current_pid = $w->pid |
568 | =item $current_pid = $w->pid |
490 | |
569 | |
491 | =item $old_pid = $w->pid ($new_pid) |
570 | =item $old_pid = $w->pid ($new_pid) |
… | |
… | |
500 | =item $pid = $w->rpid |
579 | =item $pid = $w->rpid |
501 | |
580 | |
502 | 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 |
503 | watcher for all pids). |
582 | watcher for all pids). |
504 | |
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 |
505 | |
669 | |
506 | =item $w = EV::idle $callback |
670 | =item $w = EV::idle $callback |
507 | |
671 | |
508 | =item $w = EV::idle_ns $callback |
672 | =item $w = EV::idle_ns $callback |
509 | |
673 | |
510 | 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 |
511 | 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>. |
512 | |
682 | |
513 | 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 |
514 | they will be called repeatedly until stopped. |
684 | they will be called repeatedly until stopped. |
515 | |
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 | |
516 | 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. |
517 | |
693 | |
|
|
694 | =back |
|
|
695 | |
|
|
696 | |
|
|
697 | =head3 PREPARE WATCHERS - customise your event loop! |
|
|
698 | |
|
|
699 | =over 4 |
518 | |
700 | |
519 | =item $w = EV::prepare $callback |
701 | =item $w = EV::prepare $callback |
520 | |
702 | |
521 | =item $w = EV::prepare_ns $callback |
703 | =item $w = EV::prepare_ns $callback |
522 | |
704 | |
… | |
… | |
525 | |
707 | |
526 | See the EV::check watcher, below, for explanations and an example. |
708 | See the EV::check watcher, below, for explanations and an example. |
527 | |
709 | |
528 | 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. |
529 | |
711 | |
|
|
712 | =back |
|
|
713 | |
|
|
714 | |
|
|
715 | =head3 CHECK WATCHERS - customise your event loop even more! |
|
|
716 | |
|
|
717 | =over 4 |
530 | |
718 | |
531 | =item $w = EV::check $callback |
719 | =item $w = EV::check $callback |
532 | |
720 | |
533 | =item $w = EV::check_ns $callback |
721 | =item $w = EV::check_ns $callback |
534 | |
722 | |
… | |
… | |
548 | or return; |
736 | or return; |
549 | |
737 | |
550 | # make the dispatcher handle any outstanding stuff |
738 | # make the dispatcher handle any outstanding stuff |
551 | ... not shown |
739 | ... not shown |
552 | |
740 | |
553 | # create an IO watcher for each and every socket |
741 | # create an I/O watcher for each and every socket |
554 | @snmp_watcher = ( |
742 | @snmp_watcher = ( |
555 | (map { EV::io $_, EV::READ, sub { } } |
743 | (map { EV::io $_, EV::READ, sub { } } |
556 | keys %{ $dispatcher->{_descriptors} }), |
744 | keys %{ $dispatcher->{_descriptors} }), |
557 | |
745 | |
558 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
746 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
… | |
… | |
579 | first). |
767 | first). |
580 | |
768 | |
581 | 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. |
582 | |
770 | |
583 | =back |
771 | =back |
|
|
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. |
584 | |
812 | |
585 | =head1 THREADS |
813 | =head1 THREADS |
586 | |
814 | |
587 | Threads are not supported by this module in any way. Perl pseudo-threads |
815 | Threads are not supported by this module in any way. Perl pseudo-threads |
588 | is evil stuff and must die. As soon as Perl gains real threads I will work |
816 | is evil stuff and must die. As soon as Perl gains real threads I will work |
… | |
… | |
616 | |
844 | |
617 | 1; |
845 | 1; |
618 | |
846 | |
619 | =head1 SEE ALSO |
847 | =head1 SEE ALSO |
620 | |
848 | |
621 | L<EV::DNS>. |
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). |
622 | |
851 | |
623 | =head1 AUTHOR |
852 | =head1 AUTHOR |
624 | |
853 | |
625 | Marc Lehmann <schmorp@schmorp.de> |
854 | Marc Lehmann <schmorp@schmorp.de> |
626 | http://home.schmorp.de/ |
855 | http://home.schmorp.de/ |