… | |
… | |
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::loop_done 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 |
|
|
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 = '0.8'; |
73 | our $VERSION = '2.0'; |
63 | use XSLoader; |
74 | use XSLoader; |
64 | XSLoader::load "EV", $VERSION; |
75 | XSLoader::load "EV", $VERSION; |
65 | } |
76 | } |
66 | |
77 | |
67 | @EV::Io::ISA = |
78 | @EV::IO::ISA = |
68 | @EV::Timer::ISA = |
79 | @EV::Timer::ISA = |
69 | @EV::Periodic::ISA = |
80 | @EV::Periodic::ISA = |
70 | @EV::Signal::ISA = |
81 | @EV::Signal::ISA = |
|
|
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"; |
|
|
90 | |
|
|
91 | @EV::Loop::Default::ISA = "EV::Loop"; |
|
|
92 | |
|
|
93 | =head1 EVENT LOOPS |
|
|
94 | |
|
|
95 | EV supports multiple event loops: There is a single "default event loop" |
|
|
96 | that can handle everything including signals and child watchers, and any |
|
|
97 | number of "dynamic event loops" that can use different backends (with |
|
|
98 | various limitations), but no child and signal watchers. |
|
|
99 | |
|
|
100 | You do not have to do anything to create the default event loop: When |
|
|
101 | the module is loaded a suitable backend is selected on the premise of |
|
|
102 | selecting a working backend (which for example rules out kqueue on most |
|
|
103 | BSDs). Modules should, unless they have "special needs" always use the |
|
|
104 | default loop as this is fastest (perl-wise), best supported by other |
|
|
105 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
|
|
106 | |
|
|
107 | For specific programs you cna create additional event loops dynamically. |
|
|
108 | |
|
|
109 | =over 4 |
|
|
110 | |
|
|
111 | =item $loop = new EV::loop [$flags] |
|
|
112 | |
|
|
113 | Create a new event loop as per the specified flags. Please refer to the |
|
|
114 | C<ev_loop_new ()> function description in the libev documentation |
|
|
115 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>) |
|
|
116 | for more info. |
|
|
117 | |
|
|
118 | The loop will automatically be destroyed when it is no longer referenced |
|
|
119 | by any watcher and the loop object goes out of scope. |
|
|
120 | |
|
|
121 | Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop |
|
|
122 | is protected by this module. |
|
|
123 | |
|
|
124 | =item $loop->loop_fork |
|
|
125 | |
|
|
126 | Must be called after a fork in the child, before entering or continuing |
|
|
127 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
|
|
128 | this fucntion automatically, at some performance loss (refer to the libev |
|
|
129 | documentation). |
|
|
130 | |
|
|
131 | =back |
|
|
132 | |
75 | |
133 | |
76 | =head1 BASIC INTERFACE |
134 | =head1 BASIC INTERFACE |
77 | |
135 | |
78 | =over 4 |
136 | =over 4 |
79 | |
137 | |
80 | =item $EV::DIED |
138 | =item $EV::DIED |
81 | |
139 | |
82 | Must contain a reference to a function that is called when a callback |
140 | Must contain a reference to a function that is called when a callback |
83 | throws an exception (with $@ containing thr error). The default prints an |
141 | throws an exception (with $@ containing the error). The default prints an |
84 | informative message and continues. |
142 | informative message and continues. |
85 | |
143 | |
86 | If this callback throws an exception it will be silently ignored. |
144 | If this callback throws an exception it will be silently ignored. |
87 | |
145 | |
88 | =item $time = EV::time |
146 | =item $time = EV::time |
89 | |
147 | |
90 | Returns the current time in (fractional) seconds since the epoch. |
148 | Returns the current time in (fractional) seconds since the epoch. |
91 | |
149 | |
92 | =item $time = EV::now |
150 | =item $time = EV::now |
|
|
151 | |
|
|
152 | =item $time = $loop->now |
93 | |
153 | |
94 | Returns the time the last event loop iteration has been started. This |
154 | Returns the time the last event loop iteration has been started. This |
95 | is the time that (relative) timers are based on, and refering to it is |
155 | is the time that (relative) timers are based on, and refering to it is |
96 | usually faster then calling EV::time. |
156 | usually faster then calling EV::time. |
97 | |
157 | |
98 | =item $method = EV::ev_method |
158 | =item $backend = EV::backend |
|
|
159 | |
|
|
160 | =item $backend = $loop->backend |
99 | |
161 | |
100 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
162 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
101 | or EV::METHOD_EPOLL). |
163 | or EV::METHOD_EPOLL). |
102 | |
164 | |
103 | =item EV::loop [$flags] |
165 | =item EV::loop [$flags] |
104 | |
166 | |
|
|
167 | =item $loop->loop ([$flags]) |
|
|
168 | |
105 | Begin checking for events and calling callbacks. It returns when a |
169 | Begin checking for events and calling callbacks. It returns when a |
106 | callback calls EV::loop_done. |
170 | callback calls EV::unloop. |
107 | |
171 | |
108 | The $flags argument can be one of the following: |
172 | The $flags argument can be one of the following: |
109 | |
173 | |
110 | 0 as above |
174 | 0 as above |
111 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
175 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
112 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
176 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
113 | |
177 | |
114 | =item EV::loop_done [$how] |
178 | =item EV::unloop [$how] |
115 | |
179 | |
|
|
180 | =item $loop->unloop ([$how]) |
|
|
181 | |
116 | When called with no arguments or an argument of 1, makes the innermost |
182 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
117 | call to EV::loop return. |
183 | innermost call to EV::loop return. |
118 | |
184 | |
119 | When called with an agrument of 2, all calls to EV::loop will return as |
185 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
120 | fast as possible. |
186 | fast as possible. |
121 | |
187 | |
122 | =back |
188 | =item $count = EV::loop_count |
123 | |
189 | |
124 | =head2 WATCHER |
190 | =item $count = $loop->loop_count |
|
|
191 | |
|
|
192 | Return the number of times the event loop has polled for new |
|
|
193 | events. Sometiems useful as a generation counter. |
|
|
194 | |
|
|
195 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
|
|
196 | |
|
|
197 | =item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
|
|
198 | |
|
|
199 | This function rolls together an I/O and a timer watcher for a single |
|
|
200 | one-shot event without the need for managing a watcher object. |
|
|
201 | |
|
|
202 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
|
|
203 | must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ |
|
|
204 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
|
|
205 | you do not want to wait for some I/O event, specify C<undef> for |
|
|
206 | C<$fh_or_undef> and C<0> for C<$events>). |
|
|
207 | |
|
|
208 | If timeout is C<undef> or negative, then there will be no |
|
|
209 | timeout. Otherwise a EV::timer with this value will be started. |
|
|
210 | |
|
|
211 | When an error occurs or either the timeout or I/O watcher triggers, then |
|
|
212 | the callback will be called with the received event set (in general |
|
|
213 | you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, |
|
|
214 | C<EV::WRITE> and C<EV::TIMEOUT>). |
|
|
215 | |
|
|
216 | EV::once doesn't return anything: the watchers stay active till either |
|
|
217 | of them triggers, then they will be stopped and freed, and the callback |
|
|
218 | invoked. |
|
|
219 | |
|
|
220 | =item EV::feed_fd_event ($fd, $revents) |
|
|
221 | |
|
|
222 | =item $loop->feed_fd_event ($fd, $revents) |
|
|
223 | |
|
|
224 | Feed an event on a file descriptor into EV. EV will react to this call as |
|
|
225 | if the readyness notifications specified by C<$revents> (a combination of |
|
|
226 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
|
|
227 | |
|
|
228 | =item EV::feed_signal_event ($signal) |
|
|
229 | |
|
|
230 | Feed a signal event into EV. EV will react to this call as if the signal |
|
|
231 | specified by C<$signal> had occured. |
|
|
232 | |
|
|
233 | =back |
|
|
234 | |
|
|
235 | |
|
|
236 | =head1 WATCHER OBJECTS |
125 | |
237 | |
126 | A watcher is an object that gets created to record your interest in some |
238 | A watcher is an object that gets created to record your interest in some |
127 | event. For instance, if you want to wait for STDIN to become readable, you |
239 | event. For instance, if you want to wait for STDIN to become readable, you |
128 | would create an EV::io watcher for that: |
240 | would create an EV::io watcher for that: |
129 | |
241 | |
… | |
… | |
138 | events. |
250 | events. |
139 | |
251 | |
140 | Each watcher type has its associated bit in revents, so you can use the |
252 | Each watcher type has its associated bit in revents, so you can use the |
141 | same callback for multiple watchers. The event mask is named after the |
253 | same callback for multiple watchers. The event mask is named after the |
142 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
254 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
143 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
255 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
144 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
256 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
145 | uses EV::TIMEOUT). |
257 | uses EV::TIMEOUT). |
146 | |
258 | |
147 | In the rare case where one wants to create a watcher but not start it at |
259 | In the rare case where one wants to create a watcher but not start it at |
148 | the same time, each constructor has a variant with a trailing C<_ns> in |
260 | the same time, each constructor has a variant with a trailing C<_ns> in |
… | |
… | |
154 | |
266 | |
155 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
267 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
156 | ->fh and so on) automatically stop and start it again if it is active, |
268 | ->fh and so on) automatically stop and start it again if it is active, |
157 | which means pending events get lost. |
269 | which means pending events get lost. |
158 | |
270 | |
159 | =head2 WATCHER TYPES |
271 | =head2 COMMON WATCHER METHODS |
160 | |
272 | |
161 | Now lets move to the existing watcher types and asociated methods. |
273 | This section lists methods common to all watchers. |
162 | |
|
|
163 | The following methods are available for all watchers. Then followes a |
|
|
164 | description of each watcher constructor (EV::io, EV::timer, EV::periodic, |
|
|
165 | EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by |
|
|
166 | any type-specific methods (if any). |
|
|
167 | |
274 | |
168 | =over 4 |
275 | =over 4 |
169 | |
276 | |
170 | =item $w->start |
277 | =item $w->start |
171 | |
278 | |
… | |
… | |
175 | |
282 | |
176 | =item $w->stop |
283 | =item $w->stop |
177 | |
284 | |
178 | Stop a watcher if it is active. Also clear any pending events (events that |
285 | Stop a watcher if it is active. Also clear any pending events (events that |
179 | have been received but that didn't yet result in a callback invocation), |
286 | have been received but that didn't yet result in a callback invocation), |
180 | regardless of wether the watcher was active or not. |
287 | regardless of whether the watcher was active or not. |
181 | |
288 | |
182 | =item $bool = $w->is_active |
289 | =item $bool = $w->is_active |
183 | |
290 | |
184 | Returns true if the watcher is active, false otherwise. |
291 | Returns true if the watcher is active, false otherwise. |
185 | |
292 | |
… | |
… | |
210 | watchers with higher priority will be invoked first. The valid range of |
317 | watchers with higher priority will be invoked first. The valid range of |
211 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
318 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
212 | -2). If the priority is outside this range it will automatically be |
319 | -2). If the priority is outside this range it will automatically be |
213 | normalised to the nearest valid priority. |
320 | normalised to the nearest valid priority. |
214 | |
321 | |
215 | The default priority of any newly-created weatcher is 0. |
322 | The default priority of any newly-created watcher is 0. |
216 | |
323 | |
|
|
324 | Note that the priority semantics have not yet been fleshed out and are |
|
|
325 | subject to almost certain change. |
|
|
326 | |
217 | =item $w->trigger ($revents) |
327 | =item $w->invoke ($revents) |
218 | |
328 | |
219 | Call the callback *now* with the given event mask. |
329 | Call the callback *now* with the given event mask. |
220 | |
330 | |
|
|
331 | =item $w->feed_event ($revents) |
|
|
332 | |
|
|
333 | Feed some events on this watcher into EV. EV will react to this call as if |
|
|
334 | the watcher had received the given C<$revents> mask. |
|
|
335 | |
|
|
336 | =item $revents = $w->clear_pending |
|
|
337 | |
|
|
338 | If the watcher is pending, this function returns clears its pending status |
|
|
339 | and returns its C<$revents> bitset (as if its callback was invoked). If the |
|
|
340 | watcher isn't pending it does nothing and returns C<0>. |
|
|
341 | |
|
|
342 | =item $previous_state = $w->keepalive ($bool) |
|
|
343 | |
|
|
344 | Normally, C<EV::loop> will return when there are no active watchers |
|
|
345 | (which is a "deadlock" because no progress can be made anymore). This is |
|
|
346 | convinient because it allows you to start your watchers (and your jobs), |
|
|
347 | call C<EV::loop> once and when it returns you know that all your jobs are |
|
|
348 | finished (or they forgot to register some watchers for their task :). |
|
|
349 | |
|
|
350 | Sometimes, however, this gets in your way, for example when you the module |
|
|
351 | that calls C<EV::loop> (usually the main program) is not the same module |
|
|
352 | as a long-living watcher (for example a DNS client module written by |
|
|
353 | somebody else even). Then you might want any outstanding requests to be |
|
|
354 | handled, but you would not want to keep C<EV::loop> from returning just |
|
|
355 | because you happen to have this long-running UDP port watcher. |
|
|
356 | |
|
|
357 | In this case you can clear the keepalive status, which means that even |
|
|
358 | though your watcher is active, it won't keep C<EV::loop> from returning. |
|
|
359 | |
|
|
360 | The initial value for keepalive is true (enabled), and you cna change it |
|
|
361 | any time. |
|
|
362 | |
|
|
363 | Example: Register an I/O watcher for some UDP socket but do not keep the |
|
|
364 | event loop from running just because of that watcher. |
|
|
365 | |
|
|
366 | my $udp_socket = ... |
|
|
367 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
|
|
368 | $udp_watcher->keepalive (0); |
|
|
369 | |
|
|
370 | =back |
|
|
371 | |
|
|
372 | |
|
|
373 | =head1 WATCHER TYPES |
|
|
374 | |
|
|
375 | Each of the following subsections describes a single watcher type. |
|
|
376 | |
|
|
377 | =head3 I/O WATCHERS - is this file descriptor readable or writable? |
|
|
378 | |
|
|
379 | =over 4 |
221 | |
380 | |
222 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
381 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
223 | |
382 | |
224 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
383 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
225 | |
384 | |
|
|
385 | =item $w = $loop->io 8$fileno_or_fh, $eventmask, $callback) |
|
|
386 | |
|
|
387 | =item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
|
|
388 | |
226 | As long as the returned watcher object is alive, call the C<$callback> |
389 | As long as the returned watcher object is alive, call the C<$callback> |
227 | when the events specified in C<$eventmask>. |
390 | when at least one of events specified in C<$eventmask> occurs. |
228 | |
391 | |
229 | The $eventmask can be one or more of these constants ORed together: |
392 | The $eventmask can be one or more of these constants ORed together: |
230 | |
393 | |
231 | EV::READ wait until read() wouldn't block anymore |
394 | EV::READ wait until read() wouldn't block anymore |
232 | EV::WRITE wait until write() wouldn't block anymore |
395 | EV::WRITE wait until write() wouldn't block anymore |
… | |
… | |
248 | |
411 | |
249 | =item $old_eventmask = $w->events ($new_eventmask) |
412 | =item $old_eventmask = $w->events ($new_eventmask) |
250 | |
413 | |
251 | Returns the previously set event mask and optionally set a new one. |
414 | Returns the previously set event mask and optionally set a new one. |
252 | |
415 | |
|
|
416 | =back |
|
|
417 | |
|
|
418 | |
|
|
419 | =head3 TIMER WATCHERS - relative and optionally repeating timeouts |
|
|
420 | |
|
|
421 | =over 4 |
253 | |
422 | |
254 | =item $w = EV::timer $after, $repeat, $callback |
423 | =item $w = EV::timer $after, $repeat, $callback |
255 | |
424 | |
256 | =item $w = EV::timer_ns $after, $repeat, $callback |
425 | =item $w = EV::timer_ns $after, $repeat, $callback |
257 | |
426 | |
258 | Calls the callback after C<$after> seconds. If C<$repeat> is non-zero, |
427 | =item $w = $loop->timer ($after, $repeat, $callback) |
259 | the timer will be restarted (with the $repeat value as $after) after the |
428 | |
260 | callback returns. |
429 | =item $w = $loop->timer_ns ($after, $repeat, $callback) |
|
|
430 | |
|
|
431 | Calls the callback after C<$after> seconds (which may be fractional). If |
|
|
432 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
|
|
433 | value as $after) after the callback returns. |
261 | |
434 | |
262 | This means that the callback would be called roughly after C<$after> |
435 | This means that the callback would be called roughly after C<$after> |
263 | seconds, and then every C<$repeat> seconds. "Roughly" because the time of |
436 | seconds, and then every C<$repeat> seconds. The timer does his best not |
264 | callback processing is not taken into account, so the timer will slowly |
437 | to drift, but it will not invoke the timer more often then once per event |
265 | drift. If that isn't acceptable, look at EV::periodic. |
438 | loop iteration, and might drift in other cases. If that isn't acceptable, |
|
|
439 | look at EV::periodic, which can provide long-term stable timers. |
266 | |
440 | |
267 | The timer is based on a monotonic clock, that is if somebody is sitting |
441 | The timer is based on a monotonic clock, that is, if somebody is sitting |
268 | in front of the machine while the timer is running and changes the system |
442 | in front of the machine while the timer is running and changes the system |
269 | clock, the timer will nevertheless run (roughly) the same time. |
443 | clock, the timer will nevertheless run (roughly) the same time. |
270 | |
444 | |
271 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
445 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
272 | |
446 | |
273 | =item $w->set ($after, $repeat) |
447 | =item $w->set ($after, $repeat) |
274 | |
448 | |
275 | Reconfigures the watcher, see the constructor above for details. Can be at |
449 | Reconfigures the watcher, see the constructor above for details. Can be called at |
276 | any time. |
450 | any time. |
277 | |
451 | |
278 | =item $w->again |
452 | =item $w->again |
279 | |
453 | |
280 | Similar to the C<start> method, but has special semantics for repeating timers: |
454 | Similar to the C<start> method, but has special semantics for repeating timers: |
|
|
455 | |
|
|
456 | If the timer is active and non-repeating, it will be stopped. |
281 | |
457 | |
282 | If the timer is active and repeating, reset the timeout to occur |
458 | If the timer is active and repeating, reset the timeout to occur |
283 | C<$repeat> seconds after now. |
459 | C<$repeat> seconds after now. |
284 | |
460 | |
285 | If the timer is active and non-repeating, it will be stopped. |
|
|
286 | |
|
|
287 | If the timer is in active and repeating, start it. |
461 | If the timer is inactive and repeating, start it using the repeat value. |
288 | |
462 | |
289 | Otherwise do nothing. |
463 | Otherwise do nothing. |
290 | |
464 | |
291 | This behaviour is useful when you have a timeout for some IO |
465 | This behaviour is useful when you have a timeout for some IO |
292 | operation. You create a timer object with the same value for C<$after> and |
466 | operation. You create a timer object with the same value for C<$after> and |
293 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
467 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
294 | on the timeout. |
468 | on the timeout. |
295 | |
469 | |
|
|
470 | =back |
|
|
471 | |
|
|
472 | |
|
|
473 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
|
|
474 | |
|
|
475 | =over 4 |
296 | |
476 | |
297 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
477 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
298 | |
478 | |
299 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
479 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
|
|
480 | |
|
|
481 | =item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
|
|
482 | |
|
|
483 | =item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback) |
300 | |
484 | |
301 | Similar to EV::timer, but is not based on relative timeouts but on |
485 | Similar to EV::timer, but is not based on relative timeouts but on |
302 | absolute times. Apart from creating "simple" timers that trigger "at" the |
486 | absolute times. Apart from creating "simple" timers that trigger "at" the |
303 | specified time, it can also be used for non-drifting absolute timers and |
487 | specified time, it can also be used for non-drifting absolute timers and |
304 | more complex, cron-like, setups that are not adversely affected by time |
488 | more complex, cron-like, setups that are not adversely affected by time |
… | |
… | |
372 | |
556 | |
373 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
557 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
374 | |
558 | |
375 | =item $w->set ($at, $interval, $reschedule_cb) |
559 | =item $w->set ($at, $interval, $reschedule_cb) |
376 | |
560 | |
377 | Reconfigures the watcher, see the constructor above for details. Can be at |
561 | Reconfigures the watcher, see the constructor above for details. Can be called at |
378 | any time. |
562 | any time. |
379 | |
563 | |
380 | =item $w->again |
564 | =item $w->again |
381 | |
565 | |
382 | Simply stops and starts the watcher again. |
566 | Simply stops and starts the watcher again. |
383 | |
567 | |
|
|
568 | =item $time = $w->at |
|
|
569 | |
|
|
570 | Return the time that the watcher is expected to trigger next. |
|
|
571 | |
|
|
572 | =back |
|
|
573 | |
|
|
574 | |
|
|
575 | =head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
|
|
576 | |
|
|
577 | =over 4 |
384 | |
578 | |
385 | =item $w = EV::signal $signal, $callback |
579 | =item $w = EV::signal $signal, $callback |
386 | |
580 | |
387 | =item $w = EV::signal_ns $signal, $callback |
581 | =item $w = EV::signal_ns $signal, $callback |
388 | |
582 | |
389 | Call the callback when $signal is received (the signal can be specified |
583 | Call the callback when $signal is received (the signal can be specified by |
390 | by number or by name, just as with kill or %SIG). |
584 | number or by name, just as with C<kill> or C<%SIG>). |
391 | |
585 | |
392 | EV will grab the signal for the process (the kernel only allows one |
586 | EV will grab the signal for the process (the kernel only allows one |
393 | component to receive a signal at a time) when you start a signal watcher, |
587 | component to receive a signal at a time) when you start a signal watcher, |
394 | and removes it again when you stop it. Perl does the same when you |
588 | and removes it again when you stop it. Perl does the same when you |
395 | add/remove callbacks to %SIG, so watch out. |
589 | add/remove callbacks to C<%SIG>, so watch out. |
396 | |
590 | |
397 | You can have as many signal watchers per signal as you want. |
591 | You can have as many signal watchers per signal as you want. |
398 | |
592 | |
399 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
593 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
400 | |
594 | |
401 | =item $w->set ($signal) |
595 | =item $w->set ($signal) |
402 | |
596 | |
403 | Reconfigures the watcher, see the constructor above for details. Can be at |
597 | Reconfigures the watcher, see the constructor above for details. Can be |
404 | any time. |
598 | called at any time. |
405 | |
599 | |
406 | =item $current_signum = $w->signal |
600 | =item $current_signum = $w->signal |
407 | |
601 | |
408 | =item $old_signum = $w->signal ($new_signal) |
602 | =item $old_signum = $w->signal ($new_signal) |
409 | |
603 | |
410 | Returns the previously set signal (always as a number not name) and |
604 | Returns the previously set signal (always as a number not name) and |
411 | optionally set a new one. |
605 | optionally set a new one. |
412 | |
606 | |
|
|
607 | =back |
|
|
608 | |
|
|
609 | |
|
|
610 | =head3 CHILD WATCHERS - watch out for process status changes |
|
|
611 | |
|
|
612 | =over 4 |
413 | |
613 | |
414 | =item $w = EV::child $pid, $callback |
614 | =item $w = EV::child $pid, $callback |
415 | |
615 | |
416 | =item $w = EV::child_ns $pid, $callback |
616 | =item $w = EV::child_ns $pid, $callback |
417 | |
617 | |
|
|
618 | =item $w = $loop->child ($pid, $callback) |
|
|
619 | |
|
|
620 | =item $w = $loop->child_ns ($pid, $callback) |
|
|
621 | |
418 | Call the callback when a status change for pid C<$pid> (or any pid |
622 | Call the callback when a status change for pid C<$pid> (or any pid if |
419 | if C<$pid> is 0) has been received. More precisely: when the process |
623 | C<$pid> is 0) has been received. More precisely: when the process receives |
420 | receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all |
624 | a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
421 | changed/zombie children and call the callback. |
625 | changed/zombie children and call the callback. |
422 | |
626 | |
423 | You can access both status and pid by using the C<rstatus> and C<rpid> |
627 | It is valid (and fully supported) to install a child watcher after a child |
424 | methods on the watcher object. |
628 | has exited but before the event loop has started its next iteration (for |
|
|
629 | example, first you C<fork>, then the new child process might exit, and |
|
|
630 | only then do you install a child watcher in the parent for the new pid). |
425 | |
631 | |
|
|
632 | You can access both exit (or tracing) status and pid by using the |
|
|
633 | C<rstatus> and C<rpid> methods on the watcher object. |
|
|
634 | |
426 | You can have as many pid watchers per pid as you want. |
635 | You can have as many pid watchers per pid as you want, they will all be |
|
|
636 | called. |
427 | |
637 | |
428 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
638 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
429 | |
639 | |
430 | =item $w->set ($pid) |
640 | =item $w->set ($pid) |
431 | |
641 | |
432 | Reconfigures the watcher, see the constructor above for details. Can be at |
642 | Reconfigures the watcher, see the constructor above for details. Can be called at |
433 | any time. |
643 | any time. |
434 | |
644 | |
435 | =item $current_pid = $w->pid |
645 | =item $current_pid = $w->pid |
436 | |
646 | |
437 | =item $old_pid = $w->pid ($new_pid) |
647 | =item $old_pid = $w->pid ($new_pid) |
… | |
… | |
446 | =item $pid = $w->rpid |
656 | =item $pid = $w->rpid |
447 | |
657 | |
448 | Return the pid of the awaited child (useful when you have installed a |
658 | Return the pid of the awaited child (useful when you have installed a |
449 | watcher for all pids). |
659 | watcher for all pids). |
450 | |
660 | |
|
|
661 | =back |
|
|
662 | |
|
|
663 | |
|
|
664 | =head3 STAT WATCHERS - did the file attributes just change? |
|
|
665 | |
|
|
666 | =over 4 |
|
|
667 | |
|
|
668 | =item $w = EV::stat $path, $interval, $callback |
|
|
669 | |
|
|
670 | =item $w = EV::stat_ns $path, $interval, $callback |
|
|
671 | |
|
|
672 | =item $w = $loop->stat ($path, $interval, $callback) |
|
|
673 | |
|
|
674 | =item $w = $loop->stat_ns ($path, $interval, $callback) |
|
|
675 | |
|
|
676 | Call the callback when a file status change has been detected on |
|
|
677 | C<$path>. The C<$path> does not need to exist, changing from "path exists" |
|
|
678 | to "path does not exist" is a status change like any other. |
|
|
679 | |
|
|
680 | The C<$interval> is a recommended polling interval for systems where |
|
|
681 | OS-supported change notifications don't exist or are not supported. If |
|
|
682 | you use C<0> then an unspecified default is used (which is highly |
|
|
683 | recommended!), which is to be expected to be around five seconds usually. |
|
|
684 | |
|
|
685 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
686 | as even with OS-supported change notifications, this can be |
|
|
687 | resource-intensive. |
|
|
688 | |
|
|
689 | The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
|
|
690 | |
|
|
691 | =item ... = $w->stat |
|
|
692 | |
|
|
693 | This call is very similar to the perl C<stat> built-in: It stats (using |
|
|
694 | C<lstat>) the path specified in the watcher and sets perls stat cache (as |
|
|
695 | well as EV's idea of the current stat values) to the values found. |
|
|
696 | |
|
|
697 | In scalar context, a boolean is return indicating success or failure of |
|
|
698 | the stat. In list context, the same 13-value list as with stat is returned |
|
|
699 | (except that the blksize and blocks fields are not reliable). |
|
|
700 | |
|
|
701 | In the case of an error, errno is set to C<ENOENT> (regardless of the |
|
|
702 | actual error value) and the C<nlink> value is forced to zero (if the stat |
|
|
703 | was successful then nlink is guaranteed to be non-zero). |
|
|
704 | |
|
|
705 | See also the next two entries for more info. |
|
|
706 | |
|
|
707 | =item ... = $w->attr |
|
|
708 | |
|
|
709 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
710 | the values most recently detected by EV. See the next entry for more info. |
|
|
711 | |
|
|
712 | =item ... = $w->prev |
|
|
713 | |
|
|
714 | Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
|
|
715 | the previous set of values, before the change. |
|
|
716 | |
|
|
717 | That is, when the watcher callback is invoked, C<< $w->prev >> will be set |
|
|
718 | to the values found I<before> a change was detected, while C<< $w->attr >> |
|
|
719 | returns the values found leading to the change detection. The difference (if any) |
|
|
720 | between C<prev> and C<attr> is what triggered the callback. |
|
|
721 | |
|
|
722 | If you did something to the filesystem object and do not want to trigger |
|
|
723 | yet another change, you can call C<stat> to update EV's idea of what the |
|
|
724 | current attributes are. |
|
|
725 | |
|
|
726 | =item $w->set ($path, $interval) |
|
|
727 | |
|
|
728 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
729 | called at any time. |
|
|
730 | |
|
|
731 | =item $current_path = $w->path |
|
|
732 | |
|
|
733 | =item $old_path = $w->path ($new_path) |
|
|
734 | |
|
|
735 | Returns the previously set path and optionally set a new one. |
|
|
736 | |
|
|
737 | =item $current_interval = $w->interval |
|
|
738 | |
|
|
739 | =item $old_interval = $w->interval ($new_interval) |
|
|
740 | |
|
|
741 | Returns the previously set interval and optionally set a new one. Can be |
|
|
742 | used to query the actual interval used. |
|
|
743 | |
|
|
744 | =back |
|
|
745 | |
|
|
746 | |
|
|
747 | =head3 IDLE WATCHERS - when you've got nothing better to do... |
|
|
748 | |
|
|
749 | =over 4 |
451 | |
750 | |
452 | =item $w = EV::idle $callback |
751 | =item $w = EV::idle $callback |
453 | |
752 | |
454 | =item $w = EV::idle_ns $callback |
753 | =item $w = EV::idle_ns $callback |
455 | |
754 | |
456 | Call the callback when there are no pending io, timer/periodic, signal or |
755 | =item $w = $loop->idle ($callback) |
457 | child events, i.e. when the process is idle. |
756 | |
|
|
757 | =item $w = $loop->idle_ns ($callback) |
|
|
758 | |
|
|
759 | Call the callback when there are no other pending watchers of the same or |
|
|
760 | higher priority (excluding check, prepare and other idle watchers of the |
|
|
761 | same or lower priority, of course). They are called idle watchers because |
|
|
762 | when the watcher is the highest priority pending event in the process, the |
|
|
763 | process is considered to be idle at that priority. |
|
|
764 | |
|
|
765 | If you want a watcher that is only ever called when I<no> other events are |
|
|
766 | outstanding you have to set the priority to C<EV::MINPRI>. |
458 | |
767 | |
459 | The process will not block as long as any idle watchers are active, and |
768 | The process will not block as long as any idle watchers are active, and |
460 | they will be called repeatedly until stopped. |
769 | they will be called repeatedly until stopped. |
461 | |
770 | |
|
|
771 | For example, if you have idle watchers at priority C<0> and C<1>, and |
|
|
772 | an I/O watcher at priority C<0>, then the idle watcher at priority C<1> |
|
|
773 | and the I/O watcher will always run when ready. Only when the idle watcher |
|
|
774 | at priority C<1> is stopped and the I/O watcher at priority C<0> is not |
|
|
775 | pending with the C<0>-priority idle watcher be invoked. |
|
|
776 | |
462 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
777 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
463 | |
778 | |
|
|
779 | =back |
|
|
780 | |
|
|
781 | |
|
|
782 | =head3 PREPARE WATCHERS - customise your event loop! |
|
|
783 | |
|
|
784 | =over 4 |
464 | |
785 | |
465 | =item $w = EV::prepare $callback |
786 | =item $w = EV::prepare $callback |
466 | |
787 | |
467 | =item $w = EV::prepare_ns $callback |
788 | =item $w = EV::prepare_ns $callback |
|
|
789 | |
|
|
790 | =item $w = $loop->prepare ($callback) |
|
|
791 | |
|
|
792 | =item $w = $loop->prepare_ns 8$callback) |
468 | |
793 | |
469 | Call the callback just before the process would block. You can still |
794 | Call the callback just before the process would block. You can still |
470 | create/modify any watchers at this point. |
795 | create/modify any watchers at this point. |
471 | |
796 | |
472 | See the EV::check watcher, below, for explanations and an example. |
797 | See the EV::check watcher, below, for explanations and an example. |
473 | |
798 | |
474 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
799 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
475 | |
800 | |
|
|
801 | =back |
|
|
802 | |
|
|
803 | |
|
|
804 | =head3 CHECK WATCHERS - customise your event loop even more! |
|
|
805 | |
|
|
806 | =over 4 |
476 | |
807 | |
477 | =item $w = EV::check $callback |
808 | =item $w = EV::check $callback |
478 | |
809 | |
479 | =item $w = EV::check_ns $callback |
810 | =item $w = EV::check_ns $callback |
|
|
811 | |
|
|
812 | =item $w = $loop->check ($callback) |
|
|
813 | |
|
|
814 | =item $w = $loop->check_ns ($callback) |
480 | |
815 | |
481 | Call the callback just after the process wakes up again (after it has |
816 | Call the callback just after the process wakes up again (after it has |
482 | gathered events), but before any other callbacks have been invoked. |
817 | gathered events), but before any other callbacks have been invoked. |
483 | |
818 | |
484 | This is used to integrate other event-based software into the EV |
819 | This is used to integrate other event-based software into the EV |
… | |
… | |
492 | # do nothing unless active |
827 | # do nothing unless active |
493 | $dispatcher->{_event_queue_h} |
828 | $dispatcher->{_event_queue_h} |
494 | or return; |
829 | or return; |
495 | |
830 | |
496 | # make the dispatcher handle any outstanding stuff |
831 | # make the dispatcher handle any outstanding stuff |
|
|
832 | ... not shown |
497 | |
833 | |
498 | # create an IO watcher for each and every socket |
834 | # create an I/O watcher for each and every socket |
499 | @snmp_watcher = ( |
835 | @snmp_watcher = ( |
500 | (map { EV::io $_, EV::READ, sub { } } |
836 | (map { EV::io $_, EV::READ, sub { } } |
501 | keys %{ $dispatcher->{_descriptors} }), |
837 | keys %{ $dispatcher->{_descriptors} }), |
|
|
838 | |
|
|
839 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
|
|
840 | ? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0), |
|
|
841 | 0, sub { }, |
502 | ); |
842 | ); |
503 | |
|
|
504 | # if there are any timeouts, also create a timer |
|
|
505 | push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { } |
|
|
506 | if $event->[Net::SNMP::Dispatcher::_ACTIVE]; |
|
|
507 | }; |
843 | }; |
508 | |
844 | |
509 | The callbacks are irrelevant, the only purpose of those watchers is |
845 | The callbacks are irrelevant (and are not even being called), the |
510 | to wake up the process as soon as one of those events occurs (socket |
846 | only purpose of those watchers is to wake up the process as soon as |
511 | readable, or timer timed out). The corresponding EV::check watcher will then |
847 | one of those events occurs (socket readable, or timer timed out). The |
512 | clean up: |
848 | corresponding EV::check watcher will then clean up: |
513 | |
849 | |
514 | our $snmp_check = EV::check sub { |
850 | our $snmp_check = EV::check sub { |
515 | # destroy all watchers |
851 | # destroy all watchers |
516 | @snmp_watcher = (); |
852 | @snmp_watcher = (); |
517 | |
853 | |
518 | # make the dispatcher handle any new stuff |
854 | # make the dispatcher handle any new stuff |
|
|
855 | ... not shown |
519 | }; |
856 | }; |
520 | |
857 | |
521 | The callbacks of the created watchers will not be called as the watchers |
858 | The callbacks of the created watchers will not be called as the watchers |
522 | are destroyed before this cna happen (remember EV::check gets called |
859 | are destroyed before this cna happen (remember EV::check gets called |
523 | first). |
860 | first). |
524 | |
861 | |
525 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
862 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
526 | |
863 | |
527 | =back |
864 | =back |
528 | |
865 | |
|
|
866 | |
|
|
867 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
|
|
868 | |
|
|
869 | Fork watchers are called when a C<fork ()> was detected. The invocation |
|
|
870 | is done before the event loop blocks next and before C<check> watchers |
|
|
871 | are being called, and only in the child after the fork. |
|
|
872 | |
|
|
873 | =over 4 |
|
|
874 | |
|
|
875 | =item $w = EV::fork $callback |
|
|
876 | |
|
|
877 | =item $w = EV::fork_ns $callback |
|
|
878 | |
|
|
879 | =item $w = $loop->fork ($callback) |
|
|
880 | |
|
|
881 | =item $w = $loop->fork_ns ($callback) |
|
|
882 | |
|
|
883 | Call the callback before the event loop is resumed in the child process |
|
|
884 | after a fork. |
|
|
885 | |
|
|
886 | The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
|
|
887 | |
|
|
888 | =back |
|
|
889 | |
|
|
890 | |
|
|
891 | =head1 PERL SIGNALS |
|
|
892 | |
|
|
893 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
|
|
894 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
895 | handled when Perl runs, which means your signal handler might be invoked |
|
|
896 | only the next time an event callback is invoked. |
|
|
897 | |
|
|
898 | The solution is to use EV signal watchers (see C<EV::signal>), which will |
|
|
899 | ensure proper operations with regards to other event watchers. |
|
|
900 | |
|
|
901 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
902 | to be called on every event loop iteration by installing a C<EV::check> |
|
|
903 | watcher: |
|
|
904 | |
|
|
905 | my $async_check = EV::check sub { }; |
|
|
906 | |
|
|
907 | This ensures that perl shortly gets into control for a short time, and |
|
|
908 | also ensures slower overall operation. |
|
|
909 | |
529 | =head1 THREADS |
910 | =head1 THREADS |
530 | |
911 | |
531 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
912 | Threads are not supported by this module in any way. Perl pseudo-threads |
532 | stuff and must die. |
913 | is evil stuff and must die. As soon as Perl gains real threads I will work |
|
|
914 | on thread support for it. |
|
|
915 | |
|
|
916 | =head1 FORK |
|
|
917 | |
|
|
918 | Most of the "improved" event delivering mechanisms of modern operating |
|
|
919 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
|
|
920 | not supported and usually destructive). Libev makes it possible to work |
|
|
921 | around this by having a function that recreates the kernel state after |
|
|
922 | fork in the child. |
|
|
923 | |
|
|
924 | On non-win32 platforms, this module requires the pthread_atfork |
|
|
925 | functionality to do this automatically for you. This function is quite |
|
|
926 | buggy on most BSDs, though, so YMMV. The overhead for this is quite |
|
|
927 | negligible, because everything the function currently does is set a flag |
|
|
928 | that is checked only when the event loop gets used the next time, so when |
|
|
929 | you do fork but not use EV, the overhead is minimal. |
|
|
930 | |
|
|
931 | On win32, there is no notion of fork so all this doesn't apply, of course. |
533 | |
932 | |
534 | =cut |
933 | =cut |
535 | |
934 | |
536 | our $DIED = sub { |
935 | our $DIED = sub { |
537 | warn "EV: error in callback (ignoring): $@"; |
936 | warn "EV: error in callback (ignoring): $@"; |
538 | }; |
937 | }; |
539 | |
938 | |
540 | default_loop |
939 | default_loop |
541 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; |
940 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?'; |
542 | |
941 | |
543 | 1; |
942 | 1; |
544 | |
943 | |
545 | =head1 SEE ALSO |
944 | =head1 SEE ALSO |
546 | |
945 | |
547 | L<EV::DNS>, L<EV::AnyEvent>. |
946 | L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as |
|
|
947 | event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient |
|
|
948 | coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). |
548 | |
949 | |
549 | =head1 AUTHOR |
950 | =head1 AUTHOR |
550 | |
951 | |
551 | Marc Lehmann <schmorp@schmorp.de> |
952 | Marc Lehmann <schmorp@schmorp.de> |
552 | http://home.schmorp.de/ |
953 | http://home.schmorp.de/ |