1 | =head1 NAME |
1 | =head1 NAME |
2 | |
2 | |
3 | EV - perl interface to libevent, monkey.org/~provos/libevent/ |
3 | EV - perl interface to libev, a high performance full-featured event loop |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use EV; |
7 | use EV; |
8 | |
8 | |
9 | # TIMER |
9 | # TIMERS |
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, 1, sub { |
16 | warn "is called roughly every 2s (repeat = 1)"; |
16 | warn "is called roughly every 2s (repeat = 1)"; |
17 | }; |
17 | }; |
18 | |
18 | |
19 | undef $w; # destroy event watcher again |
19 | undef $w; # destroy event watcher again |
20 | |
20 | |
21 | # IO |
|
|
22 | |
|
|
23 | my $w = EV::timer_abs 0, 60, sub { |
21 | my $w = EV::periodic 0, 60, 0, sub { |
24 | warn "is called every minute, on the minute, exactly"; |
22 | warn "is called every minute, on the minute, exactly"; |
25 | }; |
23 | }; |
26 | |
24 | |
|
|
25 | # IO |
|
|
26 | |
27 | my $w = EV::io \*STDIN, EV::READ | EV::PERSIST, sub { |
27 | my $w = EV::io *STDIN, EV::READ, sub { |
28 | my ($w, $events) = @_; # all callbacks get the watcher object and event mask |
28 | my ($w, $revents) = @_; # all callbacks get the watcher object and event mask |
29 | if ($events & EV::TIMEOUT) { |
|
|
30 | warn "nothign received on stdin for 10 seconds, retrying"; |
|
|
31 | } else { |
|
|
32 | warn "stdin is readable, you entered: ", <STDIN>; |
29 | warn "stdin is readable, you entered: ", <STDIN>; |
33 | } |
|
|
34 | }; |
30 | }; |
35 | $w->timeout (10); |
31 | |
|
|
32 | # SIGNALS |
|
|
33 | |
|
|
34 | my $w = EV::signal 'QUIT', sub { |
|
|
35 | warn "sigquit received\n"; |
|
|
36 | }; |
|
|
37 | |
|
|
38 | my $w = EV::signal 3, sub { |
|
|
39 | warn "sigquit received (this is GNU/Linux, right?)\n"; |
|
|
40 | }; |
36 | |
41 | |
|
|
42 | # CHILD/PID STATUS CHANGES |
|
|
43 | |
|
|
44 | my $w = EV::child 666, sub { |
|
|
45 | my ($w, $revents) = @_; |
|
|
46 | # my $pid = $w->rpid; |
|
|
47 | my $status = $w->rstatus; |
|
|
48 | }; |
|
|
49 | |
37 | # MAINLOOP |
50 | # MAINLOOP |
38 | EV::dispatch; # loop as long as watchers are active |
51 | EV::loop; # loop until EV::loop_done is called |
39 | EV::loop; # the same thing |
52 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
40 | EV::loop EV::LOOP_ONCE; |
53 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
41 | EV::loop EV::LOOP_ONSHOT; |
|
|
42 | |
54 | |
43 | =head1 DESCRIPTION |
55 | =head1 DESCRIPTION |
44 | |
56 | |
45 | This module provides an interface to libevent |
57 | This module provides an interface to libev |
46 | (L<http://monkey.org/~provos/libevent/>). |
58 | (L<http://software.schmorp.de/pkg/libev.html>). |
47 | |
59 | |
48 | =cut |
60 | =cut |
49 | |
61 | |
50 | package EV; |
62 | package EV; |
51 | |
63 | |
52 | use strict; |
64 | use strict; |
53 | |
65 | |
54 | BEGIN { |
66 | BEGIN { |
55 | our $VERSION = '0.01'; |
67 | our $VERSION = '0.6'; |
56 | use XSLoader; |
68 | use XSLoader; |
57 | XSLoader::load "EV", $VERSION; |
69 | XSLoader::load "EV", $VERSION; |
58 | } |
70 | } |
59 | |
71 | |
60 | =head1 FUNCTIONAL INTERFACE |
72 | @EV::Io::ISA = |
|
|
73 | @EV::Timer::ISA = |
|
|
74 | @EV::Periodic::ISA = |
|
|
75 | @EV::Signal::ISA = |
|
|
76 | @EV::Idle::ISA = |
|
|
77 | @EV::Prepare::ISA = |
|
|
78 | @EV::Check::ISA = |
|
|
79 | @EV::Child::ISA = "EV::Watcher"; |
|
|
80 | |
|
|
81 | =head1 BASIC INTERFACE |
61 | |
82 | |
62 | =over 4 |
83 | =over 4 |
63 | |
84 | |
64 | =item $EV::NPRI |
85 | =item $EV::DIED |
65 | |
86 | |
66 | How many priority levels are available. |
87 | Must contain a reference to a function that is called when a callback |
|
|
88 | throws an exception (with $@ containing thr error). The default prints an |
|
|
89 | informative message and continues. |
|
|
90 | |
|
|
91 | If this callback throws an exception it will be silently ignored. |
|
|
92 | |
|
|
93 | =item $time = EV::time |
|
|
94 | |
|
|
95 | Returns the current time in (fractional) seconds since the epoch. |
67 | |
96 | |
68 | =item $time = EV::now |
97 | =item $time = EV::now |
69 | |
98 | |
70 | Returns the time in (fractional) seconds since the epoch. |
99 | 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 |
|
|
101 | usually faster then calling EV::time. |
71 | |
102 | |
72 | =item $version = EV::version |
|
|
73 | |
|
|
74 | =item $method = EV::method |
103 | =item $method = EV::ev_method |
75 | |
104 | |
76 | Return version string and event polling method used. |
105 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
|
|
106 | or EV::METHOD_EPOLL). |
77 | |
107 | |
78 | =item EV::loop $flags # EV::LOOP_ONCE, EV::LOOP_ONESHOT |
108 | =item EV::loop [$flags] |
79 | |
109 | |
80 | =item EV::loopexit $after |
110 | Begin checking for events and calling callbacks. It returns when a |
|
|
111 | callback calls EV::loop_done. |
81 | |
112 | |
82 | Exit any active loop or dispatch after C<$after> seconds or immediately if |
113 | The $flags argument can be one of the following: |
83 | C<$after> is missing or zero. |
|
|
84 | |
114 | |
85 | =item EV::dispatch |
115 | 0 as above |
|
|
116 | 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) |
86 | |
118 | |
87 | Same as C<EV::loop 0>. |
119 | =item EV::loop_done [$how] |
88 | |
120 | |
89 | =item EV::event $callback |
121 | When called with no arguments or an argument of 1, makes the innermost |
|
|
122 | call to EV::loop return. |
90 | |
123 | |
91 | Creates a new event watcher waiting for nothing, calling the given callback. |
124 | When called with an agrument of 2, all calls to EV::loop will return as |
|
|
125 | fast as possible. |
92 | |
126 | |
|
|
127 | =back |
|
|
128 | |
|
|
129 | =head2 WATCHER |
|
|
130 | |
|
|
131 | 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 |
|
|
133 | would create an EV::io watcher for that: |
|
|
134 | |
|
|
135 | my $watcher = EV::io *STDIN, EV::READ, sub { |
|
|
136 | my ($watcher, $revents) = @_; |
|
|
137 | warn "yeah, STDIN should not be readable without blocking!\n" |
|
|
138 | }; |
|
|
139 | |
|
|
140 | All watchers can be active (waiting for events) or inactive (paused). Only |
|
|
141 | active watchers will have their callbacks invoked. All callbacks will be |
|
|
142 | called with at least two arguments: the watcher and a bitmask of received |
|
|
143 | events. |
|
|
144 | |
|
|
145 | Each watcher type has its associated bit in revents, so you can use the |
|
|
146 | same callback for multiple watchers. The event mask is named after the |
|
|
147 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
|
|
148 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
|
|
149 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
|
|
150 | uses EV::TIMEOUT). |
|
|
151 | |
|
|
152 | In the rare case where one wants to create a watcher but not start it at |
|
|
153 | the same time, each constructor has a variant with a trailing C<_ns> in |
|
|
154 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
|
|
155 | |
|
|
156 | Please note that a watcher will automatically be stopped when the watcher |
|
|
157 | object is destroyed, so you I<need> to keep the watcher objects returned by |
|
|
158 | the constructors. |
|
|
159 | |
|
|
160 | 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, |
|
|
162 | which means pending events get lost. |
|
|
163 | |
|
|
164 | =head2 WATCHER TYPES |
|
|
165 | |
|
|
166 | Now lets move to the existing watcher types and asociated methods. |
|
|
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 | |
|
|
173 | =over 4 |
|
|
174 | |
|
|
175 | =item $w->start |
|
|
176 | |
|
|
177 | Starts a watcher if it isn't active already. Does nothing to an already |
|
|
178 | active watcher. By default, all watchers start out in the active state |
|
|
179 | (see the description of the C<_ns> variants if you need stopped watchers). |
|
|
180 | |
|
|
181 | =item $w->stop |
|
|
182 | |
|
|
183 | Stop a watcher if it is active. Also clear any pending events (events that |
|
|
184 | have been received but that didn't yet result in a callback invocation), |
|
|
185 | regardless of wether the watcher was active or not. |
|
|
186 | |
|
|
187 | =item $bool = $w->is_active |
|
|
188 | |
|
|
189 | Returns true if the watcher is active, false otherwise. |
|
|
190 | |
|
|
191 | =item $current_data = $w->data |
|
|
192 | |
|
|
193 | =item $old_data = $w->data ($new_data) |
|
|
194 | |
|
|
195 | Queries a freely usable data scalar on the watcher and optionally changes |
|
|
196 | it. This is a way to associate custom data with a watcher: |
|
|
197 | |
|
|
198 | my $w = EV::timer 60, 0, sub { |
|
|
199 | warn $_[0]->data; |
|
|
200 | }; |
|
|
201 | $w->data ("print me!"); |
|
|
202 | |
|
|
203 | =item $current_cb = $w->cb |
|
|
204 | |
|
|
205 | =item $old_cb = $w->cb ($new_cb) |
|
|
206 | |
|
|
207 | Queries the callback on the watcher and optionally changes it. You can do |
|
|
208 | this at any time without the watcher restarting. |
|
|
209 | |
|
|
210 | =item $current_priority = $w->priority |
|
|
211 | |
|
|
212 | =item $old_priority = $w->priority ($new_priority) |
|
|
213 | |
|
|
214 | Queries the priority on the watcher and optionally changes it. Pending |
|
|
215 | watchers with higher priority will be invoked first. The valid range of |
|
|
216 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
|
|
217 | -2). If the priority is outside this range it will automatically be |
|
|
218 | normalised to the nearest valid priority. |
|
|
219 | |
|
|
220 | The default priority of any newly-created weatcher is 0. |
|
|
221 | |
|
|
222 | =item $w->trigger ($revents) |
|
|
223 | |
|
|
224 | Call the callback *now* with the given event mask. |
|
|
225 | |
|
|
226 | |
93 | =item my $w = EV::io $fileno_or_fh, $eventmask, $callback |
227 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
94 | |
228 | |
95 | =item my $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
229 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
96 | |
230 | |
97 | As long as the returned watcher object is alive, call the C<$callback> |
231 | As long as the returned watcher object is alive, call the C<$callback> |
98 | when the events specified in C<$eventmask> happen. Initially, the timeout |
232 | when the events specified in C<$eventmask>. |
99 | is disabled. |
|
|
100 | |
233 | |
101 | The C<io_ns> variant doesn't add/start the newly created watcher. |
|
|
102 | |
|
|
103 | Eventmask can be one or more of these constants ORed together: |
234 | The $eventmask can be one or more of these constants ORed together: |
104 | |
235 | |
105 | EV::READ wait until read() wouldn't block anymore |
236 | EV::READ wait until read() wouldn't block anymore |
106 | EV::WRITE wait until write() wouldn't block anymore |
237 | EV::WRITE wait until write() wouldn't block anymore |
107 | EV::PERSIST stay active after an event occured |
|
|
108 | |
238 | |
|
|
239 | The C<io_ns> variant doesn't start (activate) the newly created watcher. |
|
|
240 | |
|
|
241 | =item $w->set ($fileno_or_fh, $eventmask) |
|
|
242 | |
|
|
243 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
244 | called at any time. |
|
|
245 | |
|
|
246 | =item $current_fh = $w->fh |
|
|
247 | |
|
|
248 | =item $old_fh = $w->fh ($new_fh) |
|
|
249 | |
|
|
250 | Returns the previously set filehandle and optionally set a new one. |
|
|
251 | |
|
|
252 | =item $current_eventmask = $w->events |
|
|
253 | |
|
|
254 | =item $old_eventmask = $w->events ($new_eventmask) |
|
|
255 | |
|
|
256 | Returns the previously set event mask and optionally set a new one. |
|
|
257 | |
|
|
258 | |
109 | =item my $w = EV::timer $after, $repeat, $callback |
259 | =item $w = EV::timer $after, $repeat, $callback |
110 | |
260 | |
111 | =item my $w = EV::timer_ns $after, $repeat, $callback |
261 | =item $w = EV::timer_ns $after, $repeat, $callback |
112 | |
262 | |
113 | Calls the callback after C<$after> seconds. If C<$repeat> is true, the |
263 | Calls the callback after C<$after> seconds. If C<$repeat> is non-zero, |
114 | timer will be restarted after the callback returns. This means that the |
264 | the timer will be restarted (with the $repeat value as $after) after the |
115 | callback would be called roughly every C<$after> seconds, prolonged by the |
265 | callback returns. |
116 | time the callback takes. |
|
|
117 | |
266 | |
|
|
267 | 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 |
|
|
269 | callback processing is not taken into account, so the timer will slowly |
|
|
270 | drift. If that isn't acceptable, look at EV::periodic. |
|
|
271 | |
|
|
272 | 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 |
|
|
274 | clock, the timer will nevertheless run (roughly) the same time. |
|
|
275 | |
118 | The C<timer_ns> variant doesn't add/start the newly created watcher. |
276 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
119 | |
277 | |
120 | =item my $w = EV::timer_abs $at, $interval, $callback |
278 | =item $w->set ($after, $repeat) |
121 | |
279 | |
122 | =item my $w = EV::timer_abs_ns $at, $interval, $callback |
280 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
281 | any time. |
123 | |
282 | |
124 | Similar to EV::timer, but the time is given as an absolute point in time |
283 | =item $w->again |
125 | (C<$at>), plus an optional C<$interval>. |
|
|
126 | |
284 | |
127 | If the C<$interval> is zero, then the callback will be called at the time |
285 | Similar to the C<start> method, but has special semantics for repeating timers: |
128 | C<$at> if that is in the future, or as soon as possible if its in the |
|
|
129 | past. It will not automatically repeat. |
|
|
130 | |
286 | |
131 | If the C<$interval> is nonzero, then the watcher will always be scheduled |
287 | If the timer is active and repeating, reset the timeout to occur |
132 | to time out at the next C<$at + integer * $interval> time. |
288 | C<$repeat> seconds after now. |
133 | |
289 | |
134 | This can be used to schedule a callback to run at very regular intervals, |
290 | If the timer is active and non-repeating, it will be stopped. |
135 | as long as the processing time is less then the interval (otherwise |
|
|
136 | obviously events will be skipped). |
|
|
137 | |
291 | |
138 | The C<timer_abs_ns> variant doesn't add/start the newly created watcher. |
292 | If the timer is in active and repeating, start it. |
139 | |
293 | |
140 | =item my $w = EV::signal $signum, $callback |
294 | Otherwise do nothing. |
141 | |
295 | |
142 | =item my $w = EV::signal_ns $signum, $callback |
296 | This behaviour is useful when you have a timeout for some IO |
|
|
297 | operation. You create a timer object with the same value for C<$after> and |
|
|
298 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
|
|
299 | on the timeout. |
143 | |
300 | |
144 | Call the callback when signal $signum is received. |
|
|
145 | |
301 | |
146 | The C<signal_ns> variant doesn't add/start the newly created watcher. |
302 | =item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
|
|
303 | |
|
|
304 | =item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
|
|
305 | |
|
|
306 | Similar to EV::timer, but is not based on relative timeouts but on |
|
|
307 | absolute times. Apart from creating "simple" timers that trigger "at" the |
|
|
308 | specified time, it can also be used for non-drifting absolute timers and |
|
|
309 | more complex, cron-like, setups that are not adversely affected by time |
|
|
310 | jumps (i.e. when the system clock is changed by explicit date -s or other |
|
|
311 | means such as ntpd). It is also the most complex watcher type in EV. |
|
|
312 | |
|
|
313 | It has three distinct "modes": |
|
|
314 | |
|
|
315 | =over 4 |
|
|
316 | |
|
|
317 | =item * absolute timer ($interval = $reschedule_cb = 0) |
|
|
318 | |
|
|
319 | This time simply fires at the wallclock time C<$at> and doesn't repeat. It |
|
|
320 | will not adjust when a time jump occurs, that is, if it is to be run |
|
|
321 | at January 1st 2011 then it will run when the system time reaches or |
|
|
322 | surpasses this time. |
|
|
323 | |
|
|
324 | =item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
|
|
325 | |
|
|
326 | In this mode the watcher will always be scheduled to time out at the |
|
|
327 | next C<$at + N * $interval> time (for some integer N) and then repeat, |
|
|
328 | regardless of any time jumps. |
|
|
329 | |
|
|
330 | This can be used to create timers that do not drift with respect to system |
|
|
331 | time: |
|
|
332 | |
|
|
333 | my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; |
|
|
334 | |
|
|
335 | That doesn't mean there will always be 3600 seconds in between triggers, |
|
|
336 | but only that the the clalback will be called when the system time shows a |
|
|
337 | full hour (UTC). |
|
|
338 | |
|
|
339 | Another way to think about it (for the mathematically inclined) is that |
|
|
340 | EV::periodic will try to run the callback in this mode at the next |
|
|
341 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
|
|
342 | jumps. |
|
|
343 | |
|
|
344 | =item * manual reschedule mode ($reschedule_cb = coderef) |
|
|
345 | |
|
|
346 | In this mode $interval and $at are both being ignored. Instead, each time |
|
|
347 | the periodic watcher gets scheduled, the first callback ($reschedule_cb) |
|
|
348 | will be called with the watcher as first, and the current time as second |
|
|
349 | argument. |
|
|
350 | |
|
|
351 | 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 |
|
|
353 | afterwards. |
|
|
354 | |
|
|
355 | It must return the next time to trigger, based on the passed time value |
|
|
356 | (that is, the lowest time value larger than to the second argument). It |
|
|
357 | will usually be called just before the callback will be triggered, but |
|
|
358 | might be called at other times, too. |
|
|
359 | |
|
|
360 | This can be used to create very complex timers, such as a timer that |
|
|
361 | triggers on each midnight, local time (actually 24 hours after the last |
|
|
362 | midnight, to keep the example simple. If you know a way to do it correctly |
|
|
363 | in about the same space (without requiring elaborate modules), drop me a |
|
|
364 | note :): |
|
|
365 | |
|
|
366 | my $daily = EV::periodic 0, 0, sub { |
|
|
367 | my ($w, $now) = @_; |
|
|
368 | |
|
|
369 | use Time::Local (); |
|
|
370 | my (undef, undef, undef, $d, $m, $y) = localtime $now; |
|
|
371 | 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y |
|
|
372 | }, sub { |
|
|
373 | print "it's midnight or likely shortly after, now\n"; |
|
|
374 | }; |
147 | |
375 | |
148 | =back |
376 | =back |
149 | |
377 | |
150 | =head1 THE EV::Event CLASS |
378 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
151 | |
379 | |
152 | All EV functions creating an event watcher (designated by C<my $w => |
380 | =item $w->set ($at, $interval, $reschedule_cb) |
153 | above) support the following methods on the returned watcher object: |
|
|
154 | |
381 | |
155 | =over 4 |
382 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
383 | any time. |
156 | |
384 | |
157 | =item $w->add ($timeout) |
385 | =item $w->again |
158 | |
386 | |
159 | Stops and (re-)starts the event watcher, setting the optional timeout to |
387 | Simply stops and starts the watcher again. |
160 | the given value, or clearing the timeout if none is given. |
|
|
161 | |
388 | |
162 | =item $w->start |
|
|
163 | |
389 | |
164 | Stops and (re-)starts the event watcher without touching the timeout. |
390 | =item $w = EV::signal $signal, $callback |
165 | |
391 | |
166 | =item $w->del |
392 | =item $w = EV::signal_ns $signal, $callback |
167 | |
393 | |
|
|
394 | Call the callback when $signal is received (the signal can be specified |
|
|
395 | by number or by name, just as with kill or %SIG). |
|
|
396 | |
|
|
397 | 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, |
|
|
399 | and removes it again when you stop it. Perl does the same when you |
|
|
400 | add/remove callbacks to %SIG, so watch out. |
|
|
401 | |
|
|
402 | You can have as many signal watchers per signal as you want. |
|
|
403 | |
|
|
404 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
|
|
405 | |
|
|
406 | =item $w->set ($signal) |
|
|
407 | |
|
|
408 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
409 | any time. |
|
|
410 | |
|
|
411 | =item $current_signum = $w->signal |
|
|
412 | |
|
|
413 | =item $old_signum = $w->signal ($new_signal) |
|
|
414 | |
|
|
415 | Returns the previously set signal (always as a number not name) and |
|
|
416 | optionally set a new one. |
|
|
417 | |
|
|
418 | |
|
|
419 | =item $w = EV::child $pid, $callback |
|
|
420 | |
|
|
421 | =item $w = EV::child_ns $pid, $callback |
|
|
422 | |
|
|
423 | Call the callback when a status change for pid C<$pid> (or any pid |
|
|
424 | if C<$pid> is 0) has been received. More precisely: when the process |
|
|
425 | receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all |
|
|
426 | changed/zombie children and call the callback. |
|
|
427 | |
|
|
428 | You can access both status and pid by using the C<rstatus> and C<rpid> |
|
|
429 | methods on the watcher object. |
|
|
430 | |
|
|
431 | You can have as many pid watchers per pid as you want. |
|
|
432 | |
|
|
433 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
|
|
434 | |
168 | =item $w->stop |
435 | =item $w->set ($pid) |
169 | |
436 | |
170 | Stop the event watcher if it was started. |
437 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
438 | any time. |
171 | |
439 | |
172 | =item $current_callback = $w->cb |
|
|
173 | |
|
|
174 | =item $old_callback = $w->cb ($new_callback) |
|
|
175 | |
|
|
176 | Return the previously set callback and optionally set a new one. |
|
|
177 | |
|
|
178 | =item $current_fh = $w->fh |
440 | =item $current_pid = $w->pid |
179 | |
441 | |
180 | =item $old_fh = $w->fh ($new_fh) |
442 | =item $old_pid = $w->pid ($new_pid) |
181 | |
443 | |
182 | Returns the previously set filehandle and optionally set a new one. |
|
|
183 | |
|
|
184 | =item $current_eventmask = $w->events |
|
|
185 | |
|
|
186 | =item $old_eventmask = $w->events ($new_eventmask) |
|
|
187 | |
|
|
188 | Returns the previously set event mask and optionally set a new one. |
444 | Returns the previously set process id and optionally set a new one. |
189 | |
445 | |
190 | =item $w->timeout ($after, $repeat) |
446 | =item $exit_status = $w->rstatus |
191 | |
447 | |
192 | Resets the timeout (see C<EV::timer> for details). |
448 | Return the exit/wait status (as returned by waitpid, see the waitpid entry |
|
|
449 | in perlfunc). |
193 | |
450 | |
194 | =item $w->timeout_abs ($at, $interval) |
451 | =item $pid = $w->rpid |
195 | |
452 | |
196 | Resets the timeout (see C<EV::timer_abs> for details). |
453 | Return the pid of the awaited child (useful when you have installed a |
|
|
454 | watcher for all pids). |
197 | |
455 | |
198 | =item $w->priority_set ($priority) |
|
|
199 | |
456 | |
200 | Set the priority of the watcher to C<$priority> (0 <= $priority < $EV::NPRI). |
457 | =item $w = EV::idle $callback |
|
|
458 | |
|
|
459 | =item $w = EV::idle_ns $callback |
|
|
460 | |
|
|
461 | Call the callback when there are no pending io, timer/periodic, signal or |
|
|
462 | child events, i.e. when the process is idle. |
|
|
463 | |
|
|
464 | The process will not block as long as any idle watchers are active, and |
|
|
465 | they will be called repeatedly until stopped. |
|
|
466 | |
|
|
467 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
|
|
468 | |
|
|
469 | |
|
|
470 | =item $w = EV::prepare $callback |
|
|
471 | |
|
|
472 | =item $w = EV::prepare_ns $callback |
|
|
473 | |
|
|
474 | Call the callback just before the process would block. You can still |
|
|
475 | create/modify any watchers at this point. |
|
|
476 | |
|
|
477 | See the EV::check watcher, below, for explanations and an example. |
|
|
478 | |
|
|
479 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
|
|
480 | |
|
|
481 | |
|
|
482 | =item $w = EV::check $callback |
|
|
483 | |
|
|
484 | =item $w = EV::check_ns $callback |
|
|
485 | |
|
|
486 | Call the callback just after the process wakes up again (after it has |
|
|
487 | gathered events), but before any other callbacks have been invoked. |
|
|
488 | |
|
|
489 | This is used to integrate other event-based software into the EV |
|
|
490 | mainloop: You register a prepare callback and in there, you create io and |
|
|
491 | timer watchers as required by the other software. Here is a real-world |
|
|
492 | example of integrating Net::SNMP (with some details left out): |
|
|
493 | |
|
|
494 | our @snmp_watcher; |
|
|
495 | |
|
|
496 | our $snmp_prepare = EV::prepare sub { |
|
|
497 | # do nothing unless active |
|
|
498 | $dispatcher->{_event_queue_h} |
|
|
499 | or return; |
|
|
500 | |
|
|
501 | # make the dispatcher handle any outstanding stuff |
|
|
502 | |
|
|
503 | # create an IO watcher for each and every socket |
|
|
504 | @snmp_watcher = ( |
|
|
505 | (map { EV::io $_, EV::READ, sub { } } |
|
|
506 | keys %{ $dispatcher->{_descriptors} }), |
|
|
507 | ); |
|
|
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 | }; |
|
|
513 | |
|
|
514 | The callbacks are irrelevant, the only purpose of those watchers is |
|
|
515 | to wake up the process as soon as one of those events occurs (socket |
|
|
516 | readable, or timer timed out). The corresponding EV::check watcher will then |
|
|
517 | clean up: |
|
|
518 | |
|
|
519 | our $snmp_check = EV::check sub { |
|
|
520 | # destroy all watchers |
|
|
521 | @snmp_watcher = (); |
|
|
522 | |
|
|
523 | # make the dispatcher handle any new stuff |
|
|
524 | }; |
|
|
525 | |
|
|
526 | 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 |
|
|
528 | first). |
|
|
529 | |
|
|
530 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
201 | |
531 | |
202 | =back |
532 | =back |
203 | |
533 | |
204 | =head1 BUGS |
534 | =head1 THREADS |
205 | |
535 | |
206 | Lots. Libevent itself isn't well tested and rather buggy, and this module |
536 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
207 | is quite new at the moment. |
537 | stuff and must die. |
208 | |
538 | |
209 | =cut |
539 | =cut |
210 | |
540 | |
211 | our $NPRI = 4; |
541 | our $DIED = sub { |
212 | our $BASE = init; |
542 | warn "EV: error in callback (ignoring): $@"; |
213 | priority_init $NPRI; |
543 | }; |
|
|
544 | |
|
|
545 | default_loop |
|
|
546 | or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?'; |
214 | |
547 | |
215 | 1; |
548 | 1; |
216 | |
549 | |
217 | =head1 SEE ALSO |
550 | =head1 SEE ALSO |
218 | |
551 | |
219 | L<EV::DNS>, L<event(3)>, L<event.h>, L<evdns.h>. |
552 | L<EV::DNS>, L<EV::AnyEvent>. |
220 | |
553 | |
221 | =head1 AUTHOR |
554 | =head1 AUTHOR |
222 | |
555 | |
223 | Marc Lehmann <schmorp@schmorp.de> |
556 | Marc Lehmann <schmorp@schmorp.de> |
224 | http://home.schmorp.de/ |
557 | http://home.schmorp.de/ |