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 | |
… | |
… | |
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 | my $w = EV::timer_abs 0, 60, sub { |
21 | my $w = EV::periodic 0, 60, sub { |
22 | warn "is called every minute, on the minute, exactly"; |
22 | warn "is called every minute, on the minute, exactly"; |
23 | }; |
23 | }; |
24 | |
24 | |
25 | # IO |
25 | # IO |
26 | |
26 | |
27 | my $w = EV::io \*STDIN, EV::READ | EV::PERSIST, sub { |
27 | my $w = EV::io *STDIN, EV::READ, sub { |
28 | my ($w, $revents) = @_; # all callbacks get the watcher object and event mask |
28 | my ($w, $revents) = @_; # all callbacks get the watcher object and event mask |
29 | if ($revents & EV::TIMEOUT) { |
|
|
30 | warn "nothing 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 | }; |
|
|
35 | $w->timeout (10); |
|
|
36 | |
|
|
37 | my $w = EV::timed_io \*STDIN, EV::READ, 30, sub { |
|
|
38 | my ($w, $revents) = @_; |
|
|
39 | if ($revents & EV::TIMEOUT) { |
|
|
40 | warn "nothing entered within 30 seconds, bye bye.\n"; |
|
|
41 | $w->stop; |
|
|
42 | } else { |
|
|
43 | my $line = <STDIN>; |
|
|
44 | warn "you entered something, you again have 30 seconds.\n"; |
|
|
45 | } |
|
|
46 | }; |
30 | }; |
47 | |
31 | |
48 | # SIGNALS |
32 | # SIGNALS |
49 | |
33 | |
50 | my $w = EV::signal 'QUIT', sub { |
34 | my $w = EV::signal 'QUIT', sub { |
… | |
… | |
60 | my $w = EV::child 666, sub { |
44 | my $w = EV::child 666, sub { |
61 | my ($w, $revents, $status) = @_; |
45 | my ($w, $revents, $status) = @_; |
62 | }; |
46 | }; |
63 | |
47 | |
64 | # MAINLOOP |
48 | # MAINLOOP |
65 | EV::dispatch; # loop as long as watchers are active |
49 | EV::loop; # loop until EV::loop_done is called |
66 | EV::loop; # the same thing |
|
|
67 | EV::loop EV::LOOP_ONESHOT; # block until some events could be handles |
50 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
68 | EV::loop EV::LOOP_NONBLOCK; # check and handle some events, but do not wait |
51 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
69 | |
52 | |
70 | =head1 DESCRIPTION |
53 | =head1 DESCRIPTION |
71 | |
54 | |
72 | This module provides an interface to libev |
55 | This module provides an interface to libev |
73 | (L<http://software.schmorp.de/pkg/libev.html>). You probably should |
56 | (L<http://software.schmorp.de/pkg/libev.html>). |
74 | acquaint yourself with its documentation and source code to be able to use |
|
|
75 | this module fully. |
|
|
76 | |
57 | |
77 | =cut |
58 | =cut |
78 | |
59 | |
79 | package EV; |
60 | package EV; |
80 | |
61 | |
81 | use strict; |
62 | use strict; |
82 | |
63 | |
83 | BEGIN { |
64 | BEGIN { |
84 | our $VERSION = '0.03'; |
65 | our $VERSION = '0.1'; |
85 | use XSLoader; |
66 | use XSLoader; |
86 | XSLoader::load "EV", $VERSION; |
67 | XSLoader::load "EV", $VERSION; |
87 | } |
68 | } |
88 | |
69 | |
89 | @EV::Io::ISA = "EV::Watcher"; |
70 | @EV::Io::ISA = |
90 | @EV::Time::ISA = "EV::Watcher"; |
|
|
91 | @EV::Timer::ISA = "EV::Time"; |
71 | @EV::Timer::ISA = |
92 | @EV::Periodic::ISA = "EV::Time"; |
72 | @EV::Periodic::ISA = |
93 | @EV::Signal::ISA = "EV::Watcher"; |
73 | @EV::Signal::ISA = |
94 | @EV::Idle::ISA = "EV::Watcher"; |
74 | @EV::Idle::ISA = |
95 | @EV::Prepare::ISA = "EV::Watcher"; |
75 | @EV::Prepare::ISA = |
|
|
76 | @EV::Check::ISA = |
96 | @EV::Check::ISA = "EV::Watcher"; |
77 | @EV::Child::ISA = "EV::Watcher"; |
97 | |
78 | |
98 | =head1 BASIC INTERFACE |
79 | =head1 BASIC INTERFACE |
99 | |
80 | |
100 | =over 4 |
81 | =over 4 |
101 | |
|
|
102 | =item $EV::NPRI |
|
|
103 | |
|
|
104 | How many priority levels are available. |
|
|
105 | |
82 | |
106 | =item $EV::DIED |
83 | =item $EV::DIED |
107 | |
84 | |
108 | Must contain a reference to a function that is called when a callback |
85 | Must contain a reference to a function that is called when a callback |
109 | throws an exception (with $@ containing thr error). The default prints an |
86 | throws an exception (with $@ containing thr error). The default prints an |
110 | informative message and continues. |
87 | informative message and continues. |
111 | |
88 | |
112 | If this callback throws an exception it will be silently ignored. |
89 | If this callback throws an exception it will be silently ignored. |
113 | |
90 | |
|
|
91 | =item $time = EV::time |
|
|
92 | |
|
|
93 | Returns the current time in (fractional) seconds since the epoch. |
|
|
94 | |
114 | =item $time = EV::now |
95 | =item $time = EV::now |
115 | |
96 | |
116 | Returns the time in (fractional) seconds since the epoch. |
97 | Returns the time the last event loop iteration has been started. This |
|
|
98 | is the time that (relative) timers are based on, and refering to it is |
|
|
99 | usually faster then calling EV::time. |
117 | |
100 | |
118 | =item $version = EV::version |
|
|
119 | |
|
|
120 | =item $method = EV::method |
101 | =item $method = EV::ev_method |
121 | |
102 | |
122 | Return version string and event polling method used. |
103 | Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
|
|
104 | or EV::METHOD_EPOLL). |
123 | |
105 | |
124 | =item EV::loop $flags # EV::LOOP_ONCE, EV::LOOP_ONESHOT |
106 | =item EV::loop [$flags] |
125 | |
107 | |
126 | =item EV::loopexit $after |
108 | Begin checking for events and calling callbacks. It returns when a |
|
|
109 | callback calls EV::loop_done. |
127 | |
110 | |
128 | Exit any active loop or dispatch after C<$after> seconds or immediately if |
111 | The $flags argument can be one of the following: |
129 | C<$after> is missing or zero. |
|
|
130 | |
112 | |
131 | =item EV::dispatch |
113 | 0 as above |
|
|
114 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
|
|
115 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
132 | |
116 | |
133 | Same as C<EV::loop 0>. |
117 | =item EV::loop_done [$how] |
134 | |
118 | |
135 | =item EV::event $callback |
119 | When called with no arguments or an argument of 1, makes the innermost |
|
|
120 | call to EV::loop return. |
136 | |
121 | |
137 | Creates a new event watcher waiting for nothing, calling the given callback. |
122 | When called with an agrument of 2, all calls to EV::loop will return as |
|
|
123 | fast as possible. |
138 | |
124 | |
|
|
125 | =back |
|
|
126 | |
|
|
127 | =head2 WATCHER |
|
|
128 | |
|
|
129 | A watcher is an object that gets created to record your interest in some |
|
|
130 | event. For instance, if you want to wait for STDIN to become readable, you |
|
|
131 | would create an EV::io watcher for that: |
|
|
132 | |
|
|
133 | my $watcher = EV::io *STDIN, EV::READ, sub { |
|
|
134 | my ($watcher, $revents) = @_; |
|
|
135 | warn "yeah, STDIN should not be readable without blocking!\n" |
|
|
136 | }; |
|
|
137 | |
|
|
138 | All watchers can be active (waiting for events) or inactive (paused). Only |
|
|
139 | active watchers will have their callbacks invoked. All callbacks will be |
|
|
140 | called with at least two arguments: the watcher and a bitmask of received |
|
|
141 | events. |
|
|
142 | |
|
|
143 | Each watcher type has its associated bit in revents, so you can use the |
|
|
144 | same callback for multiple watchers. The event mask is named after the |
|
|
145 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
|
|
146 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO events |
|
|
147 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
|
|
148 | uses EV::TIMEOUT). |
|
|
149 | |
|
|
150 | In the rare case where one wants to create a watcher but not start it at |
|
|
151 | the same time, each constructor has a variant with a trailing C<_ns> in |
|
|
152 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
|
|
153 | |
|
|
154 | Please note that a watcher will automatically be stopped when the watcher |
|
|
155 | object is returned, so you I<need> to keep the watcher objects returned by |
|
|
156 | the constructors. |
|
|
157 | |
|
|
158 | =head2 WATCHER TYPES |
|
|
159 | |
|
|
160 | Now lets move to the existing watcher types and asociated methods. |
|
|
161 | |
|
|
162 | The following methods are available for all watchers. Then followes a |
|
|
163 | description of each watcher constructor (EV::io, EV::timer, EV::periodic, |
|
|
164 | EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by |
|
|
165 | any type-specific methods (if any). |
|
|
166 | |
|
|
167 | =over 4 |
|
|
168 | |
|
|
169 | =item $w->start |
|
|
170 | |
|
|
171 | Starts a watcher if it isn't active already. Does nothing to an already |
|
|
172 | active watcher. By default, all watchers start out in the active state |
|
|
173 | (see the description of the C<_ns> variants if you need stopped watchers). |
|
|
174 | |
|
|
175 | =item $w->stop |
|
|
176 | |
|
|
177 | Stop a watcher if it is active. Also clear any pending events (events that |
|
|
178 | have been received but that didn't yet result in a callback invocation), |
|
|
179 | regardless of wether the watcher was active or not. |
|
|
180 | |
|
|
181 | =item $bool = $w->is_active |
|
|
182 | |
|
|
183 | Returns true if the watcher is active, false otherwise. |
|
|
184 | |
|
|
185 | =item $current_cb = $w->cb |
|
|
186 | |
|
|
187 | =item $old_cb = $w->cb ($new_cb) |
|
|
188 | |
|
|
189 | Queries the callback on the watcher and optionally changes it. You cna do |
|
|
190 | this at any time. |
|
|
191 | |
|
|
192 | =item $w->trigger ($revents) |
|
|
193 | |
|
|
194 | Call the callback *now* with the given event mask. |
|
|
195 | |
|
|
196 | |
139 | =item my $w = EV::io $fileno_or_fh, $eventmask, $callback |
197 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
140 | |
198 | |
141 | =item my $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
199 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
142 | |
200 | |
143 | As long as the returned watcher object is alive, call the C<$callback> |
201 | As long as the returned watcher object is alive, call the C<$callback> |
144 | when the events specified in C<$eventmask> happen. Initially, the timeout |
202 | when the events specified in C<$eventmask>. |
145 | is disabled. |
|
|
146 | |
203 | |
147 | You can additionall set a timeout to occur on the watcher, but note that |
|
|
148 | this timeout will not be reset when you get an I/O event in the EV::PERSIST |
|
|
149 | case, and reaching a timeout will always stop the watcher even in the |
|
|
150 | EV::PERSIST case. |
|
|
151 | |
|
|
152 | If you want a timeout to occur only after a specific time of inactivity, set |
|
|
153 | a repeating timeout and do NOT use EV::PERSIST. |
|
|
154 | |
|
|
155 | Eventmask can be one or more of these constants ORed together: |
204 | The $eventmask can be one or more of these constants ORed together: |
156 | |
205 | |
157 | EV::READ wait until read() wouldn't block anymore |
206 | EV::READ wait until read() wouldn't block anymore |
158 | EV::WRITE wait until write() wouldn't block anymore |
207 | EV::WRITE wait until write() wouldn't block anymore |
159 | EV::PERSIST stay active after a (non-timeout) event occured |
|
|
160 | |
208 | |
161 | The C<io_ns> variant doesn't add/start the newly created watcher. |
209 | The C<io_ns> variant doesn't start (activate) the newly created watcher. |
162 | |
210 | |
163 | =item my $w = EV::timed_io $fileno_or_fh, $eventmask, $timeout, $callback |
211 | =item $w->set ($fileno_or_fh, $eventmask) |
164 | |
212 | |
165 | =item my $w = EV::timed_io_ns $fileno_or_fh, $eventmask, $timeout, $callback |
213 | Reconfigures the watcher, see the constructor above for details. Can be |
|
|
214 | called at any time. |
166 | |
215 | |
167 | Same as C<io> and C<io_ns>, but also specifies a timeout (as if there was |
216 | =item $current_fh = $w->fh |
168 | a call to C<< $w->timeout ($timout, 1) >>. The persist flag is not allowed |
|
|
169 | and will automatically be cleared. The watcher will be restarted after each event. |
|
|
170 | |
217 | |
171 | If the timeout is zero or undef, no timeout will be set, and a normal |
218 | =item $old_fh = $w->fh ($new_fh) |
172 | watcher (with the persist flag set!) will be created. |
|
|
173 | |
219 | |
174 | This has the effect of timing out after the specified period of inactivity |
220 | Returns the previously set filehandle and optionally set a new one. |
175 | has happened. |
|
|
176 | |
221 | |
177 | Due to the design of libevent, this is also relatively inefficient, having |
222 | =item $current_eventmask = $w->events |
178 | one or two io watchers and a separate timeout watcher that you reset on |
|
|
179 | activity (by calling its C<start> method) is usually more efficient. |
|
|
180 | |
223 | |
|
|
224 | =item $old_eventmask = $w->events ($new_eventmask) |
|
|
225 | |
|
|
226 | Returns the previously set event mask and optionally set a new one. |
|
|
227 | |
|
|
228 | |
181 | =item my $w = EV::timer $after, $repeat, $callback |
229 | =item $w = EV::timer $after, $repeat, $callback |
182 | |
230 | |
183 | =item my $w = EV::timer_ns $after, $repeat, $callback |
231 | =item $w = EV::timer_ns $after, $repeat, $callback |
184 | |
232 | |
185 | Calls the callback after C<$after> seconds. If C<$repeat> is true, the |
233 | Calls the callback after C<$after> seconds. If C<$repeat> is non-zero, |
186 | timer will be restarted after the callback returns. This means that the |
234 | the timer will be restarted (with the $repeat value as $after) after the |
187 | callback would be called roughly every C<$after> seconds, prolonged by the |
235 | callback returns. |
188 | time the callback takes. |
|
|
189 | |
236 | |
|
|
237 | This means that the callback would be called roughly after C<$after> |
|
|
238 | seconds, and then every C<$repeat> seconds. "Roughly" because the time of |
|
|
239 | callback processing is not taken into account, so the timer will slowly |
|
|
240 | drift. If that isn't acceptable, look at EV::periodic. |
|
|
241 | |
|
|
242 | The timer is based on a monotonic clock, that is if somebody is sitting |
|
|
243 | in front of the machine while the timer is running and changes the system |
|
|
244 | clock, the timer will nevertheless run (roughly) the same time. |
|
|
245 | |
190 | The C<timer_ns> variant doesn't add/start the newly created watcher. |
246 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
191 | |
247 | |
|
|
248 | =item $w->set ($after, $repeat) |
|
|
249 | |
|
|
250 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
251 | any time. |
|
|
252 | |
|
|
253 | =item $w->again |
|
|
254 | |
|
|
255 | Similar to the C<start> method, but has special semantics for repeating timers: |
|
|
256 | |
|
|
257 | If the timer is active and repeating, reset the timeout to occur |
|
|
258 | C<$repeat> seconds after now. |
|
|
259 | |
|
|
260 | If the timer is active and non-repeating, it will be stopped. |
|
|
261 | |
|
|
262 | If the timer is in active and repeating, start it. |
|
|
263 | |
|
|
264 | Otherwise do nothing. |
|
|
265 | |
|
|
266 | This behaviour is useful when you have a timeout for some IO |
|
|
267 | operation. You create a timer object with the same value for C<$after> and |
|
|
268 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
|
|
269 | on the timeout. |
|
|
270 | |
|
|
271 | |
|
|
272 | =item $w = EV::periodic $at, $interval, $callback |
|
|
273 | |
192 | =item my $w = EV::timer_abs $at, $interval, $callback |
274 | =item $w = EV::periodic_ns $at, $interval, $callback |
193 | |
|
|
194 | =item my $w = EV::timer_abs_ns $at, $interval, $callback |
|
|
195 | |
275 | |
196 | Similar to EV::timer, but the time is given as an absolute point in time |
276 | Similar to EV::timer, but the time is given as an absolute point in time |
197 | (C<$at>), plus an optional C<$interval>. |
277 | (C<$at>), plus an optional C<$interval>. |
198 | |
278 | |
199 | If the C<$interval> is zero, then the callback will be called at the time |
279 | If the C<$interval> is zero, then the callback will be called at the time |
200 | C<$at> if that is in the future, or as soon as possible if its in the |
280 | C<$at> if that is in the future, or as soon as possible if it is in the |
201 | past. It will not automatically repeat. |
281 | past. It will not automatically repeat. |
202 | |
282 | |
203 | If the C<$interval> is nonzero, then the watcher will always be scheduled |
283 | If the C<$interval> is nonzero, then the watcher will always be scheduled |
204 | to time out at the next C<$at + integer * $interval> time. |
284 | to time out at the next C<$at + N * $interval> time. |
205 | |
285 | |
206 | This can be used to schedule a callback to run at very regular intervals, |
286 | This can be used to schedule a callback to run at very regular intervals, |
207 | as long as the processing time is less then the interval (otherwise |
287 | as long as the processing time is less then the interval (otherwise |
208 | obviously events will be skipped). |
288 | obviously events will be skipped). |
209 | |
289 | |
210 | Another way to think about it (for the mathematically inclined) is that |
290 | Another way to think about it (for the mathematically inclined) is that |
211 | C<timer_abs> will try to tun the callback at the next possible time where |
291 | EV::periodic will try to run the callback at the next possible time where |
212 | C<$time = $at (mod $interval)>, regardless of any time jumps. |
292 | C<$time = $at (mod $interval)>, regardless of any time jumps. |
213 | |
293 | |
|
|
294 | This periodic timer is based on "wallclock time", that is, if the clock |
|
|
295 | changes (C<ntp>, C<date -s> etc.), then the timer will nevertheless run at |
|
|
296 | the specified time. This means it will never drift (it might jitter, but |
|
|
297 | it will not drift). |
|
|
298 | |
214 | The C<timer_abs_ns> variant doesn't add/start the newly created watcher. |
299 | The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
215 | |
300 | |
|
|
301 | =item $w->set ($at, $interval) |
|
|
302 | |
|
|
303 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
304 | any time. |
|
|
305 | |
|
|
306 | |
216 | =item my $w = EV::signal $signal, $callback |
307 | =item $w = EV::signal $signal, $callback |
217 | |
308 | |
218 | =item my $w = EV::signal_ns $signal, $callback |
309 | =item $w = EV::signal_ns $signal, $callback |
219 | |
310 | |
220 | Call the callback when $signal is received (the signal can be specified |
311 | Call the callback when $signal is received (the signal can be specified |
221 | by number or by name, just as with kill or %SIG). Signal watchers are |
312 | by number or by name, just as with kill or %SIG). |
222 | persistent no natter what. |
|
|
223 | |
313 | |
224 | EV will grab the signal for the process (the kernel only allows one |
314 | EV will grab the signal for the process (the kernel only allows one |
225 | component to receive signals) when you start a signal watcher, and |
315 | component to receive a signal at a time) when you start a signal watcher, |
226 | removes it again when you stop it. Pelr does the same when you add/remove |
316 | and removes it again when you stop it. Perl does the same when you |
227 | callbacks to %SIG, so watch out. |
317 | add/remove callbacks to %SIG, so watch out. |
228 | |
318 | |
229 | Unfortunately, only one handler can be registered per signal. Screw |
319 | You can have as many signal watchers per signal as you want. |
230 | libevent. |
|
|
231 | |
320 | |
232 | The C<signal_ns> variant doesn't add/start the newly created watcher. |
321 | The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
|
|
322 | |
|
|
323 | =item $w->set ($signal) |
|
|
324 | |
|
|
325 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
326 | any time. |
|
|
327 | |
|
|
328 | =item $current_signum = $w->signal |
|
|
329 | |
|
|
330 | =item $old_signum = $w->signal ($new_signal) |
|
|
331 | |
|
|
332 | Returns the previously set signal (always as a number not name) and |
|
|
333 | optionally set a new one. |
|
|
334 | |
|
|
335 | |
|
|
336 | =item $w = EV::child $pid, $callback |
|
|
337 | |
|
|
338 | =item $w = EV::child_ns $pid, $callback |
|
|
339 | |
|
|
340 | Call the callback when a status change for pid C<$pid> (or any pid |
|
|
341 | if C<$pid> is 0) has been received. More precisely: when the process |
|
|
342 | receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all |
|
|
343 | changed/zombie children and call the callback. |
|
|
344 | |
|
|
345 | Unlike all other callbacks, this callback will be called with an |
|
|
346 | additional third argument which is the exit status. See the C<waitpid> |
|
|
347 | function for details. |
|
|
348 | |
|
|
349 | You can have as many pid watchers per pid as you want. |
|
|
350 | |
|
|
351 | The C<child_ns> variant doesn't start (activate) the newly created watcher. |
|
|
352 | |
|
|
353 | =item $w->set ($pid) |
|
|
354 | |
|
|
355 | Reconfigures the watcher, see the constructor above for details. Can be at |
|
|
356 | any time. |
|
|
357 | |
|
|
358 | =item $current_pid = $w->pid |
|
|
359 | |
|
|
360 | =item $old_pid = $w->pid ($new_pid) |
|
|
361 | |
|
|
362 | Returns the previously set process id and optionally set a new one. |
|
|
363 | |
|
|
364 | |
|
|
365 | =item $w = EV::idle $callback |
|
|
366 | |
|
|
367 | =item $w = EV::idle_ns $callback |
|
|
368 | |
|
|
369 | Call the callback when there are no pending io, timer/periodic, signal or |
|
|
370 | child events, i.e. when the process is idle. |
|
|
371 | |
|
|
372 | The process will not block as long as any idle watchers are active, and |
|
|
373 | they will be called repeatedly until stopped. |
|
|
374 | |
|
|
375 | The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
|
|
376 | |
|
|
377 | |
|
|
378 | =item $w = EV::prepare $callback |
|
|
379 | |
|
|
380 | =item $w = EV::prepare_ns $callback |
|
|
381 | |
|
|
382 | Call the callback just before the process would block. You can still |
|
|
383 | create/modify any watchers at this point. |
|
|
384 | |
|
|
385 | See the EV::check watcher, below, for explanations and an example. |
|
|
386 | |
|
|
387 | The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
|
|
388 | |
|
|
389 | |
|
|
390 | =item $w = EV::check $callback |
|
|
391 | |
|
|
392 | =item $w = EV::check_ns $callback |
|
|
393 | |
|
|
394 | Call the callback just after the process wakes up again (after it has |
|
|
395 | gathered events), but before any other callbacks have been invoked. |
|
|
396 | |
|
|
397 | This is used to integrate other event-based software into the EV |
|
|
398 | mainloop: You register a prepare callback and in there, you create io and |
|
|
399 | timer watchers as required by the other software. Here is a real-world |
|
|
400 | example of integrating Net::SNMP (with some details left out): |
|
|
401 | |
|
|
402 | our @snmp_watcher; |
|
|
403 | |
|
|
404 | our $snmp_prepare = EV::prepare sub { |
|
|
405 | # do nothing unless active |
|
|
406 | $dispatcher->{_event_queue_h} |
|
|
407 | or return; |
|
|
408 | |
|
|
409 | # make the dispatcher handle any outstanding stuff |
|
|
410 | |
|
|
411 | # create an IO watcher for each and every socket |
|
|
412 | @snmp_watcher = ( |
|
|
413 | (map { EV::io $_, EV::READ, sub { } } |
|
|
414 | keys %{ $dispatcher->{_descriptors} }), |
|
|
415 | ); |
|
|
416 | |
|
|
417 | # if there are any timeouts, also create a timer |
|
|
418 | push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { } |
|
|
419 | if $event->[Net::SNMP::Dispatcher::_ACTIVE]; |
|
|
420 | }; |
|
|
421 | |
|
|
422 | The callbacks are irrelevant, the only purpose of those watchers is |
|
|
423 | to wake up the process as soon as one of those events occurs (socket |
|
|
424 | readable, or timer timed out). The corresponding EV::check watcher will then |
|
|
425 | clean up: |
|
|
426 | |
|
|
427 | our $snmp_check = EV::check sub { |
|
|
428 | # destroy all watchers |
|
|
429 | @snmp_watcher = (); |
|
|
430 | |
|
|
431 | # make the dispatcher handle any new stuff |
|
|
432 | }; |
|
|
433 | |
|
|
434 | The callbacks of the created watchers will not be called as the watchers |
|
|
435 | are destroyed before this cna happen (remember EV::check gets called |
|
|
436 | first). |
|
|
437 | |
|
|
438 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
233 | |
439 | |
234 | =back |
440 | =back |
235 | |
441 | |
236 | =head1 THE EV::Event CLASS |
|
|
237 | |
|
|
238 | All EV functions creating an event watcher (designated by C<my $w => |
|
|
239 | above) support the following methods on the returned watcher object: |
|
|
240 | |
|
|
241 | =over 4 |
|
|
242 | |
|
|
243 | =item $w->add ($timeout) |
|
|
244 | |
|
|
245 | Stops and (re-)starts the event watcher, setting the optional timeout to |
|
|
246 | the given value, or clearing the timeout if none is given. |
|
|
247 | |
|
|
248 | =item $w->start |
|
|
249 | |
|
|
250 | Stops and (re-)starts the event watcher without touching the timeout. |
|
|
251 | |
|
|
252 | =item $w->del |
|
|
253 | |
|
|
254 | =item $w->stop |
|
|
255 | |
|
|
256 | Stop the event watcher if it was started. |
|
|
257 | |
|
|
258 | =item $current_callback = $w->cb |
|
|
259 | |
|
|
260 | =item $old_callback = $w->cb ($new_callback) |
|
|
261 | |
|
|
262 | Return the previously set callback and optionally set a new one. |
|
|
263 | |
|
|
264 | =item $current_fh = $w->fh |
|
|
265 | |
|
|
266 | =item $old_fh = $w->fh ($new_fh) |
|
|
267 | |
|
|
268 | Returns the previously set filehandle and optionally set a new one (also |
|
|
269 | clears the EV::SIGNAL flag when setting a filehandle). |
|
|
270 | |
|
|
271 | =item $current_signal = $w->signal |
|
|
272 | |
|
|
273 | =item $old_signal = $w->signal ($new_signal) |
|
|
274 | |
|
|
275 | Returns the previously set signal number and optionally set a new one (also sets |
|
|
276 | the EV::SIGNAL flag when setting a signal). |
|
|
277 | |
|
|
278 | =item $current_eventmask = $w->events |
|
|
279 | |
|
|
280 | =item $old_eventmask = $w->events ($new_eventmask) |
|
|
281 | |
|
|
282 | Returns the previously set event mask and optionally set a new one. |
|
|
283 | |
|
|
284 | =item $w->timeout ($after, $repeat) |
|
|
285 | |
|
|
286 | Resets the timeout (see C<EV::timer> for details). |
|
|
287 | |
|
|
288 | =item $w->timeout_abs ($at, $interval) |
|
|
289 | |
|
|
290 | Resets the timeout (see C<EV::timer_abs> for details). |
|
|
291 | |
|
|
292 | =item $w->priority_set ($priority) |
|
|
293 | |
|
|
294 | Set the priority of the watcher to C<$priority> (0 <= $priority < $EV::NPRI). |
|
|
295 | |
|
|
296 | =back |
|
|
297 | |
|
|
298 | =head1 THREADS |
442 | =head1 THREADS |
299 | |
443 | |
300 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
444 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
301 | and must die. |
445 | stuff and must die. |
302 | |
|
|
303 | =head1 BUGS |
|
|
304 | |
|
|
305 | Lots. Libevent itself isn't well tested and rather buggy, and this module |
|
|
306 | is quite new at the moment. |
|
|
307 | |
|
|
308 | Please note that the epoll method is not, in general, reliable in programs |
|
|
309 | that use fork (even if no libveent calls are being made in the forked |
|
|
310 | process). If your program behaves erratically, try setting the environment |
|
|
311 | variable C<EVENT_NOEPOLL> first when running the program. |
|
|
312 | |
|
|
313 | In general, if you fork, then you can only use the EV module in one of the |
|
|
314 | children. |
|
|
315 | |
446 | |
316 | =cut |
447 | =cut |
317 | |
448 | |
318 | our $DIED = sub { |
449 | our $DIED = sub { |
319 | warn "EV: error in callback (ignoring): $@"; |
450 | warn "EV: error in callback (ignoring): $@"; |
… | |
… | |
325 | |
456 | |
326 | 1; |
457 | 1; |
327 | |
458 | |
328 | =head1 SEE ALSO |
459 | =head1 SEE ALSO |
329 | |
460 | |
330 | L<EV::DNS>, L<event(3)>, L<event.h>, L<evdns.h>. |
|
|
331 | L<EV::AnyEvent>. |
461 | L<EV::DNS>, L<EV::AnyEvent>. |
332 | |
462 | |
333 | =head1 AUTHOR |
463 | =head1 AUTHOR |
334 | |
464 | |
335 | Marc Lehmann <schmorp@schmorp.de> |
465 | Marc Lehmann <schmorp@schmorp.de> |
336 | http://home.schmorp.de/ |
466 | http://home.schmorp.de/ |