1 |
root |
1.1 |
=head1 NAME |
2 |
|
|
|
3 |
root |
1.20 |
EV - perl interface to libev, a high performance full-featured event loop |
4 |
root |
1.1 |
|
5 |
|
|
=head1 SYNOPSIS |
6 |
|
|
|
7 |
root |
1.11 |
use EV; |
8 |
|
|
|
9 |
root |
1.20 |
# TIMERS |
10 |
root |
1.11 |
|
11 |
|
|
my $w = EV::timer 2, 0, sub { |
12 |
|
|
warn "is called after 2s"; |
13 |
|
|
}; |
14 |
|
|
|
15 |
root |
1.35 |
my $w = EV::timer 2, 2, sub { |
16 |
|
|
warn "is called roughly every 2s (repeat = 2)"; |
17 |
root |
1.11 |
}; |
18 |
|
|
|
19 |
|
|
undef $w; # destroy event watcher again |
20 |
|
|
|
21 |
root |
1.30 |
my $w = EV::periodic 0, 60, 0, sub { |
22 |
root |
1.11 |
warn "is called every minute, on the minute, exactly"; |
23 |
|
|
}; |
24 |
|
|
|
25 |
|
|
# IO |
26 |
|
|
|
27 |
root |
1.20 |
my $w = EV::io *STDIN, EV::READ, sub { |
28 |
root |
1.35 |
my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
29 |
root |
1.20 |
warn "stdin is readable, you entered: ", <STDIN>; |
30 |
root |
1.11 |
}; |
31 |
|
|
|
32 |
|
|
# SIGNALS |
33 |
|
|
|
34 |
|
|
my $w = EV::signal 'QUIT', sub { |
35 |
|
|
warn "sigquit received\n"; |
36 |
|
|
}; |
37 |
|
|
|
38 |
root |
1.16 |
# CHILD/PID STATUS CHANGES |
39 |
|
|
|
40 |
root |
1.82 |
my $w = EV::child 666, 0, sub { |
41 |
root |
1.27 |
my ($w, $revents) = @_; |
42 |
|
|
my $status = $w->rstatus; |
43 |
root |
1.16 |
}; |
44 |
root |
1.54 |
|
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 |
|
|
}; |
50 |
root |
1.11 |
|
51 |
|
|
# MAINLOOP |
52 |
root |
1.39 |
EV::loop; # loop until EV::unloop is called or all watchers stop |
53 |
root |
1.20 |
EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
54 |
|
|
EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
55 |
root |
1.2 |
|
56 |
root |
1.1 |
=head1 DESCRIPTION |
57 |
|
|
|
58 |
root |
1.16 |
This module provides an interface to libev |
59 |
root |
1.52 |
(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 |
root |
1.62 |
force a specific backend with C<LIBEV_FLAGS>, or just about in any case |
64 |
|
|
because it has much more detailed information. |
65 |
root |
1.1 |
|
66 |
|
|
=cut |
67 |
|
|
|
68 |
|
|
package EV; |
69 |
|
|
|
70 |
|
|
use strict; |
71 |
|
|
|
72 |
|
|
BEGIN { |
73 |
root |
1.83 |
our $VERSION = '3.0'; |
74 |
root |
1.1 |
use XSLoader; |
75 |
|
|
XSLoader::load "EV", $VERSION; |
76 |
|
|
} |
77 |
|
|
|
78 |
root |
1.49 |
@EV::IO::ISA = |
79 |
root |
1.18 |
@EV::Timer::ISA = |
80 |
|
|
@EV::Periodic::ISA = |
81 |
|
|
@EV::Signal::ISA = |
82 |
root |
1.56 |
@EV::Child::ISA = |
83 |
|
|
@EV::Stat::ISA = |
84 |
root |
1.18 |
@EV::Idle::ISA = |
85 |
|
|
@EV::Prepare::ISA = |
86 |
|
|
@EV::Check::ISA = |
87 |
root |
1.54 |
@EV::Embed::ISA = |
88 |
root |
1.56 |
@EV::Fork::ISA = |
89 |
|
|
"EV::Watcher"; |
90 |
root |
1.15 |
|
91 |
root |
1.72 |
@EV::Loop::Default::ISA = "EV::Loop"; |
92 |
|
|
|
93 |
root |
1.73 |
=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 |
root |
1.79 |
For specific programs you can create additional event loops dynamically. |
108 |
root |
1.73 |
|
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 |
root |
1.79 |
=item $loop = EV::default_loop [$flags] |
132 |
|
|
|
133 |
|
|
Return the default loop (which is a singleton object). |
134 |
|
|
|
135 |
root |
1.73 |
=back |
136 |
|
|
|
137 |
|
|
|
138 |
root |
1.8 |
=head1 BASIC INTERFACE |
139 |
root |
1.1 |
|
140 |
|
|
=over 4 |
141 |
|
|
|
142 |
root |
1.8 |
=item $EV::DIED |
143 |
|
|
|
144 |
|
|
Must contain a reference to a function that is called when a callback |
145 |
root |
1.67 |
throws an exception (with $@ containing the error). The default prints an |
146 |
root |
1.8 |
informative message and continues. |
147 |
|
|
|
148 |
|
|
If this callback throws an exception it will be silently ignored. |
149 |
|
|
|
150 |
root |
1.79 |
=item $flags = EV::supported_backends |
151 |
|
|
|
152 |
|
|
=item $flags = EV::recommended_backends |
153 |
|
|
|
154 |
|
|
=item $flags = EV::embeddable_backends |
155 |
|
|
|
156 |
|
|
Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this |
157 |
|
|
instance of EV, the set of recommended backends (supposed to be good) for |
158 |
|
|
this platform and the set of embeddable backends (see EMBED WATCHERS). |
159 |
|
|
|
160 |
root |
1.80 |
=item EV::sleep $seconds |
161 |
|
|
|
162 |
|
|
Block the process for the given number of (fractional) seconds. |
163 |
|
|
|
164 |
root |
1.20 |
=item $time = EV::time |
165 |
|
|
|
166 |
|
|
Returns the current time in (fractional) seconds since the epoch. |
167 |
|
|
|
168 |
root |
1.2 |
=item $time = EV::now |
169 |
|
|
|
170 |
root |
1.73 |
=item $time = $loop->now |
171 |
|
|
|
172 |
root |
1.20 |
Returns the time the last event loop iteration has been started. This |
173 |
|
|
is the time that (relative) timers are based on, and refering to it is |
174 |
|
|
usually faster then calling EV::time. |
175 |
|
|
|
176 |
root |
1.73 |
=item $backend = EV::backend |
177 |
|
|
|
178 |
|
|
=item $backend = $loop->backend |
179 |
root |
1.20 |
|
180 |
|
|
Returns an integer describing the backend used by libev (EV::METHOD_SELECT |
181 |
|
|
or EV::METHOD_EPOLL). |
182 |
|
|
|
183 |
|
|
=item EV::loop [$flags] |
184 |
root |
1.2 |
|
185 |
root |
1.73 |
=item $loop->loop ([$flags]) |
186 |
|
|
|
187 |
root |
1.20 |
Begin checking for events and calling callbacks. It returns when a |
188 |
root |
1.39 |
callback calls EV::unloop. |
189 |
root |
1.2 |
|
190 |
root |
1.20 |
The $flags argument can be one of the following: |
191 |
root |
1.2 |
|
192 |
root |
1.20 |
0 as above |
193 |
|
|
EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
194 |
|
|
EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
195 |
root |
1.2 |
|
196 |
root |
1.39 |
=item EV::unloop [$how] |
197 |
root |
1.2 |
|
198 |
root |
1.73 |
=item $loop->unloop ([$how]) |
199 |
|
|
|
200 |
root |
1.39 |
When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
201 |
|
|
innermost call to EV::loop return. |
202 |
root |
1.2 |
|
203 |
root |
1.39 |
When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
204 |
root |
1.20 |
fast as possible. |
205 |
root |
1.2 |
|
206 |
root |
1.60 |
=item $count = EV::loop_count |
207 |
|
|
|
208 |
root |
1.73 |
=item $count = $loop->loop_count |
209 |
|
|
|
210 |
root |
1.60 |
Return the number of times the event loop has polled for new |
211 |
|
|
events. Sometiems useful as a generation counter. |
212 |
|
|
|
213 |
root |
1.48 |
=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
214 |
root |
1.47 |
|
215 |
root |
1.73 |
=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
216 |
|
|
|
217 |
root |
1.47 |
This function rolls together an I/O and a timer watcher for a single |
218 |
|
|
one-shot event without the need for managing a watcher object. |
219 |
|
|
|
220 |
|
|
If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
221 |
|
|
must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ |
222 |
|
|
| EV::WRITE>, indicating the type of I/O event you want to wait for. If |
223 |
|
|
you do not want to wait for some I/O event, specify C<undef> for |
224 |
|
|
C<$fh_or_undef> and C<0> for C<$events>). |
225 |
|
|
|
226 |
|
|
If timeout is C<undef> or negative, then there will be no |
227 |
|
|
timeout. Otherwise a EV::timer with this value will be started. |
228 |
|
|
|
229 |
|
|
When an error occurs or either the timeout or I/O watcher triggers, then |
230 |
|
|
the callback will be called with the received event set (in general |
231 |
root |
1.77 |
you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
232 |
root |
1.47 |
C<EV::WRITE> and C<EV::TIMEOUT>). |
233 |
|
|
|
234 |
|
|
EV::once doesn't return anything: the watchers stay active till either |
235 |
|
|
of them triggers, then they will be stopped and freed, and the callback |
236 |
|
|
invoked. |
237 |
|
|
|
238 |
root |
1.65 |
=item EV::feed_fd_event ($fd, $revents) |
239 |
|
|
|
240 |
root |
1.73 |
=item $loop->feed_fd_event ($fd, $revents) |
241 |
|
|
|
242 |
root |
1.65 |
Feed an event on a file descriptor into EV. EV will react to this call as |
243 |
|
|
if the readyness notifications specified by C<$revents> (a combination of |
244 |
|
|
C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
245 |
|
|
|
246 |
|
|
=item EV::feed_signal_event ($signal) |
247 |
|
|
|
248 |
|
|
Feed a signal event into EV. EV will react to this call as if the signal |
249 |
|
|
specified by C<$signal> had occured. |
250 |
|
|
|
251 |
root |
1.79 |
=item EV::set_io_collect_interval $time |
252 |
|
|
|
253 |
|
|
=item $loop->set_io_collect_interval ($time) |
254 |
|
|
|
255 |
|
|
=item EV::set_timeout_collect_interval $time |
256 |
|
|
|
257 |
|
|
=item $loop->set_timeout_collect_interval ($time) |
258 |
|
|
|
259 |
|
|
These advanced functions set the minimum block interval when polling for I/O events and the minimum |
260 |
|
|
wait interval for timer events. See the libev documentation at |
261 |
|
|
L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for |
262 |
|
|
a more detailed discussion. |
263 |
|
|
|
264 |
root |
1.20 |
=back |
265 |
|
|
|
266 |
root |
1.65 |
|
267 |
root |
1.73 |
=head1 WATCHER OBJECTS |
268 |
root |
1.2 |
|
269 |
root |
1.20 |
A watcher is an object that gets created to record your interest in some |
270 |
|
|
event. For instance, if you want to wait for STDIN to become readable, you |
271 |
|
|
would create an EV::io watcher for that: |
272 |
|
|
|
273 |
|
|
my $watcher = EV::io *STDIN, EV::READ, sub { |
274 |
|
|
my ($watcher, $revents) = @_; |
275 |
root |
1.77 |
warn "yeah, STDIN should now be readable without blocking!\n" |
276 |
root |
1.20 |
}; |
277 |
root |
1.2 |
|
278 |
root |
1.20 |
All watchers can be active (waiting for events) or inactive (paused). Only |
279 |
|
|
active watchers will have their callbacks invoked. All callbacks will be |
280 |
|
|
called with at least two arguments: the watcher and a bitmask of received |
281 |
|
|
events. |
282 |
|
|
|
283 |
|
|
Each watcher type has its associated bit in revents, so you can use the |
284 |
|
|
same callback for multiple watchers. The event mask is named after the |
285 |
|
|
type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
286 |
root |
1.62 |
EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
287 |
root |
1.20 |
(which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
288 |
|
|
uses EV::TIMEOUT). |
289 |
|
|
|
290 |
|
|
In the rare case where one wants to create a watcher but not start it at |
291 |
|
|
the same time, each constructor has a variant with a trailing C<_ns> in |
292 |
|
|
its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
293 |
|
|
|
294 |
|
|
Please note that a watcher will automatically be stopped when the watcher |
295 |
root |
1.23 |
object is destroyed, so you I<need> to keep the watcher objects returned by |
296 |
root |
1.20 |
the constructors. |
297 |
|
|
|
298 |
root |
1.23 |
Also, all methods changing some aspect of a watcher (->set, ->priority, |
299 |
|
|
->fh and so on) automatically stop and start it again if it is active, |
300 |
|
|
which means pending events get lost. |
301 |
|
|
|
302 |
root |
1.54 |
=head2 COMMON WATCHER METHODS |
303 |
root |
1.20 |
|
304 |
root |
1.54 |
This section lists methods common to all watchers. |
305 |
root |
1.20 |
|
306 |
|
|
=over 4 |
307 |
root |
1.2 |
|
308 |
root |
1.20 |
=item $w->start |
309 |
|
|
|
310 |
|
|
Starts a watcher if it isn't active already. Does nothing to an already |
311 |
|
|
active watcher. By default, all watchers start out in the active state |
312 |
|
|
(see the description of the C<_ns> variants if you need stopped watchers). |
313 |
|
|
|
314 |
|
|
=item $w->stop |
315 |
root |
1.2 |
|
316 |
root |
1.20 |
Stop a watcher if it is active. Also clear any pending events (events that |
317 |
|
|
have been received but that didn't yet result in a callback invocation), |
318 |
root |
1.62 |
regardless of whether the watcher was active or not. |
319 |
root |
1.2 |
|
320 |
root |
1.20 |
=item $bool = $w->is_active |
321 |
root |
1.2 |
|
322 |
root |
1.20 |
Returns true if the watcher is active, false otherwise. |
323 |
|
|
|
324 |
root |
1.30 |
=item $current_data = $w->data |
325 |
|
|
|
326 |
|
|
=item $old_data = $w->data ($new_data) |
327 |
|
|
|
328 |
|
|
Queries a freely usable data scalar on the watcher and optionally changes |
329 |
|
|
it. This is a way to associate custom data with a watcher: |
330 |
|
|
|
331 |
|
|
my $w = EV::timer 60, 0, sub { |
332 |
|
|
warn $_[0]->data; |
333 |
|
|
}; |
334 |
|
|
$w->data ("print me!"); |
335 |
|
|
|
336 |
root |
1.20 |
=item $current_cb = $w->cb |
337 |
|
|
|
338 |
|
|
=item $old_cb = $w->cb ($new_cb) |
339 |
|
|
|
340 |
root |
1.23 |
Queries the callback on the watcher and optionally changes it. You can do |
341 |
|
|
this at any time without the watcher restarting. |
342 |
|
|
|
343 |
|
|
=item $current_priority = $w->priority |
344 |
|
|
|
345 |
|
|
=item $old_priority = $w->priority ($new_priority) |
346 |
|
|
|
347 |
|
|
Queries the priority on the watcher and optionally changes it. Pending |
348 |
|
|
watchers with higher priority will be invoked first. The valid range of |
349 |
root |
1.24 |
priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
350 |
|
|
-2). If the priority is outside this range it will automatically be |
351 |
root |
1.23 |
normalised to the nearest valid priority. |
352 |
|
|
|
353 |
root |
1.50 |
The default priority of any newly-created watcher is 0. |
354 |
|
|
|
355 |
|
|
Note that the priority semantics have not yet been fleshed out and are |
356 |
|
|
subject to almost certain change. |
357 |
root |
1.20 |
|
358 |
root |
1.65 |
=item $w->invoke ($revents) |
359 |
root |
1.20 |
|
360 |
|
|
Call the callback *now* with the given event mask. |
361 |
|
|
|
362 |
root |
1.65 |
=item $w->feed_event ($revents) |
363 |
|
|
|
364 |
|
|
Feed some events on this watcher into EV. EV will react to this call as if |
365 |
|
|
the watcher had received the given C<$revents> mask. |
366 |
|
|
|
367 |
|
|
=item $revents = $w->clear_pending |
368 |
|
|
|
369 |
root |
1.78 |
If the watcher is pending, this function clears its pending status and |
370 |
|
|
returns its C<$revents> bitset (as if its callback was invoked). If the |
371 |
root |
1.65 |
watcher isn't pending it does nothing and returns C<0>. |
372 |
|
|
|
373 |
root |
1.50 |
=item $previous_state = $w->keepalive ($bool) |
374 |
|
|
|
375 |
|
|
Normally, C<EV::loop> will return when there are no active watchers |
376 |
|
|
(which is a "deadlock" because no progress can be made anymore). This is |
377 |
|
|
convinient because it allows you to start your watchers (and your jobs), |
378 |
|
|
call C<EV::loop> once and when it returns you know that all your jobs are |
379 |
|
|
finished (or they forgot to register some watchers for their task :). |
380 |
|
|
|
381 |
root |
1.77 |
Sometimes, however, this gets in your way, for example when the module |
382 |
root |
1.50 |
that calls C<EV::loop> (usually the main program) is not the same module |
383 |
|
|
as a long-living watcher (for example a DNS client module written by |
384 |
|
|
somebody else even). Then you might want any outstanding requests to be |
385 |
|
|
handled, but you would not want to keep C<EV::loop> from returning just |
386 |
|
|
because you happen to have this long-running UDP port watcher. |
387 |
|
|
|
388 |
|
|
In this case you can clear the keepalive status, which means that even |
389 |
|
|
though your watcher is active, it won't keep C<EV::loop> from returning. |
390 |
|
|
|
391 |
|
|
The initial value for keepalive is true (enabled), and you cna change it |
392 |
|
|
any time. |
393 |
|
|
|
394 |
root |
1.62 |
Example: Register an I/O watcher for some UDP socket but do not keep the |
395 |
root |
1.50 |
event loop from running just because of that watcher. |
396 |
|
|
|
397 |
|
|
my $udp_socket = ... |
398 |
|
|
my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
399 |
root |
1.74 |
$1000udp_watcher->keepalive (0); |
400 |
|
|
|
401 |
|
|
=item $loop = $w->loop |
402 |
|
|
|
403 |
|
|
Return the loop that this watcher is attached to. |
404 |
root |
1.20 |
|
405 |
root |
1.54 |
=back |
406 |
|
|
|
407 |
|
|
|
408 |
root |
1.73 |
=head1 WATCHER TYPES |
409 |
root |
1.54 |
|
410 |
|
|
Each of the following subsections describes a single watcher type. |
411 |
|
|
|
412 |
root |
1.62 |
=head3 I/O WATCHERS - is this file descriptor readable or writable? |
413 |
root |
1.54 |
|
414 |
|
|
=over 4 |
415 |
|
|
|
416 |
root |
1.20 |
=item $w = EV::io $fileno_or_fh, $eventmask, $callback |
417 |
root |
1.2 |
|
418 |
root |
1.20 |
=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
419 |
root |
1.7 |
|
420 |
root |
1.76 |
=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback) |
421 |
root |
1.73 |
|
422 |
|
|
=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
423 |
|
|
|
424 |
root |
1.20 |
As long as the returned watcher object is alive, call the C<$callback> |
425 |
root |
1.54 |
when at least one of events specified in C<$eventmask> occurs. |
426 |
root |
1.2 |
|
427 |
root |
1.20 |
The $eventmask can be one or more of these constants ORed together: |
428 |
root |
1.2 |
|
429 |
|
|
EV::READ wait until read() wouldn't block anymore |
430 |
|
|
EV::WRITE wait until write() wouldn't block anymore |
431 |
root |
1.7 |
|
432 |
root |
1.20 |
The C<io_ns> variant doesn't start (activate) the newly created watcher. |
433 |
root |
1.2 |
|
434 |
root |
1.20 |
=item $w->set ($fileno_or_fh, $eventmask) |
435 |
root |
1.10 |
|
436 |
root |
1.20 |
Reconfigures the watcher, see the constructor above for details. Can be |
437 |
|
|
called at any time. |
438 |
root |
1.10 |
|
439 |
root |
1.20 |
=item $current_fh = $w->fh |
440 |
|
|
|
441 |
|
|
=item $old_fh = $w->fh ($new_fh) |
442 |
|
|
|
443 |
|
|
Returns the previously set filehandle and optionally set a new one. |
444 |
root |
1.10 |
|
445 |
root |
1.20 |
=item $current_eventmask = $w->events |
446 |
|
|
|
447 |
|
|
=item $old_eventmask = $w->events ($new_eventmask) |
448 |
root |
1.10 |
|
449 |
root |
1.20 |
Returns the previously set event mask and optionally set a new one. |
450 |
root |
1.10 |
|
451 |
root |
1.54 |
=back |
452 |
|
|
|
453 |
|
|
|
454 |
|
|
=head3 TIMER WATCHERS - relative and optionally repeating timeouts |
455 |
|
|
|
456 |
|
|
=over 4 |
457 |
root |
1.10 |
|
458 |
root |
1.20 |
=item $w = EV::timer $after, $repeat, $callback |
459 |
root |
1.2 |
|
460 |
root |
1.20 |
=item $w = EV::timer_ns $after, $repeat, $callback |
461 |
root |
1.2 |
|
462 |
root |
1.73 |
=item $w = $loop->timer ($after, $repeat, $callback) |
463 |
|
|
|
464 |
|
|
=item $w = $loop->timer_ns ($after, $repeat, $callback) |
465 |
|
|
|
466 |
root |
1.53 |
Calls the callback after C<$after> seconds (which may be fractional). If |
467 |
|
|
C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
468 |
|
|
value as $after) after the callback returns. |
469 |
root |
1.2 |
|
470 |
root |
1.20 |
This means that the callback would be called roughly after C<$after> |
471 |
root |
1.39 |
seconds, and then every C<$repeat> seconds. The timer does his best not |
472 |
|
|
to drift, but it will not invoke the timer more often then once per event |
473 |
|
|
loop iteration, and might drift in other cases. If that isn't acceptable, |
474 |
|
|
look at EV::periodic, which can provide long-term stable timers. |
475 |
root |
1.2 |
|
476 |
root |
1.39 |
The timer is based on a monotonic clock, that is, if somebody is sitting |
477 |
root |
1.20 |
in front of the machine while the timer is running and changes the system |
478 |
|
|
clock, the timer will nevertheless run (roughly) the same time. |
479 |
root |
1.2 |
|
480 |
root |
1.20 |
The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
481 |
|
|
|
482 |
|
|
=item $w->set ($after, $repeat) |
483 |
|
|
|
484 |
root |
1.54 |
Reconfigures the watcher, see the constructor above for details. Can be called at |
485 |
root |
1.20 |
any time. |
486 |
|
|
|
487 |
|
|
=item $w->again |
488 |
|
|
|
489 |
|
|
Similar to the C<start> method, but has special semantics for repeating timers: |
490 |
|
|
|
491 |
root |
1.39 |
If the timer is active and non-repeating, it will be stopped. |
492 |
|
|
|
493 |
root |
1.20 |
If the timer is active and repeating, reset the timeout to occur |
494 |
|
|
C<$repeat> seconds after now. |
495 |
|
|
|
496 |
root |
1.39 |
If the timer is inactive and repeating, start it using the repeat value. |
497 |
root |
1.20 |
|
498 |
|
|
Otherwise do nothing. |
499 |
|
|
|
500 |
|
|
This behaviour is useful when you have a timeout for some IO |
501 |
|
|
operation. You create a timer object with the same value for C<$after> and |
502 |
|
|
C<$repeat>, and then, in the read/write watcher, run the C<again> method |
503 |
|
|
on the timeout. |
504 |
|
|
|
505 |
root |
1.54 |
=back |
506 |
|
|
|
507 |
|
|
|
508 |
|
|
=head3 PERIODIC WATCHERS - to cron or not to cron? |
509 |
|
|
|
510 |
|
|
=over 4 |
511 |
root |
1.20 |
|
512 |
root |
1.30 |
=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
513 |
root |
1.20 |
|
514 |
root |
1.30 |
=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
515 |
|
|
|
516 |
root |
1.73 |
=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
517 |
|
|
|
518 |
|
|
=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback) |
519 |
|
|
|
520 |
root |
1.30 |
Similar to EV::timer, but is not based on relative timeouts but on |
521 |
|
|
absolute times. Apart from creating "simple" timers that trigger "at" the |
522 |
|
|
specified time, it can also be used for non-drifting absolute timers and |
523 |
|
|
more complex, cron-like, setups that are not adversely affected by time |
524 |
|
|
jumps (i.e. when the system clock is changed by explicit date -s or other |
525 |
|
|
means such as ntpd). It is also the most complex watcher type in EV. |
526 |
|
|
|
527 |
|
|
It has three distinct "modes": |
528 |
|
|
|
529 |
|
|
=over 4 |
530 |
root |
1.2 |
|
531 |
root |
1.30 |
=item * absolute timer ($interval = $reschedule_cb = 0) |
532 |
root |
1.2 |
|
533 |
root |
1.30 |
This time simply fires at the wallclock time C<$at> and doesn't repeat. It |
534 |
|
|
will not adjust when a time jump occurs, that is, if it is to be run |
535 |
|
|
at January 1st 2011 then it will run when the system time reaches or |
536 |
|
|
surpasses this time. |
537 |
root |
1.2 |
|
538 |
root |
1.30 |
=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
539 |
root |
1.2 |
|
540 |
root |
1.30 |
In this mode the watcher will always be scheduled to time out at the |
541 |
|
|
next C<$at + N * $interval> time (for some integer N) and then repeat, |
542 |
|
|
regardless of any time jumps. |
543 |
|
|
|
544 |
|
|
This can be used to create timers that do not drift with respect to system |
545 |
|
|
time: |
546 |
|
|
|
547 |
|
|
my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; |
548 |
|
|
|
549 |
|
|
That doesn't mean there will always be 3600 seconds in between triggers, |
550 |
|
|
but only that the the clalback will be called when the system time shows a |
551 |
|
|
full hour (UTC). |
552 |
root |
1.2 |
|
553 |
root |
1.7 |
Another way to think about it (for the mathematically inclined) is that |
554 |
root |
1.30 |
EV::periodic will try to run the callback in this mode at the next |
555 |
|
|
possible time where C<$time = $at (mod $interval)>, regardless of any time |
556 |
|
|
jumps. |
557 |
|
|
|
558 |
|
|
=item * manual reschedule mode ($reschedule_cb = coderef) |
559 |
|
|
|
560 |
root |
1.37 |
In this mode $interval and $at are both being ignored. Instead, each |
561 |
|
|
time the periodic watcher gets scheduled, the reschedule callback |
562 |
|
|
($reschedule_cb) will be called with the watcher as first, and the current |
563 |
|
|
time as second argument. |
564 |
root |
1.30 |
|
565 |
root |
1.31 |
I<This callback MUST NOT stop or destroy this or any other periodic |
566 |
|
|
watcher, ever>. If you need to stop it, return 1e30 and stop it |
567 |
|
|
afterwards. |
568 |
root |
1.30 |
|
569 |
|
|
It must return the next time to trigger, based on the passed time value |
570 |
|
|
(that is, the lowest time value larger than to the second argument). It |
571 |
|
|
will usually be called just before the callback will be triggered, but |
572 |
|
|
might be called at other times, too. |
573 |
|
|
|
574 |
|
|
This can be used to create very complex timers, such as a timer that |
575 |
|
|
triggers on each midnight, local time (actually 24 hours after the last |
576 |
|
|
midnight, to keep the example simple. If you know a way to do it correctly |
577 |
|
|
in about the same space (without requiring elaborate modules), drop me a |
578 |
|
|
note :): |
579 |
|
|
|
580 |
|
|
my $daily = EV::periodic 0, 0, sub { |
581 |
|
|
my ($w, $now) = @_; |
582 |
|
|
|
583 |
|
|
use Time::Local (); |
584 |
|
|
my (undef, undef, undef, $d, $m, $y) = localtime $now; |
585 |
|
|
86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y |
586 |
|
|
}, sub { |
587 |
|
|
print "it's midnight or likely shortly after, now\n"; |
588 |
|
|
}; |
589 |
root |
1.7 |
|
590 |
root |
1.30 |
=back |
591 |
root |
1.20 |
|
592 |
|
|
The C<periodic_ns> variant doesn't start (activate) the newly created watcher. |
593 |
root |
1.2 |
|
594 |
root |
1.30 |
=item $w->set ($at, $interval, $reschedule_cb) |
595 |
root |
1.11 |
|
596 |
root |
1.54 |
Reconfigures the watcher, see the constructor above for details. Can be called at |
597 |
root |
1.20 |
any time. |
598 |
|
|
|
599 |
root |
1.30 |
=item $w->again |
600 |
|
|
|
601 |
|
|
Simply stops and starts the watcher again. |
602 |
|
|
|
603 |
root |
1.71 |
=item $time = $w->at |
604 |
|
|
|
605 |
|
|
Return the time that the watcher is expected to trigger next. |
606 |
|
|
|
607 |
root |
1.54 |
=back |
608 |
|
|
|
609 |
|
|
|
610 |
|
|
=head3 SIGNAL WATCHERS - signal me when a signal gets signalled! |
611 |
|
|
|
612 |
|
|
=over 4 |
613 |
root |
1.20 |
|
614 |
|
|
=item $w = EV::signal $signal, $callback |
615 |
|
|
|
616 |
|
|
=item $w = EV::signal_ns $signal, $callback |
617 |
root |
1.11 |
|
618 |
root |
1.54 |
Call the callback when $signal is received (the signal can be specified by |
619 |
|
|
number or by name, just as with C<kill> or C<%SIG>). |
620 |
root |
1.2 |
|
621 |
root |
1.11 |
EV will grab the signal for the process (the kernel only allows one |
622 |
root |
1.20 |
component to receive a signal at a time) when you start a signal watcher, |
623 |
|
|
and removes it again when you stop it. Perl does the same when you |
624 |
root |
1.54 |
add/remove callbacks to C<%SIG>, so watch out. |
625 |
root |
1.20 |
|
626 |
|
|
You can have as many signal watchers per signal as you want. |
627 |
root |
1.2 |
|
628 |
root |
1.20 |
The C<signal_ns> variant doesn't start (activate) the newly created watcher. |
629 |
root |
1.2 |
|
630 |
root |
1.20 |
=item $w->set ($signal) |
631 |
root |
1.2 |
|
632 |
root |
1.54 |
Reconfigures the watcher, see the constructor above for details. Can be |
633 |
|
|
called at any time. |
634 |
root |
1.20 |
|
635 |
root |
1.22 |
=item $current_signum = $w->signal |
636 |
|
|
|
637 |
|
|
=item $old_signum = $w->signal ($new_signal) |
638 |
|
|
|
639 |
|
|
Returns the previously set signal (always as a number not name) and |
640 |
|
|
optionally set a new one. |
641 |
|
|
|
642 |
root |
1.54 |
=back |
643 |
|
|
|
644 |
|
|
|
645 |
|
|
=head3 CHILD WATCHERS - watch out for process status changes |
646 |
|
|
|
647 |
|
|
=over 4 |
648 |
root |
1.20 |
|
649 |
root |
1.82 |
=item $w = EV::child $pid, $trace, $callback |
650 |
root |
1.20 |
|
651 |
root |
1.82 |
=item $w = EV::child_ns $pid, $trace, $callback |
652 |
root |
1.20 |
|
653 |
root |
1.82 |
=item $w = $loop->child ($pid, $trace, $callback) |
654 |
root |
1.73 |
|
655 |
root |
1.82 |
=item $w = $loop->child_ns ($pid, $trace, $callback) |
656 |
root |
1.73 |
|
657 |
root |
1.82 |
Call the callback when a status change for pid C<$pid> (or any pid |
658 |
|
|
if C<$pid> is 0) has been received (a status change happens when the |
659 |
|
|
process terminates or is killed, or, when trace is true, additionally when |
660 |
|
|
it is stopped or continued). More precisely: when the process receives |
661 |
root |
1.54 |
a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all |
662 |
root |
1.20 |
changed/zombie children and call the callback. |
663 |
|
|
|
664 |
root |
1.54 |
It is valid (and fully supported) to install a child watcher after a child |
665 |
|
|
has exited but before the event loop has started its next iteration (for |
666 |
|
|
example, first you C<fork>, then the new child process might exit, and |
667 |
|
|
only then do you install a child watcher in the parent for the new pid). |
668 |
|
|
|
669 |
|
|
You can access both exit (or tracing) status and pid by using the |
670 |
|
|
C<rstatus> and C<rpid> methods on the watcher object. |
671 |
root |
1.20 |
|
672 |
root |
1.54 |
You can have as many pid watchers per pid as you want, they will all be |
673 |
|
|
called. |
674 |
root |
1.20 |
|
675 |
|
|
The C<child_ns> variant doesn't start (activate) the newly created watcher. |
676 |
|
|
|
677 |
root |
1.82 |
=item $w->set ($pid, $trace) |
678 |
root |
1.1 |
|
679 |
root |
1.54 |
Reconfigures the watcher, see the constructor above for details. Can be called at |
680 |
root |
1.20 |
any time. |
681 |
root |
1.2 |
|
682 |
root |
1.22 |
=item $current_pid = $w->pid |
683 |
|
|
|
684 |
|
|
Returns the previously set process id and optionally set a new one. |
685 |
|
|
|
686 |
root |
1.27 |
=item $exit_status = $w->rstatus |
687 |
|
|
|
688 |
|
|
Return the exit/wait status (as returned by waitpid, see the waitpid entry |
689 |
|
|
in perlfunc). |
690 |
|
|
|
691 |
|
|
=item $pid = $w->rpid |
692 |
|
|
|
693 |
|
|
Return the pid of the awaited child (useful when you have installed a |
694 |
|
|
watcher for all pids). |
695 |
|
|
|
696 |
root |
1.54 |
=back |
697 |
|
|
|
698 |
|
|
|
699 |
root |
1.56 |
=head3 STAT WATCHERS - did the file attributes just change? |
700 |
|
|
|
701 |
|
|
=over 4 |
702 |
|
|
|
703 |
|
|
=item $w = EV::stat $path, $interval, $callback |
704 |
|
|
|
705 |
|
|
=item $w = EV::stat_ns $path, $interval, $callback |
706 |
|
|
|
707 |
root |
1.73 |
=item $w = $loop->stat ($path, $interval, $callback) |
708 |
|
|
|
709 |
|
|
=item $w = $loop->stat_ns ($path, $interval, $callback) |
710 |
|
|
|
711 |
root |
1.56 |
Call the callback when a file status change has been detected on |
712 |
|
|
C<$path>. The C<$path> does not need to exist, changing from "path exists" |
713 |
|
|
to "path does not exist" is a status change like any other. |
714 |
|
|
|
715 |
|
|
The C<$interval> is a recommended polling interval for systems where |
716 |
|
|
OS-supported change notifications don't exist or are not supported. If |
717 |
|
|
you use C<0> then an unspecified default is used (which is highly |
718 |
|
|
recommended!), which is to be expected to be around five seconds usually. |
719 |
|
|
|
720 |
|
|
This watcher type is not meant for massive numbers of stat watchers, |
721 |
|
|
as even with OS-supported change notifications, this can be |
722 |
|
|
resource-intensive. |
723 |
|
|
|
724 |
|
|
The C<stat_ns> variant doesn't start (activate) the newly created watcher. |
725 |
|
|
|
726 |
root |
1.57 |
=item ... = $w->stat |
727 |
|
|
|
728 |
|
|
This call is very similar to the perl C<stat> built-in: It stats (using |
729 |
|
|
C<lstat>) the path specified in the watcher and sets perls stat cache (as |
730 |
|
|
well as EV's idea of the current stat values) to the values found. |
731 |
|
|
|
732 |
|
|
In scalar context, a boolean is return indicating success or failure of |
733 |
|
|
the stat. In list context, the same 13-value list as with stat is returned |
734 |
|
|
(except that the blksize and blocks fields are not reliable). |
735 |
|
|
|
736 |
|
|
In the case of an error, errno is set to C<ENOENT> (regardless of the |
737 |
|
|
actual error value) and the C<nlink> value is forced to zero (if the stat |
738 |
|
|
was successful then nlink is guaranteed to be non-zero). |
739 |
|
|
|
740 |
|
|
See also the next two entries for more info. |
741 |
|
|
|
742 |
|
|
=item ... = $w->attr |
743 |
|
|
|
744 |
|
|
Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
745 |
|
|
the values most recently detected by EV. See the next entry for more info. |
746 |
|
|
|
747 |
|
|
=item ... = $w->prev |
748 |
|
|
|
749 |
|
|
Just like C<< $w->stat >>, but without the initial stat'ing: this returns |
750 |
|
|
the previous set of values, before the change. |
751 |
|
|
|
752 |
|
|
That is, when the watcher callback is invoked, C<< $w->prev >> will be set |
753 |
|
|
to the values found I<before> a change was detected, while C<< $w->attr >> |
754 |
|
|
returns the values found leading to the change detection. The difference (if any) |
755 |
|
|
between C<prev> and C<attr> is what triggered the callback. |
756 |
|
|
|
757 |
|
|
If you did something to the filesystem object and do not want to trigger |
758 |
|
|
yet another change, you can call C<stat> to update EV's idea of what the |
759 |
|
|
current attributes are. |
760 |
|
|
|
761 |
root |
1.56 |
=item $w->set ($path, $interval) |
762 |
|
|
|
763 |
|
|
Reconfigures the watcher, see the constructor above for details. Can be |
764 |
|
|
called at any time. |
765 |
|
|
|
766 |
|
|
=item $current_path = $w->path |
767 |
|
|
|
768 |
|
|
=item $old_path = $w->path ($new_path) |
769 |
|
|
|
770 |
|
|
Returns the previously set path and optionally set a new one. |
771 |
|
|
|
772 |
|
|
=item $current_interval = $w->interval |
773 |
|
|
|
774 |
|
|
=item $old_interval = $w->interval ($new_interval) |
775 |
|
|
|
776 |
|
|
Returns the previously set interval and optionally set a new one. Can be |
777 |
|
|
used to query the actual interval used. |
778 |
|
|
|
779 |
|
|
=back |
780 |
|
|
|
781 |
|
|
|
782 |
root |
1.54 |
=head3 IDLE WATCHERS - when you've got nothing better to do... |
783 |
|
|
|
784 |
|
|
=over 4 |
785 |
root |
1.2 |
|
786 |
root |
1.20 |
=item $w = EV::idle $callback |
787 |
root |
1.2 |
|
788 |
root |
1.20 |
=item $w = EV::idle_ns $callback |
789 |
root |
1.2 |
|
790 |
root |
1.73 |
=item $w = $loop->idle ($callback) |
791 |
|
|
|
792 |
|
|
=item $w = $loop->idle_ns ($callback) |
793 |
|
|
|
794 |
root |
1.62 |
Call the callback when there are no other pending watchers of the same or |
795 |
|
|
higher priority (excluding check, prepare and other idle watchers of the |
796 |
|
|
same or lower priority, of course). They are called idle watchers because |
797 |
|
|
when the watcher is the highest priority pending event in the process, the |
798 |
|
|
process is considered to be idle at that priority. |
799 |
|
|
|
800 |
|
|
If you want a watcher that is only ever called when I<no> other events are |
801 |
|
|
outstanding you have to set the priority to C<EV::MINPRI>. |
802 |
root |
1.2 |
|
803 |
root |
1.20 |
The process will not block as long as any idle watchers are active, and |
804 |
|
|
they will be called repeatedly until stopped. |
805 |
root |
1.2 |
|
806 |
root |
1.62 |
For example, if you have idle watchers at priority C<0> and C<1>, and |
807 |
|
|
an I/O watcher at priority C<0>, then the idle watcher at priority C<1> |
808 |
|
|
and the I/O watcher will always run when ready. Only when the idle watcher |
809 |
|
|
at priority C<1> is stopped and the I/O watcher at priority C<0> is not |
810 |
|
|
pending with the C<0>-priority idle watcher be invoked. |
811 |
|
|
|
812 |
root |
1.20 |
The C<idle_ns> variant doesn't start (activate) the newly created watcher. |
813 |
root |
1.2 |
|
814 |
root |
1.54 |
=back |
815 |
|
|
|
816 |
|
|
|
817 |
|
|
=head3 PREPARE WATCHERS - customise your event loop! |
818 |
|
|
|
819 |
|
|
=over 4 |
820 |
root |
1.2 |
|
821 |
root |
1.20 |
=item $w = EV::prepare $callback |
822 |
root |
1.1 |
|
823 |
root |
1.20 |
=item $w = EV::prepare_ns $callback |
824 |
root |
1.1 |
|
825 |
root |
1.73 |
=item $w = $loop->prepare ($callback) |
826 |
|
|
|
827 |
root |
1.76 |
=item $w = $loop->prepare_ns ($callback) |
828 |
root |
1.73 |
|
829 |
root |
1.20 |
Call the callback just before the process would block. You can still |
830 |
|
|
create/modify any watchers at this point. |
831 |
root |
1.1 |
|
832 |
root |
1.20 |
See the EV::check watcher, below, for explanations and an example. |
833 |
root |
1.2 |
|
834 |
root |
1.20 |
The C<prepare_ns> variant doesn't start (activate) the newly created watcher. |
835 |
root |
1.2 |
|
836 |
root |
1.54 |
=back |
837 |
|
|
|
838 |
|
|
|
839 |
|
|
=head3 CHECK WATCHERS - customise your event loop even more! |
840 |
|
|
|
841 |
|
|
=over 4 |
842 |
root |
1.2 |
|
843 |
root |
1.20 |
=item $w = EV::check $callback |
844 |
root |
1.2 |
|
845 |
root |
1.20 |
=item $w = EV::check_ns $callback |
846 |
root |
1.10 |
|
847 |
root |
1.73 |
=item $w = $loop->check ($callback) |
848 |
|
|
|
849 |
|
|
=item $w = $loop->check_ns ($callback) |
850 |
|
|
|
851 |
root |
1.20 |
Call the callback just after the process wakes up again (after it has |
852 |
|
|
gathered events), but before any other callbacks have been invoked. |
853 |
root |
1.10 |
|
854 |
root |
1.20 |
This is used to integrate other event-based software into the EV |
855 |
|
|
mainloop: You register a prepare callback and in there, you create io and |
856 |
|
|
timer watchers as required by the other software. Here is a real-world |
857 |
|
|
example of integrating Net::SNMP (with some details left out): |
858 |
root |
1.10 |
|
859 |
root |
1.20 |
our @snmp_watcher; |
860 |
root |
1.2 |
|
861 |
root |
1.20 |
our $snmp_prepare = EV::prepare sub { |
862 |
|
|
# do nothing unless active |
863 |
|
|
$dispatcher->{_event_queue_h} |
864 |
|
|
or return; |
865 |
root |
1.2 |
|
866 |
root |
1.20 |
# make the dispatcher handle any outstanding stuff |
867 |
root |
1.45 |
... not shown |
868 |
root |
1.2 |
|
869 |
root |
1.62 |
# create an I/O watcher for each and every socket |
870 |
root |
1.20 |
@snmp_watcher = ( |
871 |
|
|
(map { EV::io $_, EV::READ, sub { } } |
872 |
|
|
keys %{ $dispatcher->{_descriptors} }), |
873 |
root |
1.45 |
|
874 |
|
|
EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
875 |
|
|
? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0), |
876 |
|
|
0, sub { }, |
877 |
root |
1.20 |
); |
878 |
|
|
}; |
879 |
root |
1.2 |
|
880 |
root |
1.45 |
The callbacks are irrelevant (and are not even being called), the |
881 |
|
|
only purpose of those watchers is to wake up the process as soon as |
882 |
|
|
one of those events occurs (socket readable, or timer timed out). The |
883 |
|
|
corresponding EV::check watcher will then clean up: |
884 |
root |
1.2 |
|
885 |
root |
1.20 |
our $snmp_check = EV::check sub { |
886 |
|
|
# destroy all watchers |
887 |
|
|
@snmp_watcher = (); |
888 |
root |
1.2 |
|
889 |
root |
1.20 |
# make the dispatcher handle any new stuff |
890 |
root |
1.45 |
... not shown |
891 |
root |
1.20 |
}; |
892 |
root |
1.2 |
|
893 |
root |
1.20 |
The callbacks of the created watchers will not be called as the watchers |
894 |
|
|
are destroyed before this cna happen (remember EV::check gets called |
895 |
|
|
first). |
896 |
root |
1.2 |
|
897 |
root |
1.20 |
The C<check_ns> variant doesn't start (activate) the newly created watcher. |
898 |
root |
1.1 |
|
899 |
|
|
=back |
900 |
|
|
|
901 |
root |
1.54 |
|
902 |
root |
1.56 |
=head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
903 |
root |
1.54 |
|
904 |
root |
1.56 |
Fork watchers are called when a C<fork ()> was detected. The invocation |
905 |
|
|
is done before the event loop blocks next and before C<check> watchers |
906 |
|
|
are being called, and only in the child after the fork. |
907 |
root |
1.54 |
|
908 |
root |
1.56 |
=over 4 |
909 |
root |
1.54 |
|
910 |
root |
1.56 |
=item $w = EV::fork $callback |
911 |
root |
1.54 |
|
912 |
root |
1.56 |
=item $w = EV::fork_ns $callback |
913 |
root |
1.54 |
|
914 |
root |
1.73 |
=item $w = $loop->fork ($callback) |
915 |
|
|
|
916 |
|
|
=item $w = $loop->fork_ns ($callback) |
917 |
|
|
|
918 |
root |
1.56 |
Call the callback before the event loop is resumed in the child process |
919 |
|
|
after a fork. |
920 |
root |
1.54 |
|
921 |
root |
1.56 |
The C<fork_ns> variant doesn't start (activate) the newly created watcher. |
922 |
root |
1.54 |
|
923 |
|
|
=back |
924 |
|
|
|
925 |
|
|
|
926 |
root |
1.79 |
=head3 EMBED WATCHERS - when one backend isn't enough... |
927 |
|
|
|
928 |
|
|
This is a rather advanced watcher type that lets you embed one event loop |
929 |
|
|
into another (currently only IO events are supported in the embedded |
930 |
|
|
loop, other types of watchers might be handled in a delayed or incorrect |
931 |
|
|
fashion and must not be used). |
932 |
|
|
|
933 |
|
|
See the libev documentation at |
934 |
|
|
L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_> |
935 |
|
|
for more details. |
936 |
|
|
|
937 |
|
|
In short, this watcher is most useful on BSD systems without working |
938 |
|
|
kqueue to still be able to handle a large number of sockets: |
939 |
|
|
|
940 |
|
|
my $socket_loop; |
941 |
|
|
|
942 |
|
|
# check wether we use SELECT or POLL _and_ KQUEUE is supported |
943 |
|
|
if ( |
944 |
|
|
(EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
945 |
|
|
&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
946 |
|
|
) { |
947 |
|
|
# use kqueue for sockets |
948 |
|
|
$socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
949 |
|
|
} |
950 |
|
|
|
951 |
|
|
# use the default loop otherwise |
952 |
|
|
$socket_loop ||= EV::default_loop; |
953 |
|
|
|
954 |
|
|
=over 4 |
955 |
|
|
|
956 |
|
|
=item $w = EV::embed $otherloop, $callback |
957 |
|
|
|
958 |
|
|
=item $w = EV::embed_ns $otherloop, $callback |
959 |
|
|
|
960 |
|
|
=item $w = $loop->embed ($otherloop, $callback) |
961 |
|
|
|
962 |
|
|
=item $w = $loop->embed_ns ($otherloop, $callback) |
963 |
|
|
|
964 |
|
|
Call the callback when the embedded event loop (C<$otherloop>) has any |
965 |
|
|
I/O activity. The C<$callback> should alwas be specified as C<undef> in |
966 |
|
|
this version of EV, which means the embedded event loop will be managed |
967 |
|
|
automatically. |
968 |
|
|
|
969 |
|
|
The C<embed_ns> variant doesn't start (activate) the newly created watcher. |
970 |
|
|
|
971 |
|
|
=back |
972 |
|
|
|
973 |
|
|
|
974 |
root |
1.61 |
=head1 PERL SIGNALS |
975 |
|
|
|
976 |
|
|
While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
977 |
|
|
with EV is as the same as any other C library: Perl-signals will only be |
978 |
|
|
handled when Perl runs, which means your signal handler might be invoked |
979 |
|
|
only the next time an event callback is invoked. |
980 |
|
|
|
981 |
|
|
The solution is to use EV signal watchers (see C<EV::signal>), which will |
982 |
|
|
ensure proper operations with regards to other event watchers. |
983 |
|
|
|
984 |
|
|
If you cannot do this for whatever reason, you can also force a watcher |
985 |
|
|
to be called on every event loop iteration by installing a C<EV::check> |
986 |
|
|
watcher: |
987 |
|
|
|
988 |
|
|
my $async_check = EV::check sub { }; |
989 |
|
|
|
990 |
root |
1.75 |
This ensures that perl gets into control for a short time to handle any |
991 |
|
|
pending signals, and also ensures (slightly) slower overall operation. |
992 |
root |
1.61 |
|
993 |
root |
1.13 |
=head1 THREADS |
994 |
|
|
|
995 |
root |
1.45 |
Threads are not supported by this module in any way. Perl pseudo-threads |
996 |
root |
1.46 |
is evil stuff and must die. As soon as Perl gains real threads I will work |
997 |
|
|
on thread support for it. |
998 |
|
|
|
999 |
|
|
=head1 FORK |
1000 |
|
|
|
1001 |
|
|
Most of the "improved" event delivering mechanisms of modern operating |
1002 |
|
|
systems have quite a few problems with fork(2) (to put it bluntly: it is |
1003 |
|
|
not supported and usually destructive). Libev makes it possible to work |
1004 |
|
|
around this by having a function that recreates the kernel state after |
1005 |
|
|
fork in the child. |
1006 |
|
|
|
1007 |
|
|
On non-win32 platforms, this module requires the pthread_atfork |
1008 |
|
|
functionality to do this automatically for you. This function is quite |
1009 |
|
|
buggy on most BSDs, though, so YMMV. The overhead for this is quite |
1010 |
|
|
negligible, because everything the function currently does is set a flag |
1011 |
|
|
that is checked only when the event loop gets used the next time, so when |
1012 |
|
|
you do fork but not use EV, the overhead is minimal. |
1013 |
|
|
|
1014 |
|
|
On win32, there is no notion of fork so all this doesn't apply, of course. |
1015 |
root |
1.13 |
|
1016 |
root |
1.1 |
=cut |
1017 |
|
|
|
1018 |
root |
1.8 |
our $DIED = sub { |
1019 |
|
|
warn "EV: error in callback (ignoring): $@"; |
1020 |
|
|
}; |
1021 |
|
|
|
1022 |
root |
1.28 |
default_loop |
1023 |
root |
1.68 |
or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?'; |
1024 |
root |
1.1 |
|
1025 |
|
|
1; |
1026 |
|
|
|
1027 |
root |
1.3 |
=head1 SEE ALSO |
1028 |
|
|
|
1029 |
root |
1.73 |
L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as |
1030 |
|
|
event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient |
1031 |
|
|
coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP). |
1032 |
root |
1.3 |
|
1033 |
root |
1.1 |
=head1 AUTHOR |
1034 |
|
|
|
1035 |
|
|
Marc Lehmann <schmorp@schmorp.de> |
1036 |
|
|
http://home.schmorp.de/ |
1037 |
|
|
|
1038 |
|
|
=cut |
1039 |
|
|
|