… | |
… | |
47 | my ($w, $revents) = @_; |
47 | my ($w, $revents) = @_; |
48 | warn $w->path, " has changed somehow.\n"; |
48 | warn $w->path, " has changed somehow.\n"; |
49 | }; |
49 | }; |
50 | |
50 | |
51 | # MAINLOOP |
51 | # MAINLOOP |
52 | EV::loop; # loop until EV::unloop is called or all watchers stop |
52 | EV::run; # loop until EV::break is called or all watchers stop |
53 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
53 | EV::run EV::RUN_ONCE; # block until at least one event could be handled |
54 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
54 | EV::run EV::RUN_NOWAIT; # try to handle same events, but do not block |
|
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55 | |
|
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56 | =head1 BEFORE YOU START USING THIS MODULE |
|
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57 | |
|
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58 | If you only need timer, I/O, signal, child and idle watchers and not the |
|
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59 | advanced functionality of this module, consider using L<AnyEvent> instead, |
|
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60 | specifically the simplified API described in L<AE>. |
|
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61 | |
|
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62 | When used with EV as backend, the L<AE> API is as fast as the native L<EV> |
|
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63 | API, but your programs/modules will still run with many other event loops. |
55 | |
64 | |
56 | =head1 DESCRIPTION |
65 | =head1 DESCRIPTION |
57 | |
66 | |
58 | This module provides an interface to libev |
67 | This module provides an interface to libev |
59 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
68 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
… | |
… | |
68 | can use it through the L<AnyEvent> module, stay portable to other event |
77 | can use it through the L<AnyEvent> module, stay portable to other event |
69 | loops (if you don't rely on any watcher types not available through it) |
78 | loops (if you don't rely on any watcher types not available through it) |
70 | and still be faster than with any other event loop currently supported in |
79 | and still be faster than with any other event loop currently supported in |
71 | Perl. |
80 | Perl. |
72 | |
81 | |
|
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82 | =head2 PORTING FROM EV 3.X to 4.X |
|
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83 | |
|
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84 | EV version 4 introduces a number of incompatible changes summarised |
|
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85 | here. According to the depreciation strategy used by libev, there is a |
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86 | compatibility layer in place so programs should continue to run unchanged |
|
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87 | (the XS interface lacks this layer, so programs using that one need to be |
|
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88 | updated). |
|
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89 | |
|
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90 | This compatibility layer will be switched off in some future release. |
|
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91 | |
|
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92 | All changes relevant to Perl are renames of symbols, functions and |
|
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93 | methods: |
|
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94 | |
|
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95 | EV::loop => EV::run |
|
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96 | EV::LOOP_NONBLOCK => EV::RUN_NOWAIT |
|
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97 | EV::LOOP_ONESHOT => EV::RUN_ONCE |
|
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98 | |
|
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99 | EV::unloop => EV::break |
|
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100 | EV::UNLOOP_CANCEL => EV::BREAK_CANCEL |
|
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101 | EV::UNLOOP_ONE => EV::BREAK_ONE |
|
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102 | EV::UNLOOP_ALL => EV::BREAK_ALL |
|
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103 | |
|
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104 | EV::TIMEOUT => EV::TIMER |
|
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105 | |
|
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106 | EV::loop_count => EV::iteration |
|
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107 | EV::loop_depth => EV::depth |
|
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108 | EV::loop_verify => EV::verify |
|
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109 | |
|
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110 | The loop object methods corresponding to the functions above have been |
|
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111 | similarly renamed. |
|
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112 | |
73 | =head2 MODULE EXPORTS |
113 | =head2 MODULE EXPORTS |
74 | |
114 | |
75 | This module does not export any symbols. |
115 | This module does not export any symbols. |
76 | |
116 | |
77 | =cut |
117 | =cut |
78 | |
118 | |
79 | package EV; |
119 | package EV; |
80 | |
120 | |
81 | no warnings; |
121 | use common::sense; |
82 | use strict; |
|
|
83 | |
122 | |
84 | BEGIN { |
123 | BEGIN { |
85 | our $VERSION = '3.53'; |
124 | our $VERSION = 4.28; |
86 | use XSLoader; |
125 | use XSLoader; |
|
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126 | local $^W = 0; # avoid spurious warning |
87 | XSLoader::load "EV", $VERSION; |
127 | XSLoader::load "EV", $VERSION; |
88 | } |
128 | } |
89 | |
129 | |
90 | @EV::IO::ISA = |
130 | @EV::IO::ISA = |
91 | @EV::Timer::ISA = |
131 | @EV::Timer::ISA = |
… | |
… | |
125 | will then also service the kqueue loop to some extent. See the example in |
165 | will then also service the kqueue loop to some extent. See the example in |
126 | the section about embed watchers for an example on how to achieve that. |
166 | the section about embed watchers for an example on how to achieve that. |
127 | |
167 | |
128 | =over 4 |
168 | =over 4 |
129 | |
169 | |
130 | =item $loop = new EV::loop [$flags] |
170 | =item $loop = new EV::Loop [$flags] |
131 | |
171 | |
132 | Create a new event loop as per the specified flags. Please refer to |
172 | Create a new event loop as per the specified flags. Please refer to |
133 | the C<ev_loop_new ()> function description in the libev documentation |
173 | the C<ev_loop_new ()> function description in the libev documentation |
134 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>, |
174 | (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>, |
135 | or locally-installed as F<EV::libev> manpage) for more info. |
175 | or locally-installed as F<EV::libev> manpage) for more info. |
… | |
… | |
147 | Must be called after a fork in the child, before entering or continuing |
187 | Must be called after a fork in the child, before entering or continuing |
148 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
188 | the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls |
149 | this function automatically, at some performance loss (refer to the libev |
189 | this function automatically, at some performance loss (refer to the libev |
150 | documentation). |
190 | documentation). |
151 | |
191 | |
152 | =item $loop->loop_verify |
192 | =item $loop->verify |
153 | |
193 | |
154 | Calls C<ev_verify> to make internal consistency checks (for debugging |
194 | Calls C<ev_verify> to make internal consistency checks (for debugging |
155 | libev) and abort the program if any data structures were found to be |
195 | libev) and abort the program if any data structures were found to be |
156 | corrupted. |
196 | corrupted. |
157 | |
197 | |
… | |
… | |
202 | |
242 | |
203 | Returns the time the last event loop iteration has been started. This |
243 | Returns the time the last event loop iteration has been started. This |
204 | is the time that (relative) timers are based on, and referring to it is |
244 | is the time that (relative) timers are based on, and referring to it is |
205 | usually faster then calling EV::time. |
245 | usually faster then calling EV::time. |
206 | |
246 | |
|
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247 | =item EV::now_update |
|
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248 | |
|
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249 | =item $loop->now_update |
|
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250 | |
|
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251 | Establishes the current time by querying the kernel, updating the time |
|
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252 | returned by C<EV::now> in the progress. This is a costly operation and |
|
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253 | is usually done automatically within C<EV::run>. |
|
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254 | |
|
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255 | This function is rarely useful, but when some event callback runs for a |
|
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256 | very long time without entering the event loop, updating libev's idea of |
|
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257 | the current time is a good idea. |
|
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258 | |
|
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259 | =item EV::suspend |
|
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260 | |
|
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261 | =item $loop->suspend |
|
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262 | |
|
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263 | =item EV::resume |
|
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264 | |
|
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265 | =item $loop->resume |
|
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266 | |
|
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267 | These two functions suspend and resume a loop, for use when the loop is |
|
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268 | not used for a while and timeouts should not be processed. |
|
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269 | |
|
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270 | A typical use case would be an interactive program such as a game: When |
|
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271 | the user presses C<^Z> to suspend the game and resumes it an hour later it |
|
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272 | would be best to handle timeouts as if no time had actually passed while |
|
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273 | the program was suspended. This can be achieved by calling C<suspend> |
|
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274 | in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling |
|
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275 | C<resume> directly afterwards to resume timer processing. |
|
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276 | |
|
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277 | Effectively, all C<timer> watchers will be delayed by the time spend |
|
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278 | between C<suspend> and C<resume>, and all C<periodic> watchers |
|
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279 | will be rescheduled (that is, they will lose any events that would have |
|
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280 | occured while suspended). |
|
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281 | |
|
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282 | After calling C<suspend> you B<must not> call I<any> function on the given |
|
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283 | loop other than C<resume>, and you B<must not> call C<resume> |
|
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284 | without a previous call to C<suspend>. |
|
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285 | |
|
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286 | Calling C<suspend>/C<resume> has the side effect of updating the event |
|
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287 | loop time (see C<now_update>). |
|
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288 | |
207 | =item $backend = EV::backend |
289 | =item $backend = EV::backend |
208 | |
290 | |
209 | =item $backend = $loop->backend |
291 | =item $backend = $loop->backend |
210 | |
292 | |
211 | Returns an integer describing the backend used by libev (EV::BACKEND_SELECT |
293 | Returns an integer describing the backend used by libev (EV::BACKEND_SELECT |
212 | or EV::BACKEND_EPOLL). |
294 | or EV::BACKEND_EPOLL). |
213 | |
295 | |
214 | =item EV::loop [$flags] |
296 | =item $active = EV::run [$flags] |
215 | |
297 | |
216 | =item $loop->loop ([$flags]) |
298 | =item $active = $loop->run ([$flags]) |
217 | |
299 | |
218 | Begin checking for events and calling callbacks. It returns when a |
300 | Begin checking for events and calling callbacks. It returns when a |
219 | callback calls EV::unloop. |
301 | callback calls EV::break or the flags are nonzero (in which case the |
|
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302 | return value is true) or when there are no active watchers which reference |
|
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303 | the loop (keepalive is true), in which case the return value will be |
|
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304 | false. The return value can generally be interpreted as "if true, there is |
|
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305 | more work left to do". |
220 | |
306 | |
221 | The $flags argument can be one of the following: |
307 | The $flags argument can be one of the following: |
222 | |
308 | |
223 | 0 as above |
309 | 0 as above |
224 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
310 | EV::RUN_ONCE block at most once (wait, but do not loop) |
225 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
311 | EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait) |
226 | |
312 | |
227 | =item EV::unloop [$how] |
313 | =item EV::break [$how] |
228 | |
314 | |
229 | =item $loop->unloop ([$how]) |
315 | =item $loop->break ([$how]) |
230 | |
316 | |
231 | When called with no arguments or an argument of EV::UNLOOP_ONE, makes the |
317 | When called with no arguments or an argument of EV::BREAK_ONE, makes the |
232 | innermost call to EV::loop return. |
318 | innermost call to EV::run return. |
233 | |
319 | |
234 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
320 | When called with an argument of EV::BREAK_ALL, all calls to EV::run will |
235 | fast as possible. |
321 | return as fast as possible. |
236 | |
322 | |
237 | =item $count = EV::loop_count |
323 | When called with an argument of EV::BREAK_CANCEL, any pending break will |
|
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324 | be cancelled. |
238 | |
325 | |
|
|
326 | =item $count = EV::iteration |
|
|
327 | |
239 | =item $count = $loop->loop_count |
328 | =item $count = $loop->iteration |
240 | |
329 | |
241 | Return the number of times the event loop has polled for new |
330 | Return the number of times the event loop has polled for new |
242 | events. Sometimes useful as a generation counter. |
331 | events. Sometimes useful as a generation counter. |
243 | |
332 | |
244 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
333 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
… | |
… | |
253 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
342 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
254 | you do not want to wait for some I/O event, specify C<undef> for |
343 | you do not want to wait for some I/O event, specify C<undef> for |
255 | C<$fh_or_undef> and C<0> for C<$events>). |
344 | C<$fh_or_undef> and C<0> for C<$events>). |
256 | |
345 | |
257 | If timeout is C<undef> or negative, then there will be no |
346 | If timeout is C<undef> or negative, then there will be no |
258 | timeout. Otherwise a EV::timer with this value will be started. |
347 | timeout. Otherwise an C<EV::timer> with this value will be started. |
259 | |
348 | |
260 | When an error occurs or either the timeout or I/O watcher triggers, then |
349 | When an error occurs or either the timeout or I/O watcher triggers, then |
261 | the callback will be called with the received event set (in general |
350 | the callback will be called with the received event set (in general |
262 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
351 | you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>, |
263 | C<EV::WRITE> and C<EV::TIMEOUT>). |
352 | C<EV::WRITE> and C<EV::TIMER>). |
264 | |
353 | |
265 | EV::once doesn't return anything: the watchers stay active till either |
354 | EV::once doesn't return anything: the watchers stay active till either |
266 | of them triggers, then they will be stopped and freed, and the callback |
355 | of them triggers, then they will be stopped and freed, and the callback |
267 | invoked. |
356 | invoked. |
268 | |
357 | |
269 | =item EV::feed_fd_event ($fd, $revents) |
358 | =item EV::feed_fd_event $fd, $revents |
270 | |
359 | |
271 | =item $loop->feed_fd_event ($fd, $revents) |
360 | =item $loop->feed_fd_event ($fd, $revents) |
272 | |
361 | |
273 | Feed an event on a file descriptor into EV. EV will react to this call as |
362 | Feed an event on a file descriptor into EV. EV will react to this call as |
274 | if the readyness notifications specified by C<$revents> (a combination of |
363 | if the readyness notifications specified by C<$revents> (a combination of |
275 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
364 | C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>. |
276 | |
365 | |
277 | =item EV::feed_signal_event ($signal) |
366 | =item EV::feed_signal_event $signal |
278 | |
367 | |
279 | Feed a signal event into EV. EV will react to this call as if the signal |
368 | Feed a signal event into the default loop. EV will react to this call as |
280 | specified by C<$signal> had occured. |
369 | if the signal specified by C<$signal> had occured. |
|
|
370 | |
|
|
371 | =item EV::feed_signal $signal |
|
|
372 | |
|
|
373 | Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works |
|
|
374 | regardless of which loop has registered the signal, and is mainly useful |
|
|
375 | for custom signal implementations. |
281 | |
376 | |
282 | =item EV::set_io_collect_interval $time |
377 | =item EV::set_io_collect_interval $time |
283 | |
378 | |
284 | =item $loop->set_io_collect_interval ($time) |
379 | =item $loop->set_io_collect_interval ($time) |
285 | |
380 | |
… | |
… | |
290 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
385 | These advanced functions set the minimum block interval when polling for I/O events and the minimum |
291 | wait interval for timer events. See the libev documentation at |
386 | wait interval for timer events. See the libev documentation at |
292 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> |
387 | L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> |
293 | (locally installed as F<EV::libev>) for a more detailed discussion. |
388 | (locally installed as F<EV::libev>) for a more detailed discussion. |
294 | |
389 | |
|
|
390 | =item $count = EV::pending_count |
|
|
391 | |
|
|
392 | =item $count = $loop->pending_count |
|
|
393 | |
|
|
394 | Returns the number of currently pending watchers. |
|
|
395 | |
|
|
396 | =item EV::invoke_pending |
|
|
397 | |
|
|
398 | =item $loop->invoke_pending |
|
|
399 | |
|
|
400 | Invoke all currently pending watchers. |
|
|
401 | |
295 | =back |
402 | =back |
296 | |
403 | |
297 | |
404 | |
298 | =head1 WATCHER OBJECTS |
405 | =head1 WATCHER OBJECTS |
299 | |
406 | |
… | |
… | |
313 | |
420 | |
314 | Each watcher type has its associated bit in revents, so you can use the |
421 | Each watcher type has its associated bit in revents, so you can use the |
315 | same callback for multiple watchers. The event mask is named after the |
422 | same callback for multiple watchers. The event mask is named after the |
316 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
423 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
317 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
424 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events |
318 | (which can set both EV::READ and EV::WRITE bits), and EV::timer (which |
425 | (which can set both EV::READ and EV::WRITE bits). |
319 | uses EV::TIMEOUT). |
|
|
320 | |
426 | |
321 | In the rare case where one wants to create a watcher but not start it at |
427 | In the rare case where one wants to create a watcher but not start it at |
322 | the same time, each constructor has a variant with a trailing C<_ns> in |
428 | the same time, each constructor has a variant with a trailing C<_ns> in |
323 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
429 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
324 | |
430 | |
… | |
… | |
401 | returns its C<$revents> bitset (as if its callback was invoked). If the |
507 | returns its C<$revents> bitset (as if its callback was invoked). If the |
402 | watcher isn't pending it does nothing and returns C<0>. |
508 | watcher isn't pending it does nothing and returns C<0>. |
403 | |
509 | |
404 | =item $previous_state = $w->keepalive ($bool) |
510 | =item $previous_state = $w->keepalive ($bool) |
405 | |
511 | |
406 | Normally, C<EV::loop> will return when there are no active watchers |
512 | Normally, C<EV::run> will return when there are no active watchers |
407 | (which is a "deadlock" because no progress can be made anymore). This is |
513 | (which is a "deadlock" because no progress can be made anymore). This is |
408 | convinient because it allows you to start your watchers (and your jobs), |
514 | convenient because it allows you to start your watchers (and your jobs), |
409 | call C<EV::loop> once and when it returns you know that all your jobs are |
515 | call C<EV::run> once and when it returns you know that all your jobs are |
410 | finished (or they forgot to register some watchers for their task :). |
516 | finished (or they forgot to register some watchers for their task :). |
411 | |
517 | |
412 | Sometimes, however, this gets in your way, for example when the module |
518 | Sometimes, however, this gets in your way, for example when the module |
413 | that calls C<EV::loop> (usually the main program) is not the same module |
519 | that calls C<EV::run> (usually the main program) is not the same module |
414 | as a long-living watcher (for example a DNS client module written by |
520 | as a long-living watcher (for example a DNS client module written by |
415 | somebody else even). Then you might want any outstanding requests to be |
521 | somebody else even). Then you might want any outstanding requests to be |
416 | handled, but you would not want to keep C<EV::loop> from returning just |
522 | handled, but you would not want to keep C<EV::run> from returning just |
417 | because you happen to have this long-running UDP port watcher. |
523 | because you happen to have this long-running UDP port watcher. |
418 | |
524 | |
419 | In this case you can clear the keepalive status, which means that even |
525 | In this case you can clear the keepalive status, which means that even |
420 | though your watcher is active, it won't keep C<EV::loop> from returning. |
526 | though your watcher is active, it won't keep C<EV::run> from returning. |
421 | |
527 | |
422 | The initial value for keepalive is true (enabled), and you can change it |
528 | The initial value for keepalive is true (enabled), and you can change it |
423 | any time. |
529 | any time. |
424 | |
530 | |
425 | Example: Register an I/O watcher for some UDP socket but do not keep the |
531 | Example: Register an I/O watcher for some UDP socket but do not keep the |
… | |
… | |
492 | |
598 | |
493 | =item $w = $loop->timer ($after, $repeat, $callback) |
599 | =item $w = $loop->timer ($after, $repeat, $callback) |
494 | |
600 | |
495 | =item $w = $loop->timer_ns ($after, $repeat, $callback) |
601 | =item $w = $loop->timer_ns ($after, $repeat, $callback) |
496 | |
602 | |
497 | Calls the callback after C<$after> seconds (which may be fractional). If |
603 | Calls the callback after C<$after> seconds (which may be fractional or |
498 | C<$repeat> is non-zero, the timer will be restarted (with the $repeat |
604 | negative). If C<$repeat> is non-zero, the timer will be restarted (with |
499 | value as $after) after the callback returns. |
605 | the $repeat value as $after) after the callback returns. |
500 | |
606 | |
501 | This means that the callback would be called roughly after C<$after> |
607 | This means that the callback would be called roughly after C<$after> |
502 | seconds, and then every C<$repeat> seconds. The timer does his best not |
608 | seconds, and then every C<$repeat> seconds. The timer does his best not |
503 | to drift, but it will not invoke the timer more often then once per event |
609 | to drift, but it will not invoke the timer more often then once per event |
504 | loop iteration, and might drift in other cases. If that isn't acceptable, |
610 | loop iteration, and might drift in other cases. If that isn't acceptable, |
… | |
… | |
508 | in front of the machine while the timer is running and changes the system |
614 | in front of the machine while the timer is running and changes the system |
509 | clock, the timer will nevertheless run (roughly) the same time. |
615 | clock, the timer will nevertheless run (roughly) the same time. |
510 | |
616 | |
511 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
617 | The C<timer_ns> variant doesn't start (activate) the newly created watcher. |
512 | |
618 | |
513 | =item $w->set ($after, $repeat) |
619 | =item $w->set ($after, $repeat = 0) |
514 | |
620 | |
515 | Reconfigures the watcher, see the constructor above for details. Can be called at |
621 | Reconfigures the watcher, see the constructor above for details. Can be called at |
516 | any time. |
622 | any time. |
517 | |
623 | |
518 | =item $w->again |
624 | =item $w->again |
|
|
625 | |
|
|
626 | =item $w->again ($repeat) |
519 | |
627 | |
520 | Similar to the C<start> method, but has special semantics for repeating timers: |
628 | Similar to the C<start> method, but has special semantics for repeating timers: |
521 | |
629 | |
522 | If the timer is active and non-repeating, it will be stopped. |
630 | If the timer is active and non-repeating, it will be stopped. |
523 | |
631 | |
… | |
… | |
530 | |
638 | |
531 | This behaviour is useful when you have a timeout for some IO |
639 | This behaviour is useful when you have a timeout for some IO |
532 | operation. You create a timer object with the same value for C<$after> and |
640 | operation. You create a timer object with the same value for C<$after> and |
533 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
641 | C<$repeat>, and then, in the read/write watcher, run the C<again> method |
534 | on the timeout. |
642 | on the timeout. |
|
|
643 | |
|
|
644 | If called with a C<$repeat> argument, then it uses this a timer repeat |
|
|
645 | value. |
|
|
646 | |
|
|
647 | =item $after = $w->remaining |
|
|
648 | |
|
|
649 | Calculates and returns the remaining time till the timer will fire. |
535 | |
650 | |
536 | =back |
651 | =back |
537 | |
652 | |
538 | |
653 | |
539 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
654 | =head3 PERIODIC WATCHERS - to cron or not to cron? |
… | |
… | |
567 | surpasses this time. |
682 | surpasses this time. |
568 | |
683 | |
569 | =item * repeating interval timer ($interval > 0, $reschedule_cb = 0) |
684 | =item * repeating interval timer ($interval > 0, $reschedule_cb = 0) |
570 | |
685 | |
571 | In this mode the watcher will always be scheduled to time out at the |
686 | In this mode the watcher will always be scheduled to time out at the |
572 | next C<$at + N * $interval> time (for some integer N) and then repeat, |
687 | next C<$at + N * $interval> time (for the lowest integer N) and then repeat, |
573 | regardless of any time jumps. |
688 | regardless of any time jumps. Note that, since C<N> can be negative, the |
|
|
689 | first trigger can happen before C<$at>. |
574 | |
690 | |
575 | This can be used to create timers that do not drift with respect to system |
691 | This can be used to create timers that do not drift with respect to system |
576 | time: |
692 | time: |
577 | |
693 | |
578 | my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; |
694 | my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; |
579 | |
695 | |
580 | That doesn't mean there will always be 3600 seconds in between triggers, |
696 | That doesn't mean there will always be 3600 seconds in between triggers, |
581 | but only that the the clalback will be called when the system time shows a |
697 | but only that the the callback will be called when the system time shows a |
582 | full hour (UTC). |
698 | full hour (UTC). |
583 | |
699 | |
584 | Another way to think about it (for the mathematically inclined) is that |
700 | Another way to think about it (for the mathematically inclined) is that |
585 | EV::periodic will try to run the callback in this mode at the next |
701 | EV::periodic will try to run the callback in this mode at the next |
586 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
702 | possible time where C<$time = $at (mod $interval)>, regardless of any time |
… | |
… | |
594 | time as second argument. |
710 | time as second argument. |
595 | |
711 | |
596 | I<This callback MUST NOT stop or destroy this or any other periodic |
712 | I<This callback MUST NOT stop or destroy this or any other periodic |
597 | watcher, ever, and MUST NOT call any event loop functions or methods>. If |
713 | watcher, ever, and MUST NOT call any event loop functions or methods>. If |
598 | you need to stop it, return 1e30 and stop it afterwards. You may create |
714 | you need to stop it, return 1e30 and stop it afterwards. You may create |
599 | and start a C<EV::prepare> watcher for this task. |
715 | and start an C<EV::prepare> watcher for this task. |
600 | |
716 | |
601 | It must return the next time to trigger, based on the passed time value |
717 | It must return the next time to trigger, based on the passed time value |
602 | (that is, the lowest time value larger than or equal to to the second |
718 | (that is, the lowest time value larger than or equal to to the second |
603 | argument). It will usually be called just before the callback will be |
719 | argument). It will usually be called just before the callback will be |
604 | triggered, but might be called at other times, too. |
720 | triggered, but might be called at other times, too. |
605 | |
721 | |
606 | This can be used to create very complex timers, such as a timer that |
722 | This can be used to create very complex timers, such as a timer that |
607 | triggers on each midnight, local time (actually 24 hours after the last |
723 | triggers on each midnight, local time (actually one day after the last |
608 | midnight, to keep the example simple. If you know a way to do it correctly |
724 | midnight, to keep the example simple): |
609 | in about the same space (without requiring elaborate modules), drop me a |
|
|
610 | note :): |
|
|
611 | |
725 | |
612 | my $daily = EV::periodic 0, 0, sub { |
726 | my $daily = EV::periodic 0, 0, sub { |
613 | my ($w, $now) = @_; |
727 | my ($w, $now) = @_; |
614 | |
728 | |
615 | use Time::Local (); |
729 | use Time::Local (); |
616 | my (undef, undef, undef, $d, $m, $y) = localtime $now; |
730 | my (undef, undef, undef, $d, $m, $y) = localtime $now; |
617 | 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y |
731 | Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y |
618 | }, sub { |
732 | }, sub { |
619 | print "it's midnight or likely shortly after, now\n"; |
733 | print "it's midnight or likely shortly after, now\n"; |
620 | }; |
734 | }; |
621 | |
735 | |
622 | =back |
736 | =back |
… | |
… | |
645 | |
759 | |
646 | =item $w = EV::signal $signal, $callback |
760 | =item $w = EV::signal $signal, $callback |
647 | |
761 | |
648 | =item $w = EV::signal_ns $signal, $callback |
762 | =item $w = EV::signal_ns $signal, $callback |
649 | |
763 | |
|
|
764 | =item $w = $loop->signal ($signal, $callback) |
|
|
765 | |
|
|
766 | =item $w = $loop->signal_ns ($signal, $callback) |
|
|
767 | |
650 | Call the callback when $signal is received (the signal can be specified by |
768 | Call the callback when $signal is received (the signal can be specified by |
651 | number or by name, just as with C<kill> or C<%SIG>). |
769 | number or by name, just as with C<kill> or C<%SIG>). |
|
|
770 | |
|
|
771 | Only one event loop can grab a given signal - attempting to grab the same |
|
|
772 | signal from two EV loops will crash the program immediately or cause data |
|
|
773 | corruption. |
652 | |
774 | |
653 | EV will grab the signal for the process (the kernel only allows one |
775 | EV will grab the signal for the process (the kernel only allows one |
654 | component to receive a signal at a time) when you start a signal watcher, |
776 | component to receive a signal at a time) when you start a signal watcher, |
655 | and removes it again when you stop it. Perl does the same when you |
777 | and removes it again when you stop it. Perl does the same when you |
656 | add/remove callbacks to C<%SIG>, so watch out. |
778 | add/remove callbacks to C<%SIG>, so watch out. |
… | |
… | |
881 | =item $w = $loop->check_ns ($callback) |
1003 | =item $w = $loop->check_ns ($callback) |
882 | |
1004 | |
883 | Call the callback just after the process wakes up again (after it has |
1005 | Call the callback just after the process wakes up again (after it has |
884 | gathered events), but before any other callbacks have been invoked. |
1006 | gathered events), but before any other callbacks have been invoked. |
885 | |
1007 | |
886 | This is used to integrate other event-based software into the EV |
1008 | This can be used to integrate other event-based software into the EV |
887 | mainloop: You register a prepare callback and in there, you create io and |
1009 | mainloop: You register a prepare callback and in there, you create io and |
888 | timer watchers as required by the other software. Here is a real-world |
1010 | timer watchers as required by the other software. Here is a real-world |
889 | example of integrating Net::SNMP (with some details left out): |
1011 | example of integrating Net::SNMP (with some details left out): |
890 | |
1012 | |
891 | our @snmp_watcher; |
1013 | our @snmp_watcher; |
… | |
… | |
925 | The callbacks of the created watchers will not be called as the watchers |
1047 | The callbacks of the created watchers will not be called as the watchers |
926 | are destroyed before this can happen (remember EV::check gets called |
1048 | are destroyed before this can happen (remember EV::check gets called |
927 | first). |
1049 | first). |
928 | |
1050 | |
929 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
1051 | The C<check_ns> variant doesn't start (activate) the newly created watcher. |
|
|
1052 | |
|
|
1053 | =item EV::CHECK constant issues |
|
|
1054 | |
|
|
1055 | Like all other watcher types, there is a bitmask constant for use in |
|
|
1056 | C<$revents> and other places. The C<EV::CHECK> is special as it has |
|
|
1057 | the same name as the C<CHECK> sub called by Perl. This doesn't cause |
|
|
1058 | big issues on newer perls (beginning with 5.8.9), but it means thatthe |
|
|
1059 | constant must be I<inlined>, i.e. runtime calls will not work. That means |
|
|
1060 | that as long as you always C<use EV> and then C<EV::CHECK> you are on the |
|
|
1061 | safe side. |
930 | |
1062 | |
931 | =back |
1063 | =back |
932 | |
1064 | |
933 | |
1065 | |
934 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
1066 | =head3 FORK WATCHERS - the audacity to resume the event loop after a fork |
… | |
… | |
1002 | |
1134 | |
1003 | =back |
1135 | =back |
1004 | |
1136 | |
1005 | =head3 ASYNC WATCHERS - how to wake up another event loop |
1137 | =head3 ASYNC WATCHERS - how to wake up another event loop |
1006 | |
1138 | |
1007 | Async watchers are provided by EV, but have little use in perl directly, as perl |
1139 | Async watchers are provided by EV, but have little use in perl directly, |
1008 | neither supports threads nor direct access to signal handlers or other |
1140 | as perl neither supports threads running in parallel nor direct access to |
1009 | contexts where they could be of value. |
1141 | signal handlers or other contexts where they could be of value. |
1010 | |
1142 | |
1011 | It is, however, possible to use them from the XS level. |
1143 | It is, however, possible to use them from the XS level. |
1012 | |
1144 | |
1013 | Please see the libev documentation for further details. |
1145 | Please see the libev documentation for further details. |
1014 | |
1146 | |
… | |
… | |
1016 | |
1148 | |
1017 | =item $w = EV::async $callback |
1149 | =item $w = EV::async $callback |
1018 | |
1150 | |
1019 | =item $w = EV::async_ns $callback |
1151 | =item $w = EV::async_ns $callback |
1020 | |
1152 | |
|
|
1153 | =item $w = $loop->async ($callback) |
|
|
1154 | |
|
|
1155 | =item $w = $loop->async_ns ($callback) |
|
|
1156 | |
1021 | =item $w->send |
1157 | =item $w->send |
1022 | |
1158 | |
1023 | =item $bool = $w->async_pending |
1159 | =item $bool = $w->async_pending |
1024 | |
1160 | |
1025 | =back |
1161 | =back |
|
|
1162 | |
|
|
1163 | =head3 CLEANUP WATCHERS - how to clean up when the event loop goes away |
|
|
1164 | |
|
|
1165 | Cleanup watchers are not supported on the Perl level, they can only be |
|
|
1166 | used via XS currently. |
1026 | |
1167 | |
1027 | |
1168 | |
1028 | =head1 PERL SIGNALS |
1169 | =head1 PERL SIGNALS |
1029 | |
1170 | |
1030 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
1171 | While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour |
… | |
… | |
1042 | my $async_check = EV::check sub { }; |
1183 | my $async_check = EV::check sub { }; |
1043 | |
1184 | |
1044 | This ensures that perl gets into control for a short time to handle any |
1185 | This ensures that perl gets into control for a short time to handle any |
1045 | pending signals, and also ensures (slightly) slower overall operation. |
1186 | pending signals, and also ensures (slightly) slower overall operation. |
1046 | |
1187 | |
1047 | =head1 THREADS |
1188 | =head1 ITHREADS |
1048 | |
1189 | |
1049 | Threads are not supported by this module in any way. Perl pseudo-threads |
1190 | Ithreads are not supported by this module in any way. Perl pseudo-threads |
1050 | is evil stuff and must die. As soon as Perl gains real threads I will work |
1191 | is evil stuff and must die. Real threads as provided by Coro are fully |
1051 | on thread support for it. |
1192 | supported (and enhanced support is available via L<Coro::EV>). |
1052 | |
1193 | |
1053 | =head1 FORK |
1194 | =head1 FORK |
1054 | |
1195 | |
1055 | Most of the "improved" event delivering mechanisms of modern operating |
1196 | Most of the "improved" event delivering mechanisms of modern operating |
1056 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
1197 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
… | |
… | |
1078 | |
1219 | |
1079 | 1; |
1220 | 1; |
1080 | |
1221 | |
1081 | =head1 SEE ALSO |
1222 | =head1 SEE ALSO |
1082 | |
1223 | |
|
|
1224 | L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS> |
1083 | L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as |
1225 | (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event |
1084 | event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient |
1226 | loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread |
1085 | coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for |
1227 | integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for |
1086 | event-loop agnostic and portable event driven programming. |
1228 | event-loop agnostic and portable event driven programming. |
1087 | |
1229 | |
1088 | =head1 AUTHOR |
1230 | =head1 AUTHOR |
1089 | |
1231 | |
1090 | Marc Lehmann <schmorp@schmorp.de> |
1232 | Marc Lehmann <schmorp@schmorp.de> |