… | |
… | |
26 | puts ("stdin ready"); |
26 | puts ("stdin ready"); |
27 | // for one-shot events, one must manually stop the watcher |
27 | // for one-shot events, one must manually stop the watcher |
28 | // with its corresponding stop function. |
28 | // with its corresponding stop function. |
29 | ev_io_stop (EV_A_ w); |
29 | ev_io_stop (EV_A_ w); |
30 | |
30 | |
31 | // this causes all nested ev_loop's to stop iterating |
31 | // this causes all nested ev_run's to stop iterating |
32 | ev_unloop (EV_A_ EVUNLOOP_ALL); |
32 | ev_break (EV_A_ EVBREAK_ALL); |
33 | } |
33 | } |
34 | |
34 | |
35 | // another callback, this time for a time-out |
35 | // another callback, this time for a time-out |
36 | static void |
36 | static void |
37 | timeout_cb (EV_P_ ev_timer *w, int revents) |
37 | timeout_cb (EV_P_ ev_timer *w, int revents) |
38 | { |
38 | { |
39 | puts ("timeout"); |
39 | puts ("timeout"); |
40 | // this causes the innermost ev_loop to stop iterating |
40 | // this causes the innermost ev_run to stop iterating |
41 | ev_unloop (EV_A_ EVUNLOOP_ONE); |
41 | ev_break (EV_A_ EVBREAK_ONE); |
42 | } |
42 | } |
43 | |
43 | |
44 | int |
44 | int |
45 | main (void) |
45 | main (void) |
46 | { |
46 | { |
47 | // use the default event loop unless you have special needs |
47 | // use the default event loop unless you have special needs |
48 | struct ev_loop *loop = ev_default_loop (0); |
48 | struct ev_loop *loop = EV_DEFAULT; |
49 | |
49 | |
50 | // initialise an io watcher, then start it |
50 | // initialise an io watcher, then start it |
51 | // this one will watch for stdin to become readable |
51 | // this one will watch for stdin to become readable |
52 | ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
52 | ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
53 | ev_io_start (loop, &stdin_watcher); |
53 | ev_io_start (loop, &stdin_watcher); |
… | |
… | |
56 | // simple non-repeating 5.5 second timeout |
56 | // simple non-repeating 5.5 second timeout |
57 | ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.); |
57 | ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.); |
58 | ev_timer_start (loop, &timeout_watcher); |
58 | ev_timer_start (loop, &timeout_watcher); |
59 | |
59 | |
60 | // now wait for events to arrive |
60 | // now wait for events to arrive |
61 | ev_loop (loop, 0); |
61 | ev_run (loop, 0); |
62 | |
62 | |
63 | // unloop was called, so exit |
63 | // unloop was called, so exit |
64 | return 0; |
64 | return 0; |
65 | } |
65 | } |
66 | |
66 | |
… | |
… | |
77 | on event-based programming, nor will it introduce event-based programming |
77 | on event-based programming, nor will it introduce event-based programming |
78 | with libev. |
78 | with libev. |
79 | |
79 | |
80 | Familiarity with event based programming techniques in general is assumed |
80 | Familiarity with event based programming techniques in general is assumed |
81 | throughout this document. |
81 | throughout this document. |
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82 | |
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83 | =head1 WHAT TO READ WHEN IN A HURRY |
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84 | |
|
|
85 | This manual tries to be very detailed, but unfortunately, this also makes |
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86 | it very long. If you just want to know the basics of libev, I suggest |
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87 | reading L<ANATOMY OF A WATCHER>, then the L<EXAMPLE PROGRAM> above and |
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88 | look up the missing functions in L<GLOBAL FUNCTIONS> and the C<ev_io> and |
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89 | C<ev_timer> sections in L<WATCHER TYPES>. |
82 | |
90 | |
83 | =head1 ABOUT LIBEV |
91 | =head1 ABOUT LIBEV |
84 | |
92 | |
85 | Libev is an event loop: you register interest in certain events (such as a |
93 | Libev is an event loop: you register interest in certain events (such as a |
86 | file descriptor being readable or a timeout occurring), and it will manage |
94 | file descriptor being readable or a timeout occurring), and it will manage |
… | |
… | |
124 | this argument. |
132 | this argument. |
125 | |
133 | |
126 | =head2 TIME REPRESENTATION |
134 | =head2 TIME REPRESENTATION |
127 | |
135 | |
128 | Libev represents time as a single floating point number, representing |
136 | Libev represents time as a single floating point number, representing |
129 | the (fractional) number of seconds since the (POSIX) epoch (in practise |
137 | the (fractional) number of seconds since the (POSIX) epoch (in practice |
130 | somewhere near the beginning of 1970, details are complicated, don't |
138 | somewhere near the beginning of 1970, details are complicated, don't |
131 | ask). This type is called C<ev_tstamp>, which is what you should use |
139 | ask). This type is called C<ev_tstamp>, which is what you should use |
132 | too. It usually aliases to the C<double> type in C. When you need to do |
140 | too. It usually aliases to the C<double> type in C. When you need to do |
133 | any calculations on it, you should treat it as some floating point value. |
141 | any calculations on it, you should treat it as some floating point value. |
134 | |
142 | |
… | |
… | |
165 | |
173 | |
166 | =item ev_tstamp ev_time () |
174 | =item ev_tstamp ev_time () |
167 | |
175 | |
168 | Returns the current time as libev would use it. Please note that the |
176 | Returns the current time as libev would use it. Please note that the |
169 | C<ev_now> function is usually faster and also often returns the timestamp |
177 | C<ev_now> function is usually faster and also often returns the timestamp |
170 | you actually want to know. |
178 | you actually want to know. Also interesting is the combination of |
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179 | C<ev_update_now> and C<ev_now>. |
171 | |
180 | |
172 | =item ev_sleep (ev_tstamp interval) |
181 | =item ev_sleep (ev_tstamp interval) |
173 | |
182 | |
174 | Sleep for the given interval: The current thread will be blocked until |
183 | Sleep for the given interval: The current thread will be blocked until |
175 | either it is interrupted or the given time interval has passed. Basically |
184 | either it is interrupted or the given time interval has passed. Basically |
… | |
… | |
192 | as this indicates an incompatible change. Minor versions are usually |
201 | as this indicates an incompatible change. Minor versions are usually |
193 | compatible to older versions, so a larger minor version alone is usually |
202 | compatible to older versions, so a larger minor version alone is usually |
194 | not a problem. |
203 | not a problem. |
195 | |
204 | |
196 | Example: Make sure we haven't accidentally been linked against the wrong |
205 | Example: Make sure we haven't accidentally been linked against the wrong |
197 | version (note, however, that this will not detect ABI mismatches :). |
206 | version (note, however, that this will not detect other ABI mismatches, |
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207 | such as LFS or reentrancy). |
198 | |
208 | |
199 | assert (("libev version mismatch", |
209 | assert (("libev version mismatch", |
200 | ev_version_major () == EV_VERSION_MAJOR |
210 | ev_version_major () == EV_VERSION_MAJOR |
201 | && ev_version_minor () >= EV_VERSION_MINOR)); |
211 | && ev_version_minor () >= EV_VERSION_MINOR)); |
202 | |
212 | |
… | |
… | |
213 | assert (("sorry, no epoll, no sex", |
223 | assert (("sorry, no epoll, no sex", |
214 | ev_supported_backends () & EVBACKEND_EPOLL)); |
224 | ev_supported_backends () & EVBACKEND_EPOLL)); |
215 | |
225 | |
216 | =item unsigned int ev_recommended_backends () |
226 | =item unsigned int ev_recommended_backends () |
217 | |
227 | |
218 | Return the set of all backends compiled into this binary of libev and also |
228 | Return the set of all backends compiled into this binary of libev and |
219 | recommended for this platform. This set is often smaller than the one |
229 | also recommended for this platform, meaning it will work for most file |
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230 | descriptor types. This set is often smaller than the one returned by |
220 | returned by C<ev_supported_backends>, as for example kqueue is broken on |
231 | C<ev_supported_backends>, as for example kqueue is broken on most BSDs |
221 | most BSDs and will not be auto-detected unless you explicitly request it |
232 | and will not be auto-detected unless you explicitly request it (assuming |
222 | (assuming you know what you are doing). This is the set of backends that |
233 | you know what you are doing). This is the set of backends that libev will |
223 | libev will probe for if you specify no backends explicitly. |
234 | probe for if you specify no backends explicitly. |
224 | |
235 | |
225 | =item unsigned int ev_embeddable_backends () |
236 | =item unsigned int ev_embeddable_backends () |
226 | |
237 | |
227 | Returns the set of backends that are embeddable in other event loops. This |
238 | Returns the set of backends that are embeddable in other event loops. This |
228 | is the theoretical, all-platform, value. To find which backends |
239 | value is platform-specific but can include backends not available on the |
229 | might be supported on the current system, you would need to look at |
240 | current system. To find which embeddable backends might be supported on |
230 | C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for |
241 | the current system, you would need to look at C<ev_embeddable_backends () |
231 | recommended ones. |
242 | & ev_supported_backends ()>, likewise for recommended ones. |
232 | |
243 | |
233 | See the description of C<ev_embed> watchers for more info. |
244 | See the description of C<ev_embed> watchers for more info. |
234 | |
245 | |
235 | =item ev_set_allocator (void *(*cb)(void *ptr, long size)) [NOT REENTRANT] |
246 | =item ev_set_allocator (void *(*cb)(void *ptr, long size)) |
236 | |
247 | |
237 | Sets the allocation function to use (the prototype is similar - the |
248 | Sets the allocation function to use (the prototype is similar - the |
238 | semantics are identical to the C<realloc> C89/SuS/POSIX function). It is |
249 | semantics are identical to the C<realloc> C89/SuS/POSIX function). It is |
239 | used to allocate and free memory (no surprises here). If it returns zero |
250 | used to allocate and free memory (no surprises here). If it returns zero |
240 | when memory needs to be allocated (C<size != 0>), the library might abort |
251 | when memory needs to be allocated (C<size != 0>), the library might abort |
… | |
… | |
266 | } |
277 | } |
267 | |
278 | |
268 | ... |
279 | ... |
269 | ev_set_allocator (persistent_realloc); |
280 | ev_set_allocator (persistent_realloc); |
270 | |
281 | |
271 | =item ev_set_syserr_cb (void (*cb)(const char *msg)); [NOT REENTRANT] |
282 | =item ev_set_syserr_cb (void (*cb)(const char *msg)) |
272 | |
283 | |
273 | Set the callback function to call on a retryable system call error (such |
284 | Set the callback function to call on a retryable system call error (such |
274 | as failed select, poll, epoll_wait). The message is a printable string |
285 | as failed select, poll, epoll_wait). The message is a printable string |
275 | indicating the system call or subsystem causing the problem. If this |
286 | indicating the system call or subsystem causing the problem. If this |
276 | callback is set, then libev will expect it to remedy the situation, no |
287 | callback is set, then libev will expect it to remedy the situation, no |
… | |
… | |
290 | ... |
301 | ... |
291 | ev_set_syserr_cb (fatal_error); |
302 | ev_set_syserr_cb (fatal_error); |
292 | |
303 | |
293 | =back |
304 | =back |
294 | |
305 | |
295 | =head1 FUNCTIONS CONTROLLING THE EVENT LOOP |
306 | =head1 FUNCTIONS CONTROLLING EVENT LOOPS |
296 | |
307 | |
297 | An event loop is described by a C<struct ev_loop *> (the C<struct> |
308 | An event loop is described by a C<struct ev_loop *> (the C<struct> is |
298 | is I<not> optional in this case, as there is also an C<ev_loop> |
309 | I<not> optional in this case unless libev 3 compatibility is disabled, as |
299 | I<function>). |
310 | libev 3 had an C<ev_loop> function colliding with the struct name). |
300 | |
311 | |
301 | The library knows two types of such loops, the I<default> loop, which |
312 | The library knows two types of such loops, the I<default> loop, which |
302 | supports signals and child events, and dynamically created loops which do |
313 | supports child process events, and dynamically created event loops which |
303 | not. |
314 | do not. |
304 | |
315 | |
305 | =over 4 |
316 | =over 4 |
306 | |
317 | |
307 | =item struct ev_loop *ev_default_loop (unsigned int flags) |
318 | =item struct ev_loop *ev_default_loop (unsigned int flags) |
308 | |
319 | |
309 | This will initialise the default event loop if it hasn't been initialised |
320 | This returns the "default" event loop object, which is what you should |
310 | yet and return it. If the default loop could not be initialised, returns |
321 | normally use when you just need "the event loop". Event loop objects and |
311 | false. If it already was initialised it simply returns it (and ignores the |
322 | the C<flags> parameter are described in more detail in the entry for |
312 | flags. If that is troubling you, check C<ev_backend ()> afterwards). |
323 | C<ev_loop_new>. |
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324 | |
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325 | If the default loop is already initialised then this function simply |
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326 | returns it (and ignores the flags. If that is troubling you, check |
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327 | C<ev_backend ()> afterwards). Otherwise it will create it with the given |
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328 | flags, which should almost always be C<0>, unless the caller is also the |
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329 | one calling C<ev_run> or otherwise qualifies as "the main program". |
313 | |
330 | |
314 | If you don't know what event loop to use, use the one returned from this |
331 | If you don't know what event loop to use, use the one returned from this |
315 | function. |
332 | function (or via the C<EV_DEFAULT> macro). |
316 | |
333 | |
317 | Note that this function is I<not> thread-safe, so if you want to use it |
334 | Note that this function is I<not> thread-safe, so if you want to use it |
318 | from multiple threads, you have to lock (note also that this is unlikely, |
335 | from multiple threads, you have to employ some kind of mutex (note also |
319 | as loops cannot be shared easily between threads anyway). |
336 | that this case is unlikely, as loops cannot be shared easily between |
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337 | threads anyway). |
320 | |
338 | |
321 | The default loop is the only loop that can handle C<ev_signal> and |
339 | The default loop is the only loop that can handle C<ev_child> watchers, |
322 | C<ev_child> watchers, and to do this, it always registers a handler |
340 | and to do this, it always registers a handler for C<SIGCHLD>. If this is |
323 | for C<SIGCHLD>. If this is a problem for your application you can either |
341 | a problem for your application you can either create a dynamic loop with |
324 | create a dynamic loop with C<ev_loop_new> that doesn't do that, or you |
342 | C<ev_loop_new> which doesn't do that, or you can simply overwrite the |
325 | can simply overwrite the C<SIGCHLD> signal handler I<after> calling |
343 | C<SIGCHLD> signal handler I<after> calling C<ev_default_init>. |
326 | C<ev_default_init>. |
344 | |
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345 | Example: This is the most typical usage. |
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346 | |
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347 | if (!ev_default_loop (0)) |
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348 | fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?"); |
|
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349 | |
|
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350 | Example: Restrict libev to the select and poll backends, and do not allow |
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351 | environment settings to be taken into account: |
|
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352 | |
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353 | ev_default_loop (EVBACKEND_POLL | EVBACKEND_SELECT | EVFLAG_NOENV); |
|
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354 | |
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355 | =item struct ev_loop *ev_loop_new (unsigned int flags) |
|
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356 | |
|
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357 | This will create and initialise a new event loop object. If the loop |
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358 | could not be initialised, returns false. |
|
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359 | |
|
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360 | This function is thread-safe, and one common way to use libev with |
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361 | threads is indeed to create one loop per thread, and using the default |
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362 | loop in the "main" or "initial" thread. |
327 | |
363 | |
328 | The flags argument can be used to specify special behaviour or specific |
364 | The flags argument can be used to specify special behaviour or specific |
329 | backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>). |
365 | backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>). |
330 | |
366 | |
331 | The following flags are supported: |
367 | The following flags are supported: |
… | |
… | |
366 | environment variable. |
402 | environment variable. |
367 | |
403 | |
368 | =item C<EVFLAG_NOINOTIFY> |
404 | =item C<EVFLAG_NOINOTIFY> |
369 | |
405 | |
370 | When this flag is specified, then libev will not attempt to use the |
406 | When this flag is specified, then libev will not attempt to use the |
371 | I<inotify> API for it's C<ev_stat> watchers. Apart from debugging and |
407 | I<inotify> API for its C<ev_stat> watchers. Apart from debugging and |
372 | testing, this flag can be useful to conserve inotify file descriptors, as |
408 | testing, this flag can be useful to conserve inotify file descriptors, as |
373 | otherwise each loop using C<ev_stat> watchers consumes one inotify handle. |
409 | otherwise each loop using C<ev_stat> watchers consumes one inotify handle. |
374 | |
410 | |
375 | =item C<EVFLAG_SIGNALFD> |
411 | =item C<EVFLAG_SIGNALFD> |
376 | |
412 | |
377 | When this flag is specified, then libev will attempt to use the |
413 | When this flag is specified, then libev will attempt to use the |
378 | I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This API |
414 | I<signalfd> API for its C<ev_signal> (and C<ev_child>) watchers. This API |
379 | delivers signals synchronously, which makes it both faster and might make |
415 | delivers signals synchronously, which makes it both faster and might make |
380 | it possible to get the queued signal data. It can also simplify signal |
416 | it possible to get the queued signal data. It can also simplify signal |
381 | handling with threads, as long as you properly block signals in your |
417 | handling with threads, as long as you properly block signals in your |
382 | threads that are not interested in handling them. |
418 | threads that are not interested in handling them. |
383 | |
419 | |
… | |
… | |
427 | epoll scales either O(1) or O(active_fds). |
463 | epoll scales either O(1) or O(active_fds). |
428 | |
464 | |
429 | The epoll mechanism deserves honorable mention as the most misdesigned |
465 | The epoll mechanism deserves honorable mention as the most misdesigned |
430 | of the more advanced event mechanisms: mere annoyances include silently |
466 | of the more advanced event mechanisms: mere annoyances include silently |
431 | dropping file descriptors, requiring a system call per change per file |
467 | dropping file descriptors, requiring a system call per change per file |
432 | descriptor (and unnecessary guessing of parameters), problems with dup and |
468 | descriptor (and unnecessary guessing of parameters), problems with dup, |
|
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469 | returning before the timeout value, resulting in additional iterations |
|
|
470 | (and only giving 5ms accuracy while select on the same platform gives |
433 | so on. The biggest issue is fork races, however - if a program forks then |
471 | 0.1ms) and so on. The biggest issue is fork races, however - if a program |
434 | I<both> parent and child process have to recreate the epoll set, which can |
472 | forks then I<both> parent and child process have to recreate the epoll |
435 | take considerable time (one syscall per file descriptor) and is of course |
473 | set, which can take considerable time (one syscall per file descriptor) |
436 | hard to detect. |
474 | and is of course hard to detect. |
437 | |
475 | |
438 | Epoll is also notoriously buggy - embedding epoll fds I<should> work, but |
476 | Epoll is also notoriously buggy - embedding epoll fds I<should> work, but |
439 | of course I<doesn't>, and epoll just loves to report events for totally |
477 | of course I<doesn't>, and epoll just loves to report events for totally |
440 | I<different> file descriptors (even already closed ones, so one cannot |
478 | I<different> file descriptors (even already closed ones, so one cannot |
441 | even remove them from the set) than registered in the set (especially |
479 | even remove them from the set) than registered in the set (especially |
… | |
… | |
443 | employing an additional generation counter and comparing that against the |
481 | employing an additional generation counter and comparing that against the |
444 | events to filter out spurious ones, recreating the set when required. Last |
482 | events to filter out spurious ones, recreating the set when required. Last |
445 | not least, it also refuses to work with some file descriptors which work |
483 | not least, it also refuses to work with some file descriptors which work |
446 | perfectly fine with C<select> (files, many character devices...). |
484 | perfectly fine with C<select> (files, many character devices...). |
447 | |
485 | |
|
|
486 | Epoll is truly the train wreck analog among event poll mechanisms. |
|
|
487 | |
448 | While stopping, setting and starting an I/O watcher in the same iteration |
488 | While stopping, setting and starting an I/O watcher in the same iteration |
449 | will result in some caching, there is still a system call per such |
489 | will result in some caching, there is still a system call per such |
450 | incident (because the same I<file descriptor> could point to a different |
490 | incident (because the same I<file descriptor> could point to a different |
451 | I<file description> now), so its best to avoid that. Also, C<dup ()>'ed |
491 | I<file description> now), so its best to avoid that. Also, C<dup ()>'ed |
452 | file descriptors might not work very well if you register events for both |
492 | file descriptors might not work very well if you register events for both |
… | |
… | |
549 | If one or more of the backend flags are or'ed into the flags value, |
589 | If one or more of the backend flags are or'ed into the flags value, |
550 | then only these backends will be tried (in the reverse order as listed |
590 | then only these backends will be tried (in the reverse order as listed |
551 | here). If none are specified, all backends in C<ev_recommended_backends |
591 | here). If none are specified, all backends in C<ev_recommended_backends |
552 | ()> will be tried. |
592 | ()> will be tried. |
553 | |
593 | |
554 | Example: This is the most typical usage. |
|
|
555 | |
|
|
556 | if (!ev_default_loop (0)) |
|
|
557 | fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?"); |
|
|
558 | |
|
|
559 | Example: Restrict libev to the select and poll backends, and do not allow |
|
|
560 | environment settings to be taken into account: |
|
|
561 | |
|
|
562 | ev_default_loop (EVBACKEND_POLL | EVBACKEND_SELECT | EVFLAG_NOENV); |
|
|
563 | |
|
|
564 | Example: Use whatever libev has to offer, but make sure that kqueue is |
|
|
565 | used if available (warning, breaks stuff, best use only with your own |
|
|
566 | private event loop and only if you know the OS supports your types of |
|
|
567 | fds): |
|
|
568 | |
|
|
569 | ev_default_loop (ev_recommended_backends () | EVBACKEND_KQUEUE); |
|
|
570 | |
|
|
571 | =item struct ev_loop *ev_loop_new (unsigned int flags) |
|
|
572 | |
|
|
573 | Similar to C<ev_default_loop>, but always creates a new event loop that is |
|
|
574 | always distinct from the default loop. |
|
|
575 | |
|
|
576 | Note that this function I<is> thread-safe, and one common way to use |
|
|
577 | libev with threads is indeed to create one loop per thread, and using the |
|
|
578 | default loop in the "main" or "initial" thread. |
|
|
579 | |
|
|
580 | Example: Try to create a event loop that uses epoll and nothing else. |
594 | Example: Try to create a event loop that uses epoll and nothing else. |
581 | |
595 | |
582 | struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
596 | struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
583 | if (!epoller) |
597 | if (!epoller) |
584 | fatal ("no epoll found here, maybe it hides under your chair"); |
598 | fatal ("no epoll found here, maybe it hides under your chair"); |
585 | |
599 | |
|
|
600 | Example: Use whatever libev has to offer, but make sure that kqueue is |
|
|
601 | used if available. |
|
|
602 | |
|
|
603 | struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_KQUEUE); |
|
|
604 | |
586 | =item ev_default_destroy () |
605 | =item ev_loop_destroy (loop) |
587 | |
606 | |
588 | Destroys the default loop (frees all memory and kernel state etc.). None |
607 | Destroys an event loop object (frees all memory and kernel state |
589 | of the active event watchers will be stopped in the normal sense, so |
608 | etc.). None of the active event watchers will be stopped in the normal |
590 | e.g. C<ev_is_active> might still return true. It is your responsibility to |
609 | sense, so e.g. C<ev_is_active> might still return true. It is your |
591 | either stop all watchers cleanly yourself I<before> calling this function, |
610 | responsibility to either stop all watchers cleanly yourself I<before> |
592 | or cope with the fact afterwards (which is usually the easiest thing, you |
611 | calling this function, or cope with the fact afterwards (which is usually |
593 | can just ignore the watchers and/or C<free ()> them for example). |
612 | the easiest thing, you can just ignore the watchers and/or C<free ()> them |
|
|
613 | for example). |
594 | |
614 | |
595 | Note that certain global state, such as signal state (and installed signal |
615 | Note that certain global state, such as signal state (and installed signal |
596 | handlers), will not be freed by this function, and related watchers (such |
616 | handlers), will not be freed by this function, and related watchers (such |
597 | as signal and child watchers) would need to be stopped manually. |
617 | as signal and child watchers) would need to be stopped manually. |
598 | |
618 | |
599 | In general it is not advisable to call this function except in the |
619 | This function is normally used on loop objects allocated by |
600 | rare occasion where you really need to free e.g. the signal handling |
620 | C<ev_loop_new>, but it can also be used on the default loop returned by |
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|
621 | C<ev_default_loop>, in which case it is not thread-safe. |
|
|
622 | |
|
|
623 | Note that it is not advisable to call this function on the default loop |
|
|
624 | except in the rare occasion where you really need to free its resources. |
601 | pipe fds. If you need dynamically allocated loops it is better to use |
625 | If you need dynamically allocated loops it is better to use C<ev_loop_new> |
602 | C<ev_loop_new> and C<ev_loop_destroy>. |
626 | and C<ev_loop_destroy>. |
603 | |
627 | |
604 | =item ev_loop_destroy (loop) |
628 | =item ev_loop_fork (loop) |
605 | |
629 | |
606 | Like C<ev_default_destroy>, but destroys an event loop created by an |
|
|
607 | earlier call to C<ev_loop_new>. |
|
|
608 | |
|
|
609 | =item ev_default_fork () |
|
|
610 | |
|
|
611 | This function sets a flag that causes subsequent C<ev_loop> iterations |
630 | This function sets a flag that causes subsequent C<ev_run> iterations to |
612 | to reinitialise the kernel state for backends that have one. Despite the |
631 | reinitialise the kernel state for backends that have one. Despite the |
613 | name, you can call it anytime, but it makes most sense after forking, in |
632 | name, you can call it anytime, but it makes most sense after forking, in |
614 | the child process (or both child and parent, but that again makes little |
633 | the child process. You I<must> call it (or use C<EVFLAG_FORKCHECK>) in the |
615 | sense). You I<must> call it in the child before using any of the libev |
634 | child before resuming or calling C<ev_run>. |
616 | functions, and it will only take effect at the next C<ev_loop> iteration. |
|
|
617 | |
635 | |
618 | Again, you I<have> to call it on I<any> loop that you want to re-use after |
636 | Again, you I<have> to call it on I<any> loop that you want to re-use after |
619 | a fork, I<even if you do not plan to use the loop in the parent>. This is |
637 | a fork, I<even if you do not plan to use the loop in the parent>. This is |
620 | because some kernel interfaces *cough* I<kqueue> *cough* do funny things |
638 | because some kernel interfaces *cough* I<kqueue> *cough* do funny things |
621 | during fork. |
639 | during fork. |
622 | |
640 | |
623 | On the other hand, you only need to call this function in the child |
641 | On the other hand, you only need to call this function in the child |
624 | process if and only if you want to use the event loop in the child. If you |
642 | process if and only if you want to use the event loop in the child. If |
625 | just fork+exec or create a new loop in the child, you don't have to call |
643 | you just fork+exec or create a new loop in the child, you don't have to |
626 | it at all. |
644 | call it at all (in fact, C<epoll> is so badly broken that it makes a |
|
|
645 | difference, but libev will usually detect this case on its own and do a |
|
|
646 | costly reset of the backend). |
627 | |
647 | |
628 | The function itself is quite fast and it's usually not a problem to call |
648 | The function itself is quite fast and it's usually not a problem to call |
629 | it just in case after a fork. To make this easy, the function will fit in |
649 | it just in case after a fork. |
630 | quite nicely into a call to C<pthread_atfork>: |
|
|
631 | |
650 | |
|
|
651 | Example: Automate calling C<ev_loop_fork> on the default loop when |
|
|
652 | using pthreads. |
|
|
653 | |
|
|
654 | static void |
|
|
655 | post_fork_child (void) |
|
|
656 | { |
|
|
657 | ev_loop_fork (EV_DEFAULT); |
|
|
658 | } |
|
|
659 | |
|
|
660 | ... |
632 | pthread_atfork (0, 0, ev_default_fork); |
661 | pthread_atfork (0, 0, post_fork_child); |
633 | |
|
|
634 | =item ev_loop_fork (loop) |
|
|
635 | |
|
|
636 | Like C<ev_default_fork>, but acts on an event loop created by |
|
|
637 | C<ev_loop_new>. Yes, you have to call this on every allocated event loop |
|
|
638 | after fork that you want to re-use in the child, and how you keep track of |
|
|
639 | them is entirely your own problem. |
|
|
640 | |
662 | |
641 | =item int ev_is_default_loop (loop) |
663 | =item int ev_is_default_loop (loop) |
642 | |
664 | |
643 | Returns true when the given loop is, in fact, the default loop, and false |
665 | Returns true when the given loop is, in fact, the default loop, and false |
644 | otherwise. |
666 | otherwise. |
645 | |
667 | |
646 | =item unsigned int ev_iteration (loop) |
668 | =item unsigned int ev_iteration (loop) |
647 | |
669 | |
648 | Returns the current iteration count for the loop, which is identical to |
670 | Returns the current iteration count for the event loop, which is identical |
649 | the number of times libev did poll for new events. It starts at C<0> and |
671 | to the number of times libev did poll for new events. It starts at C<0> |
650 | happily wraps around with enough iterations. |
672 | and happily wraps around with enough iterations. |
651 | |
673 | |
652 | This value can sometimes be useful as a generation counter of sorts (it |
674 | This value can sometimes be useful as a generation counter of sorts (it |
653 | "ticks" the number of loop iterations), as it roughly corresponds with |
675 | "ticks" the number of loop iterations), as it roughly corresponds with |
654 | C<ev_prepare> and C<ev_check> calls - and is incremented between the |
676 | C<ev_prepare> and C<ev_check> calls - and is incremented between the |
655 | prepare and check phases. |
677 | prepare and check phases. |
656 | |
678 | |
657 | =item unsigned int ev_depth (loop) |
679 | =item unsigned int ev_depth (loop) |
658 | |
680 | |
659 | Returns the number of times C<ev_loop> was entered minus the number of |
681 | Returns the number of times C<ev_run> was entered minus the number of |
660 | times C<ev_loop> was exited, in other words, the recursion depth. |
682 | times C<ev_run> was exited normally, in other words, the recursion depth. |
661 | |
683 | |
662 | Outside C<ev_loop>, this number is zero. In a callback, this number is |
684 | Outside C<ev_run>, this number is zero. In a callback, this number is |
663 | C<1>, unless C<ev_loop> was invoked recursively (or from another thread), |
685 | C<1>, unless C<ev_run> was invoked recursively (or from another thread), |
664 | in which case it is higher. |
686 | in which case it is higher. |
665 | |
687 | |
666 | Leaving C<ev_loop> abnormally (setjmp/longjmp, cancelling the thread |
688 | Leaving C<ev_run> abnormally (setjmp/longjmp, cancelling the thread, |
667 | etc.), doesn't count as "exit" - consider this as a hint to avoid such |
689 | throwing an exception etc.), doesn't count as "exit" - consider this |
668 | ungentleman behaviour unless it's really convenient. |
690 | as a hint to avoid such ungentleman-like behaviour unless it's really |
|
|
691 | convenient, in which case it is fully supported. |
669 | |
692 | |
670 | =item unsigned int ev_backend (loop) |
693 | =item unsigned int ev_backend (loop) |
671 | |
694 | |
672 | Returns one of the C<EVBACKEND_*> flags indicating the event backend in |
695 | Returns one of the C<EVBACKEND_*> flags indicating the event backend in |
673 | use. |
696 | use. |
… | |
… | |
682 | |
705 | |
683 | =item ev_now_update (loop) |
706 | =item ev_now_update (loop) |
684 | |
707 | |
685 | Establishes the current time by querying the kernel, updating the time |
708 | Establishes the current time by querying the kernel, updating the time |
686 | returned by C<ev_now ()> in the progress. This is a costly operation and |
709 | returned by C<ev_now ()> in the progress. This is a costly operation and |
687 | is usually done automatically within C<ev_loop ()>. |
710 | is usually done automatically within C<ev_run ()>. |
688 | |
711 | |
689 | This function is rarely useful, but when some event callback runs for a |
712 | This function is rarely useful, but when some event callback runs for a |
690 | very long time without entering the event loop, updating libev's idea of |
713 | very long time without entering the event loop, updating libev's idea of |
691 | the current time is a good idea. |
714 | the current time is a good idea. |
692 | |
715 | |
… | |
… | |
694 | |
717 | |
695 | =item ev_suspend (loop) |
718 | =item ev_suspend (loop) |
696 | |
719 | |
697 | =item ev_resume (loop) |
720 | =item ev_resume (loop) |
698 | |
721 | |
699 | These two functions suspend and resume a loop, for use when the loop is |
722 | These two functions suspend and resume an event loop, for use when the |
700 | not used for a while and timeouts should not be processed. |
723 | loop is not used for a while and timeouts should not be processed. |
701 | |
724 | |
702 | A typical use case would be an interactive program such as a game: When |
725 | A typical use case would be an interactive program such as a game: When |
703 | the user presses C<^Z> to suspend the game and resumes it an hour later it |
726 | the user presses C<^Z> to suspend the game and resumes it an hour later it |
704 | would be best to handle timeouts as if no time had actually passed while |
727 | would be best to handle timeouts as if no time had actually passed while |
705 | the program was suspended. This can be achieved by calling C<ev_suspend> |
728 | the program was suspended. This can be achieved by calling C<ev_suspend> |
… | |
… | |
716 | without a previous call to C<ev_suspend>. |
739 | without a previous call to C<ev_suspend>. |
717 | |
740 | |
718 | Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the |
741 | Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the |
719 | event loop time (see C<ev_now_update>). |
742 | event loop time (see C<ev_now_update>). |
720 | |
743 | |
721 | =item ev_loop (loop, int flags) |
744 | =item ev_run (loop, int flags) |
722 | |
745 | |
723 | Finally, this is it, the event handler. This function usually is called |
746 | Finally, this is it, the event handler. This function usually is called |
724 | after you have initialised all your watchers and you want to start |
747 | after you have initialised all your watchers and you want to start |
725 | handling events. |
748 | handling events. It will ask the operating system for any new events, call |
|
|
749 | the watcher callbacks, an then repeat the whole process indefinitely: This |
|
|
750 | is why event loops are called I<loops>. |
726 | |
751 | |
727 | If the flags argument is specified as C<0>, it will not return until |
752 | If the flags argument is specified as C<0>, it will keep handling events |
728 | either no event watchers are active anymore or C<ev_unloop> was called. |
753 | until either no event watchers are active anymore or C<ev_break> was |
|
|
754 | called. |
729 | |
755 | |
730 | Please note that an explicit C<ev_unloop> is usually better than |
756 | Please note that an explicit C<ev_break> is usually better than |
731 | relying on all watchers to be stopped when deciding when a program has |
757 | relying on all watchers to be stopped when deciding when a program has |
732 | finished (especially in interactive programs), but having a program |
758 | finished (especially in interactive programs), but having a program |
733 | that automatically loops as long as it has to and no longer by virtue |
759 | that automatically loops as long as it has to and no longer by virtue |
734 | of relying on its watchers stopping correctly, that is truly a thing of |
760 | of relying on its watchers stopping correctly, that is truly a thing of |
735 | beauty. |
761 | beauty. |
736 | |
762 | |
|
|
763 | This function is also I<mostly> exception-safe - you can break out of |
|
|
764 | a C<ev_run> call by calling C<longjmp> in a callback, throwing a C++ |
|
|
765 | exception and so on. This does not decrement the C<ev_depth> value, nor |
|
|
766 | will it clear any outstanding C<EVBREAK_ONE> breaks. |
|
|
767 | |
737 | A flags value of C<EVLOOP_NONBLOCK> will look for new events, will handle |
768 | A flags value of C<EVRUN_NOWAIT> will look for new events, will handle |
738 | those events and any already outstanding ones, but will not block your |
769 | those events and any already outstanding ones, but will not wait and |
739 | process in case there are no events and will return after one iteration of |
770 | block your process in case there are no events and will return after one |
740 | the loop. |
771 | iteration of the loop. This is sometimes useful to poll and handle new |
|
|
772 | events while doing lengthy calculations, to keep the program responsive. |
741 | |
773 | |
742 | A flags value of C<EVLOOP_ONESHOT> will look for new events (waiting if |
774 | A flags value of C<EVRUN_ONCE> will look for new events (waiting if |
743 | necessary) and will handle those and any already outstanding ones. It |
775 | necessary) and will handle those and any already outstanding ones. It |
744 | will block your process until at least one new event arrives (which could |
776 | will block your process until at least one new event arrives (which could |
745 | be an event internal to libev itself, so there is no guarantee that a |
777 | be an event internal to libev itself, so there is no guarantee that a |
746 | user-registered callback will be called), and will return after one |
778 | user-registered callback will be called), and will return after one |
747 | iteration of the loop. |
779 | iteration of the loop. |
748 | |
780 | |
749 | This is useful if you are waiting for some external event in conjunction |
781 | This is useful if you are waiting for some external event in conjunction |
750 | with something not expressible using other libev watchers (i.e. "roll your |
782 | with something not expressible using other libev watchers (i.e. "roll your |
751 | own C<ev_loop>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is |
783 | own C<ev_run>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is |
752 | usually a better approach for this kind of thing. |
784 | usually a better approach for this kind of thing. |
753 | |
785 | |
754 | Here are the gory details of what C<ev_loop> does: |
786 | Here are the gory details of what C<ev_run> does: |
755 | |
787 | |
|
|
788 | - Increment loop depth. |
|
|
789 | - Reset the ev_break status. |
756 | - Before the first iteration, call any pending watchers. |
790 | - Before the first iteration, call any pending watchers. |
|
|
791 | LOOP: |
757 | * If EVFLAG_FORKCHECK was used, check for a fork. |
792 | - If EVFLAG_FORKCHECK was used, check for a fork. |
758 | - If a fork was detected (by any means), queue and call all fork watchers. |
793 | - If a fork was detected (by any means), queue and call all fork watchers. |
759 | - Queue and call all prepare watchers. |
794 | - Queue and call all prepare watchers. |
|
|
795 | - If ev_break was called, goto FINISH. |
760 | - If we have been forked, detach and recreate the kernel state |
796 | - If we have been forked, detach and recreate the kernel state |
761 | as to not disturb the other process. |
797 | as to not disturb the other process. |
762 | - Update the kernel state with all outstanding changes. |
798 | - Update the kernel state with all outstanding changes. |
763 | - Update the "event loop time" (ev_now ()). |
799 | - Update the "event loop time" (ev_now ()). |
764 | - Calculate for how long to sleep or block, if at all |
800 | - Calculate for how long to sleep or block, if at all |
765 | (active idle watchers, EVLOOP_NONBLOCK or not having |
801 | (active idle watchers, EVRUN_NOWAIT or not having |
766 | any active watchers at all will result in not sleeping). |
802 | any active watchers at all will result in not sleeping). |
767 | - Sleep if the I/O and timer collect interval say so. |
803 | - Sleep if the I/O and timer collect interval say so. |
|
|
804 | - Increment loop iteration counter. |
768 | - Block the process, waiting for any events. |
805 | - Block the process, waiting for any events. |
769 | - Queue all outstanding I/O (fd) events. |
806 | - Queue all outstanding I/O (fd) events. |
770 | - Update the "event loop time" (ev_now ()), and do time jump adjustments. |
807 | - Update the "event loop time" (ev_now ()), and do time jump adjustments. |
771 | - Queue all expired timers. |
808 | - Queue all expired timers. |
772 | - Queue all expired periodics. |
809 | - Queue all expired periodics. |
773 | - Unless any events are pending now, queue all idle watchers. |
810 | - Queue all idle watchers with priority higher than that of pending events. |
774 | - Queue all check watchers. |
811 | - Queue all check watchers. |
775 | - Call all queued watchers in reverse order (i.e. check watchers first). |
812 | - Call all queued watchers in reverse order (i.e. check watchers first). |
776 | Signals and child watchers are implemented as I/O watchers, and will |
813 | Signals and child watchers are implemented as I/O watchers, and will |
777 | be handled here by queueing them when their watcher gets executed. |
814 | be handled here by queueing them when their watcher gets executed. |
778 | - If ev_unloop has been called, or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
815 | - If ev_break has been called, or EVRUN_ONCE or EVRUN_NOWAIT |
779 | were used, or there are no active watchers, return, otherwise |
816 | were used, or there are no active watchers, goto FINISH, otherwise |
780 | continue with step *. |
817 | continue with step LOOP. |
|
|
818 | FINISH: |
|
|
819 | - Reset the ev_break status iff it was EVBREAK_ONE. |
|
|
820 | - Decrement the loop depth. |
|
|
821 | - Return. |
781 | |
822 | |
782 | Example: Queue some jobs and then loop until no events are outstanding |
823 | Example: Queue some jobs and then loop until no events are outstanding |
783 | anymore. |
824 | anymore. |
784 | |
825 | |
785 | ... queue jobs here, make sure they register event watchers as long |
826 | ... queue jobs here, make sure they register event watchers as long |
786 | ... as they still have work to do (even an idle watcher will do..) |
827 | ... as they still have work to do (even an idle watcher will do..) |
787 | ev_loop (my_loop, 0); |
828 | ev_run (my_loop, 0); |
788 | ... jobs done or somebody called unloop. yeah! |
829 | ... jobs done or somebody called unloop. yeah! |
789 | |
830 | |
790 | =item ev_unloop (loop, how) |
831 | =item ev_break (loop, how) |
791 | |
832 | |
792 | Can be used to make a call to C<ev_loop> return early (but only after it |
833 | Can be used to make a call to C<ev_run> return early (but only after it |
793 | has processed all outstanding events). The C<how> argument must be either |
834 | has processed all outstanding events). The C<how> argument must be either |
794 | C<EVUNLOOP_ONE>, which will make the innermost C<ev_loop> call return, or |
835 | C<EVBREAK_ONE>, which will make the innermost C<ev_run> call return, or |
795 | C<EVUNLOOP_ALL>, which will make all nested C<ev_loop> calls return. |
836 | C<EVBREAK_ALL>, which will make all nested C<ev_run> calls return. |
796 | |
837 | |
797 | This "unloop state" will be cleared when entering C<ev_loop> again. |
838 | This "break state" will be cleared on the next call to C<ev_run>. |
798 | |
839 | |
799 | It is safe to call C<ev_unloop> from outside any C<ev_loop> calls. |
840 | It is safe to call C<ev_break> from outside any C<ev_run> calls, too, in |
|
|
841 | which case it will have no effect. |
800 | |
842 | |
801 | =item ev_ref (loop) |
843 | =item ev_ref (loop) |
802 | |
844 | |
803 | =item ev_unref (loop) |
845 | =item ev_unref (loop) |
804 | |
846 | |
805 | Ref/unref can be used to add or remove a reference count on the event |
847 | Ref/unref can be used to add or remove a reference count on the event |
806 | loop: Every watcher keeps one reference, and as long as the reference |
848 | loop: Every watcher keeps one reference, and as long as the reference |
807 | count is nonzero, C<ev_loop> will not return on its own. |
849 | count is nonzero, C<ev_run> will not return on its own. |
808 | |
850 | |
809 | This is useful when you have a watcher that you never intend to |
851 | This is useful when you have a watcher that you never intend to |
810 | unregister, but that nevertheless should not keep C<ev_loop> from |
852 | unregister, but that nevertheless should not keep C<ev_run> from |
811 | returning. In such a case, call C<ev_unref> after starting, and C<ev_ref> |
853 | returning. In such a case, call C<ev_unref> after starting, and C<ev_ref> |
812 | before stopping it. |
854 | before stopping it. |
813 | |
855 | |
814 | As an example, libev itself uses this for its internal signal pipe: It |
856 | As an example, libev itself uses this for its internal signal pipe: It |
815 | is not visible to the libev user and should not keep C<ev_loop> from |
857 | is not visible to the libev user and should not keep C<ev_run> from |
816 | exiting if no event watchers registered by it are active. It is also an |
858 | exiting if no event watchers registered by it are active. It is also an |
817 | excellent way to do this for generic recurring timers or from within |
859 | excellent way to do this for generic recurring timers or from within |
818 | third-party libraries. Just remember to I<unref after start> and I<ref |
860 | third-party libraries. Just remember to I<unref after start> and I<ref |
819 | before stop> (but only if the watcher wasn't active before, or was active |
861 | before stop> (but only if the watcher wasn't active before, or was active |
820 | before, respectively. Note also that libev might stop watchers itself |
862 | before, respectively. Note also that libev might stop watchers itself |
821 | (e.g. non-repeating timers) in which case you have to C<ev_ref> |
863 | (e.g. non-repeating timers) in which case you have to C<ev_ref> |
822 | in the callback). |
864 | in the callback). |
823 | |
865 | |
824 | Example: Create a signal watcher, but keep it from keeping C<ev_loop> |
866 | Example: Create a signal watcher, but keep it from keeping C<ev_run> |
825 | running when nothing else is active. |
867 | running when nothing else is active. |
826 | |
868 | |
827 | ev_signal exitsig; |
869 | ev_signal exitsig; |
828 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
870 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
829 | ev_signal_start (loop, &exitsig); |
871 | ev_signal_start (loop, &exitsig); |
… | |
… | |
892 | ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01); |
934 | ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01); |
893 | |
935 | |
894 | =item ev_invoke_pending (loop) |
936 | =item ev_invoke_pending (loop) |
895 | |
937 | |
896 | This call will simply invoke all pending watchers while resetting their |
938 | This call will simply invoke all pending watchers while resetting their |
897 | pending state. Normally, C<ev_loop> does this automatically when required, |
939 | pending state. Normally, C<ev_run> does this automatically when required, |
898 | but when overriding the invoke callback this call comes handy. |
940 | but when overriding the invoke callback this call comes handy. This |
|
|
941 | function can be invoked from a watcher - this can be useful for example |
|
|
942 | when you want to do some lengthy calculation and want to pass further |
|
|
943 | event handling to another thread (you still have to make sure only one |
|
|
944 | thread executes within C<ev_invoke_pending> or C<ev_run> of course). |
899 | |
945 | |
900 | =item int ev_pending_count (loop) |
946 | =item int ev_pending_count (loop) |
901 | |
947 | |
902 | Returns the number of pending watchers - zero indicates that no watchers |
948 | Returns the number of pending watchers - zero indicates that no watchers |
903 | are pending. |
949 | are pending. |
904 | |
950 | |
905 | =item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P)) |
951 | =item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P)) |
906 | |
952 | |
907 | This overrides the invoke pending functionality of the loop: Instead of |
953 | This overrides the invoke pending functionality of the loop: Instead of |
908 | invoking all pending watchers when there are any, C<ev_loop> will call |
954 | invoking all pending watchers when there are any, C<ev_run> will call |
909 | this callback instead. This is useful, for example, when you want to |
955 | this callback instead. This is useful, for example, when you want to |
910 | invoke the actual watchers inside another context (another thread etc.). |
956 | invoke the actual watchers inside another context (another thread etc.). |
911 | |
957 | |
912 | If you want to reset the callback, use C<ev_invoke_pending> as new |
958 | If you want to reset the callback, use C<ev_invoke_pending> as new |
913 | callback. |
959 | callback. |
… | |
… | |
916 | |
962 | |
917 | Sometimes you want to share the same loop between multiple threads. This |
963 | Sometimes you want to share the same loop between multiple threads. This |
918 | can be done relatively simply by putting mutex_lock/unlock calls around |
964 | can be done relatively simply by putting mutex_lock/unlock calls around |
919 | each call to a libev function. |
965 | each call to a libev function. |
920 | |
966 | |
921 | However, C<ev_loop> can run an indefinite time, so it is not feasible to |
967 | However, C<ev_run> can run an indefinite time, so it is not feasible |
922 | wait for it to return. One way around this is to wake up the loop via |
968 | to wait for it to return. One way around this is to wake up the event |
923 | C<ev_unloop> and C<av_async_send>, another way is to set these I<release> |
969 | loop via C<ev_break> and C<av_async_send>, another way is to set these |
924 | and I<acquire> callbacks on the loop. |
970 | I<release> and I<acquire> callbacks on the loop. |
925 | |
971 | |
926 | When set, then C<release> will be called just before the thread is |
972 | When set, then C<release> will be called just before the thread is |
927 | suspended waiting for new events, and C<acquire> is called just |
973 | suspended waiting for new events, and C<acquire> is called just |
928 | afterwards. |
974 | afterwards. |
929 | |
975 | |
… | |
… | |
932 | |
978 | |
933 | While event loop modifications are allowed between invocations of |
979 | While event loop modifications are allowed between invocations of |
934 | C<release> and C<acquire> (that's their only purpose after all), no |
980 | C<release> and C<acquire> (that's their only purpose after all), no |
935 | modifications done will affect the event loop, i.e. adding watchers will |
981 | modifications done will affect the event loop, i.e. adding watchers will |
936 | have no effect on the set of file descriptors being watched, or the time |
982 | have no effect on the set of file descriptors being watched, or the time |
937 | waited. Use an C<ev_async> watcher to wake up C<ev_loop> when you want it |
983 | waited. Use an C<ev_async> watcher to wake up C<ev_run> when you want it |
938 | to take note of any changes you made. |
984 | to take note of any changes you made. |
939 | |
985 | |
940 | In theory, threads executing C<ev_loop> will be async-cancel safe between |
986 | In theory, threads executing C<ev_run> will be async-cancel safe between |
941 | invocations of C<release> and C<acquire>. |
987 | invocations of C<release> and C<acquire>. |
942 | |
988 | |
943 | See also the locking example in the C<THREADS> section later in this |
989 | See also the locking example in the C<THREADS> section later in this |
944 | document. |
990 | document. |
945 | |
991 | |
… | |
… | |
947 | |
993 | |
948 | =item ev_userdata (loop) |
994 | =item ev_userdata (loop) |
949 | |
995 | |
950 | Set and retrieve a single C<void *> associated with a loop. When |
996 | Set and retrieve a single C<void *> associated with a loop. When |
951 | C<ev_set_userdata> has never been called, then C<ev_userdata> returns |
997 | C<ev_set_userdata> has never been called, then C<ev_userdata> returns |
952 | C<0.> |
998 | C<0>. |
953 | |
999 | |
954 | These two functions can be used to associate arbitrary data with a loop, |
1000 | These two functions can be used to associate arbitrary data with a loop, |
955 | and are intended solely for the C<invoke_pending_cb>, C<release> and |
1001 | and are intended solely for the C<invoke_pending_cb>, C<release> and |
956 | C<acquire> callbacks described above, but of course can be (ab-)used for |
1002 | C<acquire> callbacks described above, but of course can be (ab-)used for |
957 | any other purpose as well. |
1003 | any other purpose as well. |
958 | |
1004 | |
959 | =item ev_loop_verify (loop) |
1005 | =item ev_verify (loop) |
960 | |
1006 | |
961 | This function only does something when C<EV_VERIFY> support has been |
1007 | This function only does something when C<EV_VERIFY> support has been |
962 | compiled in, which is the default for non-minimal builds. It tries to go |
1008 | compiled in, which is the default for non-minimal builds. It tries to go |
963 | through all internal structures and checks them for validity. If anything |
1009 | through all internal structures and checks them for validity. If anything |
964 | is found to be inconsistent, it will print an error message to standard |
1010 | is found to be inconsistent, it will print an error message to standard |
… | |
… | |
975 | |
1021 | |
976 | In the following description, uppercase C<TYPE> in names stands for the |
1022 | In the following description, uppercase C<TYPE> in names stands for the |
977 | watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer |
1023 | watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer |
978 | watchers and C<ev_io_start> for I/O watchers. |
1024 | watchers and C<ev_io_start> for I/O watchers. |
979 | |
1025 | |
980 | A watcher is a structure that you create and register to record your |
1026 | A watcher is an opaque structure that you allocate and register to record |
981 | interest in some event. For instance, if you want to wait for STDIN to |
1027 | your interest in some event. To make a concrete example, imagine you want |
982 | become readable, you would create an C<ev_io> watcher for that: |
1028 | to wait for STDIN to become readable, you would create an C<ev_io> watcher |
|
|
1029 | for that: |
983 | |
1030 | |
984 | static void my_cb (struct ev_loop *loop, ev_io *w, int revents) |
1031 | static void my_cb (struct ev_loop *loop, ev_io *w, int revents) |
985 | { |
1032 | { |
986 | ev_io_stop (w); |
1033 | ev_io_stop (w); |
987 | ev_unloop (loop, EVUNLOOP_ALL); |
1034 | ev_break (loop, EVBREAK_ALL); |
988 | } |
1035 | } |
989 | |
1036 | |
990 | struct ev_loop *loop = ev_default_loop (0); |
1037 | struct ev_loop *loop = ev_default_loop (0); |
991 | |
1038 | |
992 | ev_io stdin_watcher; |
1039 | ev_io stdin_watcher; |
993 | |
1040 | |
994 | ev_init (&stdin_watcher, my_cb); |
1041 | ev_init (&stdin_watcher, my_cb); |
995 | ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ); |
1042 | ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ); |
996 | ev_io_start (loop, &stdin_watcher); |
1043 | ev_io_start (loop, &stdin_watcher); |
997 | |
1044 | |
998 | ev_loop (loop, 0); |
1045 | ev_run (loop, 0); |
999 | |
1046 | |
1000 | As you can see, you are responsible for allocating the memory for your |
1047 | As you can see, you are responsible for allocating the memory for your |
1001 | watcher structures (and it is I<usually> a bad idea to do this on the |
1048 | watcher structures (and it is I<usually> a bad idea to do this on the |
1002 | stack). |
1049 | stack). |
1003 | |
1050 | |
1004 | Each watcher has an associated watcher structure (called C<struct ev_TYPE> |
1051 | Each watcher has an associated watcher structure (called C<struct ev_TYPE> |
1005 | or simply C<ev_TYPE>, as typedefs are provided for all watcher structs). |
1052 | or simply C<ev_TYPE>, as typedefs are provided for all watcher structs). |
1006 | |
1053 | |
1007 | Each watcher structure must be initialised by a call to C<ev_init |
1054 | Each watcher structure must be initialised by a call to C<ev_init (watcher |
1008 | (watcher *, callback)>, which expects a callback to be provided. This |
1055 | *, callback)>, which expects a callback to be provided. This callback is |
1009 | callback gets invoked each time the event occurs (or, in the case of I/O |
1056 | invoked each time the event occurs (or, in the case of I/O watchers, each |
1010 | watchers, each time the event loop detects that the file descriptor given |
1057 | time the event loop detects that the file descriptor given is readable |
1011 | is readable and/or writable). |
1058 | and/or writable). |
1012 | |
1059 | |
1013 | Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >> |
1060 | Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >> |
1014 | macro to configure it, with arguments specific to the watcher type. There |
1061 | macro to configure it, with arguments specific to the watcher type. There |
1015 | is also a macro to combine initialisation and setting in one call: C<< |
1062 | is also a macro to combine initialisation and setting in one call: C<< |
1016 | ev_TYPE_init (watcher *, callback, ...) >>. |
1063 | ev_TYPE_init (watcher *, callback, ...) >>. |
… | |
… | |
1067 | |
1114 | |
1068 | =item C<EV_PREPARE> |
1115 | =item C<EV_PREPARE> |
1069 | |
1116 | |
1070 | =item C<EV_CHECK> |
1117 | =item C<EV_CHECK> |
1071 | |
1118 | |
1072 | All C<ev_prepare> watchers are invoked just I<before> C<ev_loop> starts |
1119 | All C<ev_prepare> watchers are invoked just I<before> C<ev_run> starts |
1073 | to gather new events, and all C<ev_check> watchers are invoked just after |
1120 | to gather new events, and all C<ev_check> watchers are invoked just after |
1074 | C<ev_loop> has gathered them, but before it invokes any callbacks for any |
1121 | C<ev_run> has gathered them, but before it invokes any callbacks for any |
1075 | received events. Callbacks of both watcher types can start and stop as |
1122 | received events. Callbacks of both watcher types can start and stop as |
1076 | many watchers as they want, and all of them will be taken into account |
1123 | many watchers as they want, and all of them will be taken into account |
1077 | (for example, a C<ev_prepare> watcher might start an idle watcher to keep |
1124 | (for example, a C<ev_prepare> watcher might start an idle watcher to keep |
1078 | C<ev_loop> from blocking). |
1125 | C<ev_run> from blocking). |
1079 | |
1126 | |
1080 | =item C<EV_EMBED> |
1127 | =item C<EV_EMBED> |
1081 | |
1128 | |
1082 | The embedded event loop specified in the C<ev_embed> watcher needs attention. |
1129 | The embedded event loop specified in the C<ev_embed> watcher needs attention. |
1083 | |
1130 | |
1084 | =item C<EV_FORK> |
1131 | =item C<EV_FORK> |
1085 | |
1132 | |
1086 | The event loop has been resumed in the child process after fork (see |
1133 | The event loop has been resumed in the child process after fork (see |
1087 | C<ev_fork>). |
1134 | C<ev_fork>). |
|
|
1135 | |
|
|
1136 | =item C<EV_CLEANUP> |
|
|
1137 | |
|
|
1138 | The event loop is about to be destroyed (see C<ev_cleanup>). |
1088 | |
1139 | |
1089 | =item C<EV_ASYNC> |
1140 | =item C<EV_ASYNC> |
1090 | |
1141 | |
1091 | The given async watcher has been asynchronously notified (see C<ev_async>). |
1142 | The given async watcher has been asynchronously notified (see C<ev_async>). |
1092 | |
1143 | |
… | |
… | |
1264 | |
1315 | |
1265 | See also C<ev_feed_fd_event> and C<ev_feed_signal_event> for related |
1316 | See also C<ev_feed_fd_event> and C<ev_feed_signal_event> for related |
1266 | functions that do not need a watcher. |
1317 | functions that do not need a watcher. |
1267 | |
1318 | |
1268 | =back |
1319 | =back |
1269 | |
|
|
1270 | |
1320 | |
1271 | =head2 ASSOCIATING CUSTOM DATA WITH A WATCHER |
1321 | =head2 ASSOCIATING CUSTOM DATA WITH A WATCHER |
1272 | |
1322 | |
1273 | Each watcher has, by default, a member C<void *data> that you can change |
1323 | Each watcher has, by default, a member C<void *data> that you can change |
1274 | and read at any time: libev will completely ignore it. This can be used |
1324 | and read at any time: libev will completely ignore it. This can be used |
… | |
… | |
1330 | t2_cb (EV_P_ ev_timer *w, int revents) |
1380 | t2_cb (EV_P_ ev_timer *w, int revents) |
1331 | { |
1381 | { |
1332 | struct my_biggy big = (struct my_biggy *) |
1382 | struct my_biggy big = (struct my_biggy *) |
1333 | (((char *)w) - offsetof (struct my_biggy, t2)); |
1383 | (((char *)w) - offsetof (struct my_biggy, t2)); |
1334 | } |
1384 | } |
|
|
1385 | |
|
|
1386 | =head2 WATCHER STATES |
|
|
1387 | |
|
|
1388 | There are various watcher states mentioned throughout this manual - |
|
|
1389 | active, pending and so on. In this section these states and the rules to |
|
|
1390 | transition between them will be described in more detail - and while these |
|
|
1391 | rules might look complicated, they usually do "the right thing". |
|
|
1392 | |
|
|
1393 | =over 4 |
|
|
1394 | |
|
|
1395 | =item initialiased |
|
|
1396 | |
|
|
1397 | Before a watcher can be registered with the event looop it has to be |
|
|
1398 | initialised. This can be done with a call to C<ev_TYPE_init>, or calls to |
|
|
1399 | C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function. |
|
|
1400 | |
|
|
1401 | In this state it is simply some block of memory that is suitable for use |
|
|
1402 | in an event loop. It can be moved around, freed, reused etc. at will. |
|
|
1403 | |
|
|
1404 | =item started/running/active |
|
|
1405 | |
|
|
1406 | Once a watcher has been started with a call to C<ev_TYPE_start> it becomes |
|
|
1407 | property of the event loop, and is actively waiting for events. While in |
|
|
1408 | this state it cannot be accessed (except in a few documented ways), moved, |
|
|
1409 | freed or anything else - the only legal thing is to keep a pointer to it, |
|
|
1410 | and call libev functions on it that are documented to work on active watchers. |
|
|
1411 | |
|
|
1412 | =item pending |
|
|
1413 | |
|
|
1414 | If a watcher is active and libev determines that an event it is interested |
|
|
1415 | in has occurred (such as a timer expiring), it will become pending. It will |
|
|
1416 | stay in this pending state until either it is stopped or its callback is |
|
|
1417 | about to be invoked, so it is not normally pending inside the watcher |
|
|
1418 | callback. |
|
|
1419 | |
|
|
1420 | The watcher might or might not be active while it is pending (for example, |
|
|
1421 | an expired non-repeating timer can be pending but no longer active). If it |
|
|
1422 | is stopped, it can be freely accessed (e.g. by calling C<ev_TYPE_set>), |
|
|
1423 | but it is still property of the event loop at this time, so cannot be |
|
|
1424 | moved, freed or reused. And if it is active the rules described in the |
|
|
1425 | previous item still apply. |
|
|
1426 | |
|
|
1427 | It is also possible to feed an event on a watcher that is not active (e.g. |
|
|
1428 | via C<ev_feed_event>), in which case it becomes pending without being |
|
|
1429 | active. |
|
|
1430 | |
|
|
1431 | =item stopped |
|
|
1432 | |
|
|
1433 | A watcher can be stopped implicitly by libev (in which case it might still |
|
|
1434 | be pending), or explicitly by calling its C<ev_TYPE_stop> function. The |
|
|
1435 | latter will clear any pending state the watcher might be in, regardless |
|
|
1436 | of whether it was active or not, so stopping a watcher explicitly before |
|
|
1437 | freeing it is often a good idea. |
|
|
1438 | |
|
|
1439 | While stopped (and not pending) the watcher is essentially in the |
|
|
1440 | initialised state, that is it can be reused, moved, modified in any way |
|
|
1441 | you wish. |
|
|
1442 | |
|
|
1443 | =back |
1335 | |
1444 | |
1336 | =head2 WATCHER PRIORITY MODELS |
1445 | =head2 WATCHER PRIORITY MODELS |
1337 | |
1446 | |
1338 | Many event loops support I<watcher priorities>, which are usually small |
1447 | Many event loops support I<watcher priorities>, which are usually small |
1339 | integers that influence the ordering of event callback invocation |
1448 | integers that influence the ordering of event callback invocation |
… | |
… | |
1624 | ... |
1733 | ... |
1625 | struct ev_loop *loop = ev_default_init (0); |
1734 | struct ev_loop *loop = ev_default_init (0); |
1626 | ev_io stdin_readable; |
1735 | ev_io stdin_readable; |
1627 | ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ); |
1736 | ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ); |
1628 | ev_io_start (loop, &stdin_readable); |
1737 | ev_io_start (loop, &stdin_readable); |
1629 | ev_loop (loop, 0); |
1738 | ev_run (loop, 0); |
1630 | |
1739 | |
1631 | |
1740 | |
1632 | =head2 C<ev_timer> - relative and optionally repeating timeouts |
1741 | =head2 C<ev_timer> - relative and optionally repeating timeouts |
1633 | |
1742 | |
1634 | Timer watchers are simple relative timers that generate an event after a |
1743 | Timer watchers are simple relative timers that generate an event after a |
… | |
… | |
1643 | The callback is guaranteed to be invoked only I<after> its timeout has |
1752 | The callback is guaranteed to be invoked only I<after> its timeout has |
1644 | passed (not I<at>, so on systems with very low-resolution clocks this |
1753 | passed (not I<at>, so on systems with very low-resolution clocks this |
1645 | might introduce a small delay). If multiple timers become ready during the |
1754 | might introduce a small delay). If multiple timers become ready during the |
1646 | same loop iteration then the ones with earlier time-out values are invoked |
1755 | same loop iteration then the ones with earlier time-out values are invoked |
1647 | before ones of the same priority with later time-out values (but this is |
1756 | before ones of the same priority with later time-out values (but this is |
1648 | no longer true when a callback calls C<ev_loop> recursively). |
1757 | no longer true when a callback calls C<ev_run> recursively). |
1649 | |
1758 | |
1650 | =head3 Be smart about timeouts |
1759 | =head3 Be smart about timeouts |
1651 | |
1760 | |
1652 | Many real-world problems involve some kind of timeout, usually for error |
1761 | Many real-world problems involve some kind of timeout, usually for error |
1653 | recovery. A typical example is an HTTP request - if the other side hangs, |
1762 | recovery. A typical example is an HTTP request - if the other side hangs, |
… | |
… | |
1824 | |
1933 | |
1825 | =head3 The special problem of time updates |
1934 | =head3 The special problem of time updates |
1826 | |
1935 | |
1827 | Establishing the current time is a costly operation (it usually takes at |
1936 | Establishing the current time is a costly operation (it usually takes at |
1828 | least two system calls): EV therefore updates its idea of the current |
1937 | least two system calls): EV therefore updates its idea of the current |
1829 | time only before and after C<ev_loop> collects new events, which causes a |
1938 | time only before and after C<ev_run> collects new events, which causes a |
1830 | growing difference between C<ev_now ()> and C<ev_time ()> when handling |
1939 | growing difference between C<ev_now ()> and C<ev_time ()> when handling |
1831 | lots of events in one iteration. |
1940 | lots of events in one iteration. |
1832 | |
1941 | |
1833 | The relative timeouts are calculated relative to the C<ev_now ()> |
1942 | The relative timeouts are calculated relative to the C<ev_now ()> |
1834 | time. This is usually the right thing as this timestamp refers to the time |
1943 | time. This is usually the right thing as this timestamp refers to the time |
… | |
… | |
1951 | } |
2060 | } |
1952 | |
2061 | |
1953 | ev_timer mytimer; |
2062 | ev_timer mytimer; |
1954 | ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */ |
2063 | ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */ |
1955 | ev_timer_again (&mytimer); /* start timer */ |
2064 | ev_timer_again (&mytimer); /* start timer */ |
1956 | ev_loop (loop, 0); |
2065 | ev_run (loop, 0); |
1957 | |
2066 | |
1958 | // and in some piece of code that gets executed on any "activity": |
2067 | // and in some piece of code that gets executed on any "activity": |
1959 | // reset the timeout to start ticking again at 10 seconds |
2068 | // reset the timeout to start ticking again at 10 seconds |
1960 | ev_timer_again (&mytimer); |
2069 | ev_timer_again (&mytimer); |
1961 | |
2070 | |
… | |
… | |
1987 | |
2096 | |
1988 | As with timers, the callback is guaranteed to be invoked only when the |
2097 | As with timers, the callback is guaranteed to be invoked only when the |
1989 | point in time where it is supposed to trigger has passed. If multiple |
2098 | point in time where it is supposed to trigger has passed. If multiple |
1990 | timers become ready during the same loop iteration then the ones with |
2099 | timers become ready during the same loop iteration then the ones with |
1991 | earlier time-out values are invoked before ones with later time-out values |
2100 | earlier time-out values are invoked before ones with later time-out values |
1992 | (but this is no longer true when a callback calls C<ev_loop> recursively). |
2101 | (but this is no longer true when a callback calls C<ev_run> recursively). |
1993 | |
2102 | |
1994 | =head3 Watcher-Specific Functions and Data Members |
2103 | =head3 Watcher-Specific Functions and Data Members |
1995 | |
2104 | |
1996 | =over 4 |
2105 | =over 4 |
1997 | |
2106 | |
… | |
… | |
2158 | |
2267 | |
2159 | =head2 C<ev_signal> - signal me when a signal gets signalled! |
2268 | =head2 C<ev_signal> - signal me when a signal gets signalled! |
2160 | |
2269 | |
2161 | Signal watchers will trigger an event when the process receives a specific |
2270 | Signal watchers will trigger an event when the process receives a specific |
2162 | signal one or more times. Even though signals are very asynchronous, libev |
2271 | signal one or more times. Even though signals are very asynchronous, libev |
2163 | will try it's best to deliver signals synchronously, i.e. as part of the |
2272 | will try its best to deliver signals synchronously, i.e. as part of the |
2164 | normal event processing, like any other event. |
2273 | normal event processing, like any other event. |
2165 | |
2274 | |
2166 | If you want signals to be delivered truly asynchronously, just use |
2275 | If you want signals to be delivered truly asynchronously, just use |
2167 | C<sigaction> as you would do without libev and forget about sharing |
2276 | C<sigaction> as you would do without libev and forget about sharing |
2168 | the signal. You can even use C<ev_async> from a signal handler to |
2277 | the signal. You can even use C<ev_async> from a signal handler to |
… | |
… | |
2235 | Example: Try to exit cleanly on SIGINT. |
2344 | Example: Try to exit cleanly on SIGINT. |
2236 | |
2345 | |
2237 | static void |
2346 | static void |
2238 | sigint_cb (struct ev_loop *loop, ev_signal *w, int revents) |
2347 | sigint_cb (struct ev_loop *loop, ev_signal *w, int revents) |
2239 | { |
2348 | { |
2240 | ev_unloop (loop, EVUNLOOP_ALL); |
2349 | ev_break (loop, EVBREAK_ALL); |
2241 | } |
2350 | } |
2242 | |
2351 | |
2243 | ev_signal signal_watcher; |
2352 | ev_signal signal_watcher; |
2244 | ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
2353 | ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
2245 | ev_signal_start (loop, &signal_watcher); |
2354 | ev_signal_start (loop, &signal_watcher); |
… | |
… | |
2631 | |
2740 | |
2632 | Prepare and check watchers are usually (but not always) used in pairs: |
2741 | Prepare and check watchers are usually (but not always) used in pairs: |
2633 | prepare watchers get invoked before the process blocks and check watchers |
2742 | prepare watchers get invoked before the process blocks and check watchers |
2634 | afterwards. |
2743 | afterwards. |
2635 | |
2744 | |
2636 | You I<must not> call C<ev_loop> or similar functions that enter |
2745 | You I<must not> call C<ev_run> or similar functions that enter |
2637 | the current event loop from either C<ev_prepare> or C<ev_check> |
2746 | the current event loop from either C<ev_prepare> or C<ev_check> |
2638 | watchers. Other loops than the current one are fine, however. The |
2747 | watchers. Other loops than the current one are fine, however. The |
2639 | rationale behind this is that you do not need to check for recursion in |
2748 | rationale behind this is that you do not need to check for recursion in |
2640 | those watchers, i.e. the sequence will always be C<ev_prepare>, blocking, |
2749 | those watchers, i.e. the sequence will always be C<ev_prepare>, blocking, |
2641 | C<ev_check> so if you have one watcher of each kind they will always be |
2750 | C<ev_check> so if you have one watcher of each kind they will always be |
… | |
… | |
2809 | |
2918 | |
2810 | if (timeout >= 0) |
2919 | if (timeout >= 0) |
2811 | // create/start timer |
2920 | // create/start timer |
2812 | |
2921 | |
2813 | // poll |
2922 | // poll |
2814 | ev_loop (EV_A_ 0); |
2923 | ev_run (EV_A_ 0); |
2815 | |
2924 | |
2816 | // stop timer again |
2925 | // stop timer again |
2817 | if (timeout >= 0) |
2926 | if (timeout >= 0) |
2818 | ev_timer_stop (EV_A_ &to); |
2927 | ev_timer_stop (EV_A_ &to); |
2819 | |
2928 | |
… | |
… | |
2897 | if you do not want that, you need to temporarily stop the embed watcher). |
3006 | if you do not want that, you need to temporarily stop the embed watcher). |
2898 | |
3007 | |
2899 | =item ev_embed_sweep (loop, ev_embed *) |
3008 | =item ev_embed_sweep (loop, ev_embed *) |
2900 | |
3009 | |
2901 | Make a single, non-blocking sweep over the embedded loop. This works |
3010 | Make a single, non-blocking sweep over the embedded loop. This works |
2902 | similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most |
3011 | similarly to C<ev_run (embedded_loop, EVRUN_NOWAIT)>, but in the most |
2903 | appropriate way for embedded loops. |
3012 | appropriate way for embedded loops. |
2904 | |
3013 | |
2905 | =item struct ev_loop *other [read-only] |
3014 | =item struct ev_loop *other [read-only] |
2906 | |
3015 | |
2907 | The embedded event loop. |
3016 | The embedded event loop. |
… | |
… | |
2993 | disadvantage of having to use multiple event loops (which do not support |
3102 | disadvantage of having to use multiple event loops (which do not support |
2994 | signal watchers). |
3103 | signal watchers). |
2995 | |
3104 | |
2996 | When this is not possible, or you want to use the default loop for |
3105 | When this is not possible, or you want to use the default loop for |
2997 | other reasons, then in the process that wants to start "fresh", call |
3106 | other reasons, then in the process that wants to start "fresh", call |
2998 | C<ev_default_destroy ()> followed by C<ev_default_loop (...)>. Destroying |
3107 | C<ev_loop_destroy (EV_DEFAULT)> followed by C<ev_default_loop (...)>. |
2999 | the default loop will "orphan" (not stop) all registered watchers, so you |
3108 | Destroying the default loop will "orphan" (not stop) all registered |
3000 | have to be careful not to execute code that modifies those watchers. Note |
3109 | watchers, so you have to be careful not to execute code that modifies |
3001 | also that in that case, you have to re-register any signal watchers. |
3110 | those watchers. Note also that in that case, you have to re-register any |
|
|
3111 | signal watchers. |
3002 | |
3112 | |
3003 | =head3 Watcher-Specific Functions and Data Members |
3113 | =head3 Watcher-Specific Functions and Data Members |
3004 | |
3114 | |
3005 | =over 4 |
3115 | =over 4 |
3006 | |
3116 | |
3007 | =item ev_fork_init (ev_signal *, callback) |
3117 | =item ev_fork_init (ev_fork *, callback) |
3008 | |
3118 | |
3009 | Initialises and configures the fork watcher - it has no parameters of any |
3119 | Initialises and configures the fork watcher - it has no parameters of any |
3010 | kind. There is a C<ev_fork_set> macro, but using it is utterly pointless, |
3120 | kind. There is a C<ev_fork_set> macro, but using it is utterly pointless, |
3011 | believe me. |
3121 | really. |
3012 | |
3122 | |
3013 | =back |
3123 | =back |
3014 | |
3124 | |
3015 | |
3125 | |
|
|
3126 | =head2 C<ev_cleanup> - even the best things end |
|
|
3127 | |
|
|
3128 | Cleanup watchers are called just before the event loop is being destroyed |
|
|
3129 | by a call to C<ev_loop_destroy>. |
|
|
3130 | |
|
|
3131 | While there is no guarantee that the event loop gets destroyed, cleanup |
|
|
3132 | watchers provide a convenient method to install cleanup hooks for your |
|
|
3133 | program, worker threads and so on - you just to make sure to destroy the |
|
|
3134 | loop when you want them to be invoked. |
|
|
3135 | |
|
|
3136 | Cleanup watchers are invoked in the same way as any other watcher. Unlike |
|
|
3137 | all other watchers, they do not keep a reference to the event loop (which |
|
|
3138 | makes a lot of sense if you think about it). Like all other watchers, you |
|
|
3139 | can call libev functions in the callback, except C<ev_cleanup_start>. |
|
|
3140 | |
|
|
3141 | =head3 Watcher-Specific Functions and Data Members |
|
|
3142 | |
|
|
3143 | =over 4 |
|
|
3144 | |
|
|
3145 | =item ev_cleanup_init (ev_cleanup *, callback) |
|
|
3146 | |
|
|
3147 | Initialises and configures the cleanup watcher - it has no parameters of |
|
|
3148 | any kind. There is a C<ev_cleanup_set> macro, but using it is utterly |
|
|
3149 | pointless, I assure you. |
|
|
3150 | |
|
|
3151 | =back |
|
|
3152 | |
|
|
3153 | Example: Register an atexit handler to destroy the default loop, so any |
|
|
3154 | cleanup functions are called. |
|
|
3155 | |
|
|
3156 | static void |
|
|
3157 | program_exits (void) |
|
|
3158 | { |
|
|
3159 | ev_loop_destroy (EV_DEFAULT_UC); |
|
|
3160 | } |
|
|
3161 | |
|
|
3162 | ... |
|
|
3163 | atexit (program_exits); |
|
|
3164 | |
|
|
3165 | |
3016 | =head2 C<ev_async> - how to wake up an event loop |
3166 | =head2 C<ev_async> - how to wake up an event loop |
3017 | |
3167 | |
3018 | In general, you cannot use an C<ev_loop> from multiple threads or other |
3168 | In general, you cannot use an C<ev_run> from multiple threads or other |
3019 | asynchronous sources such as signal handlers (as opposed to multiple event |
3169 | asynchronous sources such as signal handlers (as opposed to multiple event |
3020 | loops - those are of course safe to use in different threads). |
3170 | loops - those are of course safe to use in different threads). |
3021 | |
3171 | |
3022 | Sometimes, however, you need to wake up an event loop you do not control, |
3172 | Sometimes, however, you need to wake up an event loop you do not control, |
3023 | for example because it belongs to another thread. This is what C<ev_async> |
3173 | for example because it belongs to another thread. This is what C<ev_async> |
… | |
… | |
3238 | =item * Priorities are not currently supported. Initialising priorities |
3388 | =item * Priorities are not currently supported. Initialising priorities |
3239 | will fail and all watchers will have the same priority, even though there |
3389 | will fail and all watchers will have the same priority, even though there |
3240 | is an ev_pri field. |
3390 | is an ev_pri field. |
3241 | |
3391 | |
3242 | =item * In libevent, the last base created gets the signals, in libev, the |
3392 | =item * In libevent, the last base created gets the signals, in libev, the |
3243 | first base created (== the default loop) gets the signals. |
3393 | base that registered the signal gets the signals. |
3244 | |
3394 | |
3245 | =item * Other members are not supported. |
3395 | =item * Other members are not supported. |
3246 | |
3396 | |
3247 | =item * The libev emulation is I<not> ABI compatible to libevent, you need |
3397 | =item * The libev emulation is I<not> ABI compatible to libevent, you need |
3248 | to use the libev header file and library. |
3398 | to use the libev header file and library. |
… | |
… | |
3530 | loop argument"). The C<EV_A> form is used when this is the sole argument, |
3680 | loop argument"). The C<EV_A> form is used when this is the sole argument, |
3531 | C<EV_A_> is used when other arguments are following. Example: |
3681 | C<EV_A_> is used when other arguments are following. Example: |
3532 | |
3682 | |
3533 | ev_unref (EV_A); |
3683 | ev_unref (EV_A); |
3534 | ev_timer_add (EV_A_ watcher); |
3684 | ev_timer_add (EV_A_ watcher); |
3535 | ev_loop (EV_A_ 0); |
3685 | ev_run (EV_A_ 0); |
3536 | |
3686 | |
3537 | It assumes the variable C<loop> of type C<struct ev_loop *> is in scope, |
3687 | It assumes the variable C<loop> of type C<struct ev_loop *> is in scope, |
3538 | which is often provided by the following macro. |
3688 | which is often provided by the following macro. |
3539 | |
3689 | |
3540 | =item C<EV_P>, C<EV_P_> |
3690 | =item C<EV_P>, C<EV_P_> |
… | |
… | |
3580 | } |
3730 | } |
3581 | |
3731 | |
3582 | ev_check check; |
3732 | ev_check check; |
3583 | ev_check_init (&check, check_cb); |
3733 | ev_check_init (&check, check_cb); |
3584 | ev_check_start (EV_DEFAULT_ &check); |
3734 | ev_check_start (EV_DEFAULT_ &check); |
3585 | ev_loop (EV_DEFAULT_ 0); |
3735 | ev_run (EV_DEFAULT_ 0); |
3586 | |
3736 | |
3587 | =head1 EMBEDDING |
3737 | =head1 EMBEDDING |
3588 | |
3738 | |
3589 | Libev can (and often is) directly embedded into host |
3739 | Libev can (and often is) directly embedded into host |
3590 | applications. Examples of applications that embed it include the Deliantra |
3740 | applications. Examples of applications that embed it include the Deliantra |
… | |
… | |
3681 | to a compiled library. All other symbols change the ABI, which means all |
3831 | to a compiled library. All other symbols change the ABI, which means all |
3682 | users of libev and the libev code itself must be compiled with compatible |
3832 | users of libev and the libev code itself must be compiled with compatible |
3683 | settings. |
3833 | settings. |
3684 | |
3834 | |
3685 | =over 4 |
3835 | =over 4 |
|
|
3836 | |
|
|
3837 | =item EV_COMPAT3 (h) |
|
|
3838 | |
|
|
3839 | Backwards compatibility is a major concern for libev. This is why this |
|
|
3840 | release of libev comes with wrappers for the functions and symbols that |
|
|
3841 | have been renamed between libev version 3 and 4. |
|
|
3842 | |
|
|
3843 | You can disable these wrappers (to test compatibility with future |
|
|
3844 | versions) by defining C<EV_COMPAT3> to C<0> when compiling your |
|
|
3845 | sources. This has the additional advantage that you can drop the C<struct> |
|
|
3846 | from C<struct ev_loop> declarations, as libev will provide an C<ev_loop> |
|
|
3847 | typedef in that case. |
|
|
3848 | |
|
|
3849 | In some future version, the default for C<EV_COMPAT3> will become C<0>, |
|
|
3850 | and in some even more future version the compatibility code will be |
|
|
3851 | removed completely. |
3686 | |
3852 | |
3687 | =item EV_STANDALONE (h) |
3853 | =item EV_STANDALONE (h) |
3688 | |
3854 | |
3689 | Must always be C<1> if you do not use autoconf configuration, which |
3855 | Must always be C<1> if you do not use autoconf configuration, which |
3690 | keeps libev from including F<config.h>, and it also defines dummy |
3856 | keeps libev from including F<config.h>, and it also defines dummy |
… | |
… | |
4040 | The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it |
4206 | The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it |
4041 | will be C<0>. |
4207 | will be C<0>. |
4042 | |
4208 | |
4043 | =item EV_VERIFY |
4209 | =item EV_VERIFY |
4044 | |
4210 | |
4045 | Controls how much internal verification (see C<ev_loop_verify ()>) will |
4211 | Controls how much internal verification (see C<ev_verify ()>) will |
4046 | be done: If set to C<0>, no internal verification code will be compiled |
4212 | be done: If set to C<0>, no internal verification code will be compiled |
4047 | in. If set to C<1>, then verification code will be compiled in, but not |
4213 | in. If set to C<1>, then verification code will be compiled in, but not |
4048 | called. If set to C<2>, then the internal verification code will be |
4214 | called. If set to C<2>, then the internal verification code will be |
4049 | called once per loop, which can slow down libev. If set to C<3>, then the |
4215 | called once per loop, which can slow down libev. If set to C<3>, then the |
4050 | verification code will be called very frequently, which will slow down |
4216 | verification code will be called very frequently, which will slow down |
… | |
… | |
4265 | userdata *u = ev_userdata (EV_A); |
4431 | userdata *u = ev_userdata (EV_A); |
4266 | pthread_mutex_lock (&u->lock); |
4432 | pthread_mutex_lock (&u->lock); |
4267 | } |
4433 | } |
4268 | |
4434 | |
4269 | The event loop thread first acquires the mutex, and then jumps straight |
4435 | The event loop thread first acquires the mutex, and then jumps straight |
4270 | into C<ev_loop>: |
4436 | into C<ev_run>: |
4271 | |
4437 | |
4272 | void * |
4438 | void * |
4273 | l_run (void *thr_arg) |
4439 | l_run (void *thr_arg) |
4274 | { |
4440 | { |
4275 | struct ev_loop *loop = (struct ev_loop *)thr_arg; |
4441 | struct ev_loop *loop = (struct ev_loop *)thr_arg; |
4276 | |
4442 | |
4277 | l_acquire (EV_A); |
4443 | l_acquire (EV_A); |
4278 | pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0); |
4444 | pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0); |
4279 | ev_loop (EV_A_ 0); |
4445 | ev_run (EV_A_ 0); |
4280 | l_release (EV_A); |
4446 | l_release (EV_A); |
4281 | |
4447 | |
4282 | return 0; |
4448 | return 0; |
4283 | } |
4449 | } |
4284 | |
4450 | |
… | |
… | |
4336 | |
4502 | |
4337 | =head3 COROUTINES |
4503 | =head3 COROUTINES |
4338 | |
4504 | |
4339 | Libev is very accommodating to coroutines ("cooperative threads"): |
4505 | Libev is very accommodating to coroutines ("cooperative threads"): |
4340 | libev fully supports nesting calls to its functions from different |
4506 | libev fully supports nesting calls to its functions from different |
4341 | coroutines (e.g. you can call C<ev_loop> on the same loop from two |
4507 | coroutines (e.g. you can call C<ev_run> on the same loop from two |
4342 | different coroutines, and switch freely between both coroutines running |
4508 | different coroutines, and switch freely between both coroutines running |
4343 | the loop, as long as you don't confuse yourself). The only exception is |
4509 | the loop, as long as you don't confuse yourself). The only exception is |
4344 | that you must not do this from C<ev_periodic> reschedule callbacks. |
4510 | that you must not do this from C<ev_periodic> reschedule callbacks. |
4345 | |
4511 | |
4346 | Care has been taken to ensure that libev does not keep local state inside |
4512 | Care has been taken to ensure that libev does not keep local state inside |
4347 | C<ev_loop>, and other calls do not usually allow for coroutine switches as |
4513 | C<ev_run>, and other calls do not usually allow for coroutine switches as |
4348 | they do not call any callbacks. |
4514 | they do not call any callbacks. |
4349 | |
4515 | |
4350 | =head2 COMPILER WARNINGS |
4516 | =head2 COMPILER WARNINGS |
4351 | |
4517 | |
4352 | Depending on your compiler and compiler settings, you might get no or a |
4518 | Depending on your compiler and compiler settings, you might get no or a |
… | |
… | |
4436 | =head3 C<kqueue> is buggy |
4602 | =head3 C<kqueue> is buggy |
4437 | |
4603 | |
4438 | The kqueue syscall is broken in all known versions - most versions support |
4604 | The kqueue syscall is broken in all known versions - most versions support |
4439 | only sockets, many support pipes. |
4605 | only sockets, many support pipes. |
4440 | |
4606 | |
4441 | Libev tries to work around this by not using C<kqueue> by default on |
4607 | Libev tries to work around this by not using C<kqueue> by default on this |
4442 | this rotten platform, but of course you can still ask for it when creating |
4608 | rotten platform, but of course you can still ask for it when creating a |
4443 | a loop. |
4609 | loop - embedding a socket-only kqueue loop into a select-based one is |
|
|
4610 | probably going to work well. |
4444 | |
4611 | |
4445 | =head3 C<poll> is buggy |
4612 | =head3 C<poll> is buggy |
4446 | |
4613 | |
4447 | Instead of fixing C<kqueue>, Apple replaced their (working) C<poll> |
4614 | Instead of fixing C<kqueue>, Apple replaced their (working) C<poll> |
4448 | implementation by something calling C<kqueue> internally around the 10.5.6 |
4615 | implementation by something calling C<kqueue> internally around the 10.5.6 |
… | |
… | |
4467 | |
4634 | |
4468 | =head3 C<errno> reentrancy |
4635 | =head3 C<errno> reentrancy |
4469 | |
4636 | |
4470 | The default compile environment on Solaris is unfortunately so |
4637 | The default compile environment on Solaris is unfortunately so |
4471 | thread-unsafe that you can't even use components/libraries compiled |
4638 | thread-unsafe that you can't even use components/libraries compiled |
4472 | without C<-D_REENTRANT> (as long as they use C<errno>), which, of course, |
4639 | without C<-D_REENTRANT> in a threaded program, which, of course, isn't |
4473 | isn't defined by default. |
4640 | defined by default. A valid, if stupid, implementation choice. |
4474 | |
4641 | |
4475 | If you want to use libev in threaded environments you have to make sure |
4642 | If you want to use libev in threaded environments you have to make sure |
4476 | it's compiled with C<_REENTRANT> defined. |
4643 | it's compiled with C<_REENTRANT> defined. |
4477 | |
4644 | |
4478 | =head3 Event port backend |
4645 | =head3 Event port backend |
4479 | |
4646 | |
4480 | The scalable event interface for Solaris is called "event ports". Unfortunately, |
4647 | The scalable event interface for Solaris is called "event |
4481 | this mechanism is very buggy. If you run into high CPU usage, your program |
4648 | ports". Unfortunately, this mechanism is very buggy in all major |
|
|
4649 | releases. If you run into high CPU usage, your program freezes or you get |
4482 | freezes or you get a large number of spurious wakeups, make sure you have |
4650 | a large number of spurious wakeups, make sure you have all the relevant |
4483 | all the relevant and latest kernel patches applied. No, I don't know which |
4651 | and latest kernel patches applied. No, I don't know which ones, but there |
4484 | ones, but there are multiple ones. |
4652 | are multiple ones to apply, and afterwards, event ports actually work |
|
|
4653 | great. |
4485 | |
4654 | |
4486 | If you can't get it to work, you can try running the program by setting |
4655 | If you can't get it to work, you can try running the program by setting |
4487 | the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and |
4656 | the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and |
4488 | C<select> backends. |
4657 | C<select> backends. |
4489 | |
4658 | |
4490 | =head2 AIX POLL BUG |
4659 | =head2 AIX POLL BUG |
4491 | |
4660 | |
4492 | AIX unfortunately has a broken C<poll.h> header. Libev works around |
4661 | AIX unfortunately has a broken C<poll.h> header. Libev works around |
4493 | this by trying to avoid the poll backend altogether (i.e. it's not even |
4662 | this by trying to avoid the poll backend altogether (i.e. it's not even |
4494 | compiled in), which normally isn't a big problem as C<select> works fine |
4663 | compiled in), which normally isn't a big problem as C<select> works fine |
4495 | with large bitsets, and AIX is dead anyway. |
4664 | with large bitsets on AIX, and AIX is dead anyway. |
4496 | |
4665 | |
4497 | =head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS |
4666 | =head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS |
4498 | |
4667 | |
4499 | =head3 General issues |
4668 | =head3 General issues |
4500 | |
4669 | |
… | |
… | |
4606 | structure (guaranteed by POSIX but not by ISO C for example), but it also |
4775 | structure (guaranteed by POSIX but not by ISO C for example), but it also |
4607 | assumes that the same (machine) code can be used to call any watcher |
4776 | assumes that the same (machine) code can be used to call any watcher |
4608 | callback: The watcher callbacks have different type signatures, but libev |
4777 | callback: The watcher callbacks have different type signatures, but libev |
4609 | calls them using an C<ev_watcher *> internally. |
4778 | calls them using an C<ev_watcher *> internally. |
4610 | |
4779 | |
|
|
4780 | =item pointer accesses must be thread-atomic |
|
|
4781 | |
|
|
4782 | Accessing a pointer value must be atomic, it must both be readable and |
|
|
4783 | writable in one piece - this is the case on all current architectures. |
|
|
4784 | |
4611 | =item C<sig_atomic_t volatile> must be thread-atomic as well |
4785 | =item C<sig_atomic_t volatile> must be thread-atomic as well |
4612 | |
4786 | |
4613 | The type C<sig_atomic_t volatile> (or whatever is defined as |
4787 | The type C<sig_atomic_t volatile> (or whatever is defined as |
4614 | C<EV_ATOMIC_T>) must be atomic with respect to accesses from different |
4788 | C<EV_ATOMIC_T>) must be atomic with respect to accesses from different |
4615 | threads. This is not part of the specification for C<sig_atomic_t>, but is |
4789 | threads. This is not part of the specification for C<sig_atomic_t>, but is |
… | |
… | |
4637 | watchers. |
4811 | watchers. |
4638 | |
4812 | |
4639 | =item C<double> must hold a time value in seconds with enough accuracy |
4813 | =item C<double> must hold a time value in seconds with enough accuracy |
4640 | |
4814 | |
4641 | The type C<double> is used to represent timestamps. It is required to |
4815 | The type C<double> is used to represent timestamps. It is required to |
4642 | have at least 51 bits of mantissa (and 9 bits of exponent), which is good |
4816 | have at least 51 bits of mantissa (and 9 bits of exponent), which is |
4643 | enough for at least into the year 4000. This requirement is fulfilled by |
4817 | good enough for at least into the year 4000 with millisecond accuracy |
|
|
4818 | (the design goal for libev). This requirement is overfulfilled by |
4644 | implementations implementing IEEE 754, which is basically all existing |
4819 | implementations using IEEE 754, which is basically all existing ones. With |
4645 | ones. With IEEE 754 doubles, you get microsecond accuracy until at least |
4820 | IEEE 754 doubles, you get microsecond accuracy until at least 2200. |
4646 | 2200. |
|
|
4647 | |
4821 | |
4648 | =back |
4822 | =back |
4649 | |
4823 | |
4650 | If you know of other additional requirements drop me a note. |
4824 | If you know of other additional requirements drop me a note. |
4651 | |
4825 | |
… | |
… | |
4721 | =back |
4895 | =back |
4722 | |
4896 | |
4723 | |
4897 | |
4724 | =head1 PORTING FROM LIBEV 3.X TO 4.X |
4898 | =head1 PORTING FROM LIBEV 3.X TO 4.X |
4725 | |
4899 | |
4726 | The major version 4 introduced some minor incompatible changes to the API. |
4900 | The major version 4 introduced some incompatible changes to the API. |
4727 | |
4901 | |
4728 | At the moment, the C<ev.h> header file tries to implement superficial |
4902 | At the moment, the C<ev.h> header file provides compatibility definitions |
4729 | compatibility, so most programs should still compile. Those might be |
4903 | for all changes, so most programs should still compile. The compatibility |
4730 | removed in later versions of libev, so better update early than late. |
4904 | layer might be removed in later versions of libev, so better update to the |
|
|
4905 | new API early than late. |
4731 | |
4906 | |
4732 | =over 4 |
4907 | =over 4 |
4733 | |
4908 | |
4734 | =item C<ev_loop_count> renamed to C<ev_iteration> |
4909 | =item C<EV_COMPAT3> backwards compatibility mechanism |
4735 | |
4910 | |
4736 | =item C<ev_loop_depth> renamed to C<ev_depth> |
4911 | The backward compatibility mechanism can be controlled by |
|
|
4912 | C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING> |
|
|
4913 | section. |
4737 | |
4914 | |
4738 | =item C<ev_loop_verify> renamed to C<ev_verify> |
4915 | =item C<ev_default_destroy> and C<ev_default_fork> have been removed |
|
|
4916 | |
|
|
4917 | These calls can be replaced easily by their C<ev_loop_xxx> counterparts: |
|
|
4918 | |
|
|
4919 | ev_loop_destroy (EV_DEFAULT_UC); |
|
|
4920 | ev_loop_fork (EV_DEFAULT); |
|
|
4921 | |
|
|
4922 | =item function/symbol renames |
|
|
4923 | |
|
|
4924 | A number of functions and symbols have been renamed: |
|
|
4925 | |
|
|
4926 | ev_loop => ev_run |
|
|
4927 | EVLOOP_NONBLOCK => EVRUN_NOWAIT |
|
|
4928 | EVLOOP_ONESHOT => EVRUN_ONCE |
|
|
4929 | |
|
|
4930 | ev_unloop => ev_break |
|
|
4931 | EVUNLOOP_CANCEL => EVBREAK_CANCEL |
|
|
4932 | EVUNLOOP_ONE => EVBREAK_ONE |
|
|
4933 | EVUNLOOP_ALL => EVBREAK_ALL |
|
|
4934 | |
|
|
4935 | EV_TIMEOUT => EV_TIMER |
|
|
4936 | |
|
|
4937 | ev_loop_count => ev_iteration |
|
|
4938 | ev_loop_depth => ev_depth |
|
|
4939 | ev_loop_verify => ev_verify |
4739 | |
4940 | |
4740 | Most functions working on C<struct ev_loop> objects don't have an |
4941 | Most functions working on C<struct ev_loop> objects don't have an |
4741 | C<ev_loop_> prefix, so it was removed. Note that C<ev_loop_fork> is |
4942 | C<ev_loop_> prefix, so it was removed; C<ev_loop>, C<ev_unloop> and |
|
|
4943 | associated constants have been renamed to not collide with the C<struct |
|
|
4944 | ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme |
|
|
4945 | as all other watcher types. Note that C<ev_loop_fork> is still called |
4742 | still called C<ev_loop_fork> because it would otherwise clash with the |
4946 | C<ev_loop_fork> because it would otherwise clash with the C<ev_fork> |
4743 | C<ev_fork> typedef. |
4947 | typedef. |
4744 | |
|
|
4745 | =item C<EV_TIMEOUT> renamed to C<EV_TIMER> in C<revents> |
|
|
4746 | |
|
|
4747 | This is a simple rename - all other watcher types use their name |
|
|
4748 | as revents flag, and now C<ev_timer> does, too. |
|
|
4749 | |
|
|
4750 | Both C<EV_TIMER> and C<EV_TIMEOUT> symbols were present in 3.x versions |
|
|
4751 | and continue to be present for the foreseeable future, so this is mostly a |
|
|
4752 | documentation change. |
|
|
4753 | |
4948 | |
4754 | =item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES> |
4949 | =item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES> |
4755 | |
4950 | |
4756 | The preprocessor symbol C<EV_MINIMAL> has been replaced by a different |
4951 | The preprocessor symbol C<EV_MINIMAL> has been replaced by a different |
4757 | mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile |
4952 | mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile |
… | |
… | |
4764 | |
4959 | |
4765 | =over 4 |
4960 | =over 4 |
4766 | |
4961 | |
4767 | =item active |
4962 | =item active |
4768 | |
4963 | |
4769 | A watcher is active as long as it has been started (has been attached to |
4964 | A watcher is active as long as it has been started and not yet stopped. |
4770 | an event loop) but not yet stopped (disassociated from the event loop). |
4965 | See L<WATCHER STATES> for details. |
4771 | |
4966 | |
4772 | =item application |
4967 | =item application |
4773 | |
4968 | |
4774 | In this document, an application is whatever is using libev. |
4969 | In this document, an application is whatever is using libev. |
|
|
4970 | |
|
|
4971 | =item backend |
|
|
4972 | |
|
|
4973 | The part of the code dealing with the operating system interfaces. |
4775 | |
4974 | |
4776 | =item callback |
4975 | =item callback |
4777 | |
4976 | |
4778 | The address of a function that is called when some event has been |
4977 | The address of a function that is called when some event has been |
4779 | detected. Callbacks are being passed the event loop, the watcher that |
4978 | detected. Callbacks are being passed the event loop, the watcher that |
4780 | received the event, and the actual event bitset. |
4979 | received the event, and the actual event bitset. |
4781 | |
4980 | |
4782 | =item callback invocation |
4981 | =item callback/watcher invocation |
4783 | |
4982 | |
4784 | The act of calling the callback associated with a watcher. |
4983 | The act of calling the callback associated with a watcher. |
4785 | |
4984 | |
4786 | =item event |
4985 | =item event |
4787 | |
4986 | |
… | |
… | |
4806 | The model used to describe how an event loop handles and processes |
5005 | The model used to describe how an event loop handles and processes |
4807 | watchers and events. |
5006 | watchers and events. |
4808 | |
5007 | |
4809 | =item pending |
5008 | =item pending |
4810 | |
5009 | |
4811 | A watcher is pending as soon as the corresponding event has been detected, |
5010 | A watcher is pending as soon as the corresponding event has been |
4812 | and stops being pending as soon as the watcher will be invoked or its |
5011 | detected. See L<WATCHER STATES> for details. |
4813 | pending status is explicitly cleared by the application. |
|
|
4814 | |
|
|
4815 | A watcher can be pending, but not active. Stopping a watcher also clears |
|
|
4816 | its pending status. |
|
|
4817 | |
5012 | |
4818 | =item real time |
5013 | =item real time |
4819 | |
5014 | |
4820 | The physical time that is observed. It is apparently strictly monotonic :) |
5015 | The physical time that is observed. It is apparently strictly monotonic :) |
4821 | |
5016 | |
… | |
… | |
4828 | =item watcher |
5023 | =item watcher |
4829 | |
5024 | |
4830 | A data structure that describes interest in certain events. Watchers need |
5025 | A data structure that describes interest in certain events. Watchers need |
4831 | to be started (attached to an event loop) before they can receive events. |
5026 | to be started (attached to an event loop) before they can receive events. |
4832 | |
5027 | |
4833 | =item watcher invocation |
|
|
4834 | |
|
|
4835 | The act of calling the callback associated with a watcher. |
|
|
4836 | |
|
|
4837 | =back |
5028 | =back |
4838 | |
5029 | |
4839 | =head1 AUTHOR |
5030 | =head1 AUTHOR |
4840 | |
5031 | |
4841 | Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson. |
5032 | Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael |
|
|
5033 | Magnusson and Emanuele Giaquinta. |
4842 | |
5034 | |