… | |
… | |
127 | .\} |
127 | .\} |
128 | .rm #[ #] #H #V #F C |
128 | .rm #[ #] #H #V #F C |
129 | .\" ======================================================================== |
129 | .\" ======================================================================== |
130 | .\" |
130 | .\" |
131 | .IX Title ""<STANDARD INPUT>" 1" |
131 | .IX Title ""<STANDARD INPUT>" 1" |
132 | .TH "<STANDARD INPUT>" 1 "2007-11-26" "perl v5.8.8" "User Contributed Perl Documentation" |
132 | .TH "<STANDARD INPUT>" 1 "2007-12-08" "perl v5.8.8" "User Contributed Perl Documentation" |
133 | .SH "NAME" |
133 | .SH "NAME" |
134 | libev \- a high performance full\-featured event loop written in C |
134 | libev \- a high performance full\-featured event loop written in C |
135 | .SH "SYNOPSIS" |
135 | .SH "SYNOPSIS" |
136 | .IX Header "SYNOPSIS" |
136 | .IX Header "SYNOPSIS" |
137 | .Vb 1 |
137 | .Vb 1 |
138 | \& #include <ev.h> |
138 | \& #include <ev.h> |
139 | .Ve |
139 | .Ve |
|
|
140 | .SH "EXAMPLE PROGRAM" |
|
|
141 | .IX Header "EXAMPLE PROGRAM" |
|
|
142 | .Vb 1 |
|
|
143 | \& #include <ev.h> |
|
|
144 | .Ve |
|
|
145 | .PP |
|
|
146 | .Vb 2 |
|
|
147 | \& ev_io stdin_watcher; |
|
|
148 | \& ev_timer timeout_watcher; |
|
|
149 | .Ve |
|
|
150 | .PP |
|
|
151 | .Vb 8 |
|
|
152 | \& /* called when data readable on stdin */ |
|
|
153 | \& static void |
|
|
154 | \& stdin_cb (EV_P_ struct ev_io *w, int revents) |
|
|
155 | \& { |
|
|
156 | \& /* puts ("stdin ready"); */ |
|
|
157 | \& ev_io_stop (EV_A_ w); /* just a syntax example */ |
|
|
158 | \& ev_unloop (EV_A_ EVUNLOOP_ALL); /* leave all loop calls */ |
|
|
159 | \& } |
|
|
160 | .Ve |
|
|
161 | .PP |
|
|
162 | .Vb 6 |
|
|
163 | \& static void |
|
|
164 | \& timeout_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
165 | \& { |
|
|
166 | \& /* puts ("timeout"); */ |
|
|
167 | \& ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */ |
|
|
168 | \& } |
|
|
169 | .Ve |
|
|
170 | .PP |
|
|
171 | .Vb 4 |
|
|
172 | \& int |
|
|
173 | \& main (void) |
|
|
174 | \& { |
|
|
175 | \& struct ev_loop *loop = ev_default_loop (0); |
|
|
176 | .Ve |
|
|
177 | .PP |
|
|
178 | .Vb 3 |
|
|
179 | \& /* initialise an io watcher, then start it */ |
|
|
180 | \& ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
|
|
181 | \& ev_io_start (loop, &stdin_watcher); |
|
|
182 | .Ve |
|
|
183 | .PP |
|
|
184 | .Vb 3 |
|
|
185 | \& /* simple non-repeating 5.5 second timeout */ |
|
|
186 | \& ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.); |
|
|
187 | \& ev_timer_start (loop, &timeout_watcher); |
|
|
188 | .Ve |
|
|
189 | .PP |
|
|
190 | .Vb 2 |
|
|
191 | \& /* loop till timeout or data ready */ |
|
|
192 | \& ev_loop (loop, 0); |
|
|
193 | .Ve |
|
|
194 | .PP |
|
|
195 | .Vb 2 |
|
|
196 | \& return 0; |
|
|
197 | \& } |
|
|
198 | .Ve |
140 | .SH "DESCRIPTION" |
199 | .SH "DESCRIPTION" |
141 | .IX Header "DESCRIPTION" |
200 | .IX Header "DESCRIPTION" |
|
|
201 | The newest version of this document is also available as a html-formatted |
|
|
202 | web page you might find easier to navigate when reading it for the first |
|
|
203 | time: <http://cvs.schmorp.de/libev/ev.html>. |
|
|
204 | .PP |
142 | Libev is an event loop: you register interest in certain events (such as a |
205 | Libev is an event loop: you register interest in certain events (such as a |
143 | file descriptor being readable or a timeout occuring), and it will manage |
206 | file descriptor being readable or a timeout occuring), and it will manage |
144 | these event sources and provide your program with events. |
207 | these event sources and provide your program with events. |
145 | .PP |
208 | .PP |
146 | To do this, it must take more or less complete control over your process |
209 | To do this, it must take more or less complete control over your process |
… | |
… | |
151 | watchers\fR, which are relatively small C structures you initialise with the |
214 | watchers\fR, which are relatively small C structures you initialise with the |
152 | details of the event, and then hand it over to libev by \fIstarting\fR the |
215 | details of the event, and then hand it over to libev by \fIstarting\fR the |
153 | watcher. |
216 | watcher. |
154 | .SH "FEATURES" |
217 | .SH "FEATURES" |
155 | .IX Header "FEATURES" |
218 | .IX Header "FEATURES" |
156 | Libev supports select, poll, the linux-specific epoll and the bsd-specific |
219 | Libev supports \f(CW\*(C`select\*(C'\fR, \f(CW\*(C`poll\*(C'\fR, the Linux-specific \f(CW\*(C`epoll\*(C'\fR, the |
157 | kqueue mechanisms for file descriptor events, relative timers, absolute |
220 | BSD-specific \f(CW\*(C`kqueue\*(C'\fR and the Solaris-specific event port mechanisms |
158 | timers with customised rescheduling, signal events, process status change |
221 | for file descriptor events (\f(CW\*(C`ev_io\*(C'\fR), the Linux \f(CW\*(C`inotify\*(C'\fR interface |
159 | events (related to \s-1SIGCHLD\s0), and event watchers dealing with the event |
222 | (for \f(CW\*(C`ev_stat\*(C'\fR), relative timers (\f(CW\*(C`ev_timer\*(C'\fR), absolute timers |
160 | loop mechanism itself (idle, prepare and check watchers). It also is quite |
223 | with customised rescheduling (\f(CW\*(C`ev_periodic\*(C'\fR), synchronous signals |
161 | fast (see this benchmark comparing |
224 | (\f(CW\*(C`ev_signal\*(C'\fR), process status change events (\f(CW\*(C`ev_child\*(C'\fR), and event |
162 | it to libevent for example). |
225 | watchers dealing with the event loop mechanism itself (\f(CW\*(C`ev_idle\*(C'\fR, |
|
|
226 | \&\f(CW\*(C`ev_embed\*(C'\fR, \f(CW\*(C`ev_prepare\*(C'\fR and \f(CW\*(C`ev_check\*(C'\fR watchers) as well as |
|
|
227 | file watchers (\f(CW\*(C`ev_stat\*(C'\fR) and even limited support for fork events |
|
|
228 | (\f(CW\*(C`ev_fork\*(C'\fR). |
|
|
229 | .PP |
|
|
230 | It also is quite fast (see this |
|
|
231 | benchmark comparing it to libevent |
|
|
232 | for example). |
163 | .SH "CONVENTIONS" |
233 | .SH "CONVENTIONS" |
164 | .IX Header "CONVENTIONS" |
234 | .IX Header "CONVENTIONS" |
165 | Libev is very configurable. In this manual the default configuration |
235 | Libev is very configurable. In this manual the default configuration will |
166 | will be described, which supports multiple event loops. For more info |
236 | be described, which supports multiple event loops. For more info about |
167 | about various configuration options please have a look at the file |
237 | various configuration options please have a look at \fB\s-1EMBED\s0\fR section in |
168 | \&\fI\s-1README\s0.embed\fR in the libev distribution. If libev was configured without |
238 | this manual. If libev was configured without support for multiple event |
169 | support for multiple event loops, then all functions taking an initial |
239 | loops, then all functions taking an initial argument of name \f(CW\*(C`loop\*(C'\fR |
170 | argument of name \f(CW\*(C`loop\*(C'\fR (which is always of type \f(CW\*(C`struct ev_loop *\*(C'\fR) |
240 | (which is always of type \f(CW\*(C`struct ev_loop *\*(C'\fR) will not have this argument. |
171 | will not have this argument. |
|
|
172 | .SH "TIME REPRESENTATION" |
241 | .SH "TIME REPRESENTATION" |
173 | .IX Header "TIME REPRESENTATION" |
242 | .IX Header "TIME REPRESENTATION" |
174 | Libev represents time as a single floating point number, representing the |
243 | Libev represents time as a single floating point number, representing the |
175 | (fractional) number of seconds since the (\s-1POSIX\s0) epoch (somewhere near |
244 | (fractional) number of seconds since the (\s-1POSIX\s0) epoch (somewhere near |
176 | the beginning of 1970, details are complicated, don't ask). This type is |
245 | the beginning of 1970, details are complicated, don't ask). This type is |
… | |
… | |
201 | Usually, it's a good idea to terminate if the major versions mismatch, |
270 | Usually, it's a good idea to terminate if the major versions mismatch, |
202 | as this indicates an incompatible change. Minor versions are usually |
271 | as this indicates an incompatible change. Minor versions are usually |
203 | compatible to older versions, so a larger minor version alone is usually |
272 | compatible to older versions, so a larger minor version alone is usually |
204 | not a problem. |
273 | not a problem. |
205 | .Sp |
274 | .Sp |
206 | Example: make sure we haven't accidentally been linked against the wrong |
275 | Example: Make sure we haven't accidentally been linked against the wrong |
207 | version: |
276 | version. |
208 | .Sp |
277 | .Sp |
209 | .Vb 3 |
278 | .Vb 3 |
210 | \& assert (("libev version mismatch", |
279 | \& assert (("libev version mismatch", |
211 | \& ev_version_major () == EV_VERSION_MAJOR |
280 | \& ev_version_major () == EV_VERSION_MAJOR |
212 | \& && ev_version_minor () >= EV_VERSION_MINOR)); |
281 | \& && ev_version_minor () >= EV_VERSION_MINOR)); |
… | |
… | |
242 | recommended ones. |
311 | recommended ones. |
243 | .Sp |
312 | .Sp |
244 | See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info. |
313 | See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info. |
245 | .IP "ev_set_allocator (void *(*cb)(void *ptr, long size))" 4 |
314 | .IP "ev_set_allocator (void *(*cb)(void *ptr, long size))" 4 |
246 | .IX Item "ev_set_allocator (void *(*cb)(void *ptr, long size))" |
315 | .IX Item "ev_set_allocator (void *(*cb)(void *ptr, long size))" |
247 | Sets the allocation function to use (the prototype is similar to the |
316 | Sets the allocation function to use (the prototype is similar \- the |
248 | realloc C function, the semantics are identical). It is used to allocate |
317 | semantics is identical \- to the realloc C function). It is used to |
249 | and free memory (no surprises here). If it returns zero when memory |
318 | allocate and free memory (no surprises here). If it returns zero when |
250 | needs to be allocated, the library might abort or take some potentially |
319 | memory needs to be allocated, the library might abort or take some |
251 | destructive action. The default is your system realloc function. |
320 | potentially destructive action. The default is your system realloc |
|
|
321 | function. |
252 | .Sp |
322 | .Sp |
253 | You could override this function in high-availability programs to, say, |
323 | You could override this function in high-availability programs to, say, |
254 | free some memory if it cannot allocate memory, to use a special allocator, |
324 | free some memory if it cannot allocate memory, to use a special allocator, |
255 | or even to sleep a while and retry until some memory is available. |
325 | or even to sleep a while and retry until some memory is available. |
256 | .Sp |
326 | .Sp |
257 | Example: replace the libev allocator with one that waits a bit and then |
327 | Example: Replace the libev allocator with one that waits a bit and then |
258 | retries: better than mine). |
328 | retries). |
259 | .Sp |
329 | .Sp |
260 | .Vb 6 |
330 | .Vb 6 |
261 | \& static void * |
331 | \& static void * |
262 | \& persistent_realloc (void *ptr, long size) |
332 | \& persistent_realloc (void *ptr, size_t size) |
263 | \& { |
333 | \& { |
264 | \& for (;;) |
334 | \& for (;;) |
265 | \& { |
335 | \& { |
266 | \& void *newptr = realloc (ptr, size); |
336 | \& void *newptr = realloc (ptr, size); |
267 | .Ve |
337 | .Ve |
… | |
… | |
289 | callback is set, then libev will expect it to remedy the sitution, no |
359 | callback is set, then libev will expect it to remedy the sitution, no |
290 | matter what, when it returns. That is, libev will generally retry the |
360 | matter what, when it returns. That is, libev will generally retry the |
291 | requested operation, or, if the condition doesn't go away, do bad stuff |
361 | requested operation, or, if the condition doesn't go away, do bad stuff |
292 | (such as abort). |
362 | (such as abort). |
293 | .Sp |
363 | .Sp |
294 | Example: do the same thing as libev does internally: |
364 | Example: This is basically the same thing that libev does internally, too. |
295 | .Sp |
365 | .Sp |
296 | .Vb 6 |
366 | .Vb 6 |
297 | \& static void |
367 | \& static void |
298 | \& fatal_error (const char *msg) |
368 | \& fatal_error (const char *msg) |
299 | \& { |
369 | \& { |
… | |
… | |
345 | or setgid) then libev will \fInot\fR look at the environment variable |
415 | or setgid) then libev will \fInot\fR look at the environment variable |
346 | \&\f(CW\*(C`LIBEV_FLAGS\*(C'\fR. Otherwise (the default), this environment variable will |
416 | \&\f(CW\*(C`LIBEV_FLAGS\*(C'\fR. Otherwise (the default), this environment variable will |
347 | override the flags completely if it is found in the environment. This is |
417 | override the flags completely if it is found in the environment. This is |
348 | useful to try out specific backends to test their performance, or to work |
418 | useful to try out specific backends to test their performance, or to work |
349 | around bugs. |
419 | around bugs. |
|
|
420 | .ie n .IP """EVFLAG_FORKCHECK""" 4 |
|
|
421 | .el .IP "\f(CWEVFLAG_FORKCHECK\fR" 4 |
|
|
422 | .IX Item "EVFLAG_FORKCHECK" |
|
|
423 | Instead of calling \f(CW\*(C`ev_default_fork\*(C'\fR or \f(CW\*(C`ev_loop_fork\*(C'\fR manually after |
|
|
424 | a fork, you can also make libev check for a fork in each iteration by |
|
|
425 | enabling this flag. |
|
|
426 | .Sp |
|
|
427 | This works by calling \f(CW\*(C`getpid ()\*(C'\fR on every iteration of the loop, |
|
|
428 | and thus this might slow down your event loop if you do a lot of loop |
|
|
429 | iterations and little real work, but is usually not noticeable (on my |
|
|
430 | Linux system for example, \f(CW\*(C`getpid\*(C'\fR is actually a simple 5\-insn sequence |
|
|
431 | without a syscall and thus \fIvery\fR fast, but my Linux system also has |
|
|
432 | \&\f(CW\*(C`pthread_atfork\*(C'\fR which is even faster). |
|
|
433 | .Sp |
|
|
434 | The big advantage of this flag is that you can forget about fork (and |
|
|
435 | forget about forgetting to tell libev about forking) when you use this |
|
|
436 | flag. |
|
|
437 | .Sp |
|
|
438 | This flag setting cannot be overriden or specified in the \f(CW\*(C`LIBEV_FLAGS\*(C'\fR |
|
|
439 | environment variable. |
350 | .ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 |
440 | .ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 |
351 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
441 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
352 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
442 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
353 | This is your standard \fIselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
443 | This is your standard \fIselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
354 | libev tries to roll its own fd_set with no limits on the number of fds, |
444 | libev tries to roll its own fd_set with no limits on the number of fds, |
… | |
… | |
448 | Similar to \f(CW\*(C`ev_default_loop\*(C'\fR, but always creates a new event loop that is |
538 | Similar to \f(CW\*(C`ev_default_loop\*(C'\fR, but always creates a new event loop that is |
449 | always distinct from the default loop. Unlike the default loop, it cannot |
539 | always distinct from the default loop. Unlike the default loop, it cannot |
450 | handle signal and child watchers, and attempts to do so will be greeted by |
540 | handle signal and child watchers, and attempts to do so will be greeted by |
451 | undefined behaviour (or a failed assertion if assertions are enabled). |
541 | undefined behaviour (or a failed assertion if assertions are enabled). |
452 | .Sp |
542 | .Sp |
453 | Example: try to create a event loop that uses epoll and nothing else. |
543 | Example: Try to create a event loop that uses epoll and nothing else. |
454 | .Sp |
544 | .Sp |
455 | .Vb 3 |
545 | .Vb 3 |
456 | \& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
546 | \& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
457 | \& if (!epoller) |
547 | \& if (!epoller) |
458 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
548 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
… | |
… | |
495 | .IP "ev_loop_fork (loop)" 4 |
585 | .IP "ev_loop_fork (loop)" 4 |
496 | .IX Item "ev_loop_fork (loop)" |
586 | .IX Item "ev_loop_fork (loop)" |
497 | Like \f(CW\*(C`ev_default_fork\*(C'\fR, but acts on an event loop created by |
587 | Like \f(CW\*(C`ev_default_fork\*(C'\fR, but acts on an event loop created by |
498 | \&\f(CW\*(C`ev_loop_new\*(C'\fR. Yes, you have to call this on every allocated event loop |
588 | \&\f(CW\*(C`ev_loop_new\*(C'\fR. Yes, you have to call this on every allocated event loop |
499 | after fork, and how you do this is entirely your own problem. |
589 | after fork, and how you do this is entirely your own problem. |
|
|
590 | .IP "unsigned int ev_loop_count (loop)" 4 |
|
|
591 | .IX Item "unsigned int ev_loop_count (loop)" |
|
|
592 | Returns the count of loop iterations for the loop, which is identical to |
|
|
593 | the number of times libev did poll for new events. It starts at \f(CW0\fR and |
|
|
594 | happily wraps around with enough iterations. |
|
|
595 | .Sp |
|
|
596 | This value can sometimes be useful as a generation counter of sorts (it |
|
|
597 | \&\*(L"ticks\*(R" the number of loop iterations), as it roughly corresponds with |
|
|
598 | \&\f(CW\*(C`ev_prepare\*(C'\fR and \f(CW\*(C`ev_check\*(C'\fR calls. |
500 | .IP "unsigned int ev_backend (loop)" 4 |
599 | .IP "unsigned int ev_backend (loop)" 4 |
501 | .IX Item "unsigned int ev_backend (loop)" |
600 | .IX Item "unsigned int ev_backend (loop)" |
502 | Returns one of the \f(CW\*(C`EVBACKEND_*\*(C'\fR flags indicating the event backend in |
601 | Returns one of the \f(CW\*(C`EVBACKEND_*\*(C'\fR flags indicating the event backend in |
503 | use. |
602 | use. |
504 | .IP "ev_tstamp ev_now (loop)" 4 |
603 | .IP "ev_tstamp ev_now (loop)" 4 |
… | |
… | |
556 | \& be handled here by queueing them when their watcher gets executed. |
655 | \& be handled here by queueing them when their watcher gets executed. |
557 | \& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
656 | \& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
558 | \& were used, return, otherwise continue with step *. |
657 | \& were used, return, otherwise continue with step *. |
559 | .Ve |
658 | .Ve |
560 | .Sp |
659 | .Sp |
561 | Example: queue some jobs and then loop until no events are outsanding |
660 | Example: Queue some jobs and then loop until no events are outsanding |
562 | anymore. |
661 | anymore. |
563 | .Sp |
662 | .Sp |
564 | .Vb 4 |
663 | .Vb 4 |
565 | \& ... queue jobs here, make sure they register event watchers as long |
664 | \& ... queue jobs here, make sure they register event watchers as long |
566 | \& ... as they still have work to do (even an idle watcher will do..) |
665 | \& ... as they still have work to do (even an idle watcher will do..) |
… | |
… | |
588 | visible to the libev user and should not keep \f(CW\*(C`ev_loop\*(C'\fR from exiting if |
687 | visible to the libev user and should not keep \f(CW\*(C`ev_loop\*(C'\fR from exiting if |
589 | no event watchers registered by it are active. It is also an excellent |
688 | no event watchers registered by it are active. It is also an excellent |
590 | way to do this for generic recurring timers or from within third-party |
689 | way to do this for generic recurring timers or from within third-party |
591 | libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR. |
690 | libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR. |
592 | .Sp |
691 | .Sp |
593 | Example: create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
692 | Example: Create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
594 | running when nothing else is active. |
693 | running when nothing else is active. |
595 | .Sp |
694 | .Sp |
596 | .Vb 4 |
695 | .Vb 4 |
597 | \& struct dv_signal exitsig; |
696 | \& struct ev_signal exitsig; |
598 | \& ev_signal_init (&exitsig, sig_cb, SIGINT); |
697 | \& ev_signal_init (&exitsig, sig_cb, SIGINT); |
599 | \& ev_signal_start (myloop, &exitsig); |
698 | \& ev_signal_start (loop, &exitsig); |
600 | \& evf_unref (myloop); |
699 | \& evf_unref (loop); |
601 | .Ve |
700 | .Ve |
602 | .Sp |
701 | .Sp |
603 | Example: for some weird reason, unregister the above signal handler again. |
702 | Example: For some weird reason, unregister the above signal handler again. |
604 | .Sp |
703 | .Sp |
605 | .Vb 2 |
704 | .Vb 2 |
606 | \& ev_ref (myloop); |
705 | \& ev_ref (loop); |
607 | \& ev_signal_stop (myloop, &exitsig); |
706 | \& ev_signal_stop (loop, &exitsig); |
608 | .Ve |
707 | .Ve |
609 | .SH "ANATOMY OF A WATCHER" |
708 | .SH "ANATOMY OF A WATCHER" |
610 | .IX Header "ANATOMY OF A WATCHER" |
709 | .IX Header "ANATOMY OF A WATCHER" |
611 | A watcher is a structure that you create and register to record your |
710 | A watcher is a structure that you create and register to record your |
612 | interest in some event. For instance, if you want to wait for \s-1STDIN\s0 to |
711 | interest in some event. For instance, if you want to wait for \s-1STDIN\s0 to |
… | |
… | |
684 | The signal specified in the \f(CW\*(C`ev_signal\*(C'\fR watcher has been received by a thread. |
783 | The signal specified in the \f(CW\*(C`ev_signal\*(C'\fR watcher has been received by a thread. |
685 | .ie n .IP """EV_CHILD""" 4 |
784 | .ie n .IP """EV_CHILD""" 4 |
686 | .el .IP "\f(CWEV_CHILD\fR" 4 |
785 | .el .IP "\f(CWEV_CHILD\fR" 4 |
687 | .IX Item "EV_CHILD" |
786 | .IX Item "EV_CHILD" |
688 | The pid specified in the \f(CW\*(C`ev_child\*(C'\fR watcher has received a status change. |
787 | The pid specified in the \f(CW\*(C`ev_child\*(C'\fR watcher has received a status change. |
|
|
788 | .ie n .IP """EV_STAT""" 4 |
|
|
789 | .el .IP "\f(CWEV_STAT\fR" 4 |
|
|
790 | .IX Item "EV_STAT" |
|
|
791 | The path specified in the \f(CW\*(C`ev_stat\*(C'\fR watcher changed its attributes somehow. |
689 | .ie n .IP """EV_IDLE""" 4 |
792 | .ie n .IP """EV_IDLE""" 4 |
690 | .el .IP "\f(CWEV_IDLE\fR" 4 |
793 | .el .IP "\f(CWEV_IDLE\fR" 4 |
691 | .IX Item "EV_IDLE" |
794 | .IX Item "EV_IDLE" |
692 | The \f(CW\*(C`ev_idle\*(C'\fR watcher has determined that you have nothing better to do. |
795 | The \f(CW\*(C`ev_idle\*(C'\fR watcher has determined that you have nothing better to do. |
693 | .ie n .IP """EV_PREPARE""" 4 |
796 | .ie n .IP """EV_PREPARE""" 4 |
… | |
… | |
703 | \&\f(CW\*(C`ev_loop\*(C'\fR has gathered them, but before it invokes any callbacks for any |
806 | \&\f(CW\*(C`ev_loop\*(C'\fR has gathered them, but before it invokes any callbacks for any |
704 | received events. Callbacks of both watcher types can start and stop as |
807 | received events. Callbacks of both watcher types can start and stop as |
705 | many watchers as they want, and all of them will be taken into account |
808 | many watchers as they want, and all of them will be taken into account |
706 | (for example, a \f(CW\*(C`ev_prepare\*(C'\fR watcher might start an idle watcher to keep |
809 | (for example, a \f(CW\*(C`ev_prepare\*(C'\fR watcher might start an idle watcher to keep |
707 | \&\f(CW\*(C`ev_loop\*(C'\fR from blocking). |
810 | \&\f(CW\*(C`ev_loop\*(C'\fR from blocking). |
|
|
811 | .ie n .IP """EV_EMBED""" 4 |
|
|
812 | .el .IP "\f(CWEV_EMBED\fR" 4 |
|
|
813 | .IX Item "EV_EMBED" |
|
|
814 | The embedded event loop specified in the \f(CW\*(C`ev_embed\*(C'\fR watcher needs attention. |
|
|
815 | .ie n .IP """EV_FORK""" 4 |
|
|
816 | .el .IP "\f(CWEV_FORK\fR" 4 |
|
|
817 | .IX Item "EV_FORK" |
|
|
818 | The event loop has been resumed in the child process after fork (see |
|
|
819 | \&\f(CW\*(C`ev_fork\*(C'\fR). |
708 | .ie n .IP """EV_ERROR""" 4 |
820 | .ie n .IP """EV_ERROR""" 4 |
709 | .el .IP "\f(CWEV_ERROR\fR" 4 |
821 | .el .IP "\f(CWEV_ERROR\fR" 4 |
710 | .IX Item "EV_ERROR" |
822 | .IX Item "EV_ERROR" |
711 | An unspecified error has occured, the watcher has been stopped. This might |
823 | An unspecified error has occured, the watcher has been stopped. This might |
712 | happen because the watcher could not be properly started because libev |
824 | happen because the watcher could not be properly started because libev |
… | |
… | |
777 | .IP "bool ev_is_pending (ev_TYPE *watcher)" 4 |
889 | .IP "bool ev_is_pending (ev_TYPE *watcher)" 4 |
778 | .IX Item "bool ev_is_pending (ev_TYPE *watcher)" |
890 | .IX Item "bool ev_is_pending (ev_TYPE *watcher)" |
779 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
891 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
780 | events but its callback has not yet been invoked). As long as a watcher |
892 | events but its callback has not yet been invoked). As long as a watcher |
781 | is pending (but not active) you must not call an init function on it (but |
893 | is pending (but not active) you must not call an init function on it (but |
782 | \&\f(CW\*(C`ev_TYPE_set\*(C'\fR is safe) and you must make sure the watcher is available to |
894 | \&\f(CW\*(C`ev_TYPE_set\*(C'\fR is safe), you must not change its priority, and you must |
783 | libev (e.g. you cnanot \f(CW\*(C`free ()\*(C'\fR it). |
895 | make sure the watcher is available to libev (e.g. you cannot \f(CW\*(C`free ()\*(C'\fR |
|
|
896 | it). |
784 | .IP "callback = ev_cb (ev_TYPE *watcher)" 4 |
897 | .IP "callback ev_cb (ev_TYPE *watcher)" 4 |
785 | .IX Item "callback = ev_cb (ev_TYPE *watcher)" |
898 | .IX Item "callback ev_cb (ev_TYPE *watcher)" |
786 | Returns the callback currently set on the watcher. |
899 | Returns the callback currently set on the watcher. |
787 | .IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 |
900 | .IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 |
788 | .IX Item "ev_cb_set (ev_TYPE *watcher, callback)" |
901 | .IX Item "ev_cb_set (ev_TYPE *watcher, callback)" |
789 | Change the callback. You can change the callback at virtually any time |
902 | Change the callback. You can change the callback at virtually any time |
790 | (modulo threads). |
903 | (modulo threads). |
|
|
904 | .IP "ev_set_priority (ev_TYPE *watcher, priority)" 4 |
|
|
905 | .IX Item "ev_set_priority (ev_TYPE *watcher, priority)" |
|
|
906 | .PD 0 |
|
|
907 | .IP "int ev_priority (ev_TYPE *watcher)" 4 |
|
|
908 | .IX Item "int ev_priority (ev_TYPE *watcher)" |
|
|
909 | .PD |
|
|
910 | Set and query the priority of the watcher. The priority is a small |
|
|
911 | integer between \f(CW\*(C`EV_MAXPRI\*(C'\fR (default: \f(CW2\fR) and \f(CW\*(C`EV_MINPRI\*(C'\fR |
|
|
912 | (default: \f(CW\*(C`\-2\*(C'\fR). Pending watchers with higher priority will be invoked |
|
|
913 | before watchers with lower priority, but priority will not keep watchers |
|
|
914 | from being executed (except for \f(CW\*(C`ev_idle\*(C'\fR watchers). |
|
|
915 | .Sp |
|
|
916 | This means that priorities are \fIonly\fR used for ordering callback |
|
|
917 | invocation after new events have been received. This is useful, for |
|
|
918 | example, to reduce latency after idling, or more often, to bind two |
|
|
919 | watchers on the same event and make sure one is called first. |
|
|
920 | .Sp |
|
|
921 | If you need to suppress invocation when higher priority events are pending |
|
|
922 | you need to look at \f(CW\*(C`ev_idle\*(C'\fR watchers, which provide this functionality. |
|
|
923 | .Sp |
|
|
924 | You \fImust not\fR change the priority of a watcher as long as it is active or |
|
|
925 | pending. |
|
|
926 | .Sp |
|
|
927 | The default priority used by watchers when no priority has been set is |
|
|
928 | always \f(CW0\fR, which is supposed to not be too high and not be too low :). |
|
|
929 | .Sp |
|
|
930 | Setting a priority outside the range of \f(CW\*(C`EV_MINPRI\*(C'\fR to \f(CW\*(C`EV_MAXPRI\*(C'\fR is |
|
|
931 | fine, as long as you do not mind that the priority value you query might |
|
|
932 | or might not have been adjusted to be within valid range. |
|
|
933 | .IP "ev_invoke (loop, ev_TYPE *watcher, int revents)" 4 |
|
|
934 | .IX Item "ev_invoke (loop, ev_TYPE *watcher, int revents)" |
|
|
935 | Invoke the \f(CW\*(C`watcher\*(C'\fR with the given \f(CW\*(C`loop\*(C'\fR and \f(CW\*(C`revents\*(C'\fR. Neither |
|
|
936 | \&\f(CW\*(C`loop\*(C'\fR nor \f(CW\*(C`revents\*(C'\fR need to be valid as long as the watcher callback |
|
|
937 | can deal with that fact. |
|
|
938 | .IP "int ev_clear_pending (loop, ev_TYPE *watcher)" 4 |
|
|
939 | .IX Item "int ev_clear_pending (loop, ev_TYPE *watcher)" |
|
|
940 | If the watcher is pending, this function returns clears its pending status |
|
|
941 | and returns its \f(CW\*(C`revents\*(C'\fR bitset (as if its callback was invoked). If the |
|
|
942 | watcher isn't pending it does nothing and returns \f(CW0\fR. |
791 | .Sh "\s-1ASSOCIATING\s0 \s-1CUSTOM\s0 \s-1DATA\s0 \s-1WITH\s0 A \s-1WATCHER\s0" |
943 | .Sh "\s-1ASSOCIATING\s0 \s-1CUSTOM\s0 \s-1DATA\s0 \s-1WITH\s0 A \s-1WATCHER\s0" |
792 | .IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER" |
944 | .IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER" |
793 | Each watcher has, by default, a member \f(CW\*(C`void *data\*(C'\fR that you can change |
945 | Each watcher has, by default, a member \f(CW\*(C`void *data\*(C'\fR that you can change |
794 | and read at any time, libev will completely ignore it. This can be used |
946 | and read at any time, libev will completely ignore it. This can be used |
795 | to associate arbitrary data with your watcher. If you need more data and |
947 | to associate arbitrary data with your watcher. If you need more data and |
… | |
… | |
816 | \& struct my_io *w = (struct my_io *)w_; |
968 | \& struct my_io *w = (struct my_io *)w_; |
817 | \& ... |
969 | \& ... |
818 | \& } |
970 | \& } |
819 | .Ve |
971 | .Ve |
820 | .PP |
972 | .PP |
821 | More interesting and less C\-conformant ways of catsing your callback type |
973 | More interesting and less C\-conformant ways of casting your callback type |
822 | have been omitted.... |
974 | instead have been omitted. |
|
|
975 | .PP |
|
|
976 | Another common scenario is having some data structure with multiple |
|
|
977 | watchers: |
|
|
978 | .PP |
|
|
979 | .Vb 6 |
|
|
980 | \& struct my_biggy |
|
|
981 | \& { |
|
|
982 | \& int some_data; |
|
|
983 | \& ev_timer t1; |
|
|
984 | \& ev_timer t2; |
|
|
985 | \& } |
|
|
986 | .Ve |
|
|
987 | .PP |
|
|
988 | In this case getting the pointer to \f(CW\*(C`my_biggy\*(C'\fR is a bit more complicated, |
|
|
989 | you need to use \f(CW\*(C`offsetof\*(C'\fR: |
|
|
990 | .PP |
|
|
991 | .Vb 1 |
|
|
992 | \& #include <stddef.h> |
|
|
993 | .Ve |
|
|
994 | .PP |
|
|
995 | .Vb 6 |
|
|
996 | \& static void |
|
|
997 | \& t1_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
998 | \& { |
|
|
999 | \& struct my_biggy big = (struct my_biggy * |
|
|
1000 | \& (((char *)w) - offsetof (struct my_biggy, t1)); |
|
|
1001 | \& } |
|
|
1002 | .Ve |
|
|
1003 | .PP |
|
|
1004 | .Vb 6 |
|
|
1005 | \& static void |
|
|
1006 | \& t2_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
1007 | \& { |
|
|
1008 | \& struct my_biggy big = (struct my_biggy * |
|
|
1009 | \& (((char *)w) - offsetof (struct my_biggy, t2)); |
|
|
1010 | \& } |
|
|
1011 | .Ve |
823 | .SH "WATCHER TYPES" |
1012 | .SH "WATCHER TYPES" |
824 | .IX Header "WATCHER TYPES" |
1013 | .IX Header "WATCHER TYPES" |
825 | This section describes each watcher in detail, but will not repeat |
1014 | This section describes each watcher in detail, but will not repeat |
826 | information given in the last section. |
1015 | information given in the last section. Any initialisation/set macros, |
|
|
1016 | functions and members specific to the watcher type are explained. |
|
|
1017 | .PP |
|
|
1018 | Members are additionally marked with either \fI[read\-only]\fR, meaning that, |
|
|
1019 | while the watcher is active, you can look at the member and expect some |
|
|
1020 | sensible content, but you must not modify it (you can modify it while the |
|
|
1021 | watcher is stopped to your hearts content), or \fI[read\-write]\fR, which |
|
|
1022 | means you can expect it to have some sensible content while the watcher |
|
|
1023 | is active, but you can also modify it. Modifying it may not do something |
|
|
1024 | sensible or take immediate effect (or do anything at all), but libev will |
|
|
1025 | not crash or malfunction in any way. |
827 | .ie n .Sh """ev_io"" \- is this file descriptor readable or writable?" |
1026 | .ie n .Sh """ev_io"" \- is this file descriptor readable or writable?" |
828 | .el .Sh "\f(CWev_io\fP \- is this file descriptor readable or writable?" |
1027 | .el .Sh "\f(CWev_io\fP \- is this file descriptor readable or writable?" |
829 | .IX Subsection "ev_io - is this file descriptor readable or writable?" |
1028 | .IX Subsection "ev_io - is this file descriptor readable or writable?" |
830 | I/O watchers check whether a file descriptor is readable or writable |
1029 | I/O watchers check whether a file descriptor is readable or writable |
831 | in each iteration of the event loop, or, more precisely, when reading |
1030 | in each iteration of the event loop, or, more precisely, when reading |
… | |
… | |
859 | it is best to always use non-blocking I/O: An extra \f(CW\*(C`read\*(C'\fR(2) returning |
1058 | it is best to always use non-blocking I/O: An extra \f(CW\*(C`read\*(C'\fR(2) returning |
860 | \&\f(CW\*(C`EAGAIN\*(C'\fR is far preferable to a program hanging until some data arrives. |
1059 | \&\f(CW\*(C`EAGAIN\*(C'\fR is far preferable to a program hanging until some data arrives. |
861 | .PP |
1060 | .PP |
862 | If you cannot run the fd in non-blocking mode (for example you should not |
1061 | If you cannot run the fd in non-blocking mode (for example you should not |
863 | play around with an Xlib connection), then you have to seperately re-test |
1062 | play around with an Xlib connection), then you have to seperately re-test |
864 | wether a file descriptor is really ready with a known-to-be good interface |
1063 | whether a file descriptor is really ready with a known-to-be good interface |
865 | such as poll (fortunately in our Xlib example, Xlib already does this on |
1064 | such as poll (fortunately in our Xlib example, Xlib already does this on |
866 | its own, so its quite safe to use). |
1065 | its own, so its quite safe to use). |
867 | .IP "ev_io_init (ev_io *, callback, int fd, int events)" 4 |
1066 | .IP "ev_io_init (ev_io *, callback, int fd, int events)" 4 |
868 | .IX Item "ev_io_init (ev_io *, callback, int fd, int events)" |
1067 | .IX Item "ev_io_init (ev_io *, callback, int fd, int events)" |
869 | .PD 0 |
1068 | .PD 0 |
… | |
… | |
871 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
1070 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
872 | .PD |
1071 | .PD |
873 | Configures an \f(CW\*(C`ev_io\*(C'\fR watcher. The \f(CW\*(C`fd\*(C'\fR is the file descriptor to |
1072 | Configures an \f(CW\*(C`ev_io\*(C'\fR watcher. The \f(CW\*(C`fd\*(C'\fR is the file descriptor to |
874 | rceeive events for and events is either \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or |
1073 | rceeive events for and events is either \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or |
875 | \&\f(CW\*(C`EV_READ | EV_WRITE\*(C'\fR to receive the given events. |
1074 | \&\f(CW\*(C`EV_READ | EV_WRITE\*(C'\fR to receive the given events. |
|
|
1075 | .IP "int fd [read\-only]" 4 |
|
|
1076 | .IX Item "int fd [read-only]" |
|
|
1077 | The file descriptor being watched. |
|
|
1078 | .IP "int events [read\-only]" 4 |
|
|
1079 | .IX Item "int events [read-only]" |
|
|
1080 | The events being watched. |
876 | .PP |
1081 | .PP |
877 | Example: call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
1082 | Example: Call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
878 | readable, but only once. Since it is likely line\-buffered, you could |
1083 | readable, but only once. Since it is likely line\-buffered, you could |
879 | attempt to read a whole line in the callback: |
1084 | attempt to read a whole line in the callback. |
880 | .PP |
1085 | .PP |
881 | .Vb 6 |
1086 | .Vb 6 |
882 | \& static void |
1087 | \& static void |
883 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1088 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
884 | \& { |
1089 | \& { |
… | |
… | |
939 | .IP "ev_timer_again (loop)" 4 |
1144 | .IP "ev_timer_again (loop)" 4 |
940 | .IX Item "ev_timer_again (loop)" |
1145 | .IX Item "ev_timer_again (loop)" |
941 | This will act as if the timer timed out and restart it again if it is |
1146 | This will act as if the timer timed out and restart it again if it is |
942 | repeating. The exact semantics are: |
1147 | repeating. The exact semantics are: |
943 | .Sp |
1148 | .Sp |
|
|
1149 | If the timer is pending, its pending status is cleared. |
|
|
1150 | .Sp |
944 | If the timer is started but nonrepeating, stop it. |
1151 | If the timer is started but nonrepeating, stop it (as if it timed out). |
945 | .Sp |
1152 | .Sp |
946 | If the timer is repeating, either start it if necessary (with the repeat |
1153 | If the timer is repeating, either start it if necessary (with the |
947 | value), or reset the running timer to the repeat value. |
1154 | \&\f(CW\*(C`repeat\*(C'\fR value), or reset the running timer to the \f(CW\*(C`repeat\*(C'\fR value. |
948 | .Sp |
1155 | .Sp |
949 | This sounds a bit complicated, but here is a useful and typical |
1156 | This sounds a bit complicated, but here is a useful and typical |
950 | example: Imagine you have a tcp connection and you want a so-called idle |
1157 | example: Imagine you have a tcp connection and you want a so-called idle |
951 | timeout, that is, you want to be called when there have been, say, 60 |
1158 | timeout, that is, you want to be called when there have been, say, 60 |
952 | seconds of inactivity on the socket. The easiest way to do this is to |
1159 | seconds of inactivity on the socket. The easiest way to do this is to |
953 | configure an \f(CW\*(C`ev_timer\*(C'\fR with after=repeat=60 and calling ev_timer_again each |
1160 | configure an \f(CW\*(C`ev_timer\*(C'\fR with a \f(CW\*(C`repeat\*(C'\fR value of \f(CW60\fR and then call |
954 | time you successfully read or write some data. If you go into an idle |
1161 | \&\f(CW\*(C`ev_timer_again\*(C'\fR each time you successfully read or write some data. If |
955 | state where you do not expect data to travel on the socket, you can stop |
1162 | you go into an idle state where you do not expect data to travel on the |
956 | the timer, and again will automatically restart it if need be. |
1163 | socket, you can \f(CW\*(C`ev_timer_stop\*(C'\fR the timer, and \f(CW\*(C`ev_timer_again\*(C'\fR will |
|
|
1164 | automatically restart it if need be. |
|
|
1165 | .Sp |
|
|
1166 | That means you can ignore the \f(CW\*(C`after\*(C'\fR value and \f(CW\*(C`ev_timer_start\*(C'\fR |
|
|
1167 | altogether and only ever use the \f(CW\*(C`repeat\*(C'\fR value and \f(CW\*(C`ev_timer_again\*(C'\fR: |
|
|
1168 | .Sp |
|
|
1169 | .Vb 8 |
|
|
1170 | \& ev_timer_init (timer, callback, 0., 5.); |
|
|
1171 | \& ev_timer_again (loop, timer); |
|
|
1172 | \& ... |
|
|
1173 | \& timer->again = 17.; |
|
|
1174 | \& ev_timer_again (loop, timer); |
|
|
1175 | \& ... |
|
|
1176 | \& timer->again = 10.; |
|
|
1177 | \& ev_timer_again (loop, timer); |
|
|
1178 | .Ve |
|
|
1179 | .Sp |
|
|
1180 | This is more slightly efficient then stopping/starting the timer each time |
|
|
1181 | you want to modify its timeout value. |
|
|
1182 | .IP "ev_tstamp repeat [read\-write]" 4 |
|
|
1183 | .IX Item "ev_tstamp repeat [read-write]" |
|
|
1184 | The current \f(CW\*(C`repeat\*(C'\fR value. Will be used each time the watcher times out |
|
|
1185 | or \f(CW\*(C`ev_timer_again\*(C'\fR is called and determines the next timeout (if any), |
|
|
1186 | which is also when any modifications are taken into account. |
957 | .PP |
1187 | .PP |
958 | Example: create a timer that fires after 60 seconds. |
1188 | Example: Create a timer that fires after 60 seconds. |
959 | .PP |
1189 | .PP |
960 | .Vb 5 |
1190 | .Vb 5 |
961 | \& static void |
1191 | \& static void |
962 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1192 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
963 | \& { |
1193 | \& { |
… | |
… | |
969 | \& struct ev_timer mytimer; |
1199 | \& struct ev_timer mytimer; |
970 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
1200 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
971 | \& ev_timer_start (loop, &mytimer); |
1201 | \& ev_timer_start (loop, &mytimer); |
972 | .Ve |
1202 | .Ve |
973 | .PP |
1203 | .PP |
974 | Example: create a timeout timer that times out after 10 seconds of |
1204 | Example: Create a timeout timer that times out after 10 seconds of |
975 | inactivity. |
1205 | inactivity. |
976 | .PP |
1206 | .PP |
977 | .Vb 5 |
1207 | .Vb 5 |
978 | \& static void |
1208 | \& static void |
979 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1209 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
… | |
… | |
1093 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
1323 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
1094 | Simply stops and restarts the periodic watcher again. This is only useful |
1324 | Simply stops and restarts the periodic watcher again. This is only useful |
1095 | when you changed some parameters or the reschedule callback would return |
1325 | when you changed some parameters or the reschedule callback would return |
1096 | a different time than the last time it was called (e.g. in a crond like |
1326 | a different time than the last time it was called (e.g. in a crond like |
1097 | program when the crontabs have changed). |
1327 | program when the crontabs have changed). |
|
|
1328 | .IP "ev_tstamp interval [read\-write]" 4 |
|
|
1329 | .IX Item "ev_tstamp interval [read-write]" |
|
|
1330 | The current interval value. Can be modified any time, but changes only |
|
|
1331 | take effect when the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being |
|
|
1332 | called. |
|
|
1333 | .IP "ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read\-write]" 4 |
|
|
1334 | .IX Item "ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read-write]" |
|
|
1335 | The current reschedule callback, or \f(CW0\fR, if this functionality is |
|
|
1336 | switched off. Can be changed any time, but changes only take effect when |
|
|
1337 | the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being called. |
1098 | .PP |
1338 | .PP |
1099 | Example: call a callback every hour, or, more precisely, whenever the |
1339 | Example: Call a callback every hour, or, more precisely, whenever the |
1100 | system clock is divisible by 3600. The callback invocation times have |
1340 | system clock is divisible by 3600. The callback invocation times have |
1101 | potentially a lot of jittering, but good long-term stability. |
1341 | potentially a lot of jittering, but good long-term stability. |
1102 | .PP |
1342 | .PP |
1103 | .Vb 5 |
1343 | .Vb 5 |
1104 | \& static void |
1344 | \& static void |
… | |
… | |
1112 | \& struct ev_periodic hourly_tick; |
1352 | \& struct ev_periodic hourly_tick; |
1113 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1353 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1114 | \& ev_periodic_start (loop, &hourly_tick); |
1354 | \& ev_periodic_start (loop, &hourly_tick); |
1115 | .Ve |
1355 | .Ve |
1116 | .PP |
1356 | .PP |
1117 | Example: the same as above, but use a reschedule callback to do it: |
1357 | Example: The same as above, but use a reschedule callback to do it: |
1118 | .PP |
1358 | .PP |
1119 | .Vb 1 |
1359 | .Vb 1 |
1120 | \& #include <math.h> |
1360 | \& #include <math.h> |
1121 | .Ve |
1361 | .Ve |
1122 | .PP |
1362 | .PP |
… | |
… | |
1130 | .PP |
1370 | .PP |
1131 | .Vb 1 |
1371 | .Vb 1 |
1132 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1372 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1133 | .Ve |
1373 | .Ve |
1134 | .PP |
1374 | .PP |
1135 | Example: call a callback every hour, starting now: |
1375 | Example: Call a callback every hour, starting now: |
1136 | .PP |
1376 | .PP |
1137 | .Vb 4 |
1377 | .Vb 4 |
1138 | \& struct ev_periodic hourly_tick; |
1378 | \& struct ev_periodic hourly_tick; |
1139 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1379 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1140 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
1380 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
… | |
… | |
1160 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
1400 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
1161 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
1401 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
1162 | .PD |
1402 | .PD |
1163 | Configures the watcher to trigger on the given signal number (usually one |
1403 | Configures the watcher to trigger on the given signal number (usually one |
1164 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
1404 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
|
|
1405 | .IP "int signum [read\-only]" 4 |
|
|
1406 | .IX Item "int signum [read-only]" |
|
|
1407 | The signal the watcher watches out for. |
1165 | .ie n .Sh """ev_child"" \- watch out for process status changes" |
1408 | .ie n .Sh """ev_child"" \- watch out for process status changes" |
1166 | .el .Sh "\f(CWev_child\fP \- watch out for process status changes" |
1409 | .el .Sh "\f(CWev_child\fP \- watch out for process status changes" |
1167 | .IX Subsection "ev_child - watch out for process status changes" |
1410 | .IX Subsection "ev_child - watch out for process status changes" |
1168 | Child watchers trigger when your process receives a \s-1SIGCHLD\s0 in response to |
1411 | Child watchers trigger when your process receives a \s-1SIGCHLD\s0 in response to |
1169 | some child status changes (most typically when a child of yours dies). |
1412 | some child status changes (most typically when a child of yours dies). |
… | |
… | |
1177 | \&\fIany\fR process if \f(CW\*(C`pid\*(C'\fR is specified as \f(CW0\fR). The callback can look |
1420 | \&\fIany\fR process if \f(CW\*(C`pid\*(C'\fR is specified as \f(CW0\fR). The callback can look |
1178 | at the \f(CW\*(C`rstatus\*(C'\fR member of the \f(CW\*(C`ev_child\*(C'\fR watcher structure to see |
1421 | at the \f(CW\*(C`rstatus\*(C'\fR member of the \f(CW\*(C`ev_child\*(C'\fR watcher structure to see |
1179 | the status word (use the macros from \f(CW\*(C`sys/wait.h\*(C'\fR and see your systems |
1422 | the status word (use the macros from \f(CW\*(C`sys/wait.h\*(C'\fR and see your systems |
1180 | \&\f(CW\*(C`waitpid\*(C'\fR documentation). The \f(CW\*(C`rpid\*(C'\fR member contains the pid of the |
1423 | \&\f(CW\*(C`waitpid\*(C'\fR documentation). The \f(CW\*(C`rpid\*(C'\fR member contains the pid of the |
1181 | process causing the status change. |
1424 | process causing the status change. |
|
|
1425 | .IP "int pid [read\-only]" 4 |
|
|
1426 | .IX Item "int pid [read-only]" |
|
|
1427 | The process id this watcher watches out for, or \f(CW0\fR, meaning any process id. |
|
|
1428 | .IP "int rpid [read\-write]" 4 |
|
|
1429 | .IX Item "int rpid [read-write]" |
|
|
1430 | The process id that detected a status change. |
|
|
1431 | .IP "int rstatus [read\-write]" 4 |
|
|
1432 | .IX Item "int rstatus [read-write]" |
|
|
1433 | The process exit/trace status caused by \f(CW\*(C`rpid\*(C'\fR (see your systems |
|
|
1434 | \&\f(CW\*(C`waitpid\*(C'\fR and \f(CW\*(C`sys/wait.h\*(C'\fR documentation for details). |
1182 | .PP |
1435 | .PP |
1183 | Example: try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1436 | Example: Try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1184 | .PP |
1437 | .PP |
1185 | .Vb 5 |
1438 | .Vb 5 |
1186 | \& static void |
1439 | \& static void |
1187 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1440 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1188 | \& { |
1441 | \& { |
… | |
… | |
1193 | .Vb 3 |
1446 | .Vb 3 |
1194 | \& struct ev_signal signal_watcher; |
1447 | \& struct ev_signal signal_watcher; |
1195 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1448 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1196 | \& ev_signal_start (loop, &sigint_cb); |
1449 | \& ev_signal_start (loop, &sigint_cb); |
1197 | .Ve |
1450 | .Ve |
|
|
1451 | .ie n .Sh """ev_stat"" \- did the file attributes just change?" |
|
|
1452 | .el .Sh "\f(CWev_stat\fP \- did the file attributes just change?" |
|
|
1453 | .IX Subsection "ev_stat - did the file attributes just change?" |
|
|
1454 | This watches a filesystem path for attribute changes. That is, it calls |
|
|
1455 | \&\f(CW\*(C`stat\*(C'\fR regularly (or when the \s-1OS\s0 says it changed) and sees if it changed |
|
|
1456 | compared to the last time, invoking the callback if it did. |
|
|
1457 | .PP |
|
|
1458 | The path does not need to exist: changing from \*(L"path exists\*(R" to \*(L"path does |
|
|
1459 | not exist\*(R" is a status change like any other. The condition \*(L"path does |
|
|
1460 | not exist\*(R" is signified by the \f(CW\*(C`st_nlink\*(C'\fR field being zero (which is |
|
|
1461 | otherwise always forced to be at least one) and all the other fields of |
|
|
1462 | the stat buffer having unspecified contents. |
|
|
1463 | .PP |
|
|
1464 | The path \fIshould\fR be absolute and \fImust not\fR end in a slash. If it is |
|
|
1465 | relative and your working directory changes, the behaviour is undefined. |
|
|
1466 | .PP |
|
|
1467 | Since there is no standard to do this, the portable implementation simply |
|
|
1468 | calls \f(CW\*(C`stat (2)\*(C'\fR regularly on the path to see if it changed somehow. You |
|
|
1469 | can specify a recommended polling interval for this case. If you specify |
|
|
1470 | a polling interval of \f(CW0\fR (highly recommended!) then a \fIsuitable, |
|
|
1471 | unspecified default\fR value will be used (which you can expect to be around |
|
|
1472 | five seconds, although this might change dynamically). Libev will also |
|
|
1473 | impose a minimum interval which is currently around \f(CW0.1\fR, but thats |
|
|
1474 | usually overkill. |
|
|
1475 | .PP |
|
|
1476 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
1477 | as even with OS-supported change notifications, this can be |
|
|
1478 | resource\-intensive. |
|
|
1479 | .PP |
|
|
1480 | At the time of this writing, only the Linux inotify interface is |
|
|
1481 | implemented (implementing kqueue support is left as an exercise for the |
|
|
1482 | reader). Inotify will be used to give hints only and should not change the |
|
|
1483 | semantics of \f(CW\*(C`ev_stat\*(C'\fR watchers, which means that libev sometimes needs |
|
|
1484 | to fall back to regular polling again even with inotify, but changes are |
|
|
1485 | usually detected immediately, and if the file exists there will be no |
|
|
1486 | polling. |
|
|
1487 | .IP "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" 4 |
|
|
1488 | .IX Item "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" |
|
|
1489 | .PD 0 |
|
|
1490 | .IP "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" 4 |
|
|
1491 | .IX Item "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" |
|
|
1492 | .PD |
|
|
1493 | Configures the watcher to wait for status changes of the given |
|
|
1494 | \&\f(CW\*(C`path\*(C'\fR. The \f(CW\*(C`interval\*(C'\fR is a hint on how quickly a change is expected to |
|
|
1495 | be detected and should normally be specified as \f(CW0\fR to let libev choose |
|
|
1496 | a suitable value. The memory pointed to by \f(CW\*(C`path\*(C'\fR must point to the same |
|
|
1497 | path for as long as the watcher is active. |
|
|
1498 | .Sp |
|
|
1499 | The callback will be receive \f(CW\*(C`EV_STAT\*(C'\fR when a change was detected, |
|
|
1500 | relative to the attributes at the time the watcher was started (or the |
|
|
1501 | last change was detected). |
|
|
1502 | .IP "ev_stat_stat (ev_stat *)" 4 |
|
|
1503 | .IX Item "ev_stat_stat (ev_stat *)" |
|
|
1504 | Updates the stat buffer immediately with new values. If you change the |
|
|
1505 | watched path in your callback, you could call this fucntion to avoid |
|
|
1506 | detecting this change (while introducing a race condition). Can also be |
|
|
1507 | useful simply to find out the new values. |
|
|
1508 | .IP "ev_statdata attr [read\-only]" 4 |
|
|
1509 | .IX Item "ev_statdata attr [read-only]" |
|
|
1510 | The most-recently detected attributes of the file. Although the type is of |
|
|
1511 | \&\f(CW\*(C`ev_statdata\*(C'\fR, this is usually the (or one of the) \f(CW\*(C`struct stat\*(C'\fR types |
|
|
1512 | suitable for your system. If the \f(CW\*(C`st_nlink\*(C'\fR member is \f(CW0\fR, then there |
|
|
1513 | was some error while \f(CW\*(C`stat\*(C'\fRing the file. |
|
|
1514 | .IP "ev_statdata prev [read\-only]" 4 |
|
|
1515 | .IX Item "ev_statdata prev [read-only]" |
|
|
1516 | The previous attributes of the file. The callback gets invoked whenever |
|
|
1517 | \&\f(CW\*(C`prev\*(C'\fR != \f(CW\*(C`attr\*(C'\fR. |
|
|
1518 | .IP "ev_tstamp interval [read\-only]" 4 |
|
|
1519 | .IX Item "ev_tstamp interval [read-only]" |
|
|
1520 | The specified interval. |
|
|
1521 | .IP "const char *path [read\-only]" 4 |
|
|
1522 | .IX Item "const char *path [read-only]" |
|
|
1523 | The filesystem path that is being watched. |
|
|
1524 | .PP |
|
|
1525 | Example: Watch \f(CW\*(C`/etc/passwd\*(C'\fR for attribute changes. |
|
|
1526 | .PP |
|
|
1527 | .Vb 15 |
|
|
1528 | \& static void |
|
|
1529 | \& passwd_cb (struct ev_loop *loop, ev_stat *w, int revents) |
|
|
1530 | \& { |
|
|
1531 | \& /* /etc/passwd changed in some way */ |
|
|
1532 | \& if (w->attr.st_nlink) |
|
|
1533 | \& { |
|
|
1534 | \& printf ("passwd current size %ld\en", (long)w->attr.st_size); |
|
|
1535 | \& printf ("passwd current atime %ld\en", (long)w->attr.st_mtime); |
|
|
1536 | \& printf ("passwd current mtime %ld\en", (long)w->attr.st_mtime); |
|
|
1537 | \& } |
|
|
1538 | \& else |
|
|
1539 | \& /* you shalt not abuse printf for puts */ |
|
|
1540 | \& puts ("wow, /etc/passwd is not there, expect problems. " |
|
|
1541 | \& "if this is windows, they already arrived\en"); |
|
|
1542 | \& } |
|
|
1543 | .Ve |
|
|
1544 | .PP |
|
|
1545 | .Vb 2 |
|
|
1546 | \& ... |
|
|
1547 | \& ev_stat passwd; |
|
|
1548 | .Ve |
|
|
1549 | .PP |
|
|
1550 | .Vb 2 |
|
|
1551 | \& ev_stat_init (&passwd, passwd_cb, "/etc/passwd"); |
|
|
1552 | \& ev_stat_start (loop, &passwd); |
|
|
1553 | .Ve |
1198 | .ie n .Sh """ev_idle"" \- when you've got nothing better to do..." |
1554 | .ie n .Sh """ev_idle"" \- when you've got nothing better to do..." |
1199 | .el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do..." |
1555 | .el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do..." |
1200 | .IX Subsection "ev_idle - when you've got nothing better to do..." |
1556 | .IX Subsection "ev_idle - when you've got nothing better to do..." |
1201 | Idle watchers trigger events when there are no other events are pending |
1557 | Idle watchers trigger events when no other events of the same or higher |
1202 | (prepare, check and other idle watchers do not count). That is, as long |
1558 | priority are pending (prepare, check and other idle watchers do not |
1203 | as your process is busy handling sockets or timeouts (or even signals, |
1559 | count). |
1204 | imagine) it will not be triggered. But when your process is idle all idle |
1560 | .PP |
1205 | watchers are being called again and again, once per event loop iteration \- |
1561 | That is, as long as your process is busy handling sockets or timeouts |
|
|
1562 | (or even signals, imagine) of the same or higher priority it will not be |
|
|
1563 | triggered. But when your process is idle (or only lower-priority watchers |
|
|
1564 | are pending), the idle watchers are being called once per event loop |
1206 | until stopped, that is, or your process receives more events and becomes |
1565 | iteration \- until stopped, that is, or your process receives more events |
1207 | busy. |
1566 | and becomes busy again with higher priority stuff. |
1208 | .PP |
1567 | .PP |
1209 | The most noteworthy effect is that as long as any idle watchers are |
1568 | The most noteworthy effect is that as long as any idle watchers are |
1210 | active, the process will not block when waiting for new events. |
1569 | active, the process will not block when waiting for new events. |
1211 | .PP |
1570 | .PP |
1212 | Apart from keeping your process non-blocking (which is a useful |
1571 | Apart from keeping your process non-blocking (which is a useful |
… | |
… | |
1217 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1576 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1218 | Initialises and configures the idle watcher \- it has no parameters of any |
1577 | Initialises and configures the idle watcher \- it has no parameters of any |
1219 | kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless, |
1578 | kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless, |
1220 | believe me. |
1579 | believe me. |
1221 | .PP |
1580 | .PP |
1222 | Example: dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR, start it, and in the |
1581 | Example: Dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR watcher, start it, and in the |
1223 | callback, free it. Alos, use no error checking, as usual. |
1582 | callback, free it. Also, use no error checking, as usual. |
1224 | .PP |
1583 | .PP |
1225 | .Vb 7 |
1584 | .Vb 7 |
1226 | \& static void |
1585 | \& static void |
1227 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1586 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1228 | \& { |
1587 | \& { |
… | |
… | |
1307 | \& if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
1666 | \& if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
1308 | \& if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
1667 | \& if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
1309 | \& } |
1668 | \& } |
1310 | .Ve |
1669 | .Ve |
1311 | .PP |
1670 | .PP |
1312 | .Vb 7 |
1671 | .Vb 8 |
1313 | \& // create io watchers for each fd and a timer before blocking |
1672 | \& // create io watchers for each fd and a timer before blocking |
1314 | \& static void |
1673 | \& static void |
1315 | \& adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1674 | \& adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1316 | \& { |
1675 | \& { |
1317 | \& int timeout = 3600000;truct pollfd fds [nfd]; |
1676 | \& int timeout = 3600000; |
|
|
1677 | \& struct pollfd fds [nfd]; |
1318 | \& // actual code will need to loop here and realloc etc. |
1678 | \& // actual code will need to loop here and realloc etc. |
1319 | \& adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1679 | \& adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1320 | .Ve |
1680 | .Ve |
1321 | .PP |
1681 | .PP |
1322 | .Vb 3 |
1682 | .Vb 3 |
… | |
… | |
1449 | .IP "ev_embed_sweep (loop, ev_embed *)" 4 |
1809 | .IP "ev_embed_sweep (loop, ev_embed *)" 4 |
1450 | .IX Item "ev_embed_sweep (loop, ev_embed *)" |
1810 | .IX Item "ev_embed_sweep (loop, ev_embed *)" |
1451 | Make a single, non-blocking sweep over the embedded loop. This works |
1811 | Make a single, non-blocking sweep over the embedded loop. This works |
1452 | similarly to \f(CW\*(C`ev_loop (embedded_loop, EVLOOP_NONBLOCK)\*(C'\fR, but in the most |
1812 | similarly to \f(CW\*(C`ev_loop (embedded_loop, EVLOOP_NONBLOCK)\*(C'\fR, but in the most |
1453 | apropriate way for embedded loops. |
1813 | apropriate way for embedded loops. |
|
|
1814 | .IP "struct ev_loop *loop [read\-only]" 4 |
|
|
1815 | .IX Item "struct ev_loop *loop [read-only]" |
|
|
1816 | The embedded event loop. |
|
|
1817 | .ie n .Sh """ev_fork"" \- the audacity to resume the event loop after a fork" |
|
|
1818 | .el .Sh "\f(CWev_fork\fP \- the audacity to resume the event loop after a fork" |
|
|
1819 | .IX Subsection "ev_fork - the audacity to resume the event loop after a fork" |
|
|
1820 | Fork watchers are called when a \f(CW\*(C`fork ()\*(C'\fR was detected (usually because |
|
|
1821 | whoever is a good citizen cared to tell libev about it by calling |
|
|
1822 | \&\f(CW\*(C`ev_default_fork\*(C'\fR or \f(CW\*(C`ev_loop_fork\*(C'\fR). The invocation is done before the |
|
|
1823 | event loop blocks next and before \f(CW\*(C`ev_check\*(C'\fR watchers are being called, |
|
|
1824 | and only in the child after the fork. If whoever good citizen calling |
|
|
1825 | \&\f(CW\*(C`ev_default_fork\*(C'\fR cheats and calls it in the wrong process, the fork |
|
|
1826 | handlers will be invoked, too, of course. |
|
|
1827 | .IP "ev_fork_init (ev_signal *, callback)" 4 |
|
|
1828 | .IX Item "ev_fork_init (ev_signal *, callback)" |
|
|
1829 | Initialises and configures the fork watcher \- it has no parameters of any |
|
|
1830 | kind. There is a \f(CW\*(C`ev_fork_set\*(C'\fR macro, but using it is utterly pointless, |
|
|
1831 | believe me. |
1454 | .SH "OTHER FUNCTIONS" |
1832 | .SH "OTHER FUNCTIONS" |
1455 | .IX Header "OTHER FUNCTIONS" |
1833 | .IX Header "OTHER FUNCTIONS" |
1456 | There are some other functions of possible interest. Described. Here. Now. |
1834 | There are some other functions of possible interest. Described. Here. Now. |
1457 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4 |
1835 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4 |
1458 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" |
1836 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" |
… | |
… | |
1530 | .PP |
1908 | .PP |
1531 | .Vb 1 |
1909 | .Vb 1 |
1532 | \& #include <ev++.h> |
1910 | \& #include <ev++.h> |
1533 | .Ve |
1911 | .Ve |
1534 | .PP |
1912 | .PP |
1535 | (it is not installed by default). This automatically includes \fIev.h\fR |
1913 | This automatically includes \fIev.h\fR and puts all of its definitions (many |
1536 | and puts all of its definitions (many of them macros) into the global |
1914 | of them macros) into the global namespace. All \*(C+ specific things are |
1537 | namespace. All \*(C+ specific things are put into the \f(CW\*(C`ev\*(C'\fR namespace. |
1915 | put into the \f(CW\*(C`ev\*(C'\fR namespace. It should support all the same embedding |
|
|
1916 | options as \fIev.h\fR, most notably \f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. |
1538 | .PP |
1917 | .PP |
1539 | It should support all the same embedding options as \fIev.h\fR, most notably |
1918 | Care has been taken to keep the overhead low. The only data member the \*(C+ |
1540 | \&\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. |
1919 | classes add (compared to plain C\-style watchers) is the event loop pointer |
|
|
1920 | that the watcher is associated with (or no additional members at all if |
|
|
1921 | you disable \f(CW\*(C`EV_MULTIPLICITY\*(C'\fR when embedding libev). |
|
|
1922 | .PP |
|
|
1923 | Currently, functions, and static and non-static member functions can be |
|
|
1924 | used as callbacks. Other types should be easy to add as long as they only |
|
|
1925 | need one additional pointer for context. If you need support for other |
|
|
1926 | types of functors please contact the author (preferably after implementing |
|
|
1927 | it). |
1541 | .PP |
1928 | .PP |
1542 | Here is a list of things available in the \f(CW\*(C`ev\*(C'\fR namespace: |
1929 | Here is a list of things available in the \f(CW\*(C`ev\*(C'\fR namespace: |
1543 | .ie n .IP """ev::READ""\fR, \f(CW""ev::WRITE"" etc." 4 |
1930 | .ie n .IP """ev::READ""\fR, \f(CW""ev::WRITE"" etc." 4 |
1544 | .el .IP "\f(CWev::READ\fR, \f(CWev::WRITE\fR etc." 4 |
1931 | .el .IP "\f(CWev::READ\fR, \f(CWev::WRITE\fR etc." 4 |
1545 | .IX Item "ev::READ, ev::WRITE etc." |
1932 | .IX Item "ev::READ, ev::WRITE etc." |
… | |
… | |
1557 | which is called \f(CW\*(C`ev::sig\*(C'\fR to avoid clashes with the \f(CW\*(C`signal\*(C'\fR macro |
1944 | which is called \f(CW\*(C`ev::sig\*(C'\fR to avoid clashes with the \f(CW\*(C`signal\*(C'\fR macro |
1558 | defines by many implementations. |
1945 | defines by many implementations. |
1559 | .Sp |
1946 | .Sp |
1560 | All of those classes have these methods: |
1947 | All of those classes have these methods: |
1561 | .RS 4 |
1948 | .RS 4 |
1562 | .IP "ev::TYPE::TYPE (object *, object::method *)" 4 |
1949 | .IP "ev::TYPE::TYPE ()" 4 |
1563 | .IX Item "ev::TYPE::TYPE (object *, object::method *)" |
1950 | .IX Item "ev::TYPE::TYPE ()" |
1564 | .PD 0 |
1951 | .PD 0 |
1565 | .IP "ev::TYPE::TYPE (object *, object::method *, struct ev_loop *)" 4 |
1952 | .IP "ev::TYPE::TYPE (struct ev_loop *)" 4 |
1566 | .IX Item "ev::TYPE::TYPE (object *, object::method *, struct ev_loop *)" |
1953 | .IX Item "ev::TYPE::TYPE (struct ev_loop *)" |
1567 | .IP "ev::TYPE::~TYPE" 4 |
1954 | .IP "ev::TYPE::~TYPE" 4 |
1568 | .IX Item "ev::TYPE::~TYPE" |
1955 | .IX Item "ev::TYPE::~TYPE" |
1569 | .PD |
1956 | .PD |
1570 | The constructor takes a pointer to an object and a method pointer to |
1957 | The constructor (optionally) takes an event loop to associate the watcher |
1571 | the event handler callback to call in this class. The constructor calls |
1958 | with. If it is omitted, it will use \f(CW\*(C`EV_DEFAULT\*(C'\fR. |
1572 | \&\f(CW\*(C`ev_init\*(C'\fR for you, which means you have to call the \f(CW\*(C`set\*(C'\fR method |
1959 | .Sp |
1573 | before starting it. If you do not specify a loop then the constructor |
1960 | The constructor calls \f(CW\*(C`ev_init\*(C'\fR for you, which means you have to call the |
1574 | automatically associates the default loop with this watcher. |
1961 | \&\f(CW\*(C`set\*(C'\fR method before starting it. |
|
|
1962 | .Sp |
|
|
1963 | It will not set a callback, however: You have to call the templated \f(CW\*(C`set\*(C'\fR |
|
|
1964 | method to set a callback before you can start the watcher. |
|
|
1965 | .Sp |
|
|
1966 | (The reason why you have to use a method is a limitation in \*(C+ which does |
|
|
1967 | not allow explicit template arguments for constructors). |
1575 | .Sp |
1968 | .Sp |
1576 | The destructor automatically stops the watcher if it is active. |
1969 | The destructor automatically stops the watcher if it is active. |
|
|
1970 | .IP "w\->set<class, &class::method> (object *)" 4 |
|
|
1971 | .IX Item "w->set<class, &class::method> (object *)" |
|
|
1972 | This method sets the callback method to call. The method has to have a |
|
|
1973 | signature of \f(CW\*(C`void (*)(ev_TYPE &, int)\*(C'\fR, it receives the watcher as |
|
|
1974 | first argument and the \f(CW\*(C`revents\*(C'\fR as second. The object must be given as |
|
|
1975 | parameter and is stored in the \f(CW\*(C`data\*(C'\fR member of the watcher. |
|
|
1976 | .Sp |
|
|
1977 | This method synthesizes efficient thunking code to call your method from |
|
|
1978 | the C callback that libev requires. If your compiler can inline your |
|
|
1979 | callback (i.e. it is visible to it at the place of the \f(CW\*(C`set\*(C'\fR call and |
|
|
1980 | your compiler is good :), then the method will be fully inlined into the |
|
|
1981 | thunking function, making it as fast as a direct C callback. |
|
|
1982 | .Sp |
|
|
1983 | Example: simple class declaration and watcher initialisation |
|
|
1984 | .Sp |
|
|
1985 | .Vb 4 |
|
|
1986 | \& struct myclass |
|
|
1987 | \& { |
|
|
1988 | \& void io_cb (ev::io &w, int revents) { } |
|
|
1989 | \& } |
|
|
1990 | .Ve |
|
|
1991 | .Sp |
|
|
1992 | .Vb 3 |
|
|
1993 | \& myclass obj; |
|
|
1994 | \& ev::io iow; |
|
|
1995 | \& iow.set <myclass, &myclass::io_cb> (&obj); |
|
|
1996 | .Ve |
|
|
1997 | .IP "w\->set<function> (void *data = 0)" 4 |
|
|
1998 | .IX Item "w->set<function> (void *data = 0)" |
|
|
1999 | Also sets a callback, but uses a static method or plain function as |
|
|
2000 | callback. The optional \f(CW\*(C`data\*(C'\fR argument will be stored in the watcher's |
|
|
2001 | \&\f(CW\*(C`data\*(C'\fR member and is free for you to use. |
|
|
2002 | .Sp |
|
|
2003 | The prototype of the \f(CW\*(C`function\*(C'\fR must be \f(CW\*(C`void (*)(ev::TYPE &w, int)\*(C'\fR. |
|
|
2004 | .Sp |
|
|
2005 | See the method\-\f(CW\*(C`set\*(C'\fR above for more details. |
|
|
2006 | .Sp |
|
|
2007 | Example: |
|
|
2008 | .Sp |
|
|
2009 | .Vb 2 |
|
|
2010 | \& static void io_cb (ev::io &w, int revents) { } |
|
|
2011 | \& iow.set <io_cb> (); |
|
|
2012 | .Ve |
1577 | .IP "w\->set (struct ev_loop *)" 4 |
2013 | .IP "w\->set (struct ev_loop *)" 4 |
1578 | .IX Item "w->set (struct ev_loop *)" |
2014 | .IX Item "w->set (struct ev_loop *)" |
1579 | Associates a different \f(CW\*(C`struct ev_loop\*(C'\fR with this watcher. You can only |
2015 | Associates a different \f(CW\*(C`struct ev_loop\*(C'\fR with this watcher. You can only |
1580 | do this when the watcher is inactive (and not pending either). |
2016 | do this when the watcher is inactive (and not pending either). |
1581 | .IP "w\->set ([args])" 4 |
2017 | .IP "w\->set ([args])" 4 |
1582 | .IX Item "w->set ([args])" |
2018 | .IX Item "w->set ([args])" |
1583 | Basically the same as \f(CW\*(C`ev_TYPE_set\*(C'\fR, with the same args. Must be |
2019 | Basically the same as \f(CW\*(C`ev_TYPE_set\*(C'\fR, with the same args. Must be |
1584 | called at least once. Unlike the C counterpart, an active watcher gets |
2020 | called at least once. Unlike the C counterpart, an active watcher gets |
1585 | automatically stopped and restarted. |
2021 | automatically stopped and restarted when reconfiguring it with this |
|
|
2022 | method. |
1586 | .IP "w\->start ()" 4 |
2023 | .IP "w\->start ()" 4 |
1587 | .IX Item "w->start ()" |
2024 | .IX Item "w->start ()" |
1588 | Starts the watcher. Note that there is no \f(CW\*(C`loop\*(C'\fR argument as the |
2025 | Starts the watcher. Note that there is no \f(CW\*(C`loop\*(C'\fR argument, as the |
1589 | constructor already takes the loop. |
2026 | constructor already stores the event loop. |
1590 | .IP "w\->stop ()" 4 |
2027 | .IP "w\->stop ()" 4 |
1591 | .IX Item "w->stop ()" |
2028 | .IX Item "w->stop ()" |
1592 | Stops the watcher if it is active. Again, no \f(CW\*(C`loop\*(C'\fR argument. |
2029 | Stops the watcher if it is active. Again, no \f(CW\*(C`loop\*(C'\fR argument. |
1593 | .ie n .IP "w\->again () ""ev::timer""\fR, \f(CW""ev::periodic"" only" 4 |
2030 | .ie n .IP "w\->again () ""ev::timer""\fR, \f(CW""ev::periodic"" only" 4 |
1594 | .el .IP "w\->again () \f(CWev::timer\fR, \f(CWev::periodic\fR only" 4 |
2031 | .el .IP "w\->again () \f(CWev::timer\fR, \f(CWev::periodic\fR only" 4 |
… | |
… | |
1597 | \&\f(CW\*(C`ev_TYPE_again\*(C'\fR function. |
2034 | \&\f(CW\*(C`ev_TYPE_again\*(C'\fR function. |
1598 | .ie n .IP "w\->sweep () ""ev::embed"" only" 4 |
2035 | .ie n .IP "w\->sweep () ""ev::embed"" only" 4 |
1599 | .el .IP "w\->sweep () \f(CWev::embed\fR only" 4 |
2036 | .el .IP "w\->sweep () \f(CWev::embed\fR only" 4 |
1600 | .IX Item "w->sweep () ev::embed only" |
2037 | .IX Item "w->sweep () ev::embed only" |
1601 | Invokes \f(CW\*(C`ev_embed_sweep\*(C'\fR. |
2038 | Invokes \f(CW\*(C`ev_embed_sweep\*(C'\fR. |
|
|
2039 | .ie n .IP "w\->update () ""ev::stat"" only" 4 |
|
|
2040 | .el .IP "w\->update () \f(CWev::stat\fR only" 4 |
|
|
2041 | .IX Item "w->update () ev::stat only" |
|
|
2042 | Invokes \f(CW\*(C`ev_stat_stat\*(C'\fR. |
1602 | .RE |
2043 | .RE |
1603 | .RS 4 |
2044 | .RS 4 |
1604 | .RE |
2045 | .RE |
1605 | .PP |
2046 | .PP |
1606 | Example: Define a class with an \s-1IO\s0 and idle watcher, start one of them in |
2047 | Example: Define a class with an \s-1IO\s0 and idle watcher, start one of them in |
… | |
… | |
1616 | .Vb 2 |
2057 | .Vb 2 |
1617 | \& myclass (); |
2058 | \& myclass (); |
1618 | \& } |
2059 | \& } |
1619 | .Ve |
2060 | .Ve |
1620 | .PP |
2061 | .PP |
1621 | .Vb 6 |
2062 | .Vb 4 |
1622 | \& myclass::myclass (int fd) |
2063 | \& myclass::myclass (int fd) |
1623 | \& : io (this, &myclass::io_cb), |
|
|
1624 | \& idle (this, &myclass::idle_cb) |
|
|
1625 | \& { |
2064 | \& { |
|
|
2065 | \& io .set <myclass, &myclass::io_cb > (this); |
|
|
2066 | \& idle.set <myclass, &myclass::idle_cb> (this); |
|
|
2067 | .Ve |
|
|
2068 | .PP |
|
|
2069 | .Vb 2 |
1626 | \& io.start (fd, ev::READ); |
2070 | \& io.start (fd, ev::READ); |
1627 | \& } |
2071 | \& } |
|
|
2072 | .Ve |
|
|
2073 | .SH "MACRO MAGIC" |
|
|
2074 | .IX Header "MACRO MAGIC" |
|
|
2075 | Libev can be compiled with a variety of options, the most fundemantal is |
|
|
2076 | \&\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines whether (most) functions and |
|
|
2077 | callbacks have an initial \f(CW\*(C`struct ev_loop *\*(C'\fR argument. |
|
|
2078 | .PP |
|
|
2079 | To make it easier to write programs that cope with either variant, the |
|
|
2080 | following macros are defined: |
|
|
2081 | .ie n .IP """EV_A""\fR, \f(CW""EV_A_""" 4 |
|
|
2082 | .el .IP "\f(CWEV_A\fR, \f(CWEV_A_\fR" 4 |
|
|
2083 | .IX Item "EV_A, EV_A_" |
|
|
2084 | This provides the loop \fIargument\fR for functions, if one is required (\*(L"ev |
|
|
2085 | loop argument\*(R"). The \f(CW\*(C`EV_A\*(C'\fR form is used when this is the sole argument, |
|
|
2086 | \&\f(CW\*(C`EV_A_\*(C'\fR is used when other arguments are following. Example: |
|
|
2087 | .Sp |
|
|
2088 | .Vb 3 |
|
|
2089 | \& ev_unref (EV_A); |
|
|
2090 | \& ev_timer_add (EV_A_ watcher); |
|
|
2091 | \& ev_loop (EV_A_ 0); |
|
|
2092 | .Ve |
|
|
2093 | .Sp |
|
|
2094 | It assumes the variable \f(CW\*(C`loop\*(C'\fR of type \f(CW\*(C`struct ev_loop *\*(C'\fR is in scope, |
|
|
2095 | which is often provided by the following macro. |
|
|
2096 | .ie n .IP """EV_P""\fR, \f(CW""EV_P_""" 4 |
|
|
2097 | .el .IP "\f(CWEV_P\fR, \f(CWEV_P_\fR" 4 |
|
|
2098 | .IX Item "EV_P, EV_P_" |
|
|
2099 | This provides the loop \fIparameter\fR for functions, if one is required (\*(L"ev |
|
|
2100 | loop parameter\*(R"). The \f(CW\*(C`EV_P\*(C'\fR form is used when this is the sole parameter, |
|
|
2101 | \&\f(CW\*(C`EV_P_\*(C'\fR is used when other parameters are following. Example: |
|
|
2102 | .Sp |
|
|
2103 | .Vb 2 |
|
|
2104 | \& // this is how ev_unref is being declared |
|
|
2105 | \& static void ev_unref (EV_P); |
|
|
2106 | .Ve |
|
|
2107 | .Sp |
|
|
2108 | .Vb 2 |
|
|
2109 | \& // this is how you can declare your typical callback |
|
|
2110 | \& static void cb (EV_P_ ev_timer *w, int revents) |
|
|
2111 | .Ve |
|
|
2112 | .Sp |
|
|
2113 | It declares a parameter \f(CW\*(C`loop\*(C'\fR of type \f(CW\*(C`struct ev_loop *\*(C'\fR, quite |
|
|
2114 | suitable for use with \f(CW\*(C`EV_A\*(C'\fR. |
|
|
2115 | .ie n .IP """EV_DEFAULT""\fR, \f(CW""EV_DEFAULT_""" 4 |
|
|
2116 | .el .IP "\f(CWEV_DEFAULT\fR, \f(CWEV_DEFAULT_\fR" 4 |
|
|
2117 | .IX Item "EV_DEFAULT, EV_DEFAULT_" |
|
|
2118 | Similar to the other two macros, this gives you the value of the default |
|
|
2119 | loop, if multiple loops are supported (\*(L"ev loop default\*(R"). |
|
|
2120 | .PP |
|
|
2121 | Example: Declare and initialise a check watcher, utilising the above |
|
|
2122 | macros so it will work regardless of whether multiple loops are supported |
|
|
2123 | or not. |
|
|
2124 | .PP |
|
|
2125 | .Vb 5 |
|
|
2126 | \& static void |
|
|
2127 | \& check_cb (EV_P_ ev_timer *w, int revents) |
|
|
2128 | \& { |
|
|
2129 | \& ev_check_stop (EV_A_ w); |
|
|
2130 | \& } |
|
|
2131 | .Ve |
|
|
2132 | .PP |
|
|
2133 | .Vb 4 |
|
|
2134 | \& ev_check check; |
|
|
2135 | \& ev_check_init (&check, check_cb); |
|
|
2136 | \& ev_check_start (EV_DEFAULT_ &check); |
|
|
2137 | \& ev_loop (EV_DEFAULT_ 0); |
1628 | .Ve |
2138 | .Ve |
1629 | .SH "EMBEDDING" |
2139 | .SH "EMBEDDING" |
1630 | .IX Header "EMBEDDING" |
2140 | .IX Header "EMBEDDING" |
1631 | Libev can (and often is) directly embedded into host |
2141 | Libev can (and often is) directly embedded into host |
1632 | applications. Examples of applications that embed it include the Deliantra |
2142 | applications. Examples of applications that embed it include the Deliantra |
… | |
… | |
1681 | .Vb 1 |
2191 | .Vb 1 |
1682 | \& ev_win32.c required on win32 platforms only |
2192 | \& ev_win32.c required on win32 platforms only |
1683 | .Ve |
2193 | .Ve |
1684 | .PP |
2194 | .PP |
1685 | .Vb 5 |
2195 | .Vb 5 |
1686 | \& ev_select.c only when select backend is enabled (which is by default) |
2196 | \& ev_select.c only when select backend is enabled (which is enabled by default) |
1687 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
2197 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
1688 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
2198 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
1689 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
2199 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
1690 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
2200 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
1691 | .Ve |
2201 | .Ve |
… | |
… | |
1812 | otherwise another method will be used as fallback. This is the preferred |
2322 | otherwise another method will be used as fallback. This is the preferred |
1813 | backend for Solaris 10 systems. |
2323 | backend for Solaris 10 systems. |
1814 | .IP "\s-1EV_USE_DEVPOLL\s0" 4 |
2324 | .IP "\s-1EV_USE_DEVPOLL\s0" 4 |
1815 | .IX Item "EV_USE_DEVPOLL" |
2325 | .IX Item "EV_USE_DEVPOLL" |
1816 | reserved for future expansion, works like the \s-1USE\s0 symbols above. |
2326 | reserved for future expansion, works like the \s-1USE\s0 symbols above. |
|
|
2327 | .IP "\s-1EV_USE_INOTIFY\s0" 4 |
|
|
2328 | .IX Item "EV_USE_INOTIFY" |
|
|
2329 | If defined to be \f(CW1\fR, libev will compile in support for the Linux inotify |
|
|
2330 | interface to speed up \f(CW\*(C`ev_stat\*(C'\fR watchers. Its actual availability will |
|
|
2331 | be detected at runtime. |
1817 | .IP "\s-1EV_H\s0" 4 |
2332 | .IP "\s-1EV_H\s0" 4 |
1818 | .IX Item "EV_H" |
2333 | .IX Item "EV_H" |
1819 | The name of the \fIev.h\fR header file used to include it. The default if |
2334 | The name of the \fIev.h\fR header file used to include it. The default if |
1820 | undefined is \f(CW\*(C`<ev.h>\*(C'\fR in \fIevent.h\fR and \f(CW"ev.h"\fR in \fIev.c\fR. This |
2335 | undefined is \f(CW\*(C`<ev.h>\*(C'\fR in \fIevent.h\fR and \f(CW"ev.h"\fR in \fIev.c\fR. This |
1821 | can be used to virtually rename the \fIev.h\fR header file in case of conflicts. |
2336 | can be used to virtually rename the \fIev.h\fR header file in case of conflicts. |
… | |
… | |
1839 | If undefined or defined to \f(CW1\fR, then all event-loop-specific functions |
2354 | If undefined or defined to \f(CW1\fR, then all event-loop-specific functions |
1840 | will have the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument, and you can create |
2355 | will have the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument, and you can create |
1841 | additional independent event loops. Otherwise there will be no support |
2356 | additional independent event loops. Otherwise there will be no support |
1842 | for multiple event loops and there is no first event loop pointer |
2357 | for multiple event loops and there is no first event loop pointer |
1843 | argument. Instead, all functions act on the single default loop. |
2358 | argument. Instead, all functions act on the single default loop. |
|
|
2359 | .IP "\s-1EV_MINPRI\s0" 4 |
|
|
2360 | .IX Item "EV_MINPRI" |
|
|
2361 | .PD 0 |
|
|
2362 | .IP "\s-1EV_MAXPRI\s0" 4 |
|
|
2363 | .IX Item "EV_MAXPRI" |
|
|
2364 | .PD |
|
|
2365 | The range of allowed priorities. \f(CW\*(C`EV_MINPRI\*(C'\fR must be smaller or equal to |
|
|
2366 | \&\f(CW\*(C`EV_MAXPRI\*(C'\fR, but otherwise there are no non-obvious limitations. You can |
|
|
2367 | provide for more priorities by overriding those symbols (usually defined |
|
|
2368 | to be \f(CW\*(C`\-2\*(C'\fR and \f(CW2\fR, respectively). |
|
|
2369 | .Sp |
|
|
2370 | When doing priority-based operations, libev usually has to linearly search |
|
|
2371 | all the priorities, so having many of them (hundreds) uses a lot of space |
|
|
2372 | and time, so using the defaults of five priorities (\-2 .. +2) is usually |
|
|
2373 | fine. |
|
|
2374 | .Sp |
|
|
2375 | If your embedding app does not need any priorities, defining these both to |
|
|
2376 | \&\f(CW0\fR will save some memory and cpu. |
1844 | .IP "\s-1EV_PERIODICS\s0" 4 |
2377 | .IP "\s-1EV_PERIODIC_ENABLE\s0" 4 |
1845 | .IX Item "EV_PERIODICS" |
2378 | .IX Item "EV_PERIODIC_ENABLE" |
1846 | If undefined or defined to be \f(CW1\fR, then periodic timers are supported, |
2379 | If undefined or defined to be \f(CW1\fR, then periodic timers are supported. If |
1847 | otherwise not. This saves a few kb of code. |
2380 | defined to be \f(CW0\fR, then they are not. Disabling them saves a few kB of |
|
|
2381 | code. |
|
|
2382 | .IP "\s-1EV_IDLE_ENABLE\s0" 4 |
|
|
2383 | .IX Item "EV_IDLE_ENABLE" |
|
|
2384 | If undefined or defined to be \f(CW1\fR, then idle watchers are supported. If |
|
|
2385 | defined to be \f(CW0\fR, then they are not. Disabling them saves a few kB of |
|
|
2386 | code. |
|
|
2387 | .IP "\s-1EV_EMBED_ENABLE\s0" 4 |
|
|
2388 | .IX Item "EV_EMBED_ENABLE" |
|
|
2389 | If undefined or defined to be \f(CW1\fR, then embed watchers are supported. If |
|
|
2390 | defined to be \f(CW0\fR, then they are not. |
|
|
2391 | .IP "\s-1EV_STAT_ENABLE\s0" 4 |
|
|
2392 | .IX Item "EV_STAT_ENABLE" |
|
|
2393 | If undefined or defined to be \f(CW1\fR, then stat watchers are supported. If |
|
|
2394 | defined to be \f(CW0\fR, then they are not. |
|
|
2395 | .IP "\s-1EV_FORK_ENABLE\s0" 4 |
|
|
2396 | .IX Item "EV_FORK_ENABLE" |
|
|
2397 | If undefined or defined to be \f(CW1\fR, then fork watchers are supported. If |
|
|
2398 | defined to be \f(CW0\fR, then they are not. |
|
|
2399 | .IP "\s-1EV_MINIMAL\s0" 4 |
|
|
2400 | .IX Item "EV_MINIMAL" |
|
|
2401 | If you need to shave off some kilobytes of code at the expense of some |
|
|
2402 | speed, define this symbol to \f(CW1\fR. Currently only used for gcc to override |
|
|
2403 | some inlining decisions, saves roughly 30% codesize of amd64. |
|
|
2404 | .IP "\s-1EV_PID_HASHSIZE\s0" 4 |
|
|
2405 | .IX Item "EV_PID_HASHSIZE" |
|
|
2406 | \&\f(CW\*(C`ev_child\*(C'\fR watchers use a small hash table to distribute workload by |
|
|
2407 | pid. The default size is \f(CW16\fR (or \f(CW1\fR with \f(CW\*(C`EV_MINIMAL\*(C'\fR), usually more |
|
|
2408 | than enough. If you need to manage thousands of children you might want to |
|
|
2409 | increase this value (\fImust\fR be a power of two). |
|
|
2410 | .IP "\s-1EV_INOTIFY_HASHSIZE\s0" 4 |
|
|
2411 | .IX Item "EV_INOTIFY_HASHSIZE" |
|
|
2412 | \&\f(CW\*(C`ev_staz\*(C'\fR watchers use a small hash table to distribute workload by |
|
|
2413 | inotify watch id. The default size is \f(CW16\fR (or \f(CW1\fR with \f(CW\*(C`EV_MINIMAL\*(C'\fR), |
|
|
2414 | usually more than enough. If you need to manage thousands of \f(CW\*(C`ev_stat\*(C'\fR |
|
|
2415 | watchers you might want to increase this value (\fImust\fR be a power of |
|
|
2416 | two). |
1848 | .IP "\s-1EV_COMMON\s0" 4 |
2417 | .IP "\s-1EV_COMMON\s0" 4 |
1849 | .IX Item "EV_COMMON" |
2418 | .IX Item "EV_COMMON" |
1850 | By default, all watchers have a \f(CW\*(C`void *data\*(C'\fR member. By redefining |
2419 | By default, all watchers have a \f(CW\*(C`void *data\*(C'\fR member. By redefining |
1851 | this macro to a something else you can include more and other types of |
2420 | this macro to a something else you can include more and other types of |
1852 | members. You have to define it each time you include one of the files, |
2421 | members. You have to define it each time you include one of the files, |
… | |
… | |
1882 | interface) and \fI\s-1EV\s0.xs\fR (implementation) files. Only the \fI\s-1EV\s0.xs\fR file |
2451 | interface) and \fI\s-1EV\s0.xs\fR (implementation) files. Only the \fI\s-1EV\s0.xs\fR file |
1883 | will be compiled. It is pretty complex because it provides its own header |
2452 | will be compiled. It is pretty complex because it provides its own header |
1884 | file. |
2453 | file. |
1885 | .Sp |
2454 | .Sp |
1886 | The usage in rxvt-unicode is simpler. It has a \fIev_cpp.h\fR header file |
2455 | The usage in rxvt-unicode is simpler. It has a \fIev_cpp.h\fR header file |
1887 | that everybody includes and which overrides some autoconf choices: |
2456 | that everybody includes and which overrides some configure choices: |
1888 | .Sp |
2457 | .Sp |
1889 | .Vb 4 |
2458 | .Vb 9 |
|
|
2459 | \& #define EV_MINIMAL 1 |
1890 | \& #define EV_USE_POLL 0 |
2460 | \& #define EV_USE_POLL 0 |
1891 | \& #define EV_MULTIPLICITY 0 |
2461 | \& #define EV_MULTIPLICITY 0 |
1892 | \& #define EV_PERIODICS 0 |
2462 | \& #define EV_PERIODIC_ENABLE 0 |
|
|
2463 | \& #define EV_STAT_ENABLE 0 |
|
|
2464 | \& #define EV_FORK_ENABLE 0 |
1893 | \& #define EV_CONFIG_H <config.h> |
2465 | \& #define EV_CONFIG_H <config.h> |
|
|
2466 | \& #define EV_MINPRI 0 |
|
|
2467 | \& #define EV_MAXPRI 0 |
1894 | .Ve |
2468 | .Ve |
1895 | .Sp |
2469 | .Sp |
1896 | .Vb 1 |
2470 | .Vb 1 |
1897 | \& #include "ev++.h" |
2471 | \& #include "ev++.h" |
1898 | .Ve |
2472 | .Ve |
… | |
… | |
1906 | .SH "COMPLEXITIES" |
2480 | .SH "COMPLEXITIES" |
1907 | .IX Header "COMPLEXITIES" |
2481 | .IX Header "COMPLEXITIES" |
1908 | In this section the complexities of (many of) the algorithms used inside |
2482 | In this section the complexities of (many of) the algorithms used inside |
1909 | libev will be explained. For complexity discussions about backends see the |
2483 | libev will be explained. For complexity discussions about backends see the |
1910 | documentation for \f(CW\*(C`ev_default_init\*(C'\fR. |
2484 | documentation for \f(CW\*(C`ev_default_init\*(C'\fR. |
|
|
2485 | .Sp |
|
|
2486 | All of the following are about amortised time: If an array needs to be |
|
|
2487 | extended, libev needs to realloc and move the whole array, but this |
|
|
2488 | happens asymptotically never with higher number of elements, so O(1) might |
|
|
2489 | mean it might do a lengthy realloc operation in rare cases, but on average |
|
|
2490 | it is much faster and asymptotically approaches constant time. |
1911 | .RS 4 |
2491 | .RS 4 |
1912 | .IP "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" 4 |
2492 | .IP "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" 4 |
1913 | .IX Item "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" |
2493 | .IX Item "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" |
1914 | .PD 0 |
2494 | This means that, when you have a watcher that triggers in one hour and |
|
|
2495 | there are 100 watchers that would trigger before that then inserting will |
|
|
2496 | have to skip those 100 watchers. |
1915 | .IP "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" 4 |
2497 | .IP "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" 4 |
1916 | .IX Item "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" |
2498 | .IX Item "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" |
|
|
2499 | That means that for changing a timer costs less than removing/adding them |
|
|
2500 | as only the relative motion in the event queue has to be paid for. |
1917 | .IP "Starting io/check/prepare/idle/signal/child watchers: O(1)" 4 |
2501 | .IP "Starting io/check/prepare/idle/signal/child watchers: O(1)" 4 |
1918 | .IX Item "Starting io/check/prepare/idle/signal/child watchers: O(1)" |
2502 | .IX Item "Starting io/check/prepare/idle/signal/child watchers: O(1)" |
1919 | .IP "Stopping check/prepare/idle watchers: O(1)" 4 |
2503 | These just add the watcher into an array or at the head of a list. |
1920 | .IX Item "Stopping check/prepare/idle watchers: O(1)" |
2504 | =item Stopping check/prepare/idle watchers: O(1) |
1921 | .IP "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))" 4 |
2505 | .IP "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % \s-1EV_PID_HASHSIZE\s0))" 4 |
1922 | .IX Item "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))" |
2506 | .IX Item "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))" |
|
|
2507 | These watchers are stored in lists then need to be walked to find the |
|
|
2508 | correct watcher to remove. The lists are usually short (you don't usually |
|
|
2509 | have many watchers waiting for the same fd or signal). |
1923 | .IP "Finding the next timer per loop iteration: O(1)" 4 |
2510 | .IP "Finding the next timer per loop iteration: O(1)" 4 |
1924 | .IX Item "Finding the next timer per loop iteration: O(1)" |
2511 | .IX Item "Finding the next timer per loop iteration: O(1)" |
|
|
2512 | .PD 0 |
1925 | .IP "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" 4 |
2513 | .IP "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" 4 |
1926 | .IX Item "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" |
2514 | .IX Item "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" |
|
|
2515 | .PD |
|
|
2516 | A change means an I/O watcher gets started or stopped, which requires |
|
|
2517 | libev to recalculate its status (and possibly tell the kernel). |
1927 | .IP "Activating one watcher: O(1)" 4 |
2518 | .IP "Activating one watcher: O(1)" 4 |
1928 | .IX Item "Activating one watcher: O(1)" |
2519 | .IX Item "Activating one watcher: O(1)" |
|
|
2520 | .PD 0 |
|
|
2521 | .IP "Priority handling: O(number_of_priorities)" 4 |
|
|
2522 | .IX Item "Priority handling: O(number_of_priorities)" |
|
|
2523 | .PD |
|
|
2524 | Priorities are implemented by allocating some space for each |
|
|
2525 | priority. When doing priority-based operations, libev usually has to |
|
|
2526 | linearly search all the priorities. |
1929 | .RE |
2527 | .RE |
1930 | .RS 4 |
2528 | .RS 4 |
1931 | .PD |
|
|
1932 | .SH "AUTHOR" |
2529 | .SH "AUTHOR" |
1933 | .IX Header "AUTHOR" |
2530 | .IX Header "AUTHOR" |
1934 | Marc Lehmann <libev@schmorp.de>. |
2531 | Marc Lehmann <libev@schmorp.de>. |