… | |
… | |
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 "2007-11-27" "perl v5.8.8" "User Contributed Perl Documentation" |
132 | .TH "<STANDARD INPUT>" 1 "2007-11-28" "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" |
|
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142 | .Vb 1 |
|
|
143 | \& #include <ev.h> |
|
|
144 | .Ve |
|
|
145 | .PP |
|
|
146 | .Vb 2 |
|
|
147 | \& ev_io stdin_watcher; |
|
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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"); */ |
|
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167 | \& ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */ |
|
|
168 | \& } |
|
|
169 | .Ve |
|
|
170 | .PP |
|
|
171 | .Vb 4 |
|
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172 | \& int |
|
|
173 | \& main (void) |
|
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174 | \& { |
|
|
175 | \& struct ev_loop *loop = ev_default_loop (0); |
|
|
176 | .Ve |
|
|
177 | .PP |
|
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178 | .Vb 3 |
|
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179 | \& /* initialise an io watcher, then start it */ |
|
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180 | \& ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
|
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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.); |
|
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187 | \& ev_timer_start (loop, &timeout_watcher); |
|
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188 | .Ve |
|
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189 | .PP |
|
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190 | .Vb 2 |
|
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191 | \& /* loop till timeout or data ready */ |
|
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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" |
142 | Libev is an event loop: you register interest in certain events (such as a |
201 | 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 |
202 | file descriptor being readable or a timeout occuring), and it will manage |
144 | these event sources and provide your program with events. |
203 | these event sources and provide your program with events. |
… | |
… | |
151 | watchers\fR, which are relatively small C structures you initialise with the |
210 | 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 |
211 | details of the event, and then hand it over to libev by \fIstarting\fR the |
153 | watcher. |
212 | watcher. |
154 | .SH "FEATURES" |
213 | .SH "FEATURES" |
155 | .IX Header "FEATURES" |
214 | .IX Header "FEATURES" |
156 | Libev supports select, poll, the linux-specific epoll and the bsd-specific |
215 | 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 |
216 | 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 |
217 | 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 |
218 | (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 |
219 | with customised rescheduling (\f(CW\*(C`ev_periodic\*(C'\fR), synchronous signals |
161 | fast (see this benchmark comparing |
220 | (\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). |
221 | watchers dealing with the event loop mechanism itself (\f(CW\*(C`ev_idle\*(C'\fR, |
|
|
222 | \&\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 |
|
|
223 | file watchers (\f(CW\*(C`ev_stat\*(C'\fR) and even limited support for fork events |
|
|
224 | (\f(CW\*(C`ev_fork\*(C'\fR). |
|
|
225 | .PP |
|
|
226 | It also is quite fast (see this |
|
|
227 | benchmark comparing it to libevent |
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|
228 | for example). |
163 | .SH "CONVENTIONS" |
229 | .SH "CONVENTIONS" |
164 | .IX Header "CONVENTIONS" |
230 | .IX Header "CONVENTIONS" |
165 | Libev is very configurable. In this manual the default configuration |
231 | Libev is very configurable. In this manual the default configuration will |
166 | will be described, which supports multiple event loops. For more info |
232 | be described, which supports multiple event loops. For more info about |
167 | about various configuration options please have a look at the file |
233 | 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 |
234 | this manual. If libev was configured without support for multiple event |
169 | support for multiple event loops, then all functions taking an initial |
235 | 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) |
236 | (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" |
237 | .SH "TIME REPRESENTATION" |
173 | .IX Header "TIME REPRESENTATION" |
238 | .IX Header "TIME REPRESENTATION" |
174 | Libev represents time as a single floating point number, representing the |
239 | Libev represents time as a single floating point number, representing the |
175 | (fractional) number of seconds since the (\s-1POSIX\s0) epoch (somewhere near |
240 | (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 |
241 | 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, |
266 | Usually, it's a good idea to terminate if the major versions mismatch, |
202 | as this indicates an incompatible change. Minor versions are usually |
267 | as this indicates an incompatible change. Minor versions are usually |
203 | compatible to older versions, so a larger minor version alone is usually |
268 | compatible to older versions, so a larger minor version alone is usually |
204 | not a problem. |
269 | not a problem. |
205 | .Sp |
270 | .Sp |
206 | Example: make sure we haven't accidentally been linked against the wrong |
271 | Example: Make sure we haven't accidentally been linked against the wrong |
207 | version: |
272 | version. |
208 | .Sp |
273 | .Sp |
209 | .Vb 3 |
274 | .Vb 3 |
210 | \& assert (("libev version mismatch", |
275 | \& assert (("libev version mismatch", |
211 | \& ev_version_major () == EV_VERSION_MAJOR |
276 | \& ev_version_major () == EV_VERSION_MAJOR |
212 | \& && ev_version_minor () >= EV_VERSION_MINOR)); |
277 | \& && ev_version_minor () >= EV_VERSION_MINOR)); |
… | |
… | |
242 | recommended ones. |
307 | recommended ones. |
243 | .Sp |
308 | .Sp |
244 | See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info. |
309 | 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 |
310 | .IP "ev_set_allocator (void *(*cb)(void *ptr, long size))" 4 |
246 | .IX Item "ev_set_allocator (void *(*cb)(void *ptr, long size))" |
311 | .IX Item "ev_set_allocator (void *(*cb)(void *ptr, long size))" |
247 | Sets the allocation function to use (the prototype is similar to the |
312 | Sets the allocation function to use (the prototype is similar \- the |
248 | realloc C function, the semantics are identical). It is used to allocate |
313 | 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 |
314 | 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 |
315 | memory needs to be allocated, the library might abort or take some |
251 | destructive action. The default is your system realloc function. |
316 | potentially destructive action. The default is your system realloc |
|
|
317 | function. |
252 | .Sp |
318 | .Sp |
253 | You could override this function in high-availability programs to, say, |
319 | 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, |
320 | 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. |
321 | or even to sleep a while and retry until some memory is available. |
256 | .Sp |
322 | .Sp |
257 | Example: replace the libev allocator with one that waits a bit and then |
323 | Example: Replace the libev allocator with one that waits a bit and then |
258 | retries: better than mine). |
324 | retries). |
259 | .Sp |
325 | .Sp |
260 | .Vb 6 |
326 | .Vb 6 |
261 | \& static void * |
327 | \& static void * |
262 | \& persistent_realloc (void *ptr, long size) |
328 | \& persistent_realloc (void *ptr, size_t size) |
263 | \& { |
329 | \& { |
264 | \& for (;;) |
330 | \& for (;;) |
265 | \& { |
331 | \& { |
266 | \& void *newptr = realloc (ptr, size); |
332 | \& void *newptr = realloc (ptr, size); |
267 | .Ve |
333 | .Ve |
… | |
… | |
289 | callback is set, then libev will expect it to remedy the sitution, no |
355 | 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 |
356 | 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 |
357 | requested operation, or, if the condition doesn't go away, do bad stuff |
292 | (such as abort). |
358 | (such as abort). |
293 | .Sp |
359 | .Sp |
294 | Example: do the same thing as libev does internally: |
360 | Example: This is basically the same thing that libev does internally, too. |
295 | .Sp |
361 | .Sp |
296 | .Vb 6 |
362 | .Vb 6 |
297 | \& static void |
363 | \& static void |
298 | \& fatal_error (const char *msg) |
364 | \& fatal_error (const char *msg) |
299 | \& { |
365 | \& { |
… | |
… | |
448 | Similar to \f(CW\*(C`ev_default_loop\*(C'\fR, but always creates a new event loop that is |
514 | 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 |
515 | 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 |
516 | 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). |
517 | undefined behaviour (or a failed assertion if assertions are enabled). |
452 | .Sp |
518 | .Sp |
453 | Example: try to create a event loop that uses epoll and nothing else. |
519 | Example: Try to create a event loop that uses epoll and nothing else. |
454 | .Sp |
520 | .Sp |
455 | .Vb 3 |
521 | .Vb 3 |
456 | \& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
522 | \& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
457 | \& if (!epoller) |
523 | \& if (!epoller) |
458 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
524 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
… | |
… | |
556 | \& be handled here by queueing them when their watcher gets executed. |
622 | \& be handled here by queueing them when their watcher gets executed. |
557 | \& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
623 | \& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
558 | \& were used, return, otherwise continue with step *. |
624 | \& were used, return, otherwise continue with step *. |
559 | .Ve |
625 | .Ve |
560 | .Sp |
626 | .Sp |
561 | Example: queue some jobs and then loop until no events are outsanding |
627 | Example: Queue some jobs and then loop until no events are outsanding |
562 | anymore. |
628 | anymore. |
563 | .Sp |
629 | .Sp |
564 | .Vb 4 |
630 | .Vb 4 |
565 | \& ... queue jobs here, make sure they register event watchers as long |
631 | \& ... 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..) |
632 | \& ... 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 |
654 | 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 |
655 | 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 |
656 | 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. |
657 | libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR. |
592 | .Sp |
658 | .Sp |
593 | Example: create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
659 | Example: Create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
594 | running when nothing else is active. |
660 | running when nothing else is active. |
595 | .Sp |
661 | .Sp |
596 | .Vb 4 |
662 | .Vb 4 |
597 | \& struct dv_signal exitsig; |
663 | \& struct ev_signal exitsig; |
598 | \& ev_signal_init (&exitsig, sig_cb, SIGINT); |
664 | \& ev_signal_init (&exitsig, sig_cb, SIGINT); |
599 | \& ev_signal_start (myloop, &exitsig); |
665 | \& ev_signal_start (loop, &exitsig); |
600 | \& evf_unref (myloop); |
666 | \& evf_unref (loop); |
601 | .Ve |
667 | .Ve |
602 | .Sp |
668 | .Sp |
603 | Example: for some weird reason, unregister the above signal handler again. |
669 | Example: For some weird reason, unregister the above signal handler again. |
604 | .Sp |
670 | .Sp |
605 | .Vb 2 |
671 | .Vb 2 |
606 | \& ev_ref (myloop); |
672 | \& ev_ref (loop); |
607 | \& ev_signal_stop (myloop, &exitsig); |
673 | \& ev_signal_stop (loop, &exitsig); |
608 | .Ve |
674 | .Ve |
609 | .SH "ANATOMY OF A WATCHER" |
675 | .SH "ANATOMY OF A WATCHER" |
610 | .IX Header "ANATOMY OF A WATCHER" |
676 | .IX Header "ANATOMY OF A WATCHER" |
611 | A watcher is a structure that you create and register to record your |
677 | 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 |
678 | interest in some event. For instance, if you want to wait for \s-1STDIN\s0 to |
… | |
… | |
792 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
858 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
793 | events but its callback has not yet been invoked). As long as a watcher |
859 | events but its callback has not yet been invoked). As long as a watcher |
794 | is pending (but not active) you must not call an init function on it (but |
860 | is pending (but not active) you must not call an init function on it (but |
795 | \&\f(CW\*(C`ev_TYPE_set\*(C'\fR is safe) and you must make sure the watcher is available to |
861 | \&\f(CW\*(C`ev_TYPE_set\*(C'\fR is safe) and you must make sure the watcher is available to |
796 | libev (e.g. you cnanot \f(CW\*(C`free ()\*(C'\fR it). |
862 | libev (e.g. you cnanot \f(CW\*(C`free ()\*(C'\fR it). |
797 | .IP "callback = ev_cb (ev_TYPE *watcher)" 4 |
863 | .IP "callback ev_cb (ev_TYPE *watcher)" 4 |
798 | .IX Item "callback = ev_cb (ev_TYPE *watcher)" |
864 | .IX Item "callback ev_cb (ev_TYPE *watcher)" |
799 | Returns the callback currently set on the watcher. |
865 | Returns the callback currently set on the watcher. |
800 | .IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 |
866 | .IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 |
801 | .IX Item "ev_cb_set (ev_TYPE *watcher, callback)" |
867 | .IX Item "ev_cb_set (ev_TYPE *watcher, callback)" |
802 | Change the callback. You can change the callback at virtually any time |
868 | Change the callback. You can change the callback at virtually any time |
803 | (modulo threads). |
869 | (modulo threads). |
… | |
… | |
829 | \& struct my_io *w = (struct my_io *)w_; |
895 | \& struct my_io *w = (struct my_io *)w_; |
830 | \& ... |
896 | \& ... |
831 | \& } |
897 | \& } |
832 | .Ve |
898 | .Ve |
833 | .PP |
899 | .PP |
834 | More interesting and less C\-conformant ways of catsing your callback type |
900 | More interesting and less C\-conformant ways of casting your callback type |
835 | have been omitted.... |
901 | instead have been omitted. |
|
|
902 | .PP |
|
|
903 | Another common scenario is having some data structure with multiple |
|
|
904 | watchers: |
|
|
905 | .PP |
|
|
906 | .Vb 6 |
|
|
907 | \& struct my_biggy |
|
|
908 | \& { |
|
|
909 | \& int some_data; |
|
|
910 | \& ev_timer t1; |
|
|
911 | \& ev_timer t2; |
|
|
912 | \& } |
|
|
913 | .Ve |
|
|
914 | .PP |
|
|
915 | In this case getting the pointer to \f(CW\*(C`my_biggy\*(C'\fR is a bit more complicated, |
|
|
916 | you need to use \f(CW\*(C`offsetof\*(C'\fR: |
|
|
917 | .PP |
|
|
918 | .Vb 1 |
|
|
919 | \& #include <stddef.h> |
|
|
920 | .Ve |
|
|
921 | .PP |
|
|
922 | .Vb 6 |
|
|
923 | \& static void |
|
|
924 | \& t1_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
925 | \& { |
|
|
926 | \& struct my_biggy big = (struct my_biggy * |
|
|
927 | \& (((char *)w) - offsetof (struct my_biggy, t1)); |
|
|
928 | \& } |
|
|
929 | .Ve |
|
|
930 | .PP |
|
|
931 | .Vb 6 |
|
|
932 | \& static void |
|
|
933 | \& t2_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
934 | \& { |
|
|
935 | \& struct my_biggy big = (struct my_biggy * |
|
|
936 | \& (((char *)w) - offsetof (struct my_biggy, t2)); |
|
|
937 | \& } |
|
|
938 | .Ve |
836 | .SH "WATCHER TYPES" |
939 | .SH "WATCHER TYPES" |
837 | .IX Header "WATCHER TYPES" |
940 | .IX Header "WATCHER TYPES" |
838 | This section describes each watcher in detail, but will not repeat |
941 | This section describes each watcher in detail, but will not repeat |
839 | information given in the last section. Any initialisation/set macros, |
942 | information given in the last section. Any initialisation/set macros, |
840 | functions and members specific to the watcher type are explained. |
943 | functions and members specific to the watcher type are explained. |
… | |
… | |
901 | The file descriptor being watched. |
1004 | The file descriptor being watched. |
902 | .IP "int events [read\-only]" 4 |
1005 | .IP "int events [read\-only]" 4 |
903 | .IX Item "int events [read-only]" |
1006 | .IX Item "int events [read-only]" |
904 | The events being watched. |
1007 | The events being watched. |
905 | .PP |
1008 | .PP |
906 | Example: call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
1009 | Example: Call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
907 | readable, but only once. Since it is likely line\-buffered, you could |
1010 | readable, but only once. Since it is likely line\-buffered, you could |
908 | attempt to read a whole line in the callback: |
1011 | attempt to read a whole line in the callback. |
909 | .PP |
1012 | .PP |
910 | .Vb 6 |
1013 | .Vb 6 |
911 | \& static void |
1014 | \& static void |
912 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1015 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
913 | \& { |
1016 | \& { |
… | |
… | |
1005 | .IX Item "ev_tstamp repeat [read-write]" |
1108 | .IX Item "ev_tstamp repeat [read-write]" |
1006 | The current \f(CW\*(C`repeat\*(C'\fR value. Will be used each time the watcher times out |
1109 | The current \f(CW\*(C`repeat\*(C'\fR value. Will be used each time the watcher times out |
1007 | or \f(CW\*(C`ev_timer_again\*(C'\fR is called and determines the next timeout (if any), |
1110 | or \f(CW\*(C`ev_timer_again\*(C'\fR is called and determines the next timeout (if any), |
1008 | which is also when any modifications are taken into account. |
1111 | which is also when any modifications are taken into account. |
1009 | .PP |
1112 | .PP |
1010 | Example: create a timer that fires after 60 seconds. |
1113 | Example: Create a timer that fires after 60 seconds. |
1011 | .PP |
1114 | .PP |
1012 | .Vb 5 |
1115 | .Vb 5 |
1013 | \& static void |
1116 | \& static void |
1014 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1117 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1015 | \& { |
1118 | \& { |
… | |
… | |
1021 | \& struct ev_timer mytimer; |
1124 | \& struct ev_timer mytimer; |
1022 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
1125 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
1023 | \& ev_timer_start (loop, &mytimer); |
1126 | \& ev_timer_start (loop, &mytimer); |
1024 | .Ve |
1127 | .Ve |
1025 | .PP |
1128 | .PP |
1026 | Example: create a timeout timer that times out after 10 seconds of |
1129 | Example: Create a timeout timer that times out after 10 seconds of |
1027 | inactivity. |
1130 | inactivity. |
1028 | .PP |
1131 | .PP |
1029 | .Vb 5 |
1132 | .Vb 5 |
1030 | \& static void |
1133 | \& static void |
1031 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1134 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
… | |
… | |
1156 | .IX Item "ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read-write]" |
1259 | .IX Item "ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read-write]" |
1157 | The current reschedule callback, or \f(CW0\fR, if this functionality is |
1260 | The current reschedule callback, or \f(CW0\fR, if this functionality is |
1158 | switched off. Can be changed any time, but changes only take effect when |
1261 | switched off. Can be changed any time, but changes only take effect when |
1159 | the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being called. |
1262 | the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being called. |
1160 | .PP |
1263 | .PP |
1161 | Example: call a callback every hour, or, more precisely, whenever the |
1264 | Example: Call a callback every hour, or, more precisely, whenever the |
1162 | system clock is divisible by 3600. The callback invocation times have |
1265 | system clock is divisible by 3600. The callback invocation times have |
1163 | potentially a lot of jittering, but good long-term stability. |
1266 | potentially a lot of jittering, but good long-term stability. |
1164 | .PP |
1267 | .PP |
1165 | .Vb 5 |
1268 | .Vb 5 |
1166 | \& static void |
1269 | \& static void |
… | |
… | |
1174 | \& struct ev_periodic hourly_tick; |
1277 | \& struct ev_periodic hourly_tick; |
1175 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1278 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1176 | \& ev_periodic_start (loop, &hourly_tick); |
1279 | \& ev_periodic_start (loop, &hourly_tick); |
1177 | .Ve |
1280 | .Ve |
1178 | .PP |
1281 | .PP |
1179 | Example: the same as above, but use a reschedule callback to do it: |
1282 | Example: The same as above, but use a reschedule callback to do it: |
1180 | .PP |
1283 | .PP |
1181 | .Vb 1 |
1284 | .Vb 1 |
1182 | \& #include <math.h> |
1285 | \& #include <math.h> |
1183 | .Ve |
1286 | .Ve |
1184 | .PP |
1287 | .PP |
… | |
… | |
1192 | .PP |
1295 | .PP |
1193 | .Vb 1 |
1296 | .Vb 1 |
1194 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1297 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1195 | .Ve |
1298 | .Ve |
1196 | .PP |
1299 | .PP |
1197 | Example: call a callback every hour, starting now: |
1300 | Example: Call a callback every hour, starting now: |
1198 | .PP |
1301 | .PP |
1199 | .Vb 4 |
1302 | .Vb 4 |
1200 | \& struct ev_periodic hourly_tick; |
1303 | \& struct ev_periodic hourly_tick; |
1201 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1304 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1202 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
1305 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
… | |
… | |
1253 | .IP "int rstatus [read\-write]" 4 |
1356 | .IP "int rstatus [read\-write]" 4 |
1254 | .IX Item "int rstatus [read-write]" |
1357 | .IX Item "int rstatus [read-write]" |
1255 | The process exit/trace status caused by \f(CW\*(C`rpid\*(C'\fR (see your systems |
1358 | The process exit/trace status caused by \f(CW\*(C`rpid\*(C'\fR (see your systems |
1256 | \&\f(CW\*(C`waitpid\*(C'\fR and \f(CW\*(C`sys/wait.h\*(C'\fR documentation for details). |
1359 | \&\f(CW\*(C`waitpid\*(C'\fR and \f(CW\*(C`sys/wait.h\*(C'\fR documentation for details). |
1257 | .PP |
1360 | .PP |
1258 | Example: try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1361 | Example: Try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1259 | .PP |
1362 | .PP |
1260 | .Vb 5 |
1363 | .Vb 5 |
1261 | \& static void |
1364 | \& static void |
1262 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1365 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1263 | \& { |
1366 | \& { |
… | |
… | |
1281 | not exist\*(R" is a status change like any other. The condition \*(L"path does |
1384 | not exist\*(R" is a status change like any other. The condition \*(L"path does |
1282 | not exist\*(R" is signified by the \f(CW\*(C`st_nlink\*(C'\fR field being zero (which is |
1385 | not exist\*(R" is signified by the \f(CW\*(C`st_nlink\*(C'\fR field being zero (which is |
1283 | otherwise always forced to be at least one) and all the other fields of |
1386 | otherwise always forced to be at least one) and all the other fields of |
1284 | the stat buffer having unspecified contents. |
1387 | the stat buffer having unspecified contents. |
1285 | .PP |
1388 | .PP |
|
|
1389 | The path \fIshould\fR be absolute and \fImust not\fR end in a slash. If it is |
|
|
1390 | relative and your working directory changes, the behaviour is undefined. |
|
|
1391 | .PP |
1286 | Since there is no standard to do this, the portable implementation simply |
1392 | Since there is no standard to do this, the portable implementation simply |
1287 | calls \f(CW\*(C`stat (2)\*(C'\fR regulalry on the path to see if it changed somehow. You |
1393 | calls \f(CW\*(C`stat (2)\*(C'\fR regularly on the path to see if it changed somehow. You |
1288 | can specify a recommended polling interval for this case. If you specify |
1394 | can specify a recommended polling interval for this case. If you specify |
1289 | a polling interval of \f(CW0\fR (highly recommended!) then a \fIsuitable, |
1395 | a polling interval of \f(CW0\fR (highly recommended!) then a \fIsuitable, |
1290 | unspecified default\fR value will be used (which you can expect to be around |
1396 | unspecified default\fR value will be used (which you can expect to be around |
1291 | five seconds, although this might change dynamically). Libev will also |
1397 | five seconds, although this might change dynamically). Libev will also |
1292 | impose a minimum interval which is currently around \f(CW0.1\fR, but thats |
1398 | impose a minimum interval which is currently around \f(CW0.1\fR, but thats |
… | |
… | |
1294 | .PP |
1400 | .PP |
1295 | This watcher type is not meant for massive numbers of stat watchers, |
1401 | This watcher type is not meant for massive numbers of stat watchers, |
1296 | as even with OS-supported change notifications, this can be |
1402 | as even with OS-supported change notifications, this can be |
1297 | resource\-intensive. |
1403 | resource\-intensive. |
1298 | .PP |
1404 | .PP |
1299 | At the time of this writing, no specific \s-1OS\s0 backends are implemented, but |
1405 | At the time of this writing, only the Linux inotify interface is |
1300 | if demand increases, at least a kqueue and inotify backend will be added. |
1406 | implemented (implementing kqueue support is left as an exercise for the |
|
|
1407 | reader). Inotify will be used to give hints only and should not change the |
|
|
1408 | semantics of \f(CW\*(C`ev_stat\*(C'\fR watchers, which means that libev sometimes needs |
|
|
1409 | to fall back to regular polling again even with inotify, but changes are |
|
|
1410 | usually detected immediately, and if the file exists there will be no |
|
|
1411 | polling. |
1301 | .IP "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" 4 |
1412 | .IP "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" 4 |
1302 | .IX Item "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" |
1413 | .IX Item "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" |
1303 | .PD 0 |
1414 | .PD 0 |
1304 | .IP "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" 4 |
1415 | .IP "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" 4 |
1305 | .IX Item "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" |
1416 | .IX Item "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" |
… | |
… | |
1387 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1498 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1388 | Initialises and configures the idle watcher \- it has no parameters of any |
1499 | Initialises and configures the idle watcher \- it has no parameters of any |
1389 | kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless, |
1500 | kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless, |
1390 | believe me. |
1501 | believe me. |
1391 | .PP |
1502 | .PP |
1392 | Example: dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR, start it, and in the |
1503 | Example: Dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR watcher, start it, and in the |
1393 | callback, free it. Alos, use no error checking, as usual. |
1504 | callback, free it. Also, use no error checking, as usual. |
1394 | .PP |
1505 | .PP |
1395 | .Vb 7 |
1506 | .Vb 7 |
1396 | \& static void |
1507 | \& static void |
1397 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1508 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1398 | \& { |
1509 | \& { |
… | |
… | |
2069 | otherwise another method will be used as fallback. This is the preferred |
2180 | otherwise another method will be used as fallback. This is the preferred |
2070 | backend for Solaris 10 systems. |
2181 | backend for Solaris 10 systems. |
2071 | .IP "\s-1EV_USE_DEVPOLL\s0" 4 |
2182 | .IP "\s-1EV_USE_DEVPOLL\s0" 4 |
2072 | .IX Item "EV_USE_DEVPOLL" |
2183 | .IX Item "EV_USE_DEVPOLL" |
2073 | reserved for future expansion, works like the \s-1USE\s0 symbols above. |
2184 | reserved for future expansion, works like the \s-1USE\s0 symbols above. |
|
|
2185 | .IP "\s-1EV_USE_INOTIFY\s0" 4 |
|
|
2186 | .IX Item "EV_USE_INOTIFY" |
|
|
2187 | If defined to be \f(CW1\fR, libev will compile in support for the Linux inotify |
|
|
2188 | interface to speed up \f(CW\*(C`ev_stat\*(C'\fR watchers. Its actual availability will |
|
|
2189 | be detected at runtime. |
2074 | .IP "\s-1EV_H\s0" 4 |
2190 | .IP "\s-1EV_H\s0" 4 |
2075 | .IX Item "EV_H" |
2191 | .IX Item "EV_H" |
2076 | The name of the \fIev.h\fR header file used to include it. The default if |
2192 | The name of the \fIev.h\fR header file used to include it. The default if |
2077 | undefined is \f(CW\*(C`<ev.h>\*(C'\fR in \fIevent.h\fR and \f(CW"ev.h"\fR in \fIev.c\fR. This |
2193 | undefined is \f(CW\*(C`<ev.h>\*(C'\fR in \fIevent.h\fR and \f(CW"ev.h"\fR in \fIev.c\fR. This |
2078 | can be used to virtually rename the \fIev.h\fR header file in case of conflicts. |
2194 | can be used to virtually rename the \fIev.h\fR header file in case of conflicts. |
… | |
… | |
2123 | .IP "\s-1EV_PID_HASHSIZE\s0" 4 |
2239 | .IP "\s-1EV_PID_HASHSIZE\s0" 4 |
2124 | .IX Item "EV_PID_HASHSIZE" |
2240 | .IX Item "EV_PID_HASHSIZE" |
2125 | \&\f(CW\*(C`ev_child\*(C'\fR watchers use a small hash table to distribute workload by |
2241 | \&\f(CW\*(C`ev_child\*(C'\fR watchers use a small hash table to distribute workload by |
2126 | pid. The default size is \f(CW16\fR (or \f(CW1\fR with \f(CW\*(C`EV_MINIMAL\*(C'\fR), usually more |
2242 | pid. The default size is \f(CW16\fR (or \f(CW1\fR with \f(CW\*(C`EV_MINIMAL\*(C'\fR), usually more |
2127 | than enough. If you need to manage thousands of children you might want to |
2243 | than enough. If you need to manage thousands of children you might want to |
2128 | increase this value. |
2244 | increase this value (\fImust\fR be a power of two). |
|
|
2245 | .IP "\s-1EV_INOTIFY_HASHSIZE\s0" 4 |
|
|
2246 | .IX Item "EV_INOTIFY_HASHSIZE" |
|
|
2247 | \&\f(CW\*(C`ev_staz\*(C'\fR watchers use a small hash table to distribute workload by |
|
|
2248 | inotify watch id. The default size is \f(CW16\fR (or \f(CW1\fR with \f(CW\*(C`EV_MINIMAL\*(C'\fR), |
|
|
2249 | usually more than enough. If you need to manage thousands of \f(CW\*(C`ev_stat\*(C'\fR |
|
|
2250 | watchers you might want to increase this value (\fImust\fR be a power of |
|
|
2251 | two). |
2129 | .IP "\s-1EV_COMMON\s0" 4 |
2252 | .IP "\s-1EV_COMMON\s0" 4 |
2130 | .IX Item "EV_COMMON" |
2253 | .IX Item "EV_COMMON" |
2131 | By default, all watchers have a \f(CW\*(C`void *data\*(C'\fR member. By redefining |
2254 | By default, all watchers have a \f(CW\*(C`void *data\*(C'\fR member. By redefining |
2132 | this macro to a something else you can include more and other types of |
2255 | this macro to a something else you can include more and other types of |
2133 | members. You have to define it each time you include one of the files, |
2256 | members. You have to define it each time you include one of the files, |
… | |
… | |
2197 | .IX Item "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" |
2320 | .IX Item "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" |
2198 | .IP "Starting io/check/prepare/idle/signal/child watchers: O(1)" 4 |
2321 | .IP "Starting io/check/prepare/idle/signal/child watchers: O(1)" 4 |
2199 | .IX Item "Starting io/check/prepare/idle/signal/child watchers: O(1)" |
2322 | .IX Item "Starting io/check/prepare/idle/signal/child watchers: O(1)" |
2200 | .IP "Stopping check/prepare/idle watchers: O(1)" 4 |
2323 | .IP "Stopping check/prepare/idle watchers: O(1)" 4 |
2201 | .IX Item "Stopping check/prepare/idle watchers: O(1)" |
2324 | .IX Item "Stopping check/prepare/idle watchers: O(1)" |
2202 | .IP "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))" 4 |
2325 | .IP "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % \s-1EV_PID_HASHSIZE\s0))" 4 |
2203 | .IX Item "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))" |
2326 | .IX Item "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))" |
2204 | .IP "Finding the next timer per loop iteration: O(1)" 4 |
2327 | .IP "Finding the next timer per loop iteration: O(1)" 4 |
2205 | .IX Item "Finding the next timer per loop iteration: O(1)" |
2328 | .IX Item "Finding the next timer per loop iteration: O(1)" |
2206 | .IP "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" 4 |
2329 | .IP "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" 4 |
2207 | .IX Item "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" |
2330 | .IX Item "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" |
2208 | .IP "Activating one watcher: O(1)" 4 |
2331 | .IP "Activating one watcher: O(1)" 4 |