… | |
… | |
163 | C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for |
163 | C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for |
164 | recommended ones. |
164 | recommended ones. |
165 | |
165 | |
166 | See the description of C<ev_embed> watchers for more info. |
166 | See the description of C<ev_embed> watchers for more info. |
167 | |
167 | |
168 | =item ev_set_allocator (void *(*cb)(void *ptr, size_t size)) |
168 | =item ev_set_allocator (void *(*cb)(void *ptr, long size)) |
169 | |
169 | |
170 | Sets the allocation function to use (the prototype and semantics are |
170 | Sets the allocation function to use (the prototype is similar - the |
171 | identical to the realloc C function). It is used to allocate and free |
171 | semantics is identical - to the realloc C function). It is used to |
172 | memory (no surprises here). If it returns zero when memory needs to be |
172 | allocate and free memory (no surprises here). If it returns zero when |
173 | allocated, the library might abort or take some potentially destructive |
173 | memory needs to be allocated, the library might abort or take some |
174 | action. The default is your system realloc function. |
174 | potentially destructive action. The default is your system realloc |
|
|
175 | function. |
175 | |
176 | |
176 | You could override this function in high-availability programs to, say, |
177 | You could override this function in high-availability programs to, say, |
177 | free some memory if it cannot allocate memory, to use a special allocator, |
178 | free some memory if it cannot allocate memory, to use a special allocator, |
178 | or even to sleep a while and retry until some memory is available. |
179 | or even to sleep a while and retry until some memory is available. |
179 | |
180 | |
… | |
… | |
264 | or setgid) then libev will I<not> look at the environment variable |
265 | or setgid) then libev will I<not> look at the environment variable |
265 | C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will |
266 | C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will |
266 | override the flags completely if it is found in the environment. This is |
267 | override the flags completely if it is found in the environment. This is |
267 | useful to try out specific backends to test their performance, or to work |
268 | useful to try out specific backends to test their performance, or to work |
268 | around bugs. |
269 | around bugs. |
|
|
270 | |
|
|
271 | =item C<EVFLAG_FORKCHECK> |
|
|
272 | |
|
|
273 | Instead of calling C<ev_default_fork> or C<ev_loop_fork> manually after |
|
|
274 | a fork, you can also make libev check for a fork in each iteration by |
|
|
275 | enabling this flag. |
|
|
276 | |
|
|
277 | This works by calling C<getpid ()> on every iteration of the loop, |
|
|
278 | and thus this might slow down your event loop if you do a lot of loop |
|
|
279 | iterations and little real work, but is usually not noticeable (on my |
|
|
280 | Linux system for example, C<getpid> is actually a simple 5-insn sequence |
|
|
281 | without a syscall and thus I<very> fast, but my Linux system also has |
|
|
282 | C<pthread_atfork> which is even faster). |
|
|
283 | |
|
|
284 | The big advantage of this flag is that you can forget about fork (and |
|
|
285 | forget about forgetting to tell libev about forking) when you use this |
|
|
286 | flag. |
|
|
287 | |
|
|
288 | This flag setting cannot be overriden or specified in the C<LIBEV_FLAGS> |
|
|
289 | environment variable. |
269 | |
290 | |
270 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
291 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
271 | |
292 | |
272 | This is your standard select(2) backend. Not I<completely> standard, as |
293 | This is your standard select(2) backend. Not I<completely> standard, as |
273 | libev tries to roll its own fd_set with no limits on the number of fds, |
294 | libev tries to roll its own fd_set with no limits on the number of fds, |
… | |
… | |
915 | =item ev_timer_again (loop) |
936 | =item ev_timer_again (loop) |
916 | |
937 | |
917 | This will act as if the timer timed out and restart it again if it is |
938 | This will act as if the timer timed out and restart it again if it is |
918 | repeating. The exact semantics are: |
939 | repeating. The exact semantics are: |
919 | |
940 | |
|
|
941 | If the timer is pending, its pending status is cleared. |
|
|
942 | |
920 | If the timer is started but nonrepeating, stop it. |
943 | If the timer is started but nonrepeating, stop it (as if it timed out). |
921 | |
944 | |
922 | If the timer is repeating, either start it if necessary (with the repeat |
945 | If the timer is repeating, either start it if necessary (with the |
923 | value), or reset the running timer to the repeat value. |
946 | C<repeat> value), or reset the running timer to the C<repeat> value. |
924 | |
947 | |
925 | This sounds a bit complicated, but here is a useful and typical |
948 | This sounds a bit complicated, but here is a useful and typical |
926 | example: Imagine you have a tcp connection and you want a so-called |
949 | example: Imagine you have a tcp connection and you want a so-called idle |
927 | idle timeout, that is, you want to be called when there have been, |
950 | timeout, that is, you want to be called when there have been, say, 60 |
928 | say, 60 seconds of inactivity on the socket. The easiest way to do |
951 | seconds of inactivity on the socket. The easiest way to do this is to |
929 | this is to configure an C<ev_timer> with C<after>=C<repeat>=C<60> and calling |
952 | configure an C<ev_timer> with a C<repeat> value of C<60> and then call |
930 | C<ev_timer_again> each time you successfully read or write some data. If |
953 | C<ev_timer_again> each time you successfully read or write some data. If |
931 | you go into an idle state where you do not expect data to travel on the |
954 | you go into an idle state where you do not expect data to travel on the |
932 | socket, you can stop the timer, and again will automatically restart it if |
955 | socket, you can C<ev_timer_stop> the timer, and C<ev_timer_again> will |
933 | need be. |
956 | automatically restart it if need be. |
934 | |
957 | |
935 | You can also ignore the C<after> value and C<ev_timer_start> altogether |
958 | That means you can ignore the C<after> value and C<ev_timer_start> |
936 | and only ever use the C<repeat> value: |
959 | altogether and only ever use the C<repeat> value and C<ev_timer_again>: |
937 | |
960 | |
938 | ev_timer_init (timer, callback, 0., 5.); |
961 | ev_timer_init (timer, callback, 0., 5.); |
939 | ev_timer_again (loop, timer); |
962 | ev_timer_again (loop, timer); |
940 | ... |
963 | ... |
941 | timer->again = 17.; |
964 | timer->again = 17.; |
942 | ev_timer_again (loop, timer); |
965 | ev_timer_again (loop, timer); |
943 | ... |
966 | ... |
944 | timer->again = 10.; |
967 | timer->again = 10.; |
945 | ev_timer_again (loop, timer); |
968 | ev_timer_again (loop, timer); |
946 | |
969 | |
947 | This is more efficient then stopping/starting the timer eahc time you want |
970 | This is more slightly efficient then stopping/starting the timer each time |
948 | to modify its timeout value. |
971 | you want to modify its timeout value. |
949 | |
972 | |
950 | =item ev_tstamp repeat [read-write] |
973 | =item ev_tstamp repeat [read-write] |
951 | |
974 | |
952 | The current C<repeat> value. Will be used each time the watcher times out |
975 | The current C<repeat> value. Will be used each time the watcher times out |
953 | or C<ev_timer_again> is called and determines the next timeout (if any), |
976 | or C<ev_timer_again> is called and determines the next timeout (if any), |
… | |
… | |
1221 | The path does not need to exist: changing from "path exists" to "path does |
1244 | The path does not need to exist: changing from "path exists" to "path does |
1222 | not exist" is a status change like any other. The condition "path does |
1245 | not exist" is a status change like any other. The condition "path does |
1223 | not exist" is signified by the C<st_nlink> field being zero (which is |
1246 | not exist" is signified by the C<st_nlink> field being zero (which is |
1224 | otherwise always forced to be at least one) and all the other fields of |
1247 | otherwise always forced to be at least one) and all the other fields of |
1225 | the stat buffer having unspecified contents. |
1248 | the stat buffer having unspecified contents. |
|
|
1249 | |
|
|
1250 | The path I<should> be absolute and I<must not> end in a slash. If it is |
|
|
1251 | relative and your working directory changes, the behaviour is undefined. |
1226 | |
1252 | |
1227 | Since there is no standard to do this, the portable implementation simply |
1253 | Since there is no standard to do this, the portable implementation simply |
1228 | calls C<stat (2)> regularly on the path to see if it changed somehow. You |
1254 | calls C<stat (2)> regularly on the path to see if it changed somehow. You |
1229 | can specify a recommended polling interval for this case. If you specify |
1255 | can specify a recommended polling interval for this case. If you specify |
1230 | a polling interval of C<0> (highly recommended!) then a I<suitable, |
1256 | a polling interval of C<0> (highly recommended!) then a I<suitable, |
… | |
… | |
1431 | |
1457 | |
1432 | // create io watchers for each fd and a timer before blocking |
1458 | // create io watchers for each fd and a timer before blocking |
1433 | static void |
1459 | static void |
1434 | adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1460 | adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1435 | { |
1461 | { |
1436 | int timeout = 3600000;truct pollfd fds [nfd]; |
1462 | int timeout = 3600000; |
|
|
1463 | struct pollfd fds [nfd]; |
1437 | // actual code will need to loop here and realloc etc. |
1464 | // actual code will need to loop here and realloc etc. |
1438 | adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1465 | adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1439 | |
1466 | |
1440 | /* the callback is illegal, but won't be called as we stop during check */ |
1467 | /* the callback is illegal, but won't be called as we stop during check */ |
1441 | ev_timer_init (&tw, 0, timeout * 1e-3); |
1468 | ev_timer_init (&tw, 0, timeout * 1e-3); |
… | |
… | |
1822 | Similar to the other two macros, this gives you the value of the default |
1849 | Similar to the other two macros, this gives you the value of the default |
1823 | loop, if multiple loops are supported ("ev loop default"). |
1850 | loop, if multiple loops are supported ("ev loop default"). |
1824 | |
1851 | |
1825 | =back |
1852 | =back |
1826 | |
1853 | |
1827 | Example: Declare and initialise a check watcher, working regardless of |
1854 | Example: Declare and initialise a check watcher, utilising the above |
1828 | wether multiple loops are supported or not. |
1855 | macros so it will work regardless of wether multiple loops are supported |
|
|
1856 | or not. |
1829 | |
1857 | |
1830 | static void |
1858 | static void |
1831 | check_cb (EV_P_ ev_timer *w, int revents) |
1859 | check_cb (EV_P_ ev_timer *w, int revents) |
1832 | { |
1860 | { |
1833 | ev_check_stop (EV_A_ w); |
1861 | ev_check_stop (EV_A_ w); |
… | |
… | |
1835 | |
1863 | |
1836 | ev_check check; |
1864 | ev_check check; |
1837 | ev_check_init (&check, check_cb); |
1865 | ev_check_init (&check, check_cb); |
1838 | ev_check_start (EV_DEFAULT_ &check); |
1866 | ev_check_start (EV_DEFAULT_ &check); |
1839 | ev_loop (EV_DEFAULT_ 0); |
1867 | ev_loop (EV_DEFAULT_ 0); |
1840 | |
|
|
1841 | |
1868 | |
1842 | =head1 EMBEDDING |
1869 | =head1 EMBEDDING |
1843 | |
1870 | |
1844 | Libev can (and often is) directly embedded into host |
1871 | Libev can (and often is) directly embedded into host |
1845 | applications. Examples of applications that embed it include the Deliantra |
1872 | applications. Examples of applications that embed it include the Deliantra |
… | |
… | |
1885 | ev_vars.h |
1912 | ev_vars.h |
1886 | ev_wrap.h |
1913 | ev_wrap.h |
1887 | |
1914 | |
1888 | ev_win32.c required on win32 platforms only |
1915 | ev_win32.c required on win32 platforms only |
1889 | |
1916 | |
1890 | ev_select.c only when select backend is enabled (which is by default) |
1917 | ev_select.c only when select backend is enabled (which is enabled by default) |
1891 | ev_poll.c only when poll backend is enabled (disabled by default) |
1918 | ev_poll.c only when poll backend is enabled (disabled by default) |
1892 | ev_epoll.c only when the epoll backend is enabled (disabled by default) |
1919 | ev_epoll.c only when the epoll backend is enabled (disabled by default) |
1893 | ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
1920 | ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
1894 | ev_port.c only when the solaris port backend is enabled (disabled by default) |
1921 | ev_port.c only when the solaris port backend is enabled (disabled by default) |
1895 | |
1922 | |
… | |
… | |
2137 | interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file |
2164 | interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file |
2138 | will be compiled. It is pretty complex because it provides its own header |
2165 | will be compiled. It is pretty complex because it provides its own header |
2139 | file. |
2166 | file. |
2140 | |
2167 | |
2141 | The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file |
2168 | The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file |
2142 | that everybody includes and which overrides some autoconf choices: |
2169 | that everybody includes and which overrides some configure choices: |
2143 | |
2170 | |
|
|
2171 | #define EV_MINIMAL 1 |
2144 | #define EV_USE_POLL 0 |
2172 | #define EV_USE_POLL 0 |
2145 | #define EV_MULTIPLICITY 0 |
2173 | #define EV_MULTIPLICITY 0 |
2146 | #define EV_PERIODICS 0 |
2174 | #define EV_PERIODIC_ENABLE 0 |
|
|
2175 | #define EV_STAT_ENABLE 0 |
|
|
2176 | #define EV_FORK_ENABLE 0 |
2147 | #define EV_CONFIG_H <config.h> |
2177 | #define EV_CONFIG_H <config.h> |
|
|
2178 | #define EV_MINPRI 0 |
|
|
2179 | #define EV_MAXPRI 0 |
2148 | |
2180 | |
2149 | #include "ev++.h" |
2181 | #include "ev++.h" |
2150 | |
2182 | |
2151 | And a F<ev_cpp.C> implementation file that contains libev proper and is compiled: |
2183 | And a F<ev_cpp.C> implementation file that contains libev proper and is compiled: |
2152 | |
2184 | |