… | |
… | |
265 | 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 |
266 | C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will |
266 | C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will |
267 | 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 |
268 | 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 |
269 | around bugs. |
269 | around bugs. |
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|
270 | |
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|
271 | =item C<EVFLAG_FORKCHECK> |
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|
272 | |
|
|
273 | Instead of calling C<ev_default_fork> or C<ev_loop_fork> manually after |
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|
274 | a fork, you can also make libev check for a fork in each iteration by |
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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 |
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|
279 | iterations and little real work, but is usually not noticable (on my |
|
|
280 | Linux system for example, C<getpid> is actually a simple 5-insn sequence |
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|
281 | without a syscall and thus I<very> fast, but my Linux system also has |
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|
282 | C<pthread_atfork> which is even faster). |
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283 | |
|
|
284 | The big advantage of this flag is that you can forget about fork (and |
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285 | forget about forgetting to tell libev about forking) when you use this |
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286 | flag. |
|
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287 | |
|
|
288 | This flag setting cannot be overriden or specified in the C<LIBEV_FLAGS> |
|
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289 | environment variable. |
270 | |
290 | |
271 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
291 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
272 | |
292 | |
273 | 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 |
274 | 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, |
… | |
… | |
916 | =item ev_timer_again (loop) |
936 | =item ev_timer_again (loop) |
917 | |
937 | |
918 | 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 |
919 | repeating. The exact semantics are: |
939 | repeating. The exact semantics are: |
920 | |
940 | |
|
|
941 | If the timer is pending, its pending status is cleared. |
|
|
942 | |
921 | If the timer is started but nonrepeating, stop it. |
943 | If the timer is started but nonrepeating, stop it (as if it timed out). |
922 | |
944 | |
923 | 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 |
924 | value), or reset the running timer to the repeat value. |
946 | C<repeat> value), or reset the running timer to the C<repeat> value. |
925 | |
947 | |
926 | 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 |
927 | 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 |
928 | 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 |
929 | 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 |
930 | 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 |
931 | 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 |
932 | 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 |
933 | 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 |
934 | need be. |
956 | automatically restart it if need be. |
935 | |
957 | |
936 | 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> |
937 | and only ever use the C<repeat> value: |
959 | altogether and only ever use the C<repeat> value and C<ev_timer_again>: |
938 | |
960 | |
939 | ev_timer_init (timer, callback, 0., 5.); |
961 | ev_timer_init (timer, callback, 0., 5.); |
940 | ev_timer_again (loop, timer); |
962 | ev_timer_again (loop, timer); |
941 | ... |
963 | ... |
942 | timer->again = 17.; |
964 | timer->again = 17.; |
943 | ev_timer_again (loop, timer); |
965 | ev_timer_again (loop, timer); |
944 | ... |
966 | ... |
945 | timer->again = 10.; |
967 | timer->again = 10.; |
946 | ev_timer_again (loop, timer); |
968 | ev_timer_again (loop, timer); |
947 | |
969 | |
948 | 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 |
949 | to modify its timeout value. |
971 | you want to modify its timeout value. |
950 | |
972 | |
951 | =item ev_tstamp repeat [read-write] |
973 | =item ev_tstamp repeat [read-write] |
952 | |
974 | |
953 | 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 |
954 | 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), |
… | |
… | |
1435 | |
1457 | |
1436 | // create io watchers for each fd and a timer before blocking |
1458 | // create io watchers for each fd and a timer before blocking |
1437 | static void |
1459 | static void |
1438 | adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1460 | adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1439 | { |
1461 | { |
1440 | int timeout = 3600000;truct pollfd fds [nfd]; |
1462 | int timeout = 3600000; |
|
|
1463 | struct pollfd fds [nfd]; |
1441 | // actual code will need to loop here and realloc etc. |
1464 | // actual code will need to loop here and realloc etc. |
1442 | adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1465 | adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1443 | |
1466 | |
1444 | /* 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 */ |
1445 | ev_timer_init (&tw, 0, timeout * 1e-3); |
1468 | ev_timer_init (&tw, 0, timeout * 1e-3); |
… | |
… | |
1826 | 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 |
1827 | loop, if multiple loops are supported ("ev loop default"). |
1850 | loop, if multiple loops are supported ("ev loop default"). |
1828 | |
1851 | |
1829 | =back |
1852 | =back |
1830 | |
1853 | |
1831 | Example: Declare and initialise a check watcher, working regardless of |
1854 | Example: Declare and initialise a check watcher, utilising the above |
1832 | wether multiple loops are supported or not. |
1855 | macros so it will work regardless of wether multiple loops are supported |
|
|
1856 | or not. |
1833 | |
1857 | |
1834 | static void |
1858 | static void |
1835 | check_cb (EV_P_ ev_timer *w, int revents) |
1859 | check_cb (EV_P_ ev_timer *w, int revents) |
1836 | { |
1860 | { |
1837 | ev_check_stop (EV_A_ w); |
1861 | ev_check_stop (EV_A_ w); |
… | |
… | |
1839 | |
1863 | |
1840 | ev_check check; |
1864 | ev_check check; |
1841 | ev_check_init (&check, check_cb); |
1865 | ev_check_init (&check, check_cb); |
1842 | ev_check_start (EV_DEFAULT_ &check); |
1866 | ev_check_start (EV_DEFAULT_ &check); |
1843 | ev_loop (EV_DEFAULT_ 0); |
1867 | ev_loop (EV_DEFAULT_ 0); |
1844 | |
|
|
1845 | |
1868 | |
1846 | =head1 EMBEDDING |
1869 | =head1 EMBEDDING |
1847 | |
1870 | |
1848 | Libev can (and often is) directly embedded into host |
1871 | Libev can (and often is) directly embedded into host |
1849 | applications. Examples of applications that embed it include the Deliantra |
1872 | applications. Examples of applications that embed it include the Deliantra |
… | |
… | |
1889 | ev_vars.h |
1912 | ev_vars.h |
1890 | ev_wrap.h |
1913 | ev_wrap.h |
1891 | |
1914 | |
1892 | ev_win32.c required on win32 platforms only |
1915 | ev_win32.c required on win32 platforms only |
1893 | |
1916 | |
1894 | 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) |
1895 | 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) |
1896 | 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) |
1897 | 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) |
1898 | 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) |
1899 | |
1922 | |
… | |
… | |
2141 | 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 |
2142 | 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 |
2143 | file. |
2166 | file. |
2144 | |
2167 | |
2145 | 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 |
2146 | that everybody includes and which overrides some autoconf choices: |
2169 | that everybody includes and which overrides some configure choices: |
2147 | |
2170 | |
|
|
2171 | #define EV_MINIMAL 1 |
2148 | #define EV_USE_POLL 0 |
2172 | #define EV_USE_POLL 0 |
2149 | #define EV_MULTIPLICITY 0 |
2173 | #define EV_MULTIPLICITY 0 |
2150 | #define EV_PERIODICS 0 |
2174 | #define EV_PERIODIC_ENABLE 0 |
|
|
2175 | #define EV_STAT_ENABLE 0 |
|
|
2176 | #define EV_FORK_ENABLE 0 |
2151 | #define EV_CONFIG_H <config.h> |
2177 | #define EV_CONFIG_H <config.h> |
|
|
2178 | #define EV_MINPRI 0 |
|
|
2179 | #define EV_MAXPRI 0 |
2152 | |
2180 | |
2153 | #include "ev++.h" |
2181 | #include "ev++.h" |
2154 | |
2182 | |
2155 | 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: |
2156 | |
2184 | |