… | |
… | |
43 | |
43 | |
44 | int |
44 | int |
45 | main (void) |
45 | main (void) |
46 | { |
46 | { |
47 | // use the default event loop unless you have special needs |
47 | // use the default event loop unless you have special needs |
48 | ev_loop *loop = ev_default_loop (0); |
48 | struct ev_loop *loop = ev_default_loop (0); |
49 | |
49 | |
50 | // initialise an io watcher, then start it |
50 | // initialise an io watcher, then start it |
51 | // this one will watch for stdin to become readable |
51 | // this one will watch for stdin to become readable |
52 | ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
52 | ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
53 | ev_io_start (loop, &stdin_watcher); |
53 | ev_io_start (loop, &stdin_watcher); |
… | |
… | |
2012 | the process. The exception are C<ev_stat> watchers - those call C<stat |
2012 | the process. The exception are C<ev_stat> watchers - those call C<stat |
2013 | ()>, which is a synchronous operation. |
2013 | ()>, which is a synchronous operation. |
2014 | |
2014 | |
2015 | For local paths, this usually doesn't matter: unless the system is very |
2015 | For local paths, this usually doesn't matter: unless the system is very |
2016 | busy or the intervals between stat's are large, a stat call will be fast, |
2016 | busy or the intervals between stat's are large, a stat call will be fast, |
2017 | as the path data is suually in memory already (except when starting the |
2017 | as the path data is usually in memory already (except when starting the |
2018 | watcher). |
2018 | watcher). |
2019 | |
2019 | |
2020 | For networked file systems, calling C<stat ()> can block an indefinite |
2020 | For networked file systems, calling C<stat ()> can block an indefinite |
2021 | time due to network issues, and even under good conditions, a stat call |
2021 | time due to network issues, and even under good conditions, a stat call |
2022 | often takes multiple milliseconds. |
2022 | often takes multiple milliseconds. |
… | |
… | |
2891 | |
2891 | |
2892 | myclass obj; |
2892 | myclass obj; |
2893 | ev::io iow; |
2893 | ev::io iow; |
2894 | iow.set <myclass, &myclass::io_cb> (&obj); |
2894 | iow.set <myclass, &myclass::io_cb> (&obj); |
2895 | |
2895 | |
|
|
2896 | =item w->set (object *) |
|
|
2897 | |
|
|
2898 | This is an B<experimental> feature that might go away in a future version. |
|
|
2899 | |
|
|
2900 | This is a variation of a method callback - leaving out the method to call |
|
|
2901 | will default the method to C<operator ()>, which makes it possible to use |
|
|
2902 | functor objects without having to manually specify the C<operator ()> all |
|
|
2903 | the time. Incidentally, you can then also leave out the template argument |
|
|
2904 | list. |
|
|
2905 | |
|
|
2906 | The C<operator ()> method prototype must be C<void operator ()(watcher &w, |
|
|
2907 | int revents)>. |
|
|
2908 | |
|
|
2909 | See the method-C<set> above for more details. |
|
|
2910 | |
|
|
2911 | Example: use a functor object as callback. |
|
|
2912 | |
|
|
2913 | struct myfunctor |
|
|
2914 | { |
|
|
2915 | void operator() (ev::io &w, int revents) |
|
|
2916 | { |
|
|
2917 | ... |
|
|
2918 | } |
|
|
2919 | } |
|
|
2920 | |
|
|
2921 | myfunctor f; |
|
|
2922 | |
|
|
2923 | ev::io w; |
|
|
2924 | w.set (&f); |
|
|
2925 | |
2896 | =item w->set<function> (void *data = 0) |
2926 | =item w->set<function> (void *data = 0) |
2897 | |
2927 | |
2898 | Also sets a callback, but uses a static method or plain function as |
2928 | Also sets a callback, but uses a static method or plain function as |
2899 | callback. The optional C<data> argument will be stored in the watcher's |
2929 | callback. The optional C<data> argument will be stored in the watcher's |
2900 | C<data> member and is free for you to use. |
2930 | C<data> member and is free for you to use. |
… | |
… | |
3215 | |
3245 | |
3216 | If defined to be C<1>, libev will try to use a direct syscall instead |
3246 | If defined to be C<1>, libev will try to use a direct syscall instead |
3217 | of calling the system-provided C<clock_gettime> function. This option |
3247 | of calling the system-provided C<clock_gettime> function. This option |
3218 | exists because on GNU/Linux, C<clock_gettime> is in C<librt>, but C<librt> |
3248 | exists because on GNU/Linux, C<clock_gettime> is in C<librt>, but C<librt> |
3219 | unconditionally pulls in C<libpthread>, slowing down single-threaded |
3249 | unconditionally pulls in C<libpthread>, slowing down single-threaded |
3220 | programs needlessly. Using a direct syscall is slightly slower, because |
3250 | programs needlessly. Using a direct syscall is slightly slower (in |
3221 | no optimised vdso implementation can be used, but avoids the pthread |
3251 | theory), because no optimised vdso implementation can be used, but avoids |
3222 | dependency. Defaults to C<1> on GNU/Linux with glibc 2.x or higher. |
3252 | the pthread dependency. Defaults to C<1> on GNU/Linux with glibc 2.x or |
|
|
3253 | higher, as it simplifies linking (no need for C<-lrt>). |
3223 | |
3254 | |
3224 | =item EV_USE_NANOSLEEP |
3255 | =item EV_USE_NANOSLEEP |
3225 | |
3256 | |
3226 | If defined to be C<1>, libev will assume that C<nanosleep ()> is available |
3257 | If defined to be C<1>, libev will assume that C<nanosleep ()> is available |
3227 | and will use it for delays. Otherwise it will use C<select ()>. |
3258 | and will use it for delays. Otherwise it will use C<select ()>. |