diff options
Diffstat (limited to 'ev.3')
| -rw-r--r-- | ev.3 | 45 |
1 files changed, 41 insertions, 4 deletions
@@ -858,8 +858,8 @@ events but its callback has not yet been invoked). As long as a watcher is pending (but not active) you must not call an init function on it (but \&\f(CW\*(C`ev_TYPE_set\*(C'\fR is safe) and you must make sure the watcher is available to libev (e.g. you cnanot \f(CW\*(C`free ()\*(C'\fR it). -.IP "callback = ev_cb (ev_TYPE *watcher)" 4 -.IX Item "callback = ev_cb (ev_TYPE *watcher)" +.IP "callback ev_cb (ev_TYPE *watcher)" 4 +.IX Item "callback ev_cb (ev_TYPE *watcher)" Returns the callback currently set on the watcher. .IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 .IX Item "ev_cb_set (ev_TYPE *watcher, callback)" @@ -895,8 +895,45 @@ can cast it back to your own type: \& } .Ve .PP -More interesting and less C\-conformant ways of catsing your callback type -have been omitted.... +More interesting and less C\-conformant ways of casting your callback type +instead have been omitted. +.PP +Another common scenario is having some data structure with multiple +watchers: +.PP +.Vb 6 +\& struct my_biggy +\& { +\& int some_data; +\& ev_timer t1; +\& ev_timer t2; +\& } +.Ve +.PP +In this case getting the pointer to \f(CW\*(C`my_biggy\*(C'\fR is a bit more complicated, +you need to use \f(CW\*(C`offsetof\*(C'\fR: +.PP +.Vb 1 +\& #include <stddef.h> +.Ve +.PP +.Vb 6 +\& static void +\& t1_cb (EV_P_ struct ev_timer *w, int revents) +\& { +\& struct my_biggy big = (struct my_biggy * +\& (((char *)w) - offsetof (struct my_biggy, t1)); +\& } +.Ve +.PP +.Vb 6 +\& static void +\& t2_cb (EV_P_ struct ev_timer *w, int revents) +\& { +\& struct my_biggy big = (struct my_biggy * +\& (((char *)w) - offsetof (struct my_biggy, t2)); +\& } +.Ve .SH "WATCHER TYPES" .IX Header "WATCHER TYPES" This section describes each watcher in detail, but will not repeat |