diff options
Diffstat (limited to 'ev.pod')
| -rw-r--r-- | ev.pod | 35 |
1 files changed, 32 insertions, 3 deletions
@@ -705,7 +705,7 @@ is pending (but not active) you must not call an init function on it (but C<ev_TYPE_set> is safe) and you must make sure the watcher is available to libev (e.g. you cnanot C<free ()> it). -=item callback = ev_cb (ev_TYPE *watcher) +=item callback ev_cb (ev_TYPE *watcher) Returns the callback currently set on the watcher. @@ -743,8 +743,37 @@ can cast it back to your own type: ... } -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. + +Another common scenario is having some data structure with multiple +watchers: + + struct my_biggy + { + int some_data; + ev_timer t1; + ev_timer t2; + } + +In this case getting the pointer to C<my_biggy> is a bit more complicated, +you need to use C<offsetof>: + + #include <stddef.h> + + 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)); + } + + 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)); + } =head1 WATCHER TYPES |