diff options
Diffstat (limited to 'ev.pod')
| -rw-r--r-- | ev.pod | 16 |
1 files changed, 11 insertions, 5 deletions
@@ -1008,7 +1008,11 @@ data: int otherfd; void *somedata; struct whatever *mostinteresting; - } + }; + + ... + struct my_io w; + ev_io_init (&w.io, my_cb, fd, EV_READ); And since your callback will be called with a pointer to the watcher, you can cast it back to your own type: @@ -1022,8 +1026,8 @@ can cast it back to your own type: 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: +Another common scenario is to use some data structure with multiple +embedded watchers: struct my_biggy { @@ -1032,8 +1036,10 @@ watchers: ev_timer t2; } -In this case getting the pointer to C<my_biggy> is a bit more complicated, -you need to use C<offsetof>: +In this case getting the pointer to C<my_biggy> is a bit more +complicated: Either you store the address of your C<my_biggy> struct +in the C<data> member of the watcher, or you need to use some pointer +arithmetic using C<offsetof> inside your watchers: #include <stddef.h> |