On mac I am using kqueue, it states that udata is unchanged. However the array returned in event_data of kevent call is being modified somewhat. What could cause this? I am passing in the pointer to string casted to void*, and when i read after kevent after the first 3 characters the rest are coming out modified.
Thanks
The kernel only saves and returns the value of the pointer itself, not the contents of the memory it points to. Chances are that you're passing a pointer to memory that is being overwritten later on.
The kqueue64() system call is a little bit more explicit about this by defining the field as a uint64_t.