Function rtapi_shmem_getptr 

pub unsafe extern "C" fn rtapi_shmem_getptr(
    shmem_id: c_int,
    ptr: *mut *mut c_void,
) -> c_int

‘rtapi_shmem_getptr()’ sets ‘*ptr’ to point to shared memory block associated with ‘shmem_id’. Returns a status code. May be called from user code, init/cleanup code, or realtime tasks.