pub unsafe trait SubDevice<Parent: IoDevice>: IoDevice { }Expand description
Implemented by IoDevice implementations that are “sub-devices” of
another device, specified as type parameter Parent.
This is just a marker trait used to check type safety for
super::File::ioctl; it has no behavior of its own and merely permits
the safe abstraction to send requests that were intended for the parent
device type to files representing the implementer (the “child”).
Devices don’t actually need to form a strict tree. It is fine for a device type to have multiple parents, or for the structure implied by this trait to not resemble a tree at all, as long as the safety guarantees are met. If A is parent of B and B is parent of C then A is not automatically parent of C unless also explicitly implemented.
Safety: The implementer must be able to safely accept all of the
ioctl requests of Parent without compromising memory safety. The
parent requests do not necessarily need to succeed; it is sufficient
for them to fail safely without making any use of the given argument.
Implementors§
impl SubDevice<Ipv4SocketDevice> for TcpSocketDevice
impl SubDevice<Ipv6SocketDevice> for TcpSocketDevice
impl SubDevice<SocketDevice> for Ipv4SocketDevice
impl SubDevice<SocketDevice> for Ipv6SocketDevice
impl SubDevice<SocketDevice> for TcpSocketDevice
impl<T: IoDevice> SubDevice<T> for T
Any IoDevice type can by definition safely accept its own ioctl requests,
assuming that those requests are themselves defined per the safety
requirements of IoctlReq.