ostd::mm::frame::meta

Trait AnyFrameMeta

Source 
pub unsafe trait AnyFrameMeta:
    Any
    + Send
    + Sync {
    // Provided methods
    fn on_drop(&mut self, _reader: &mut VmReader<'_, Infallible>) { ... }
    fn is_untyped(&self) -> bool { ... }
}
Expand description

All frame metadata types must implement this trait.

If a frame type needs specific drop behavior, it should specify when implementing this trait. When we drop the last handle to this frame, the on_drop method will be called. The on_drop method is called with the physical address of the frame.

The implemented structure should have a size less than or equal to FRAME_METADATA_MAX_SIZE and an alignment less than or equal to FRAME_METADATA_MAX_ALIGN. Otherwise, the metadata type cannot be used because storing it will fail compile-time assertions.

§Safety

If on_drop reads the page using the provided VmReader, the implementer must ensure that the frame is safe to read.

Provided Methods§

Source

fn on_drop(&mut self, _reader: &mut VmReader<'_, Infallible>)

Called when the last handle to the frame is dropped.

Source

fn is_untyped(&self) -> bool

Whether the metadata’s associated frame is untyped.

If a type implements AnyUFrameMeta, this should be true. Otherwise, it should be false.

Implementations on Foreign Types§

Source§

impl AnyFrameMeta for ()

Source§

fn is_untyped(&self) -> bool

Implementors§