Struct PropertyBlob 

pub struct PropertyBlob<'a> { /* private fields */ }

A kernel property blob, freed when it is dropped.

MODE_ID takes a blob id rather than a value, so a scene that sets a mode has to create one and keep it alive for as long as the mode is set. Letting it leak would be invisible until a long-running compositor that re-modesets often ran the kernel out of blob ids.

The borrow of the device is what makes freeing it safe. Holding a raw descriptor instead would compile, and would destroy a blob on whatever the kernel had since recycled that number into if the blob ever outlived the device it came from.

Implementations

impl PropertyBlob<'_>

pub const fn id(&self) -> u64

The blob id, to be written into a blob-typed property.

pub fn forget(self)

Give up the blob without asking the kernel to destroy it.

For when the descriptor the blob was created on is gone – a libseat session pause revokes it, and the kernel reclaimed every blob on it at that moment. Destroying through the replacement descriptor would at best fail and at worst free a different blob that happens to have been given the same id there.

This leaks nothing: the blob is already gone. Do not reach for it to silence an ordinary drop – on a live descriptor that really is a leak, and a long-running compositor that re-modesets will run the kernel out of blob ids.

Trait Implementations

impl Debug for PropertyBlob<'_>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

The id, without the device – a blob is identified by its id, and printing the device behind it would be noise at best.

impl Drop for PropertyBlob<'_>

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.