Enum SourceError 

#[non_exhaustive]
pub enum SourceError {
    WouldBlock,
    Unsupported,
    Failed(Errno),
}

Why an acquire did not produce a buffer.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

WouldBlock

Flow control, not a failure. The source has no frame to contribute this vblank.

The layer keeps its plane and goes on showing its previous framebuffer – or is left out, if it has never produced one – and acquire is called again on the next commit; the layer is counted in layers_skipped_no_frame, never in the failure paths. A live source returns this before its first sample lands, and any time the producer falls behind with no cached frame to re-issue.

This is DR-6: a distinct variant, never io::ErrorKind::WouldBlock. Squinting at an I/O error to recover flow control is exactly how the EAGAIN contract gets lost in a refactor — and losing it turns a stalled producer into an aborted commit.

Unsupported

The operation is not supported by this source.

Returned by the default map and export_dma_buf. A source that does not support map is uncompositable: when the allocator cannot place it, the scene has no way to rescue it and the layer stays dropped for the frame.

Failed(Errno)

A real failure. Aborts the commit.

Trait Implementations

impl Debug for SourceError

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

Formats the value using the given formatter.

impl Display for SourceError

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

Formats the value using the given formatter.

impl Error for SourceError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

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

Provides type-based access to context intended for error reports.

impl From<Errno> for SourceError

fn from(source: Errno) -> Self

Converts to this type from the input type.

impl From<SourceError> for SceneError

fn from(source: SourceError) -> Self

Converts to this type from the input type.