Enum Priority

#[non_exhaustive]
pub enum Priority {
    UserInteractive,
    UserInitiated,
    Utility,
    Background,
    Unknown,
}

Defines an abstract priority for tasks.

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.

UserInteractive

The task runs at UI priority.

Generally, we expect this task to paint the screen or respond to user input as soon as possible.

In systems with a single-threaded UI, the task runs on the UI thread. Work performed at this priority may block the UI thread.

UserInitiated

The task runs at a high priority.

Use this priority for tasks that respond to user input, and expect to complete quickly, before the user switches focus (e.g. on the order of a second).

Use this priority for tasks where the user is likely waiting on the input.

Utility

This task runs at a medium priority.

Use this priority for tasks with expected such that the user may switch focus before they complete (e.g. on the order of a 10+ seconds).

Use this priority for tasks where we might display a progress bar and ideally the user can move onto other work during completion.

Background

This task runs at a low priority.

Use this priority for tasks that are not time-sensitive, and can run in the background.

Use this priority for tasks that are not visible to the user, and do not require user input.

Unknown

The priority of the task is not known.

Avoid the use of this value. It should be used in cases where the priority cannot be reasonably determined.

Implementations

impl Priority

pub const fn highest_async() -> Self

Returns the highest priority that is suitable for general, blocking, async work.

At the time of this writing, this returns Priority::UserInitiated.

pub const fn unit_test() -> Self

A priority suitable for unit testing.

Trait Implementations

impl Clone for Priority

fn clone(&self) -> Priority

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Priority

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

Formats the value using the given formatter.

impl Hash for Priority

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Priority

fn cmp(&self, other: &Priority) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Priority

fn eq(&self, other: &Priority) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Priority

fn partial_cmp(&self, other: &Priority) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for Priority

impl Eq for Priority

impl StructuralPartialEq for Priority