Enum TaskPriority 

#[repr(u8)]
pub enum TaskPriority {
    Input = 0,
    UserBlocking = 1,
    Normal = 2,
    Timer = 3,
    BestEffort = 4,
    Idle = 5,
}

Priority levels for tasks — determines scheduling order.

Ordered from highest to lowest. The scheduler always picks from the highest non-empty priority level (with anti-starvation for lower levels).

Chrome mapping

Kozan	Chrome equivalent
Input	Input task source (highest)
UserBlocking	base::TaskPriority::USER_BLOCKING
Normal	base::TaskPriority::USER_VISIBLE
Timer	Timer task source (throttleable)
BestEffort	base::TaskPriority::BEST_EFFORT
Idle	requestIdleCallback task source

Variants

Input = 0

Input events: mouse, keyboard, touch, pointer. Always processed first — responsiveness is critical.

UserBlocking = 1

User is actively waiting for the result. Example: loading a resource the user just clicked on.

Normal = 2

Normal DOM work, network callbacks, general application logic. The default priority for most tasks.

Timer = 3

Timer callbacks (setTimeout/setInterval equivalent). Can be throttled for background windows.

BestEffort = 4

Background work the user won’t notice if delayed. Example: prefetching, metrics, analytics.

Idle = 5

Idle tasks — only run when the frame budget has spare time. Example: requestIdleCallback equivalent, GC-like cleanup.

Implementations

impl TaskPriority

pub const COUNT: usize = 6

Total number of priority levels. Used to size the per-priority queue array.

pub const fn as_index(self) -> usize

Convert to array index (0 = highest priority).

pub const fn from_index(index: usize) -> Option<Self>

Convert from array index. Returns None if out of range.

Trait Implementations

impl Clone for TaskPriority

fn clone(&self) -> TaskPriority

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TaskPriority

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

Formats the value using the given formatter.

impl Default for TaskPriority

fn default() -> Self

Returns the “default value” for a type.

impl Display for TaskPriority

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

Formats the value using the given formatter.

impl Hash for TaskPriority

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 TaskPriority

fn cmp(&self, other: &TaskPriority) -> 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 TaskPriority

fn eq(&self, other: &TaskPriority) -> 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 TaskPriority

fn partial_cmp(&self, other: &TaskPriority) -> 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 TaskPriority

impl Eq for TaskPriority

impl StructuralPartialEq for TaskPriority