Struct Scheduler 

pub struct Scheduler { /* private fields */ }

Tracks the state of every task and serves the next ready task by priority.

The scheduler owns the authoritative TaskRecord map. The executor pushes tasks in as they become runnable and pulls the highest-priority one out.

Implementations

impl Scheduler

pub fn new() -> Self

Create an empty scheduler.

pub fn with_records(records: HashMap<String, TaskRecord>) -> Self

Seed the scheduler with previously persisted records (for recovery).

pub fn ensure_record(&mut self, id: &str) -> &mut TaskRecord

Ensure a record exists for id, creating a Pending one if not.

pub fn record(&self, id: &str) -> Option<&TaskRecord>

Immutable access to a record.

pub fn records(&self) -> &HashMap<String, TaskRecord>

The full record map.

pub fn records_mut(&mut self) -> &mut HashMap<String, TaskRecord>

Mutable access to the full record map.

pub fn state(&self, id: &str) -> Option<TaskState>

Current state of id, if known.

pub fn transition(&mut self, id: &str, state: TaskState) -> bool

Apply a state transition, returning whether it was legal/applied.

pub fn mark_ready(&mut self, id: &str, priority: u8)

Mark id ready and enqueue it at priority.

pub fn next_ready(&mut self) -> Option<String>

Pop the highest-priority task that is still in the Ready state.

Stale heap entries (whose record has since moved on) are discarded.

pub fn has_ready(&self) -> bool

Whether any task is queued ready to run.

pub fn all_terminal(&self) -> bool

Whether every known task has reached a terminal state.

pub fn count_in(&self, state: TaskState) -> usize

Count records currently in state.

Trait Implementations

impl Default for Scheduler

fn default() -> Scheduler

Returns the “default value” for a type.