Struct TaskContext 

pub struct TaskContext {
    pub child_id: ChildId,
    pub path: SupervisorPath,
    pub generation: Generation,
    pub attempt: Attempt,
    /* private fields */
}

Context passed to a task for a single attempt.

Fields

child_id: ChildId

Stable child identifier for the task attempt.

path: SupervisorPath

Full path of the child in the supervisor tree.

generation: Generation

Generation for the runtime slot that owns this attempt.

attempt: Attempt

Attempt number for the running task.

Implementations

impl TaskContext

pub fn new( child_id: ChildId, path: SupervisorPath, generation: Generation, attempt: Attempt, ) -> (Self, Receiver<Option<Instant>>)

Creates a task context for a child attempt.

Arguments

• child_id: Stable child identifier.
• path: Full supervisor tree path for this child.
• generation: Runtime slot generation.
• attempt: Attempt number for this execution.

Returns

Returns the context and a heartbeat receiver for runtime observers.

Examples

let (ctx, _heartbeat) = rust_supervisor::task::context::TaskContext::new(
    rust_supervisor::id::types::ChildId::new("worker"),
    rust_supervisor::id::types::SupervisorPath::root().join("worker"),
    rust_supervisor::id::types::Generation::initial(),
    rust_supervisor::id::types::Attempt::first(),
);
assert!(!ctx.is_cancelled());

pub fn with_ready_signal( child_id: ChildId, path: SupervisorPath, generation: Generation, attempt: Attempt, ready_signal: ReadySignal, ) -> (Self, Receiver<Option<Instant>>)

Creates a task context with an existing readiness signal.

Arguments

• child_id: Stable child identifier.
• path: Full supervisor tree path for this child.
• generation: Runtime slot generation.
• attempt: Attempt number for this execution.
• ready_signal: Signal used to publish readiness.

Returns

Returns the context and a heartbeat receiver for runtime observers.

pub fn mark_ready(&self)

Reports that the task is ready.

Arguments

This function has no arguments.

Returns

This function does not return a value.

Examples found in repository

examples/supervisor_tree_story.rs (line 90)

fn worker(id: &str, name: &str) -> ChildSpec {
    // Capture the task name for the async task.
    let task_name = name.to_owned();
    // Create a task factory from a closure.
    let factory = service_fn(move |ctx| {
        // Clone the captured task name for this attempt.
        let task_name = task_name.clone();
        // Return the async task body.
        async move {
            // Emit a heartbeat from the task context.
            ctx.heartbeat();
            // Mark the task as ready.
            ctx.mark_ready();
            // Print the task path for learners.
            println!("worker={task_name} path={}", ctx.path);
            // Report a successful task result.
            TaskResult::Succeeded
            // Finish the async task body.
        }
        // Finish the task factory closure.
    });

    // Create the worker child specification.
    ChildSpec::worker(
        // Set the child identifier.
        ChildId::new(id),
        // Set the child name.
        name,
        // Set the task kind.
        TaskKind::AsyncWorker,
        // Store the task factory behind shared ownership.
        Arc::new(factory),
        // Finish the worker child specification.
    )
    // Finish the worker builder.
}

pub fn heartbeat(&self)

Emits a heartbeat with the current monotonic time.

Arguments

This function has no arguments.

Returns

This function does not return a value.

Examples found in repository

examples/supervisor_tree_story.rs (line 88)

fn worker(id: &str, name: &str) -> ChildSpec {
    // Capture the task name for the async task.
    let task_name = name.to_owned();
    // Create a task factory from a closure.
    let factory = service_fn(move |ctx| {
        // Clone the captured task name for this attempt.
        let task_name = task_name.clone();
        // Return the async task body.
        async move {
            // Emit a heartbeat from the task context.
            ctx.heartbeat();
            // Mark the task as ready.
            ctx.mark_ready();
            // Print the task path for learners.
            println!("worker={task_name} path={}", ctx.path);
            // Report a successful task result.
            TaskResult::Succeeded
            // Finish the async task body.
        }
        // Finish the task factory closure.
    });

    // Create the worker child specification.
    ChildSpec::worker(
        // Set the child identifier.
        ChildId::new(id),
        // Set the child name.
        name,
        // Set the task kind.
        TaskKind::AsyncWorker,
        // Store the task factory behind shared ownership.
        Arc::new(factory),
        // Finish the worker child specification.
    )
    // Finish the worker builder.
}

pub fn cancel(&self)

Requests cancellation for this task attempt.

Arguments

This function has no arguments.

Returns

This function does not return a value.

pub fn is_cancelled(&self) -> bool

Returns whether cancellation was requested.

Arguments

This function has no arguments.

Returns

Returns true when cancellation was requested.

pub fn cancellation_token(&self) -> CancellationToken

Returns a clone of the cancellation token.

Arguments

This function has no arguments.

Returns

Returns the cancellation token for asynchronous selection.

pub fn readiness_receiver(&self) -> Receiver<bool>

Subscribes to readiness updates.

Arguments

This function has no arguments.

Returns

Returns a receiver that observes readiness changes.

Trait Implementations

impl Clone for TaskContext

fn clone(&self) -> TaskContext

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TaskContext

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

Formats the value using the given formatter.