Struct Task

struct Task {
    desc: String,
    state: TaskState,
    fut: Option<TaskFutureInfo>,
}

Record of a single task

Tracks a spawned task, or the main task (the argument to block_on).

Stored in Data.tasks.

Fields

desc: String

For debugging output

state: TaskState

Has this been woken via a waker? (And is it in Data.awake?)

Set to Awake only by Task::set_awake, preserving the invariant that every Awake task is in Data.awake.

fut: Option<TaskFutureInfo>

The actual future (or a placeholder for it)

May be None briefly in the executor main loop, because we’ve temporarily moved it out so we can poll it, or if this is a Subthread task which is currently running sync code (in which case we’re blocked in the executor waiting to be woken up by thread_context_switch.

Note that the None can be observed outside the main loop, because the main loop unlocks while it polls, so other (non-main-loop) code might see it.

Implementations

impl Task

fn set_awake(&mut self, id: TaskId, data_awake: &mut VecDeque<TaskId>)

Set task id to Awake and arrange that it will be polled.

Trait Implementations

impl Debug for Task

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

Formats the value using the given formatter.