Trait futures_core::executor::Executor[][src]

pub trait Executor {
    fn spawn(
        &mut self,
        f: Box<Future<Item = (), Error = Never> + Send>
    ) -> Result<(), SpawnError>; fn status(&self) -> Result<(), SpawnError> { ... } }

A task executor.

A task is a ()-producing future that runs at the top level, and will be polled until completion. It's also the unit at which wake-up notifications occur. Executors, such as thread pools, allow tasks to be spawned and are responsible for putting tasks onto ready queues when they are woken up, and polling them when they are ready.

Required Methods

Spawn the given task, polling it until completion.

Tasks must be infallible, as the type suggests; it is the client's reponsibility to route any errors elsewhere via a channel or some other means of communication.


The executor may be unable to spawn tasks, either because it has been shut down or is resource-constrained.

Provided Methods

Determine whether the executor is able to spawn new tasks.


An Ok return means the executor is likely (but not guaranteed) to accept a subsequent spawn attempt. Likewise, an Err return means that spawn is likely, but not guaranteed, to yield an error.