Struct RuntimeHandle 

pub struct RuntimeHandle { /* private fields */ }

A cloneable handle to a Runtime, to spawn on it from anywhere. It does not keep the runtime running.

Implementations

impl RuntimeHandle

pub fn enter(&self) -> EnterGuard<'_>

Sets the handle’s runtime on the calling thread until the guard drops.

pub fn id(&self) -> RuntimeId

The runtime’s id.

pub fn try_current() -> Result<Self, TryCurrentError>

The handle of the runtime set on this thread (inside its block_on, on one of its workers, or under enter); unlike current it never falls back to the default runtime.

impl RuntimeHandle

pub fn workers(&self) -> usize

The workers the runtime has started, stopped ones included: the indices spawn_on_worker takes are 0..workers().

pub fn spawn_on_worker<F>( &self, worker: usize, future: F, ) -> Result<Task<F::Output>>

where F: Future + Send + 'static, F::Output: Send + 'static,

Spawns future on worker worker, where it stays: a handoff of the worker’s shard moves the task with it, so it runs on that worker for its whole life.

Errors

InvalidInput when the runtime has no such worker, or the worker stopped (or is stopping) and takes no new task.

pub fn spawn_local_on_worker<M, F>( &self, worker: usize, make: M, ) -> Result<Task<F::Output>>

where M: FnOnce() -> F + Send + 'static, F: Future + 'static, F::Output: Send + 'static,

Runs make on worker worker and spawns the future it makes there, which need not be Send: it stays on the thread that made it, as a spawn_local task does.

A handoff of the worker’s shard leaves such a future on the thread that made it, off the worker: it finishes there, where worker_index answers None and shard-local values are out of reach. The handle is that of the task that makes the future on the worker and waits for it: its id is not the one task::id answers inside the future, and dropping it cancels both.

Errors

As for spawn_on_worker.

pub fn on_each_worker<M, F>(&self, make: M) -> JoinSet<F::Output>

where M: Fn() -> F + Send + Sync + 'static, F: Future + 'static, F::Output: Send + 'static,

Runs make on every worker that takes tasks and spawns the future it makes there, as spawn_local_on_worker does: the set holds one task per worker. A runtime with no worker gives an empty set.

impl RuntimeHandle

pub fn stats(&self) -> Stats

A snapshot of the counters of the handle’s runtime; see Runtime::stats.

impl RuntimeHandle

pub fn block_on<F: Future>(&self, future: F) -> F::Output

Runs future to its end on the calling thread; see block_on.

pub fn spawn<F>(&self, future: F) -> Task<F::Output>

where F: Future + Send + 'static, F::Output: Send + 'static,

Spawns a task on one of the runtime’s shards; see spawn.

pub fn spawn_blocking<F, T>(&self, f: F) -> Task<T>

where F: FnOnce() -> T + Send + 'static, T: Send + 'static,

Runs f on the runtime’s blocking pool; see spawn_blocking.

pub fn current() -> Self

The handle of the runtime this thread is inside, or of the default runtime (started now if it is not running yet).

Trait Implementations

impl Clone for RuntimeHandle

fn clone(&self) -> RuntimeHandle

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RuntimeHandle

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

Formats the value using the given formatter.