Trait polkadot_node_subsystem::gen::futures::task::LocalSpawnExt
source · pub trait LocalSpawnExt: LocalSpawn {
// Provided methods
fn spawn_local<Fut>(&self, future: Fut) -> Result<(), SpawnError>
where Fut: Future<Output = ()> + 'static { ... }
fn spawn_local_with_handle<Fut>(
&self,
future: Fut
) -> Result<RemoteHandle<<Fut as Future>::Output>, SpawnError>
where Fut: Future + 'static { ... }
}
Expand description
Extension trait for LocalSpawn
.
Provided Methods§
sourcefn spawn_local<Fut>(&self, future: Fut) -> Result<(), SpawnError>where
Fut: Future<Output = ()> + 'static,
fn spawn_local<Fut>(&self, future: Fut) -> Result<(), SpawnError>where Fut: Future<Output = ()> + 'static,
Spawns a task that polls the given future with output ()
to
completion.
This method returns a Result
that contains a SpawnError
if
spawning fails.
You can use spawn_with_handle
if
you want to spawn a future with output other than ()
or if you want
to be able to await its completion.
Note this method will eventually be replaced with the upcoming
Spawn::spawn
method which will take a dyn Future
as input.
Technical limitations prevent Spawn::spawn
from being implemented
today. Feel free to use this method in the meantime.
use futures::executor::LocalPool;
use futures::task::LocalSpawnExt;
let executor = LocalPool::new();
let spawner = executor.spawner();
let future = async { /* ... */ };
spawner.spawn_local(future).unwrap();
sourcefn spawn_local_with_handle<Fut>(
&self,
future: Fut
) -> Result<RemoteHandle<<Fut as Future>::Output>, SpawnError>where
Fut: Future + 'static,
fn spawn_local_with_handle<Fut>( &self, future: Fut ) -> Result<RemoteHandle<<Fut as Future>::Output>, SpawnError>where Fut: Future + 'static,
Spawns a task that polls the given future to completion and returns a future that resolves to the spawned future’s output.
This method returns a Result
that contains a RemoteHandle
, or, if
spawning fails, a SpawnError
. RemoteHandle
is a future that
resolves to the output of the spawned future.
use futures::executor::LocalPool;
use futures::task::LocalSpawnExt;
let mut executor = LocalPool::new();
let spawner = executor.spawner();
let future = async { 1 };
let join_handle_fut = spawner.spawn_local_with_handle(future).unwrap();
assert_eq!(executor.run_until(join_handle_fut), 1);