Struct BlockingBridge 

pub struct BlockingBridge { /* private fields */ }

A capability, captured where the backend’s executor is reachable, to run async work from a plain blocking thread (iocsh, a REPL, a script thread).

block_on_sync answers “may I block here, now?” per call and can only use whatever runtime is visible on the calling thread. This type answers the reachability question once, at capture time, and carries the answer to a thread the runtime is otherwise invisible from: a tokio handle is thread-local state, so a blocking thread spawned before it exists has no way to find it. The exec backend’s executor is process-global, so there is nothing to carry and the bridge is a ZST — which is what makes an API taking a BlockingBridge compile and work on both backends, where one taking tokio::runtime::Handle pinned every caller to tokio.

Implementations

impl BlockingBridge

pub fn capture() -> Self

Capture the current tokio runtime.

Panics

Panics when no runtime is entered on this thread — call it on the async setup path (where the runtime is known), not on the blocking thread the bridge is being made for.

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

Drive fut to completion on this thread, with the captured runtime entered so the future may spawn and use the reactor.

Panics

Panics on a runtime worker thread: blocking one parks tasks that may include the future’s own wakers (the same refusal block_on_sync reports as a value).

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

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

Spawn future onto the captured runtime — spawn for a thread the runtime is not entered on.

Trait Implementations

impl Clone for BlockingBridge

fn clone(&self) -> BlockingBridge

Returns a duplicate of the value.

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

Performs copy-assignment from source.