Trait ObserverHandle 

pub trait ObserverHandle: Send {
    // Required methods
    fn recv(
        &mut self,
    ) -> Pin<Box<dyn Future<Output = Result<ProgressEvent, ObserverRecvError>> + Send + '_>>;
    fn try_recv(&mut self) -> Result<ProgressEvent, ObserverRecvError>;
    fn close(self: Box<Self>);
}

Handle returned by crate::execution::ExecutionService::observe.

Wraps a tokio::sync::broadcast::Receiver<ProgressEvent> (provided by the engine layer, Subtask 2). Multiple handles may exist concurrently; each receives the full event stream independently. When the session’s broadcast sender is dropped (session terminates), recv() returns Err(ObserverRecvError::Closed).

This is a trait to allow the engine layer (Subtask 2) to provide a concrete BroadcastObserverHandle struct without a circular dependency on core.

Required Methods

fn recv( &mut self, ) -> Pin<Box<dyn Future<Output = Result<ProgressEvent, ObserverRecvError>> + Send + '_>>

Receive the next event, waiting asynchronously.

Returns Err(ObserverRecvError::Closed) when the broadcast sender is dropped (session terminated). Returns Err(ObserverRecvError::Lagged(n)) when the receiver fell behind and n events were skipped; subsequent calls continue from the latest available event.

fn try_recv(&mut self) -> Result<ProgressEvent, ObserverRecvError>

Non-blocking receive. Returns an event if one is immediately available, Err(ObserverRecvError::Closed) if the sender is gone, or Err(ObserverRecvError::Lagged(n)) on a lag event.

Callers should treat Err variants consistently with Self::recv.

fn close(self: Box<Self>)

Consume and close this handle. After calling close the handle is dropped and no further events can be received.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors