Enum devices::virtio::async_device::AsyncQueueState

pub enum AsyncQueueState<T: 'static> {
    Stopped(T),
    Running((TaskHandle<T>, Executor, AbortHandle)),
    Broken,
}

A queue for which processing can be started on an async executor.

T is the resource type of the queue, i.e. the device-specific data it needs in order to run. For instance, a block device will likely need a file to provide its data.

Variants

Stopped(T)

Queue is currently stopped.

Running((TaskHandle<T>, Executor, AbortHandle))

Queue is being processed as a Task on an Executor, and can be stopped by aborting the AbortHandle.

Broken

Something terrible happened and this queue is in a non-recoverable state.

Implementations

impl<T: 'static> AsyncQueueState<T>

pub fn start<U: Future<Output = T> + 'static, F: FnOnce(T, Abortable<Pending<()>>) -> Result<U>>( &mut self, ex: &Executor, fut_provider: F ) -> Result<()>

Start processing of the queue on ex, or stop and restart it with the new parameters if it was already running.

fut_provider is a closure that is passed the resource of the queue, as well as a Abortable future. It must return a Future that takes ownership of the device’s resource and processes the queue for as long as possible, but immediately quits and returns the device resource when the Abortable is signaled.

If fut_provider or the Future it returns end with an error, the queue is considered broken and cannot be used anymore.

The task is only scheduled and no processing actually starts in this method. The task is scheduled locally, which implies that ex must be run on the current thread.

pub fn stop(&mut self) -> AsyncResult<bool>

Stops a previously started queue.

The executor on which the task has been started will be run if needed in order to retrieve the queue’s resource.

Returns true if the queue was running, false if it wasn’t.

pub async fn stop_async(&mut self) -> AsyncResult<bool>

Stops a previously started queue.

The executor on which the task has been started will be run if needed in order to retrieve the queue’s resource.

Returns true if the queue was running, false if it wasn’t.