Struct SignalFuture

pub struct SignalFuture<T = ()> { /* private fields */ }

A simple future that can be programmatically resolved externally using the controller that is provided in tandem when creating a SignalFuture. This makes it useful as a way to signal to some consumer of the future that something has completed, using standard async syntax and semantics.

Examples

struct DelayedWriter { fd: File, pending: Mutex<Vec<(u64, Vec<u8>, SignalFutureController)>> }
impl DelayedWriter {
  pub async fn write(&self, offset: u64, data: Vec<u8>) {
    let (fut, fut_ctl) = SignalFuture::new();
    self.pending.lock().await.push((offset, data, fut_ctl));
    fut.await
  }
  pub async fn background_loop(&self) {
    loop {
      sleep(Duration::from_millis(500));
      for (offset, data, fut_ctl) in self.pending.lock().await.drain(..) {
        self.fd.write_at(offset, data).await;
        fut_ctl.signal(());
      };
    };
  }
}

Implementations

impl<T> SignalFuture<T>

pub fn new() -> (SignalFuture<T>, SignalFutureController<T>)

Trait Implementations

impl<T> Future for SignalFuture<T>

type Output = T

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>

Attempts to resolve the future to a final value, registering the current task for wakeup if the value is not yet available.