Struct WatchHandle 

pub struct WatchHandle { /* private fields */ }

Available on crate feature watch only.

Keeps a watcher alive. Dropping it stops watching.

The handle owns the notification backend, and the background thread owns only the receiving end. Dropping the handle closes the channel, which is what ends the thread — no flag to poll, no wake-up latency.

A server usually wants the watcher to outlive everything, which is what detach is for. Anything with a lifecycle — a test, a library, a subcommand — should hold the handle instead, so watching stops when the thing being configured goes away.

Implementations

impl WatchHandle

pub fn detach(self)

Watches for the remainder of the process.

Leaks the backend on purpose: a watcher that must never stop has no owner to hold it, and pretending otherwise is how the handle ends up dropped at the end of main’s first statement.

pub fn stop(self)

Stops watching. The same as dropping it, spelled out.

pub async fn run_until(self, shutdown: impl Future<Output = ()>)

Watches until shutdown completes, then stops.

The shape a server wants: a watch is not something to remember to stop, it is something that ends when the process is winding down.

Config::builder("svc")
    .watch(Duration::from_millis(100))?
    .run_until(shutdown_signal())
    .await;

Takes self because that is what stopping is here: the handle owns the notification backend, and dropping it closes the channel the background thread is reading. There is no flag to poll and no wake-up latency — and no runtime is imposed, because the future is driven by whichever executor is already running the caller.

pub fn name(&self) -> &'static str

The type name this watcher was started for.

Trait Implementations

impl Debug for WatchHandle

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Drop for WatchHandle

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

🔬This is a nightly-only experimental API. (pin_ergonomics)

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.