Struct NotifyOnce

pub struct NotifyOnce { /* private fields */ }

Notify once allows waiter to register for certain conditions and unblocks waiter when condition is signalled with notify method.

The functionality is somewhat similar to a tokio watch channel with subscribe method, however it is much less error prone to use NotifyOnce rather then tokio watch.

Specifically with tokio watch you may miss notification, if you subscribe to it after the value was changed (Note that this is not a bug in tokio watch, but rather a mis-use of it).

NotifyOnce guarantees that wait() will return once notify() is called, regardless of whether wait() was called before or after notify().

Implementations

impl NotifyOnce

pub fn new() -> Self

pub fn notify(&self) -> Result<(), ()>

Notify all waiters, present and future about event

After this method all pending and future calls to .wait() will return

This method returns errors if called more then once

pub async fn wait(&self)

Awaits for notify method to be called.

This future is cancellation safe.

Trait Implementations

impl Debug for NotifyOnce

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

Formats the value using the given formatter.

impl Default for NotifyOnce

fn default() -> Self

Returns the “default value” for a type.