Struct OptionGuard

Source

pub struct OptionGuard<'a, T> { /* private fields */ }

Expand description

An exclusive guard for the value of an OptionLock

Implementations§

Source §

impl<T> OptionGuard<'_, T>

Source

pub fn as_ref(&self) -> Option<&T>

Obtain a shared reference to the contained value, if any.

Source

pub fn as_mut(&mut self) -> Option<&mut T>

Obtain an exclusive reference to the contained value, if any.

Source

pub fn is_none(&self) -> bool

Check if the lock contains None.

Source

pub fn is_some(&self) -> bool

Check if the lock contains Some(T).

Source

pub fn replace(&mut self, value: T) -> Option<T>

Replace the value in the lock, returning the previous value, if any.

Examples found in repository ?

examples/atomic-wake.rs (line 25)

20    pub fn poll(&self, waker: Option<&Waker>) -> Option<Result<T, E>> {
21        match self.state.try_lock() {
22            Ok(mut guard) => match guard.take() {
23                Some(ResultState::Ready(result)) => Some(result),
24                Some(ResultState::Wake(_)) | None => {
25                    waker.map(|waker| guard.replace(ResultState::Wake(waker.clone())));
26                    None
27                }
28            },
29            _ => {
30                // result is currently being stored
31                waker.map(Waker::wake_by_ref);
32                None
33            }
34        }
35    }
36
37    pub fn fulfill(&self, result: Result<T, E>) -> Result<(), Result<T, E>> {
38        // retry method is left up to the caller (spin, yield thread, etc)
39        if let Ok(mut guard) = self.state.try_lock() {
40            let prev = guard.replace(ResultState::Ready(result));
41            drop(guard);
42            if let Some(ResultState::Wake(waker)) = prev {
43                waker.wake();
44            }
45            Ok(())
46        } else {
47            Err(result)
48        }
49    }

Source

pub fn take(&mut self) -> Option<T>

Take the current value from the lock, if any.

Examples found in repository ?

examples/atomic-wake.rs (line 22)

20    pub fn poll(&self, waker: Option<&Waker>) -> Option<Result<T, E>> {
21        match self.state.try_lock() {
22            Ok(mut guard) => match guard.take() {
23                Some(ResultState::Ready(result)) => Some(result),
24                Some(ResultState::Wake(_)) | None => {
25                    waker.map(|waker| guard.replace(ResultState::Wake(waker.clone())));
26                    None
27                }
28            },
29            _ => {
30                // result is currently being stored
31                waker.map(Waker::wake_by_ref);
32                None
33            }
34        }
35    }