pub struct FlagBlock { /* private fields */ }
Expand description

A basic condition variable for async tasks. If you call wait() you get back a future that you can await on, which will complete once another tasks calls signal_all(). But there’s a gotcha here.

Okay so you know the rule with mutexes and condition variables? Like, you have some predicate that tells you “ready” or not, and this is tested with the mutex held, followed by waiting on the condition variable (which automatically releases and reaquires the lock).

We have something similar. You need to call wait() with that mutex held, and then after you release the lock, you call await on the future returned by wait().

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impl FlagBlock

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pub fn new() -> Self

Construct a new FlagBlock.

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pub fn signal_all(&self)

Signal anyone waiting.

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pub fn wait(&self) -> FlagBlockFuture<'_>

Return an awaitable future for the “readiness” of this condition variable.

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impl Default for FlagBlock

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fn default() -> FlagBlock

Returns the “default value” for a type. Read more

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impl<T> Any for Twhere T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for Twhere T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for Twhere T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for Twhere U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T, U> TryFrom<U> for Twhere U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.