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ShutdownRequest

Struct ShutdownRequest 

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pub struct ShutdownRequest { /* private fields */ }
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A standing request from the host that this process shut down.

Hosts deliver this differently – a POSIX signal, a Windows console control event injected on a thread of the OS’s choosing – but both arrive in a context where almost nothing is safe to do. A handler may not allocate, log, take a lock, or join a thread. So neither host runs the caller’s code: each sets one flag, and the caller reads it whenever it is somewhere it can act.

That is why this is a poll rather than a callback. A callback would invite exactly the work the delivery context forbids.

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impl ShutdownRequest

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pub fn watching(flag: &'static AtomicBool) -> Self

Build a handle watching a flag the caller already owns.

The host implementations use this to hand out a view of their own static. It is public because a caller that already has a shutdown flag – one set by a supervisor protocol, or by a test – can present it through the same type rather than the loop it feeds needing two shapes of “should I stop”.

'static is not incidental: a handler set by the OS outlives any scope, so the flag it writes has to as well.

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pub fn requested(&self) -> bool

Whether the host has asked this process to shut down.

Latching, not edge-triggered: once true it stays true, so a caller that checks between two pieces of work cannot miss a request delivered while it was busy.

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impl Debug for ShutdownRequest

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

Formats the value using the given formatter. Read more

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

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Calls U::from(self).

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

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const ALIGN: usize

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type Init = T

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unsafe fn init(init: <T as Pointable>::Init) -> usize

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

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