Struct PoisonGuard 

pub struct PoisonGuard<'a> { /* private fields */ }

A RAII guard that marks a connection as poisoned if dropped before disarmed.

This is a structural guarantee that protects protocol integrity when async operations are cancelled (e.g., by timeouts).

Safety

The guard must live across the entire critical section. Dropping it early or disarming before all I/O completes defeats its purpose.

Implementations

impl<'a> PoisonGuard<'a>

pub fn new(flag: &'a mut bool) -> Self

Create a new guard, immediately marking the connection as poisoned.

The connection will remain poisoned unless disarm() is called.

pub fn disarm(self)

Disarm the guard, marking the connection as healthy.

Only call this when the entire I/O operation has completed successfully.

Example

let guard = PoisonGuard::new(&mut is_poisoned);

// Perform all I/O operations
// ...

// Only disarm after everything succeeds
guard.disarm();