Struct KeyGate 

pub struct KeyGate { /* private fields */ }

A key gate state that tracks which run (if any) holds each concurrency key.

Implementations

impl KeyGate

pub fn new() -> Self

Creates a new empty key gate.

Empty initialization is safe post-recovery because the dispatch loop is single-threaded and acquires concurrency keys at dispatch time (step 6 of the tick cycle), not at recovery time. Runs that were in-flight when a crash occurred recover to the Ready state via the uncertainty clause and must re-acquire their concurrency keys before being dispatched again. This means there is no window where a recovered run could bypass the key gate.

pub fn acquire(&mut self, key: ConcurrencyKey, run_id: RunId) -> AcquireResult

Attempts to acquire a concurrency key for a run.

Returns AcquireResult::Acquired if the key is free or already held by the same run. Returns AcquireResult::Occupied if another run holds the key.

pub fn release(&mut self, key: ConcurrencyKey, run_id: RunId) -> ReleaseResult

Attempts to release a concurrency key from a run.

Returns ReleaseResult::Released if the key was held by the specified run. Returns ReleaseResult::NotHeld if the key was not held by the run or was already free.

pub fn is_key_occupied(&self, key: &ConcurrencyKey) -> bool

Queries whether a concurrency key is currently occupied.

pub fn key_holder(&self, key: &ConcurrencyKey) -> Option<RunId>

Returns the run that currently holds the key, if any.

Trait Implementations

impl Clone for KeyGate

fn clone(&self) -> KeyGate

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for KeyGate

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

Formats the value using the given formatter.

impl Default for KeyGate

fn default() -> KeyGate

Returns the “default value” for a type.