Class: StepContinuationQueue

Defined in: runtime/locks/step-continuation-queue.ts:10

Per-stepExecId asynchronous FIFO serialization queue for ContinuationFrame[] mutations (SPEC.md §3.7.2).

Coordinates all concurrent updates to a step's continuation call stack via a per-step PQueue (concurrency: 1) so sibling downward forks and speculative branches never overwrite each other in LedgerStore.updateContinuationStack.

Constructors

Constructor

new StepContinuationQueue(): StepContinuationQueue;

Returns

StepContinuationQueue

Methods

clearStep()

clearStep(stepExecId): void;

Defined in: runtime/locks/step-continuation-queue.ts:82

Clears and removes any PQueue entry tracked for stepExecId.

Invoked when a step execution reaches a terminal state and no further stack mutations can occur.

Parameters

Parameter	Type	Description
stepExecId	string	Step execution identifier to clear.

Returns

void

---

enqueueUpdate()

enqueueUpdate<TResult>(
   stepExecId, 
   task, 
   signal?
): Promise<TResult>;

Defined in: runtime/locks/step-continuation-queue.ts:28

Enqueues task behind all prior updates for stepExecId and returns its completion promise.

Continues draining subsequent queued tasks for stepExecId even if an earlier task rejects or is cancelled via signal, and evicts the step's PQueue instance once idle.

Type Parameters

Type Parameter	Description
TResult	Return type of the queued update callback.

Parameters

Parameter	Type	Description
stepExecId	string	Unique step execution identifier to serialize on.
task	() => Promise<TResult>	Asynchronous continuation update callback.
signal?	AbortSignal	Optional cancellation signal for queued updates.

Returns

Promise<TResult>

Promise resolving or rejecting with the outcome of task.

---

hasStepQueue()

hasStepQueue(stepExecId): boolean;

Defined in: runtime/locks/step-continuation-queue.ts:71

Checks whether stepExecId currently holds an active or queued PQueue instance.

Returns false once all pending and queued continuation updates for stepExecId have drained.

Parameters

Parameter	Type	Description
stepExecId	string	Step execution identifier to inspect.

Returns

boolean

True when a non-evicted queue entry exists for stepExecId.