import type { RunControlLike } from '../types/graph.js';
/**
 * Stops graph runs cleanly: each finishes its current superstep, writes its checkpoint, and ends with
 * `GraphDrainedError`, so another worker can `continue()` it.
 *
 * An abort signal stops a run in the middle of a superstep, cancelling the nodes in flight. A drain
 * waits for them, which is what a rolling deploy, a spot eviction, or a scale-down wants: nothing
 * half done, nothing lost. One control can drain any number of runs at once.
 *
 * @example
 * ```ts
 * const control = new RunControl();
 * process.on('SIGTERM', () => control.drain('sigterm'));
 * await graph.invoke(input, { threadId, control });
 * ```
 */
export declare class RunControl implements RunControlLike {
    private requested;
    private readonly listeners;
    /** True once `drain()` was called. */
    get draining(): boolean;
    /** Why the drain was requested. */
    get reason(): string | undefined;
    /** Asks every run using this control to stop after its current superstep. A second call is ignored. */
    drain(reason?: string): void;
    /** Calls `listener` when a drain is requested. Returns a function that removes it. */
    onDrain(listener: (reason?: string) => void): () => void;
}