import type { Json, Target } from "./protocol.js";
export interface Stall {
    stalled: true;
    stalledSince: string;
    stallFor: number;
}
export interface StallReaders {
    screen: (target: Target) => Promise<string>;
    transcript: (target: Target) => Promise<string>;
    now: () => number;
    threshold: () => number;
}
export declare function stallThreshold(): number;
/** Requires successful observations of both sources. Identity, terminal, work
 * status and either source changing all reset the clock. Missing data is unknown.
 * `live` reads the awaited work the pane's turn still waits on (`liveWork`:
 * awaited background shells and monitors, running children). A worker that
 * ended its turn on purpose while a build runs sits still on screen and in its
 * transcript, so once the clock runs out `live` is asked, and any live work
 * starts the clock over instead of reporting a stall, for at most
 * BACKGROUND_STALE_MS: work that never ends (a build deadlocked on a lock, a
 * child that died without its completion record) does not hide a stall forever. */
export declare class StallDetector {
    private readers;
    private entries;
    constructor(readers?: StallReaders);
    observe(target: Target, pane: Json, live?: () => Promise<number | undefined>): Promise<Stall | undefined>;
}
export declare const sessionStalls: StallDetector;