export interface PollEngineOptions {
    intervalMs: number | (() => number);
    timeoutMs?: number | (() => number);
    timeoutFloorMs?: number;
    onError?: (err: unknown) => void;
    /** Handles the poll deadline separately from an attempt rejection. */
    onTimeout?: (err: unknown) => void;
    leading?: boolean;
}
export interface PollEngineHandle {
    start(): void;
    /** Stops scheduling and waits (bounded by timeoutMs) for any in-flight attempt. */
    stop(): Promise<void>;
    pollNow(): void;
    reschedule(): void;
    readonly isRunning: boolean;
}
export declare function createPollEngine(attempt: (signal: AbortSignal) => Promise<void>, options: PollEngineOptions): PollEngineHandle;