export declare const PASS_TIMED_OUT: unique symbol;
export type ConcurrencyMode = 'sequential' | 'concurrent';
export interface LoopOptions {
    intervalMs: number;
    jitterRatio: number;
    timeoutMs: number;
    concurrency: ConcurrencyMode;
    maxConcurrent: number;
}
export interface LoopHooks {
    onError: (error: unknown) => void;
    onTimeout: (context: {
        timeoutMs: number;
    }) => void;
    onSkippedTick: (context: {
        inFlight: number;
        limit: number;
    }) => void;
}
export declare class Loop {
    private readonly pass;
    private readonly options;
    private readonly hooks;
    private readonly random;
    private readonly now;
    private readonly alarm;
    private readonly inFlight;
    private readonly inFlightControllers;
    private timeline?;
    private stopped;
    private readonly limit;
    constructor(pass: (signal: AbortSignal) => Promise<unknown>, options: LoopOptions, hooks: LoopHooks, random?: () => number, now?: () => number);
    start(): void;
    stop(): Promise<void>;
    private tick;
    private launch;
    private runOnce;
    private runPass;
}