export interface Clock {
    now(): number;
    setTimer(callback: () => void, delayMs: number): unknown;
    clearTimer(timer: unknown): void;
}
export declare const systemClock: Clock;
export declare class LoopScheduler {
    private readonly clock;
    private wakeTimer?;
    private deadlineTimer?;
    private generation;
    constructor(clock: Clock);
    arm(wakeAt: number | undefined, deadlineAt: number | undefined, onWake: () => void, onDeadline: () => void): void;
    cancel(): void;
}