/** 并发限制器（对标 wave-agent ConcurrencyLimiter）。 */
export declare class ConcurrencyLimiter {
    private running;
    private queue;
    private readonly maxConcurrency;
    constructor(maxConcurrency: number);
    acquire(): Promise<void>;
    release(): void;
    get activeCount(): number;
    get pendingCount(): number;
    run<T>(fn: () => Promise<T>): Promise<T>;
}