export declare const DEFAULT_CONCURRENCY = 3;
export declare class Semaphore {
    private readonly limit;
    private running;
    private queue;
    constructor(limit?: number);
    acquire(): Promise<void>;
    release(): void;
    get available(): number;
    get pending(): number;
    get active(): number;
}
export declare function getSkillSemaphore(skillKey: string, limit?: number): Semaphore;