import { PoolOptions, PoolConnection } from "mysql2/promise";
export declare class ConnectionPool {
    private static _initMutex;
    static init(poolConfig: PoolOptions): Promise<void>;
    static closePool(): Promise<void>;
    private static getPool;
    static getConnection(): Promise<PoolConnection>;
    static closeConnection(conn?: PoolConnection | null): Promise<void>;
}