/**
 * Get or create a worker instance from the default pool.
 * If WorkerPool is provided in options, use it instead of default pool.
 *
 * @internal
 */
export declare function getWorker(workerURL?: string | URL): Promise<Worker>;
/**
 * Get next request ID for message tracking from the default pool.
 *
 * @internal
 */
export declare function getNextRequestId(): number;
/**
 * Release a worker back to the default pool.
 * For the default transient pool, this terminates the worker.
 *
 * @internal
 */
export declare function releaseWorker(worker: Worker): void;
/**
 * Get the current size of the default pool.
 * This is mainly for testing purposes.
 *
 * @internal
 */
export declare function getPoolSize(): number;