import type { Batch } from "./batch";
import type { Sender } from "./sender";
/**
 * 简单的异步发送线程池，实现基于 MaxSenderCount 的并发控制。
 */
export declare class ThreadPool {
    private readonly sender;
    private readonly maxConcurrency;
    private queue;
    private activeCount;
    private stopped;
    private forceQuit;
    private stopResolve?;
    constructor(sender: Sender, maxConcurrency: number);
    /**
     * 提交一个批次到线程池中异步发送。
     */
    submit(batch: Batch | undefined | null): void;
    /**
     * 优雅关闭：等待队列消费完且所有发送任务结束。
     */
    stopGracefully(): Promise<void>;
    /**
     * 强制关闭：清空待发送队列，不再等待未完成任务。
     */
    stopForce(): void;
    private drain;
}