/** @internal One-shot async signal that awaiters can wait on until set. */
export declare class AsyncEvent {
    private _set;
    private _waiters;
    isSet(): boolean;
    set(): void;
    clear(): void;
    wait(): Promise<void>;
}
/** @internal A promise with externally callable resolve/reject. */
export declare class Deferred<T> {
    readonly promise: Promise<T>;
    private _resolve;
    private _reject;
    settled: boolean;
    constructor();
    resolve(value: T): void;
    reject(err: unknown): void;
}
/** @internal Async FIFO queue with a maximum size and backpressure. */
export declare class BoundedQueue<T> {
    private readonly _maxsize;
    private readonly _buffer;
    private readonly _getWaiters;
    private readonly _putWaiters;
    constructor(maxsize: number);
    get size(): number;
    private get _full();
    putNowait(item: T): void;
    put(item: T): Promise<void>;
    get(): Promise<T>;
    /** @internal Timed {@link get}; rejects with {@link WaitTimeoutError} after `timeoutMs`. Removes its own waiter on timeout so a later `put()` isn't delivered (FIFO) to a dead waiter and lost. */
    getWithTimeout(timeoutMs: number): Promise<T>;
}