/**
 * A simple async lock implementation. This lock
 * is not reentrant.
 */
export declare class AsyncLock {
    private locked;
    private waitingResolvers;
    /**
     *  Acquire the lock. If the lock is already
     * acquired, the next caller  wait until it is
     * released.
     * @returns a promise that resolves when the
     * lock is acquired
     */
    acquire(): Promise<void>;
    /**
     * Release the lock. If there are waiting promises,
     * resolve the first one.
     */
    release(): void;
}