export declare class AsyncExecutionStack {
    private executionSlots;
    private isProcessing;
    /** Maximum concurrent non-exclusive tasks (Infinity = unlimited) */
    private nonExclusiveMaxConcurrency;
    /** Currently running non-exclusive task count */
    private nonExclusiveCurrentCount;
    /** Queue of resolvers waiting for a non-exclusive slot */
    private nonExclusivePendingQueue;
    getExclusiveExecutionSlot<T = any>(funcArg: () => Promise<T>, timeoutArg?: number): Promise<T>;
    getNonExclusiveExecutionSlot<T = any>(funcArg: () => Promise<T>, timeoutArg?: number): Promise<T>;
    /**
     * Set the maximum number of concurrent non-exclusive tasks.
     * @param concurrency minimum 1 (Infinity means unlimited)
     */
    setNonExclusiveMaxConcurrency(concurrency: number): void;
    /** Get the configured max concurrency for non-exclusive tasks */
    getNonExclusiveMaxConcurrency(): number;
    /** Number of non-exclusive tasks currently running */
    getActiveNonExclusiveCount(): number;
    /** Number of non-exclusive tasks waiting for a free slot */
    getPendingNonExclusiveCount(): number;
    private processExecutionSlots;
    private executeExclusiveSlot;
    private executeNonExclusiveSlots;
    /**
     * Wait until a non-exclusive slot is available (respects max concurrency).
     */
    private waitForNonExclusiveSlot;
    /** Release a non-exclusive slot and wake the next waiter, if any. */
    private releaseNonExclusiveSlot;
}