如果我声明在一个queue类中声明Queue<string[]> emailQueue = new Queue<string[]>();我怎么锁定emailQueue ,当入队的时候不能出队,当出队的时候不能入队

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Collections.Generic;

/// <summary>
///queue 的摘要说明
/// </summary>
public class queue
{
    //public queue()
    //{
    //    //
    //    //TODO: 在此处添加构造函数逻辑
    //    //
    //}

    static Queue<string[]> emailQueue = new Queue<string[]>();

    //入队;
    public  void enQueue(string[] queValue)
    {
      
        emailQueue.Enqueue(queValue);
    }

    //出队;
    public string[] delQueue()
    {
        int queCount = emailQueue.Count;
        if (queCount > 0)
        {
            string[] backQue = emailQueue.Peek();
            emailQueue.Dequeue();
            return backQue;
        }
        else
        {
            return null;
        }
    }

    //总数
    public int QueueCount()
    {
        return emailQueue.Count;
    }


}

因为入队的地方很多,我现在要锁定,如何锁定啊.????