C#线程同步SemaphoreSlim类介绍

SemaphoreSlim类限制了同时访问一个资源的线程数量

代码如下:

  static SemaphoreSlim semaphoreSlim = new SemaphoreSlim(4);

        static void AccessDatabase(string name, int seconds)
        {
            Console.WriteLine($"{name}等待访问数据库");
            semaphoreSlim.Wait();
            Console.WriteLine($"{name}被授权访问数据库");
            Thread.Sleep(TimeSpan.FromSeconds(seconds));
            Console.WriteLine($"{name}访问数据库已经完成");
            semaphoreSlim.Release();
        }

        static void Main(string[] args)
        {
            for (int i = 1; i <= 6; i++)
            {
                string threadName = $"线程{i}";
                int secondsToWait = 2 + 2 * i;
                var t = new Thread(() => AccessDatabase(threadName, secondsToWait));
                t.Start();
            }
            Console.ReadLine();
        }

运行结果：