C#線程同步SemaphoreSlim類介紹

SemaphoreSlim類限制了同時訪問一個資源的線程數量

代碼如下:

 1   static SemaphoreSlim semaphoreSlim = new SemaphoreSlim(4);
 2 
 3         static void AccessDatabase(string name, int seconds)
 4         {
 5             Console.WriteLine($"{name}等待訪問數據庫");
 6             semaphoreSlim.Wait();
 7             Console.WriteLine($"{name}被授權訪問數據庫");
 8             Thread.Sleep(TimeSpan.FromSeconds(seconds));
 9             Console.WriteLine($"{name}訪問數據庫已經完成");
10             semaphoreSlim.Release();
11         }
12 
13         static void Main(string[] args)
14         {
15             for (int i = 1; i <= 6; i++)
16             {
17                 string threadName = $"線程{i}";
18                 int secondsToWait = 2 + 2 * i;
19                 var t = new Thread(() => AccessDatabase(threadName, secondsToWait));
20                 t.Start();
21             }
22             Console.ReadLine();
23         }

運行結果：