namespace 使用Semaphore { class Program { //第1個(gè)參數(shù)指定當(dāng)前運(yùn)行多少條線程進(jìn)入，第2個(gè)參數(shù)表示 允許多少個(gè)線程同時(shí)進(jìn)入 static Semaphore sem = new Semaphore(2, 2); static void Main(string[] args) { for (int i = 1; i <=4; i++) { new Thread (ThreadEntry).Start (i); } } static void ThreadEntry(object id) { Console.WriteLine("thread {0} wants to get in",id); sem.WaitOne(); //在調(diào)用waitone方法時(shí)，如果有空位，則占位；如果沒有，則等待； Console.WriteLine("thread {0} gets in",id ); Thread.Sleep(100); Console.WriteLine("thread {0} is leaving",id ); sem.Release(); //釋放1個(gè)空位； } } }