C#多线程---Semaphore实现线程同步

一、简介

Semaphore类限制可同时访问某一资源或资源池的线程数。线程通过调用 WaitOne方法将信号量减1，并通过调用 Release方法把信号量加1。

构造函数：public Semaphore(int initialCount,int maximumCount);通过两个参数来设置信号的初始计数和最大计数。

二、例子

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace ThreadMutex
{
    class Program
    {
        private static Mutex mutex = new Mutex();
        private static Semaphore semaphore = new Semaphore(3, 10);
        private static int sum = 0;
        static void Main(string[] args)
        {
            for (int i = 0; i < 10; i++)
            {
                Task<int> task = new Task<int>(ThreadFunction);
                task.Start();
            }
            Console.WriteLine($"{DateTime.Now} task started!");
            Console.Read();

        }
        private static int ThreadFunction()
        {
            Thread.Sleep(100);
            if(semaphore.WaitOne(2000))
            {
                Console.WriteLine($"Thread {Thread.CurrentThread.ManagedThreadId} get semaphore successed!");
            }
            else
            {
                Console.WriteLine($"Thread {Thread.CurrentThread.ManagedThreadId} get semaphore failed!");
            }
          
            return sum;
        }
    }
}

运行结果如下：