关注我
一段比较经典的多线程学习代码。
1、用到了多线程的同步问题。
2、用到了多线程的顺序问题。
如果有兴趣的请仔细阅读下面的代码。注意其中代码段的顺序，思考一下，这些代码的顺序能否互相调换，为什么？这应该对学习很有帮助的。为了演示，让所有的线程都Sleep了一段时间。
using System.Net;
using System;
using System.IO;
using System.Text;
using System.Threading;
using System.Diagnostics;
namespace Webb.Study
{
class TestThread
{
static Mutex m_Mutex = new Mutex();
static Thread[] m_testThreads = new Thread[10];
static int m_threadIndex = 0;
static void ThreadCallBack()
{
TestThread.m_Mutex.WaitOne();
int m_index = m_threadIndex;
TestThread.m_Mutex.ReleaseMutex();
Console.WriteLine("Thread {0} start.", m_index);
for (int i = 0; i <= 10; i++)
{
TestThread.m_Mutex.WaitOne();
Console.WriteLine("Thread {0}: is running. {1}", m_index, i);
TestThread.m_Mutex.ReleaseMutex();
Thread.Sleep(100);
}
Console.WriteLine("Thread {0} end.", m_index);
}
public static void Main(String[] args)
{
Console.WriteLine("Main thread start.");
for (int i = 0; i < TestThread.m_testThreads.Length; i++)
{
TestThread.m_threadIndex = i;
TestThread.m_testThreads[i] = new Thread(new ThreadStart(ThreadCallBack));
TestThread.m_testThreads[i].Start();
Thread.Sleep(100);
}
for (int i = 0; i < TestThread.m_testThreads.Length; i++)
{
TestThread.m_testThreads[i].Join();
}
Console.WriteLine("Main thread exit.");
}
}
}
1、主函数中这两句能否互换？为什么？
TestThread.m_testThreads[i].Start();
Thread.Sleep(100);
2、CallBack函数中这两句能否互换？为什么？会有什么不同的结果？
TestThread.m_Mutex.ReleaseMutex();
Thread.Sleep(100);
3、主函数能否写成这样？为什么？会有什么不同的结果？
public static void Main(String[] args)
{
Console.WriteLine("Main thread start.");
for (int i = 0; i < TestThread.m_testThreads.Length; i++)
{
TestThread.m_threadIndex = i;
TestThread.m_testThreads[i] = new Thread(new ThreadStart(ThreadCallBack));
TestThread.m_testThreads[i].Start();
TestThread.m_testThreads[i].Join();
Thread.Sleep(100);
}
Console.WriteLine("Main thread exit.");
}
4、这几句的作用是什么？那么程序中还存在什么样的问题？应该做怎样的修改？
TestThread.m_Mutex.WaitOne();
int m_index = m_threadIndex;
TestThread.m_Mutex.ReleaseMutex();