C#线程本地化存储

      有时以单个线程为基础存储信息比较方便，所存储的信息只对该线程有用，这叫做线程本地化存储。通常用Thread对象的AllocateNamedDataSlot方法创建存储名，用GetData取出内容，最后用FreeNamedDataSlot释放。

     

/*
  Example14_4.cs illustrates the use of thread-local storage
*/

using System;
using System.Threading;

class Example14_4 
{

    // the WriteError method writes error info from the current thread
    public static void WriteError()
    {
        Console.WriteLine("Error number = " + Thread.GetData(Thread.GetNamedDataSlot("ErrNo")));
        Console.WriteLine("Error source = " + Thread.GetData(Thread.GetNamedDataSlot("ErrSource")));
    }

    // the SetError method sets a random error number
    public static void SetError() 
    {
        Random r = new Random();
        Thread.SetData(Thread.GetNamedDataSlot("ErrNo"), r.Next(100));
        Thread.SetData(Thread.GetNamedDataSlot("ErrSource") ,Thread.CurrentThread.Name);
        WriteError();
    }

    public static void Main() 
    {
        // allocate some named data slots
        Thread.AllocateNamedDataSlot("ErrNo");
        Thread.AllocateNamedDataSlot("ErrSource");

        // create and start a second thread
        Thread t2 = new Thread(new ThreadStart(SetError));
        t2.Name = "t2";
        t2.Start();

        // create a third thread
        Thread t3 = new Thread(new ThreadStart(SetError));
        t3.Name = "t3";
        t3.Start();

        // clean up the data slots
        Thread.FreeNamedDataSlot("ErrNo");
        Thread.FreeNamedDataSlot("ErrSource");

    }

}