标签：多线程 interlocked类
在C#中，赋值和简单的数字运算都不是原子型操作。在多线程环境下，会产生数据安全的问题。
在多线程环境下，我们可以通过使用System.Threading.Interlocked类来实现原子型操作当个数据，使用它比使用Monitor类跟简单。
Interlocked类主要方法
| 方法 | 作用 |
| CompareExchange() | 安全比较两个值是不是相等。如果相等，将第三个值于其中一个值交换 |
| Decrement() | 安全递减1,相当于 i-- |
| Exchange() | 安全交换数据,相当于 a = 30 |
| Increment() | 安全递加1,相当于 i++ |
| Add() | 安全相加一个数值,相当于 a = a + 3 |
| Read() | 安全读取数值，相等于int a=b |
例子1：
private int value1 = 0;
public void TestIncrementUnSafe()
{
for (int i = 0; i < 5; i++)
{
Thread t = new Thread(IncrementValue1);
t.Name = "t1 " + i;
t.Start();
}
Thread.Sleep(2000);
//value maybe 500000
Console.WriteLine("value1 = " + value1);
}
private int value2 = 0;
public void TestIncrementSafe()
{
for (int i = 0; i < 5; i++)
{
Thread t = new Thread(IncrementValue2);
t.Name = "t2 " + i;
t.Start();
}
Thread.Sleep(2000);
//value should be 500000
Console.WriteLine("value2 = " + value2);
}
private void IncrementValue1()
{
for (int i = 0; i < 1000000; i++)
{
value1++;
//Console.WriteLine(Thread.CurrentThread.Name);
}
}
private void IncrementValue2()
{
for (int i = 0; i < 1000000; i++)
{
Interlocked.Increment(ref value2);
}
}控制台输出：
运行结果1
value1 = 4612592
value2 = 5000000
运行结果2
value1 = 4697979
value2 = 5000000
例子2
private int value3 = 0;
public void TestExchangeSafe()
{
for (int i = 0; i < 5; i++)
{
Thread t = new Thread(ExchangeValue3);
t.Name = "t2 " + i;
t.Start();
}
Thread.Sleep(2000);
//value should be 83
Console.WriteLine("value3 = " + value3);
}
private void ExchangeValue3()
{
Interlocked.Exchange(ref value3, 83);
}
private int value4 = 0;
public void TestCompareExchangeSafe()
{
for (int i = 0; i < 5; i++)
{
Thread t = new Thread(ExchangeValue3);
t.Name = "t2 " + i;
t.Start();
}
Thread.Sleep(2000);
//value should be 99 or 0
Console.WriteLine("value4 = " + value4);
}
private void ExchangeValue4()
{
//if value4=0, set value4=99
Interlocked.CompareExchange(ref value4, 99,0);
}控制台输出:
value4 = 0
value3 = 83
C# Interlocked类的使用,布布扣,bubuko.com
标签：多线程 interlocked类
原文地址：http://samonliang.blog.51cto.com/9096807/1530358
