二、串行（同步）：
1.lock、Monitor--注意锁定的对象必需是引用类型（string类型除外）
示例：
private static object syncObject = new object(); private static void TaskWork(object i) { Console.WriteLine("我是任务：{0}",i); lock (syncObject) { Thread.Sleep(1000); Console.WriteLine("我是任务：{0},线程ID:{1}",i,Thread.CurrentThread.ManagedThreadId); } try { Monitor.Enter(syncObject); Console.WriteLine("我是任务：{0},线程ID:{1}", i, Thread.CurrentThread.ManagedThreadId); } finally { Monitor.Exit(syncObject); } }//调用Task.Factory.StartNew(TaskWork,1);Task.Factory.StartNew(TaskWork, 2);2.Interlocked
示例：
int i=1; Interlocked.Increment(ref i); //增量+1=2; Console.WriteLine("i当前的值：{0}", i); Interlocked.Decrement(ref i); //减量-1=0; Console.WriteLine("i当前的值：{0}", i); Interlocked.Exchange(ref i, 2);//赋值=2; Console.WriteLine("i当前的值：{0}",i); Interlocked.CompareExchange(ref i, 10, 2);//比较交换值，当i=2时，则将i赋值为10； Console.WriteLine("i当前的值：{0}", i);3.Mutex--可以实现进程间的同步，甚至是两个远程进程间的同步
示例：
var t1 = new Task(() => { Console.WriteLine("我是第一个任务！"); Mutex m = new Mutex(false, "test"); m.WaitOne(); Console.WriteLine("第一个任务完成！"); m.ReleaseMutex(); }); var t2 = new Task(() => { Console.WriteLine("我是第二个任务！"); Mutex m = new Mutex(false, "test"); m.WaitOne(); Console.WriteLine("第二个任务完成！"); m.ReleaseMutex(); }); t1.Start(); t2.Start();4.ReaderWriterLock 、ReaderWriterLockSlim--如果在某一时刻资源并没有获取写的独占权,那么可以获得多个读的访问权,单个写入的独占权,如果某一时刻已经获取了写入的独占权,那么其它读取的访问权必须进行等待.
示例：
static ReaderWriterLock rwLock = new ReaderWriterLock(); static void Read(object state) { Console.WriteLine("我是读线程，线程ID是：{0}",Thread.CurrentThread.ManagedThreadId); rwLock.AcquireReaderLock(Timeout.Infinite);//无限期等待,需要显式调用ReleaseReaderLock释放锁 var readList = state as IEnumerable<int>; foreach (int item in readList) { Console.WriteLine("读取当前的值为：{0}", item); Thread.Sleep(500); } Console.WriteLine("读完成，线程ID是：{0}", Thread.CurrentThread.ManagedThreadId); rwLock.ReleaseReaderLock(); } static void Write(object state) { Console.WriteLine("我是写线程，线程ID是：{0}", Thread.CurrentThread.ManagedThreadId); rwLock.AcquireWriterLock(Timeout.Infinite); //无限期等待,需要显式调用ReleaseWriterLock释放锁 var writeList = state as List<int>; int lastCount=writeList.Count(); for (int i = lastCount; i <= 10+lastCount; i++) { writeList.Add(i); Console.WriteLine("写入当前值：{0}",i); Thread.Sleep(500); } Console.WriteLine("写完成，线程ID是：{0}", Thread.CurrentThread.ManagedThreadId); rwLock.ReleaseWriterLock(); } //调用： var rwList = new List<int>(); var t1 = new Thread(Write); var t2 = new Thread(Read); var t3 = new Thread(Write); var t4 = new Thread(Read); t1.Start(rwList); t2.Start(rwList); t3.Start(rwList); t4.Start(rwList);
5.SynchronizationAttribute--确保某个类的实例在同一时刻只能被一个线程访问，类的定义要求：A.类上必需标记SynchronizationAttribute特性，B.类必需继承自System.ContextBoundObject对象
示例：
[Synchronization(SynchronizationAttribute.REQUIRED,true)] public class Account : System.ContextBoundObject { private static int _balance; public int Blance { get { return _balance; } } public Account() { _balance = 1000; } public void WithDraw(string name,object money) { if ((int)money <= _balance) { Thread.Sleep(2000); _balance = _balance - (int)money; Console.WriteLine("{0} 取钱成功！余额={1}", name, _balance); } else { Console.WriteLine("{0} 取钱失败！余额不足！", name); } } }//调用： var account = new Account(); Parallel.Invoke(() => { account.WithDraw("张三",600); }, () => { account.WithDraw("李四",600); });6.MethodImplAttribute--使整个方法上锁，直到方法返回，才释放锁
示例：
public class Account { private static int _balance; public int Blance { get { return _balance; } } public Account() { _balance = 1000; } [MethodImpl(MethodImplOptions.Synchronized)] public void WithDraw(string name,object money) { if ((int)money <= _balance) { Thread.Sleep(2000); _balance = _balance - (int)money; Console.WriteLine("{0} 取钱成功！余额={1}", name, _balance); } else { Console.WriteLine("{0} 取钱失败！余额不足！", name); } } }//调用 var account = new Account(); Parallel.Invoke(() => { account.WithDraw("张三",600); }, () => { account.WithDraw("李四",600); });7.AutoResetEvent、ManualResetEvent、ManualResetEventSlim--调用WaitOne、WaitAny或WaitAll来使线程等待事件,调用Set方法发送信号，事件将变为终止状态，等待的线程被唤醒
示例：
AutoResetEvent arEvent = new AutoResetEvent(false);//默认为无信号，处于非终止状态 Task.Factory.StartNew((o) => { for (int i = 1; i <= 10; i++) { Console.WriteLine("循环第{0}次",i); } arEvent.Set();//发送信号，处于终止状态 },arEvent); arEvent.WaitOne();//等待信号，收到信号后则继续下面的执行 Console.WriteLine("我是主线程，我继续执行！"); Console.Read();8.Sempaphore、SemaphoreSlim（不可跨进程）--信号量，可实现线程、进程间同步
示例：
public class WashRoom { private readonly Semaphore sem; public WashRoom(int maxUseableCount) { sem = new Semaphore(maxUseableCount, maxUseableCount, "WC"); } public void Use(int i) { Task.Factory.StartNew(() => { Console.WriteLine("第{0}个人等待进入", i); // WaitOne:如果还有“空位”，则占位，如果没有空位，则等待； sem.WaitOne(); Console.WriteLine("第{0}个人成功进入，使用中", i); // 模拟线程执行了一些操作 Thread.Sleep(100); Console.WriteLine("第{0}个人用完，离开了", i); // Release:释放一个“空位” sem.Release(); }); } }//调用： var wc = new WashRoom(5); for (int i = 1; i <= 7; i++) { wc.Use(i); }9.Barrier--屏障，使多个任务能够采用并行方式依据某种算法在多个阶段中协同工作，即：将一个阶段的事情分成多个线程来异步执行，执行完毕后再同时进入下一个阶段
示例：
int taskSize = 5; Barrier barrier = new Barrier(taskSize, (b) => { Console.WriteLine(string.Format("{0}当前阶段编号：{1}{0}", "-".PadRight(15, '-'), b.CurrentPhaseNumber)); }); var tasks = new Task[taskSize]; for (int i = 0; i < taskSize; i++) { tasks[i] = Task.Factory.StartNew((n) => { Console.WriteLine("Task : #{0} ----> 处理了第一部份数据。", n); barrier.SignalAndWait(); Console.WriteLine("Task : #{0} ----> 处理了第二部份数据。", n); barrier.SignalAndWait(); Console.WriteLine("Task : #{0} ----> 处理了第三部份数据。", n); barrier.SignalAndWait(); }, i); } Task.WaitAll(tasks);10.SpinLock--自旋锁,仅限锁定的时间较短
示例：
SpinLock sLock = new SpinLock(); int num = 0; Action action = () => { bool lockTaken = false; for (int i = 0; i < 10; i++) { lockTaken = false; try { sLock.Enter(ref lockTaken); Console.WriteLine("{0}+1={1} ---线程ID:[{2}]", num, ++num,Thread.CurrentThread.ManagedThreadId); Thread.Sleep(new Random().Next(9)); } finally { //真正获取之后，才释放 if (lockTaken) sLock.Exit(); } } };//多线程调用： Parallel.Invoke(action, action, action); Console.WriteLine("合计：{0}", num);11.SpinWait--自旋等待，轻量级
Thread.Sleep(1000);//线程等待1S; Console.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff")); SpinWait.SpinUntil(() => false, 1000);//自旋等待1S Console.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff")); Thread.SpinWait(100000);//指定CPU的循环次数，时间间隔处决于处理器的运行速度,一般不建议使用 Console.WriteLine(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss.fff"));12.CountdownEvent--与Sempaphore功能类似，但CountdownEvent支持动态调整信号计数
示例：
static void TimeLimitShopping(int custCount,int times,CountdownEvent countdown) { var customers = Enumerable.Range(1, custCount); foreach (var customer in customers) { int currentCustomer = customer; Task.Factory.StartNew(()=> { SpinWait.SpinUntil(() => false, 1000); Console.WriteLine("第{0}波客户购买情况：Customer-{1}-已购买.", times, currentCustomer); countdown.Signal(); }); //countdown.AddCount(); } }//调用：var countdown = new CountdownEvent(5); TimeLimitShopping(5, 1, countdown); countdown.Wait(); countdown.Reset(10); TimeLimitShopping(10, 2, countdown); countdown.Wait(); countdown.Reset(20); TimeLimitShopping(20, 3, countdown); countdown.Wait();最后分享在System.Collections.Concurrent命名空间下的几个并发集合类：
ConcurrentBag<T>：表示线程安全的无序集合；
ConcurrentDictionary<T>：表示线程安全的多个键值对集合；
ConcurrentQueue<T>：表示线程安全的先进先出集合；
ConcurrentStack<T>：表示线程安全的后进先出集合；
线程的几个状态(以下图片来源于这篇文章：http://www.cnblogs.com/edisonchou/p/4848131.html)：
参考以下相关文章：