C# 同步

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• Interlocked
  simple 

  arithmetic operations are not atomic.Interlocked类提供了一个专门的机制用于完成这些特定的操作。这个类提供了Increment、Decrement、Add静态方法用于对int或long型变量的递增、递减或相加操作

  Interlocked.Increment(ref counter);

   

• AutoResetEvent
  One simple, and thread-safe way to force a thread to wait until another is completed is to use the AutoResetEvent class
  Wait将阻塞线程

• AutoResetEvent waitHandle = new AutoResetEvent(false);
  
  Thread t = new Thread(...);
  t.Start();
  
  // Wait (with timeout) here until you are notified!
  waitHandle.WaitOne(2000);
  Console.WriteLine("Other thread is done!");
  
  // in thread t
  // Tell other thread we are done.
  waitHandle.Set();

  同步事件有两种：AutoResetEvent和 ManualResetEvent。它们之间唯一不同的地方就是在激活线程之后，状态是否自动由终止变为非终止。AutoResetEvent自动变为 no-signal. AutoResetEvent只能激活一个线程。而ManualResetEvent要等到它的Reset方法被调用，状态才变为no-signal，在这之前，ManualResetEvent可以激活任意多个线程。

• C# lock Keyword
  This keyword allows you to define a scope of statements that must be synchronized between thread
  MSDN:最佳做法是定义 private 对象来锁定, 或 private static 对象变量来保护所有实例所共有的数据。

• // Lock token.
  private object threadLock = new object();
  
  // Use the private object lock token.
  lock (threadLock)
  { ... 
  // All code within this scope is thread safe.
  }

   

• Monitor
  the lock keyword is equals to

• Monitor.Enter(threadLock, ref lockTaken);
  try
  { ... }
  finally
  {
  　　if (lockTaken) Monitor.Exit(threadLock);
  }
  
  

  让当前线程在等待1000秒后根据返回的bool值来决定是否继续下面的操作

  bool gotLock = Monitor.TryEnter（threadLock,1000）

  Monitor.Pulse/wait:

             |- 拥有锁的线程
  lockObj -> |- 就绪队列(ready queue)
             |- 等待队列(wait queue)

  User Wait to go to the wait queue, use Pulse/PulseAll to push (all) from wait queue to ready queue 

• [Synchronization] Attribute
  In essence, this class-level attribute effectively locks down all instance member code of the object for thread safety.
  

  public class SynchronizationClass : ContextBoundObject 
  { ... }

•  [MethodImpl(MethodImplOptions.Synchronized)] 
  如果临界区是跨越整个方法的，也就是说，整个方法内部的代码都需要上锁的话，使用MethodImplAttribute属性会更简单一些.
  
  
• ReaderWriterLock
  C#提供了System.Threading.ReaderWriterLock类以适应多用户读/单用户写的场景。
  

  private static ReaderWriterLock m_readerWriterLock = new ReaderWriterLock();
  
  m_readerWriterLock.AcquireReaderLock(10000);
   ... 
  m_readerWriterLock.ReleaseReaderLock();
  
  m_readerWriterLock.AcquireWriterLock(1000);
  ...
  m_readerWriterLock.ReleaseWriterLock();
  
  

  m_readerWriterLock.UpgradeToWriterLock(1000);

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C# 同步

标签：style   class   blog   code   tar   ext   

原文地址：http://www.cnblogs.com/leihdm/p/3794956.html