这个古老的话题，
这里是一个大杂烩；
首先让我们看stackoverflow中一个经典的问题：
Volatile vs. Interlocked vs. lock
然后连接看答案：
https://stackoverflow.com/questions/154551/volatile-vs-interlocked-vs-lock
这里的误区，主要是对volatile的解释和使用；
关于volatile的解释和示例:
http://www.jaylee.org/post/2004/08/05/Dont-get-C-volatile-the-wrong-way.aspx
这里还有一篇较好的文章：
http://igoro.com/archive/volatile-keyword-in-c-memory-model-explained/ (这篇文章讲得非常好，非常好，强烈推荐)
一些文字摘要：
The memory model is a fascinating topic – it touches on hardware, concurrency, compiler optimizations, and even math.
The memory model defines what state a thread may see when it reads a memory location modified by other threads. For example, if one thread updates a regular non-volatile field, it is possible that another thread reading the field will never observe the new value. This program never terminates (in a release build):
这里我们再进行 synchronization 中 Barrier 的使用；
https://msdn.microsoft.com/en-us/library/system.threading.barrier(v=vs.110).aspx (微软官网示例方法)
它的另外一种用法滴啊；
How to: Synchronize Concurrent Operations with a Barrier
https://docs.microsoft.com/en-us/dotnet/standard/threading/how-to-synchronize-concurrent-operations-with-a-barrier
还有这个例子：
http://dotnetpattern.com/threading-barrier
这里关于 readerwriterlockslim and readerwritelock 之间的基本区别；
ReaderWriterLockSlim is similar to ReaderWriterLock, but it has simplified rules for recursion and for upgrading and downgrading lock state.
ReaderWriterLockSlimavoids many cases of potential deadlock. In addition, the performance of ReaderWriterLockSlim is significantly better than ReaderWriterLock. ReaderWriterLockSlim is recommended for all new development.
关于readerWriterLockSlim 是文章：
https://msdn.microsoft.com/en-us/library/system.threading.readerwriterlockslim.aspx
关于c#同步机制的一个总结：
https://docs.microsoft.com/en-us/dotnet/standard/threading/overview-of-synchronization-primitives