synchronization

线程通信，主要通过共享访问进程资源。这种通信方式非常高效，但存在两个问题：thread interference & memory consistensy errors

解决这两种问题的工具就是 Synchronization

然而，Synchronization 会引入 Thread contention。当多个线程试图同时访问同一个资源时，Synchronization 会导致一个或几个线程执行变得更慢，甚至 suspend 线程的执行。

• Thread Interference describes how errors are introduced when multiple threads access shared data.
• Memory Consistency Errors describes errors that result from inconsistent views of shared memory.
• Synchronized Methods describes a simple idiom that can effectively prevent thread interference and memory consistency errors.
• Implicit Locks and Synchronization describes a more general synchronization idiom, and describes how synchronization is based on implicit locks.
• Atomic Access talks about the general idea of operations that can’t be interfered with by other threads.