Similarly, as part of acquiring the monitor when entering a synchronized block, local caches are invalidated so that subsequent reads will go directly to main memory and not the local cache.
Also, each Home instance is cached once found, so that subsequent lookups will obtain it from the cache, and this cache access is protected with a synchronized block.
而且，一旦找到缓存的主机实例，随后的查找都可以从缓存中获取，这种缓存访问受到同步块的保护。
3
When a thread exits a synchronized block as part of releasing the associated monitor, the JMM requires that the local processor cache be flushed to main memory.