Introduction Jump table is a data structure for storing a sorted list of elements with the help of a linked table hierarchy connected to a subsequence of elements. Jump table allows to handle item lookups in an efficient way. A jump table is a probabilistic data structure, which means that it skips several elements of the entire list, hence the name. We can think of a jump table as an extended version of a linked table.
Preface In the previous articleAbstractQueuedSynchronizer implementation principle - 1, we explained the acquisition and release of exclusive synchronization state in AbstractQueuedSynchronizer, and here we start to explain the acquisition and release of shared synchronization state in AbstractQueuedSynchronizer. Shared Synchronous State Acquisition and Release Shared lock as the name implies is that multiple threads can share a lock, use acquireShared in the synchronizer to get the shared lock (synchronous state), the source code of the method is as follows.
Preface AbstractQueuedSynchronizer is the basic framework for implementing concurrency tools in the JDK, and a deeper understanding of it will help us to better use its features and related tools. We hope you will read this article carefully and gain something from it. In Java, access to shared resources by multiple threads is controlled by lock. We know that the lock function can be implemented by the synchronized keyword, which can implicitly acquire locks, that is, we do not need to care about the process of acquiring and releasing locks by using this keyword, but while it provides convenience, it also means that its flexibility is reduced.