Java Concurrency: Inside the JDK Source Code

This book examines the internal workings of Java concurrency, using the java.util.concurrent package in the JDK as its main thread and dissecting the implementation mechanisms behind commonly used concurrency components layer by layer. The book has eight chapters. Chapter 1 starts with multithreading fundamentals, sorting out easily confused topics such as thread shutdown, interruption, synchronized, wait/notify, volatile, the Java Memory Model and happens-before, memory barriers, and final semantics, and closes with lock-free queues, stacks, and linked lists as comprehensive case studies. Chapter 2 covers the Atomic classes, from CAS and Unsafe to underlying spinning and blocking, the ABA problem, field updaters and array atomics, and Striped64 and LongAdder's segmented accumulation and false sharing. Chapter 3 dissects Lock and Condition, explaining mutex reentrancy, fair and nonfair implementations, AQS blocking queues and wakeup mechanisms, read-write locks, Condition, and StampedLock. Chapter 4 covers synchronization utilities such as Semaphore, CountDownLatch, CyclicBarrier, Exchanger, and Phaser. Chapters 5 through 8 cover concurrent containers including blocking queues, BlockingDeque, CopyOnWrite, ConcurrentLinkedQueue, ConcurrentHashMap, and ConcurrentSkipListMap; thread pools and Future; the work-stealing principle of ForkJoinPool; and the asynchronous orchestration and internal computation graph of CompletableFuture. The book proceeds from shallow to deep, layer by layer, aiming to give readers an intuitive yet deep understanding of multithreaded programming rather than leaving them at the level of concepts.