Java

What PriorityBlockingQueue is, binary-heap basics, usage, and source analysis of growth, offer/put, take, and heap adjustment.

1. What it is. A blocking queue implemented internally with a singly linked structure that does not store elements. A writer must have a reader at the same time in order to proceed, and vice versa; otherwise the writer or reader remains blocked. 2. Usage. 3. Principles. 3.1. Constructor. 3.1.1. Transfer. 3.1.2. QNode. 3.2. put blocking. 3.2.1. Calls TransferQueue.

1. What it is. Thread-safe atomic classes implemented with CAS. 2. Usage, using AtomicInteger as an example. 3. Principle analysis. 4. Problems with AtomicInteger: high CPU usage and the ABA problem, plus a version-number solution with AtomicStampedReference.

Summary and answers for 24 JVM interview questions - Juejin.

Troubleshooting memory saturation, CPU/thread problems, deadlocks, JVM tuning, and related references.

Reference counting, reachability analysis, GC Roots, concrete garbage collection algorithms, and references.

The class lifecycle: loading, linking, initialization, use, unloading, class loaders, parent delegation, and related questions.

JVM memory regions: shared heap and method area, per-thread stack and program counter, and PermGen/Metaspace.

Goals of tuning, overall production steps, JMeter load-test tuning, and CMS tuning flow.

Mark-sweep, mark-compact, copying, and generational collection.