100 questions to solve the Java virtual machine

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100 questions to solve the big data theory system
1000 questions to solve the big data technology system

Directory Structure

1. Why should Java code run in a virtual machine?
2. How does Java code run in a virtual machine?
3. How to divide the data area when the JVM is running?
4. What is the difference between heap and stack?
5. What is the runtime stack frame structure?
6. How is the Java heap divided?
7. Why does the JVM adopt an architecture oriented to the operand stack instead of registers?
8. What is the relationship between the method area, permanent generation, constant pool, and metaspace?
9. How is String.intern() implemented?
10. How does Java use direct memory?
11. What is the process of the new keyword in the virtual machine? What are the steps for the JVM to construct an object?
12. What is the storage layout of objects in heap memory?
13. What is the problem of virtual sharing of object fields? How to solve the problem of virtual sharing of object fields?
14. How to judge whether the object is dead?
15. What is the difference between Minor GC and Full GC?
16. How to understand GC logs?
17. The difference between the four types of references in Java?
18. What are the garbage collection algorithms?
19. What do safe points and safe areas mean?
20. What garbage collectors are there in the JVM?
21. What is G1 GC?
22. How to tune GC?
23. What are the JVM performance monitoring and troubleshooting tools?
24. What is Arthas? how to use?
25. What is the process of calling a Java method?
26. How does the Java virtual machine identify the target method?
27. How is the virtual method call implemented in the Java virtual machine?
28. How is invokedynamic implemented?
29. How is Java8's Lambda expression implemented?
30. How does the JVM handle exceptions?
31. How does the JVM implement reflection?
32. What is the structure of the class class file?
33. What is the implementation principle of this and super in Java?
34. When is the class loaded?
35. What is the process of class loading?
36. How does array type accomplish class loading?
37. What is the parental delegation model?
38. In which cases classloading does not need to obey the parental delegation model?
39. What are some common bytecode instructions?
40. What is Java Agent?
41. What are the Java syntax sugar?
42. What is just-in-time compilation? What is tiered compilation?
43. What is profiling of JVM?
44. What are the types of compilers in Java?
45. What optimizations does the just-in-time compiler have?
46. What does the JVM do when optimizing Java code?
47. What is method inlining?
48. Under what circumstances will a method call be inlined?
49. What is the devirtualization of the just-in-time compiler?
50. What is intrinsic in HotSpot virtual machine?
51. What is the Unsafe class in Java?
52. What do escape analysis, stack allocation, scalar replacement, synchronization elimination, and lock elimination refer to?
53. What is the optimization of the just-in-time compiler for field read and store instructions?
54. Under what circumstances would loop code be optimized? What optimizations does the JVM have for looping code?
55. Under what circumstances will object allocation be optimized? Are all objects in the JVM only allocated on the heap?
56. What is the vectorization optimization of the just-in-time compiler? What exactly are SIMDs?
57. What is the underlying principle of JDK9 strings?
58. What is the implementation principle of the annotation processor? What is the implementation principle of Lombok?
59. The realization principle of the final field?
60. What is the Java memory model?
61. What is main memory and working memory?
62. What is the happens-before principle?
63. How does the Java virtual machine implement synchronized?
64. What is the implementation principle of volatile?
65. What is the implementation principle of JNI?
66. How to avoid JVM memory leaks?

references

1. "In-depth Understanding of Java Virtual Machine: JVM Advanced Features and Best Practices 3rd Edition" by Zhou Zhiming
2. Geek Time column "In-depth dismantling of the Java virtual machine" Zheng Yudi
3. Geek Time column "Java performance tuning in practice" Liu Chao
4. Geek Time column "Java core technology interview essence" Yang Xiaofeng
5. "JVM G1 Source Code Analysis and Tuning" edited by Peng Chenghan
6. "The Logic of Java Programming" by Ma Junchang
7. Distinguish between several constant pools in Java (string constant pool, class constant pool and runtime constant pool)
8. In the garbage collection mechanism, how does the reference counting method maintain all object references?
9. Accessibility Analysis Explained
10. Introduction to JVM ZGC
11. Java cutting-edge technology - ZGC ZGC introduction
12. PC register of JVM
13. The latest Ali interview questions: talk about the underlying implementation principles of THIS and SUPER keywords in JAVA
14. Detailed explanation of String's Intern method
15. Analysis of syntactic sugar in java
16. If you don’t understand these 12 grammatical sugars, don’t say you know Java!
17. What syntactic sugar is there in Java?
18. ClickHouse official website
19. On Java 8