current position:Home>Crazy blessing! Tencent boss's "million JVM learning notes", real topic of Huawei Java interview 2020-2021

Crazy blessing! Tencent boss's "million JVM learning notes", real topic of Huawei Java interview 2020-2021

2021-08-21 14:22:23 be on call

One:JVM Practical thinking map ( Full version )

Two: approach Java

summary + Java Technical system +Java The history of +Java Virtual machine family :(Sun Classic/Exact VM、HotSpot VM、Mobile/Embedded VM、BEA JRockit/IBM J9 VM、BEA Liquid VM/Azul VM、Apache Harmony/Google Android Dalvik VM、Microsoft JVM And others )+ expectation Java The future of Technology + actual combat : Compile it yourself JDK

Three: Automatic memory management

Java Memory area and memory overflow exception : Run time data area :( Program counter +Java Virtual machine stack + Native Method Stack + Java Pile up + Method area + Runtime constant pool + Direct memory )tSpot Exploring virtual machine objects + actual combat :OutOfMemoryError abnormal (Java Heap overflow + Virtual machine stack and local method stack overflow + Method area and runtime constant pool overflow + Local direct memory overflow )

** Garbage collector and memory allocation strategy :** The object is dead. ?+ Garbage collection algorithm +HotSpot The algorithm details of the implementation of + The classic garbage collector + Low latency garbage collector + Choose the right garbage collector + actual combat : Memory allocation and recycling strategy

** Virtual machine performance monitoring 、 Troubleshooting tools :** Basic troubleshooting tools + Visual fault handling tool +HotSpot Virtual machine plug-ins and tools

** Tuning case analysis and practice :** case analysis :( Program deployment strategy on large memory hardware + Memory overflow caused by synchronization between clusters + Overflow error due to out of heap memory + External commands cause the system to slow down + The server virtual machine process crashed + Improper data structure leads to excessive memory consumption + from Windows Long pause caused by virtual memory + Long pause caused by safety point )

Four: Virtual machine execution subsystem

** Class file structure :** The cornerstone of irrelevance +Class Class file structure + Introduction to bytecode instruction + Public design , Private implementation +Class The development of document structure

** Virtual machine class loading mechanism :** Class load time + The process of class loading + Class loader +Java Modular system

VM bytecode execution engine :? Runtime stack frame structure + Method call + Dynamic type language support + Stack based bytecode interpretation execution engine

** Class loading and execution subsystem cases and actual combat :** case analysis :( Tomcat: The orthodox classloader Architecture + OSGi: Flexible classloader Architecture + Bytecode generation technology and implementation of dynamic proxy +Backport Tools :Java Your time machine )+ actual combat : Do it yourself to realize remote execution function

Five: Program compilation and code optimization

** Front end compilation and optimization :**Javac compiler +Java The taste of grammar sugar ( Generic + Automatic boxing 、 Unpacking and traversing cycle + Conditional compilation )+ actual combat : Plug in annotation processor

** Back end compilation and optimization :** Just in time compiler + Ahead of time compiler + Compiler optimization technology + In depth understanding of Graal compiler

Six: Efficient concurrent

**Java Memory model and thread :** Efficiency and consistency of hardware +Java Memory model ( Main memory and working memory + Inter memory interaction + about volatile Special rules for type variables + in the light of long and double Special rules for type variables + Atomicity 、 Visibility and order + Antecedent principle )+Java With threads ( Implementation of threads +Java Thread scheduling + State transition )+Java With the process

Is that enough ? No , It's not enough !

Getting familiar with Ali's interview questions in previous years in advance must be of great help to the interview , But as a technical profession , Having solid skills in hand is the most useful weapon for you to face the interviewer , This is self-confidence emanating from the inside .

The most time I spent preparing for Ali was learning technology , It accounts for... Percent of all my study plans 70, These are some learning notes that I think are very good during my study , And learning videos are   You can click here for free Of !

Why should I write this article , In fact, I think learning can't stop , Share with you on the Internet , Discuss together , You can't just meet more of the same people , You can broaden your horizons , Learn more technology , I will be in csdn、 Blog 、 Share technology on websites such as nuggets , This is also a way of learning .

I'll share it with you today , Thank you for your attention , I will share more dry goods to you in the future !

 Ali fell off his horse , I'll finish this “ Ali interview Dictionary ” after , Ashore ant gold clothes

 Ali fell off his horse , I'll finish this “ Ali interview Dictionary ” after , Ashore ant gold clothes


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