JVM quick start

1. JVM exploration? Several interview questions: 1. Would you please talk about your understanding of jvm? Java 8 virtual machine and previous changes update? 2. What is oom? What is stack overflow? How to analyze? 3. What are the common tuning parameters for the jvm? 4. How to capture memory snapshots and analyze Dump files? 5. What ...

Posted on Mon, 06 Dec 2021 15:16:03 -0500 by Im Jake

JVM monitoring and diagnostic tool - jstack of command

1, Introduction Jstag (JVM stack trace): used to generate a thread snapshot (virtual machine stack trace) of the specified process of the virtual machine at the current time. A thread snapshot is a collection of method stacks being executed by each thread of the specified process in the current virtual machine Function of generating threa ...

Posted on Tue, 30 Nov 2021 19:10:54 -0500 by senorpuerco

JVM learning notes - memory structure

catalogue Overall architecture diagram Program Counter Register effect characteristic Java virtual machine stacks definition Problem Formulation Stack memory overflow Thread run diagnostics Native Method Stack definition Heap definition characteristic Heap memory overflow Heap memory diagnostics Method area definition Compo ...

Posted on Sun, 28 Nov 2021 01:25:08 -0500 by obrienkev

[JVM source code analysis] the template interpreter interprets and executes Java bytecode instructions

This article is compiled and published by jiumo (Ma Zhi), chief lecturer of HeapDump performance communityChapter 17 - x86-64 registerThe system of machine language that can be interpreted by different CPUs is called ISA (Instruction Set Architecture), or instruction set. Intel calls the 32-bit CPU Instruction Set Architecture among x86 series ...

Posted on Thu, 25 Nov 2021 00:26:19 -0500 by Evoke

JVM Part 15 (conclusion: memory model)

JMM (java memory model) Java Memory Model means Java Memory Model (JMM). In short, JMM defines a set of rules and guarantees for the visibility, ordering and atomicity of data when reading and writing shared data (member variables and arrays) by multiple threads. Atomicity Atomicity: one or more operations are non interruptible, either a ...

Posted on Sat, 20 Nov 2021 17:52:14 -0500 by will35010

[JVM] 04 virtual machine stack

1. Background of virtual machine stack Q1 why is the execution of jvm instructions based on stack structure? In order to achieve cross platform features Because of the register based structure and different CPU architectures on different platforms, cross platform characteristics cannot be realized. Cross platform can be realized based on st ...

Posted on Sat, 20 Nov 2021 17:45:35 -0500 by b-real

JVM Part 14 (class loading and bytecode Technology V)

Class loading phase The class loading stage is divided into three stages: loading, linking and initialization. load Load the bytecode of the class into the method area, and use instanceKlass of C + + to describe the java class. Its important field s are: _ java_mirror, that is, the class image of Java. For example, for String, it is Stri ...

Posted on Fri, 19 Nov 2021 08:09:13 -0500 by jefkin

Spring Cloud quality project, Feign's use extension

1 Preface SpringCloud is a development framework based on Restful. In the overall call process, even if Eureka is introduced, the consumer needs to use a complete path to normally access the remote interface. At the same time, the developer also needs to manually use RestTemplate to convert the call and return results. In order to solve th ...

Posted on Wed, 17 Nov 2021 01:00:09 -0500 by maxkbr

Concurrent programming ThreadLocal principle analysis and memory leakage

Basic introduction What is ThreadLocal? First, we refer to the source code annotation of ThreadLocal This class provides thread-local variables. These variables differ from their normal counterparts in that each thread that accesses one has its own, independently initialized copy of the variable. ThreadLocal instances are typically pri ...

Posted on Thu, 11 Nov 2021 17:16:22 -0500 by PHPNewbie55

Class loader details

Classification of class loaders The JVM supports two types of loaders, namely * * * Bootstrap Class Loader * * and * * * User-Defined Class Loader * *.Conceptually, a custom class loader generally refers to a class loader defined by developers in a program, but the Java virtual machine specification does not define it, but * * * divides all cl ...

Posted on Wed, 10 Nov 2021 16:56:50 -0500 by WindomEarle