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#JVM basics section 1 JVM introduction java Non running on virtual machine platform Java Language program java source code->Binary bytecode(.class (file) ->JVM-> interpreter->Machine code->CPU It only cares about "bytecode" files Java Not the most powerful language, but JVM Is the most powerful virtual machine ...

This article is compiled and published by jiumo (Ma Zhi), chief lecturer of HeapDump performance communityPart 22 - virtual machine bytecode operation instructionsThe operation related bytecode instructions in the virtual machine specification are shown in the following table. 0x60iaddAdd two int values at the top of the stack and press the r ...

equals and = = Application and difference (in-depth understanding of source code) Double equal sign (= =) Two cases of double equal sign comparison For the = = sign, only two cases need to be considered: The basic data type uses = =, comparing valuesThe reference data type is = =, which compares the (heap) memory address of the object s ...

What is BTrace BTrace is a killer for checking and solving online problems. BTrace can obtain all information during program execution by writing scripts. Note that there is no need to restart the service. Yes, there is no need to restart the service. Write a script and execute it directly with commands without touching the code of the origina ...

1, Object loading process So, how is an image loaded when it is new? What are the steps and how to allocate memory space? 1.1 main process of object creation Take this code as an example: public static void main(String[] args) { Math math = new Math(); math.compute(); new Thread().start(); } When we create a New Math object, ...

Atomicity Many people confuse [java memory structure] with [Java Memory Model]. Java Memory Model means Java Memory Model (JMM). For its authoritative explanation, please refer to https://download.oracle.com/otn-pub/jcp/memory_model-1.0-pfd-spec-oth-JSpec/memory_model-1_0-pfd-spec.pdf?AuthParam=1562811549_4d4994cbd5b59d964cd2907ea22ca08b ...

The three main features of JAVA are inheritance, encapsulation, and polymorphism. The dispatch call process will reveal some of the most basic manifestations of polymorphism, such as override and overload. 1. Static Assignment Before introducing static assignment, let's look at a piece of code public class StaticDispatch { static abstrac ...

Content Review: 1. Core overview of Heap Description of 1.1 heap memory There is only one heap memory for a JVM instance, and the heap is also the core area of Java memory management.The Java heap area is created when the JVM starts and its size is determined. It is the largest piece of memory space managed by the JVM. The size of hea ...

1, Reachability analysis algorithm In heap memory, there is a root object GC root, and CG root objects are generally the following: The reference object in the local variable table in the stack frame in the thread stack;Static reference objects in the method area;Constant reference objects in the method area;The referenced obj ...

1. Strong References (Objects) Features: Strong references provide direct access to the target object. Will not be recycled. Two, soft reference (SoftReference class) Features: When GC reclaims based on JVM memory, JVM reclaims when it finds it is out of memory Conditions for freeing up space: JVM found insufficient m ...