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Method area of jvm definition (1) The method area, like the java heap, is a memory area shared by all threads (2) The method area is created when the jvm starts, and its actual physical memory space can be discontinuous like the java heap area (3) The size of the method area, like the heap space, can be fixed or expanded (4) The size of the m ...

Most of the environments described in this article are based on linux. For a program, under Linux, we can find the corresponding process ID according to the program response information: ps -ef | grep java | grep -v grep | |awk '{print $2}' In this way, we can get the process id and PID of the corresponding program After obtaining the PI ...

Deep understanding of JVM (XI) -- class loading and bytecode Technology (V) 6. Operation period optimization Layered compilation The JVM divides the execution state into five levels: Layer 0: interpret and execute, and translate bytecode into machine code with interpreterLayer 1: compile and execute with C1 real-time compiler (without p ...

Reprinted from: Original link Author: https://gosaintmrc.github.io/ Recently, a meituan interview question appeared on the Internet: "after one thread is OOM, can other threads still run?". I think there are many unreliable answers on the Internet. This question is actually very difficult. The knowledge points involved include ...

All Rights Reserved © jackiegu.cn 1. JVM runtime memory data area division Program counterJava virtual machine stackNative Method Stack Java heapMethod areaRuntime Constant Pool 2. Program counter The program counter is a small memory space, which can be understood as the line number indicator of the bytecode file executed by the curr ...

Deep understanding of JVM (2) -- memory structure (2) 4. Pile definition Objects created with the new keyword are placed in heap memory characteristic The safety of all threads in the heap needs to be consideredThere is a garbage collection mechanism Heap memory overflow java.lang.OutofMemoryError : java heap space. Heap memory over ...

1. Strong reference Strong references are the most common kind of references. 99.9999% of the codes we write are strong references: 2. Soft reference Soft reference is to wrap the object with SoftReference. When we need to get the wrapped object from the soft reference object, we just need to get it characteristic: When the memory is ...

In short, a Native Method is an interface for Java to call non java code. A Native Method is a Java method that is implemented by a non Java language, such as C. This feature is not unique to Java. Many other programming languages have this mechanism. For example, in C + +, you can use extern "C" to tell the C + + compiler to c ...

Chapter 4 implements the runtime data areas such as Java virtual machine stack and frame, which lays a foundation for the implementation of the method. Chapter 5 implements a simple interpreter and more than 150 instructions, which can execute a single method. Chapter 6 implements the method area, which clears the obstacles for method invocatio ...

First look at the simplest print System.out.println(new Object()); The fully qualified class name and a string of strings of this class will be output: java.lang.Object@6659c656 What's after the @ symbol? Is it hashcode or the memory address of the object? Or something else? ​ In fact, @ what follows is only the hashcode value of the objec ...