java 1 7 virtual machine

Deep understanding of Java Virtual Machine: JVM advanced features and best practices (in-depth analysis of JVM Based on issues such as memory management and high concurrency) Provides a comprehensive and in-depth analysis of JVM based on core content such as memory management, execution subsystem, programming compilation and optimization, and efficient concurrenc

heap.The method area is created when the virtual machine is started.The capacity of a method area can be a fixed size, or it can be scaled dynamically as the requirements of the program execute, and shrink automatically when too much space is not required.The method area can be discontinuous in the actual memory space.The Java

the program code, and the Instance defined in the parent class are also inherited. Align padding (Padding): There is no special meaning, the size of the object must be a 8-byte integer multiple. 3.3 Object access and positioningThe object is created to use the object, and the Java program needs to manipulate the object on the reference data stored on the stack, the reference type is a reference to the object, and does not define how the song

thread private; 3) Local method Stack The native method used by the corresponding virtual machine, similar to the Java Virtual Machine stack; 4) java heap When a virtual

Java run-time memory areaWhen running a Java program, a Java Virtual machine divides the area of memory it manages into several different regions. Each zone has its own purpose, creation, and time to destroy. Some exist with the startup of the

parsing class files, getting class information, as usual, variable information, Java method directives, and so on, and putting the information in an organized memory, usually called the method area.The Executive engine is responsible for the specification of the virtual machine, interpretation instructions, Java

What is 1.JVM?　　Jvm:java virtual mechinal (Java vm). It is a fictional computer that is implemented by simulating various functions on a real computer. The main task of the JVM is to interpret its own set of instructions (bytecode, such as Java source code compiled into a class file to run on a

a class variable is defined as: public static int value=123; The initial value of the variable value after the prep phase is 0 instead of 123. Since no Java methods have been executed at this time, the putstatic instruction that assigns value 123 is that the program is compiled and stored in the class constructor () method. So an action that assigns value to 123 will not be executed until the initialization stage.As for "special case" m

: (parameter list) descriptorReferencing Chang constants6. Collection of method tables　　　　Attribute table for 7.class, fields, methods, etc.There are 21 predefined, each of which has its own structure.1.Code Properties　　　　Attribute_name_index is an index that points to a Constant_utf8_info constant whose constant value is fixed as "Code", which represents the property name of the attributeAttribute_length i

I. Class File Content Note: Each Java class can only have one class file or interface. In the following discussion, U4 represents four bytes, while U2 represents two bytes. The content of the class file is as follows: Magic (magic number)-U4 (U4 indicates 4 bytes) 0 xcafebabe, which is used to easily identify Java class files and non-Java class files;

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[Chen Wenwen 5] interface, but the assignment of class variable initialization will generate the [Chen Wenwen 6] the [Chen Wenwen 7] subclass accesses static fields of parent class, does not initialize subclasses Array definition to refer to the class, not to start this class. Initializes an array class. Inherits the subclass of object. Array properties and methods. Constants are stored in a constant pool in the calling class in the

1. OverviewFor those engaged in C, C + + program development, in the memory management field, they both have the highest power of the "emperor" is also engaged in the basic work of the "working people"---have each object of "ownership", but also assume the life of each object to the end of the maintenance responsibility.But for Java programmers, with the help of the vir