jvm memory management

I stitched up a JVM memory graph from online search: as shown in:Let's consider a few questions:How does the 1.jVM work?How is the 2.JVM runtime memory allocated?3. In what area do we write Java code (classes, objects, methods, constants, variables, etc.) in the end?VM Run-t

First, the JVM memory structureThe Java Virtual opportunity divides the memory into several different management areas, each of which has its own purpose, depending on the characteristics of different tasks and the use of different algorithms in garbage collection. The whole is divided into the following sections:Progr

quarter.Usually we say that the JVM memory recycle is always referred to as heap memory recycling, indeed only the content in the heap is dynamically requested to allocate, so the young and old generations of the above objects refer to the JVM's heap space, and the persistent generation is the previously mentioned method area, which is not part of the heap.After

run, it is not responsible for it, it is responsible for the execution engine,As long as the "JVM specification" Chinese such as the definition of class file structure.2. Execution engine Execution enginesThe execution engine, also called the Interpreter (interpreter), is responsible for interpreting the command and committing the operating system execution.3. Native interface Local InterfaceThe role of the local interface is to fuse different progra

eclipse crashes, error message:MyEclipse has detected, less than 5% of the 64MB of PermGen (non-heap memory) space remains. It is strongly recommendedThat, you exit, and restart MyEclipse with the new virtual machine memoryparamters to increase this memory. Failure to does so can result indata loss. The recommended Eclipse memory parameters is:eclipse.exe-vmargs-

I. Overview Java GC (Garbage Collection, garbage collection, garbage collector) mechanism, is one of the main differences between Java and C++/C, as Java developers, generally do not need to write memory and garbage cleaning code, memory leaks and overflow problems, It doesn't need to be as jittery as a C programmer. After such a long period of development, the Java GC mechanism has been improving, almost

http://blog.csdn.net/kobejayandy/article/details/8496651 Four, Heap heap The Heap (heap) is the memory data area of the JVM. Heap's management is complex, allocating an indefinite amount of memory each time, specifically to hold an instance of the object. Allocating a certain amount of

resizing the heap after each GC. The heap memory of an object is reclaimed by an automatic memory management system that becomes the garbage collector　　　Non-heap memory allocations:①:JVM uses-xx:permsize to set the initial value of non-heap

). Wanyuanhu not live several times extortion there is no money, GC see no value, directly kill off.3, into the genured Gen(pension area) people can basically ensure the safety of the person, but the billionaire will also splurge into the poor, as long as the money is gone, GC or kill off.The purpose of the partition: the new district because the object produces more and most of it is toward the birth, so the direct use of marker-cleanup algorithm. And the old-life is very strong, the use of rep

http://backend.blog.163.com/blog/static/20229412620128233285220/Memory management and garbage collection are two of the core components of the JVM, and mastering its internal implementation is a prerequisite for Java developers to develop high-quality Java systems. Recently compiled some knowledge about JVM

Deep understanding of the memory management mechanism of JVM Notes Runtime data Region program counter JVM stack local method stack Java heap method area run frequent pool Direct Memory object access OutOfMemoryError exception Java heap overflow sample

First, the memory area of the JVM For C, C + + programmers, in the field of memory management, they both have the "ownership" of each object, and assume the responsibility of maintaining each object's life beginning to the end. For Java programmers, with the help of the virtual machine's automatic

1.JVM Memory management mechanismThe memory space is divided into: the Sun JDK complies with the JVM specification when implemented, dividing the memory space into heaps, JVM method sta

The Java virtual machine has a heap. The heap is the data area during runtime, and the memory of all class instances and arrays is allocated from this place. The heap is created when the Java Virtual Machine is started, while the JVM uses-XX: permsize to set the non-heap memory initial value. The default value is 1/64 of the physical

. The only purpose of Java heap is to store object instances. Most object instances are allocated here. This is described in vmspec: all instances and arrays are allocated on the stack (Original: the heap is the runtime data area from which memory for all classinstances and arrays is allocated ), however, after the emergence of escape analysis and scalar replacement optimization technology, the description of the VM spec is not so accurate. In the Jav

Memory Management and garbage collection are critical aspects of JVM. For Java performance analysis, it is very important to understand the basic memory management and garbage collection policies. This article describes Sun JVM 6.

The first article in this series is expected to have two or three cases at the end of this series. Java is different from C and C ++. Java does not need coder for manual memory management, and all of this is handed over to JVM for automatic memory management, to some extent,

Memory management and garbage collection are critical points for the JVM, and it is important to understand the basic strategies of memory management and garbage collection for the analysis of Java performance. This article describes the

In the JVM, memory is divided into two parts, stack (stack) and heap (heap), where we know the stack and heap from the perspective of the memory management principle of the JVM, and these principles recognize the problem of static and static properties in Java.In general, th

From the logical structure of the Java platform, we can see the JVM from the following illustration: From the above, you can see clearly the various logical modules contained in the Java platform and the difference between the JDK and the JRE. For the physical structure of the JVM itself, we can look at the following image: For the study of the JVM, it seems to