jvm architecture

under the JDK installation directory to store JRE files. JVM (JavaVirtualMachine, Java Virtual Machine) is part of JRE. It is a fictitious computer that simulates various computer functions on an actual computer. JVM has its own complete hardware architecture, such as processor, stack, and register, as well as corresponding command systems. The most important fe

Memory Allocation for various data types in jvm, and jvm allocation for Data TypesJvm runtime data zone: the memory managed by JVM is divided into the following runtime data zones: Program counters, Java Virtual Machine stacks, local method stacks, Java stacks, and method zones. This article mainly involves: java Virtual Machine station (java stack for short), ja

JVM-1. Compilation, jvm-1 CompilationDirectory 1. compiler Overview 2. compiler Composition 3. Example 4. a deep understanding of the JVM compiler 5. Syntax sugar 6. Supplement 1. compiler Overview 1. The essence of the compiler is the specification is transformed into another specification; it is easy for humans to understand machines. Javac converts the source

[In-depth research on Java] 2. JVM class loading mechanism, in-depth research on jvm 1. First, let's take a look at the Code Execution Process: Ii. significance of research on class loading mechanism It can be seen that class loading is the first step in Java program execution. Studying class loading helps you understand the JVM Execution Process and guides dev

Jvm intermittent crash analysis, jvm intermittent crashHttp://www.cnblogs.com/LBSer/p/4417148.html1 Problem Description A service has two machines, and the alarm load is high every few days. At the beginning, the monitoring system found that the gc Time Jitter was very high, so it was thought that fullgc caused choppy and did not pay attention to it, then, log on to the online machine and check the log. It

What are the common garbage collectors in Java?In fact, the garbage collector (Gc,garbage Collector) is closely related to the specific JVM implementations, and different vendors (IBM, Oracle), different versions of the JVM, offer different choices. Next, I'll talk about the most mainstream Oracle JDK. Serial GC It is the oldest garbage collector, "Serial" embodied in its collection work is si

Try to talk about static methods and static properties from the point of view of the JVM's memory management principles, please correct me where it is wrong. (joezheng123.javaeye.com/blog/264695)The JVM's memory is divided into two parts: Stack and heap:Stack (stack) is the memory instruction area of the JVM. Stack management is simple, push a certain length byte of data or instruction, stack pointer stack corresponding byte displacement; pop a certai

Jvm learning notes 1 (garbage collection algorithm) and jvm learning notes I. Reasons for the garbage collection mechanism In java, when no object reference points to the memory originally allocated to an object, the memory becomes garbage. A jvm system-level thread Automatically releases the memory block. Garbage collection means that the object no longer needed

Memory, as an important resource in the system, plays a key role in the stable operation and efficient operation of the system, unlike languages like Java and C, which do not require the developer to allocate memory and reclaim memory, but rather the JVM manages the allocation of object memory and the collection of object memory (also known as garbage Collection, GC). This greatly reduces the difficulty of writing the program for developers, but one s

When we found in the IDE console:The value of the persistent generation set for the JVM is too small, you need to open the window->preferences->java->installed JRE in Eclispe, click the Edit button on the right, and the default VM Arguments option, increase the value of-xx:permsize and-xx:maxpermsize.If you understand JVM performance tuning, you can learn about the relationship from Jstat monitoring. The fo

Last written 1. A preliminary understanding of the JVM-the JVM sequence, followed today to write the JVM's operating mechanism.First, the JVM startup processThe Java platform includes the JVM and the Java language, where the JVM is also an application process running in the

JVM garbage collection and jvm garbage collection JVM garbage collection This article attempts to briefly introduce the mainstream JVM garbage collection mechanism. Scope of a garbage collection Discussion JVM memory is divided into several parts: Method Area,

Talking about JVM and memory allocation, talking about JVM Memory Allocation 1. program memory allocation Initial Memory Allocation When a program is ready to run, it first needs memory from the Java virtual machine, but the Java Virtual Machine itself does not have the permission. It can only apply for memory from the operating system. At this time, the Java Virtual Machine will have an initial memory, He

Java.lang.OutOfMemoryError:PermGen Space Found that many people attribute the problem to: Spring,hibernate,tomcat, because they generate classes dynamically, causing permanent heap overflow in the JVM. Then there is a divergence of opinions about how to upgrade the Tomcat version to the latest or even simply without Tomcat. There are also questions about spring that are hotly discussed at the Spring Forum, because spring's use of cblib in AOP creates

JVM Automatic Memory Management-Java memory area and memory overflow exceptions, jvm-java Abstract: JVM memory division, which may cause memory overflow exceptions. 1. JVMRuntime memory Zone The JVM divides the memory managed by the Java program into the following areas: 1.1Program counters The program counter is a sm

Chapter 8 JVM performance monitoring and troubleshooting tools (2), jvm troubleshooting Note: This blog is mainly recorded in "deep understanding of Java Virtual Machine (version 2)" Note: For details about JVM performance monitoring and troubleshooting tools on the command line, see Chapter 7 JVM performance monitorin

The implementation of bytecode commands in jvm is important, and the implementation of bytecode in jvm is important. Java is interpreted and executed, including the dynamic link feature, which provides a lot of space for flexible expansion during parsing or running. How to compile and parse the inheritance, encapsulation, and polymorphism features of object-oriented languages in

Chapter 4 JVM garbage collection algorithm and Chapter 4 jvm garbage collection Note: Before reading this article, you need to know how to determine whether the object is alive or not. For details, see Chapter 3 JVM memory recycle area + object survival judgment + reference type + garbage collection thread. Note: This article mainly refers to the distributed Java

Chapter 9 JVM tuning recommendations and chapter 9 JVM tuning recommendations Note: This article mainly references distributed Java applications: basics and practices 1. JVM optimization is mainly about memory optimization, mainly in two aspects: Size of each generation Garbage Collector Selection 2. Size of each generation Common Adjustment Parameters

Solve JVM memory overflow and jvm memory overflow Today I encountered a problem. When I restarted Tomcat 6 when adding the configuration file (*. xml) content, the console reported the error: java. lang. StackOverflowError; That is, stack overflow error. Memory overflow occurs when the memory used by the program is larger than the maximum memory provided by the virtual machine. Memory overflow depends on