cas operation

Data synchronization need to rely on the lock, the synchronization of the lock who depends on? The answer given by synchronized is that it relies on the JVM at the software level, and lock gives the option to rely on special CPU instructions at the

Before you learn about lightweight locks, you first need to know what a CAsCas--compare and swap compare and swap--determine if the data is being updated by comparing the values in the old values passed in with the value in the original memory

In Java, there are four ways to synchronize mutually exclusive access: The synchronized, Lock, wait ()/notify ()/Notifyall () method, and the CAS (Hardware CPU synchronization primitive).First, synchronized1. Synchronizing code blocks1 synchronized (

Learn a little bit of programming every day PDF ebook, video tutorial free download:Http://www.shitanlife.com/codeThis is the second chapter of multithreading.Multithreading is like Kong Cong to the star-sucking Dafa, understanding the use of good

One: Java basics1. Briefly describe the string object, StringBuffer, StringBuilder distinguishThe string is final, storing the data internally with a final type of char array, which is less efficient to splice, actually by creating a stringbuffer,

In server development, in order to make full use of multicore or even multiple CPUs, or to simplify the difficulty of writing logic, multi-processes (such as a process responsible for a logical) multithreading (assigning different users to different

Reference

Reference Links:http://blog.csdn.net/liu88010988/article/details/50799978The Java.util.concurrent package is built entirely on CAS, and there is no CAs to have this package. The importance of CAs is visible.CasCas:compare and swap, translated into

Synchronized the principle of ensuring thread safety First, the theoretical level Synchronized can ensure that the method or code is running at the same time only one method can enter the critical section, while it can also guarantee the memory

In modern operating systems, atomic operations are generally provided to achieve some synchronous operations, the so-called atomic operation, which is an independent and indivisible operation. In a single-core environment, the normal meaning of the

The concept of thread safety is limited to the premise that shared data access exists between multiple threads, because if a piece of code does not share data with other threads at all, then from a thread-safe point of view, whether the program is

Recently looking at Java and contracted the source code, found the magic of unsafe class, carefully studied, here to share with you.The unsafe class is under the Sun.misc package and is not part of the Java standard. However, many basic Java

One: What is the type of lock for Java synchronization?---> There are two kinds of locking mechanisms in Java: Synchonized and lockThe--->lock interface and its implementation class are JDK5 additions, the author of which is the famous concurrency

Talking about the problem and avoidance of ABA in Java, and talking about avoiding Java ABA This article mainly studies the ABA problem in Java and the related content to avoid, specifically as follows. In Chapter 15th of Java concurrency practice,

Java lock and object header, java object I. Object Header In a hot spot virtual machine, the layout of objects stored in memory can be divided into three areas: object Header, Instance Data, and Padding ). The Object Header of the HotSpot Virtual

Read a bunch of articles, and finally the principle of Java CAs in-depth analysis clearly.Thanks to Google's powerful search, take this sarcasm Baidu, rely on Baidu what all learn!Reference Documentation:Http://www.blogjava.net/xylz/archive/2010/07/0

JAVA concurrent programming J. U. C learning summary, java concurrent programming j. u. cPreface After learning J. U. C for a while, I plan to make a summary. I personally feel that the summary is very important. Otherwise, I always feel that the

Turn from: http://blog.csdn.net/chen77716/article/details/6618779, and add a small amount of your own understandingThere are two kinds of locking mechanisms in Java: The synchronized and Lock,lock interfaces and their implementation classes are JDK5

Cocurrenthashmap effectHashtable by locking the whole table to achieve concurrent hash lookup and storage, COCURRENTHASHMAPT through segment way can achieve the same function, but more efficient, At the time of jdk1.6, Cocuenthashmap had a weak

Original address: http://coderbee.net/index.php/open-source/20130812/400What is Disruptor?Disruptor is a high-performance asynchronous processing framework that can also be thought of as a message framework that implements the observer