cas operation

Class inheritance Relationships:Nonfairsync = Sync = AbstractqueuedsynchronizerClass NonfairsyncFinal void Lock () {if (compareandsetstate (0, 1))Setexclusiveownerthread (Thread.CurrentThread ());ElseAcquire (1);}Analysis:Compareandsetstate (0, 1):

Reentrantreadwritelock-based AQS implementation of read-write lock synchronization:1. Using the shared mode to achieve read lock, exclusive mode to achieve write lock;2. Support for fair and non-fair, non-fair situations where a read lock blocking

Http://www.infoq.com/cn/articles/java-se-16-synchronized1 IntroductionIn multi-threaded concurrent programming, synchronized has always been an elder role, and many people will call it a heavyweight lock, but with the various optimizations that Java

Talking about high concurrency (33) Understanding Java Memory Models from a consistency (consistency) perspective we said the hardware layer provides the ability to meet certain conformance requirements, and the Java memory model uses the

http://blog.csdn.net/chen77716/article/details/6618779There are two kinds of locking mechanisms in Java: The synchronized and Lock,lock interfaces and their implementation classes are JDK5 additions, and the author is the famous concurrency expert

About this DocumentApache HBase (TM) is not an ACID compliant database. However, it does guarantee certain specific properties.This specification enumerates the ACID properties of HBase.DefinitionsFor the sake of common vocabulary, we define the

Synchronized used to lock objects and methods or blocks of code, when it locks a method or a block of code, at most one thread at a time executes the code. When two concurrent threads access the same object in the same lock synchronization code

This is just to verify the security of the Atomicinteger in a multithreaded environment.Through the source code is not difficult to find two points:1. The Value property is volatile modified2. CAs operation with unsafeThrough the above two points,

Atomicinteger Source Analysis--optimistic lock implementation based on CAS1. Pessimistic lock and optimistic lockWe all know that the CPU is time-division multiplexing, that is, the CPU is allocated to different thread/process in turn, time slices

Memcach is a powerful tool for improving the performance of web applications and Drupal applications. Recently, Memcache has been used to find many minor problems. Therefore, the author has summarized several issues for your reference.1. Differences

PHP with memcached is already a standard for including women. Again, it seems to make people feel too "?" , but there are some details not everyone is clear, such as pecl there are two memcached modules, Memcache and memcached, most of the current

Java concurrent package Lock implementation principle, java concurrent package lockIntroduction and use of Lock Lock is a thread synchronization tool introduced in java 1.5. It is mainly used to control shared resources under multiple threads.

Lockless programming and distributed programming which is more suitable for multi-core CPU? In the previous article, we analyzed the acceleration ratio of three typical lock competitions in multi-core systems. In particular, the acceleration ratio

Document directory 1. thread status and State Conversion 2. spin lock 3. Biased lock 4. Summary Currently, there are two lock mechanisms in Java: synchronized and lock. The lock interface and its implementation class are added by jdk5. the

The discussion of this issue comes from an internal discussion about the "security problem of using hashmap in multi-threaded environments". The problem of hashmap multithreading has been raised once before. See the previous blog. This

Volatile, replacing synchronization with a lower cost Why?Is volatile cheaper than synchronization?The synchronization cost is mainly determined by its coverage. If the synchronization coverage can be reduced, the program performance can be greatly

Concurrentincluqueue is a thread security implementation of queue.It is an unbounded thread security Queue Based on Link nodes. This queue sorts the elements according to the FIFO principle. The queue header is the longest element in the queue.The

[Java concurrent programming practice] -- synchronized, asynchronous ynchronized In our practical application, we may often encounter such a scenario: multiple threads read or write the same data, access the same file, and so on. If we do not

Detailed description of telnet connection to memcache server, telnetmemcache As an excellent out-of-process cache, memcache is often used in high-concurrency system architecture. Here we will talk about how to use the telnet tool to view the running

In the previous article "JVM internal details: Synchronized keywords and implementation details", we have mentioned the concept of biased locking, before understanding what is a biased lock, you must first understand what is a lightweight lock ).