How does JDK 5.0 works

Hi all,

I work with with a project that using JDK 4.0, when i will run the application on some browser i feel some trouble. It is not compatible with windows 7. then i will merge my apps to JDK 5.0. But i want to know more about JDK 5.0. How does it works at all. please share some experience. Thanks.

JDK 5.0 for developers to develop high-performance concurrent applications that provides some very effective new choice. For example, Java.util.concurrent.lock the class ReentrantLock be synchronized as the Java language features alternative, it has the same memory semantics, the same lock, but in race conditions, there is better performance, in addition, it is There are other features not provided by synchronized. Does this mean we should forget about synchronized, instead ReentrantLock only do?. check and reply.

JDK 5 have more feature. Multi-threading, and concurrency is not new content, but the Java language design, one of the innovations is that it is the first one directly to the cross-platform threading model and formal memory model into the language of the mainstream language. Core library contains a Thread class, you can use it to build, launch and manipulate threads, Java language, including an inter-thread communication concurrency constraint structure - synchronized and volatile. In the simplification and platform-independent development of concurrent classes at the same time, it is by no means to make the preparation of concurrency classes have become more complicated, but make it easier. Best of luck.

It have new class called java.util.concurrent.lock The Lock framework is locked in an abstract, which allows the realization of the lock as a Java class, rather than as a language feature to implement. This provides a variety of implementation Lock left room for a variety of implementation may have different scheduling algorithms, performance characteristics, or lock semantics. ReentrantLock class implements the Lock, it has the same concurrency and synchronized and memory semantics, but it added a similar lock to vote, timing lock waiting and interruption of lock waiting for some of the features. Check and reply.

JDK 5.0 also provides a context in fierce contention for better performance. In other words, when many threads want to access shared resources, JVM can spend less time to schedule the threads, the more time spent on implementation of the thread.It has a lock associated with access to counters, if you have a thread once again lock the lock, then get a counter on the increase, and then the lock needs to be released twice to get a real release. Best of luck.

You need to check the JDK 5.0 synchronized feature that a code block is declared synchronized, there are two important consequences, usually refers to the code has the atomic (atomicity) and visibility (visibility). Atomic means that a thread can only monitor the implementation by a designated object (lock) to protect the code, in order to prevent multiple threads updating the shared state conflict. Visibility is more subtle; it to deal with memory cache, and compiler optimization of a variety of abnormal behaviors. Best of luck.