java concurrency course

First, the key problem in concurrency and its solutionKey issues in Concurrency:1. How threads communicate--how information is exchanged between threads2. How threads are synchronized-control the relative execution order of threadsTwo ways to solve the problem:1. Implicit communication, display synchronization----the implicit communication between threads through a common state in shared memory, you must di

= new Reentrantlock ()//The default use of unfair locks, if you want to use a fair lock, you need to pass in the argument true ... Lock.lock (); try { //Update object status //catch exception, revert to original invariant constraint if necessary//if there is return statement, put it here } finally { lock.unlock (); The lock must be released in the finally block comparison between Reetranklock and synchronizedPerformance Comp

19) Java concurrency, 19java concurrency > Synchronized Synchronized keyword, It includes two usage methods: synchronized Method and synchronized Block. 1> synchronized Method: Declare the synchronized Method by adding the synchronized keyword to the method declaration. Public synchronized void accessVal (int newVal ); The synchronized method controls access

JAVA-1-course 1: Basic knowledge 1, java-1-CourseZookeeper This article is an important point in the summary record of personal learning. I hope it will be useful for beginners. Video 04 statements, functions, Arrays 1. Function Overloading 2. Array Memory Space Division Stack and stack Video 05 Array 1. Bubble Sorting Select sort 2. Binary, ASCII, and forc

java.util.concurrent.ExecutionException exception,This is because our submitted task java.util.concurrent.Callable allows any exception to be thrown in the call () method, and the regular thread execution may throw a runtimeexception, so it simply wraps up all the exceptions, Executionexception thrown as an exception that occurs during execution.The above is the entire anomaly system, all concurrent operation exceptions can be attributed to the above categories.In many cases processing time is

Reprint Please specify source:http://blog.csdn.net/ns_code/article/details/17511147Blocking QueuesThe blocking queue is the content in the new Java 5 concurrency feature, and the interface for the blocking queue is Java.util.concurrent.BlockingQueue, which has multiple implementation classes: Arrayblockingqueue, Delayqueue, Linkedblockingqueue, Priorityblockingqueue, Synchronousqueue, etc., the use of a sim

Unit,BlockingqueueThreadfactory Threadfactory,Rejectedexecutionhandler handler)For the thread pool, if there is always a backlog of tasks, you can increase the corepoolsize size appropriately, and if the machine load is low, you can increase the maximumpoolsize size appropriately. , reducing the KeepAliveTime time in a task queue can help reduce the load, and the length of the task queue and the task queue's deny policy also have some impact on the processing of the task.In layman's

; }} enq (node);return node; Where the queue operation is as follows/*** Inserts node into queue, initializing if necessary. See picture above.* @param node The node to insert * @return node ' s predecessor*/private node Enq (Final node node) { For (;;) {Node T =tail; if (t = = null) { //must initialize if (Compareandsethead (new Node ())) tail = head; }else {Node.prev = t; if (compareandsettail (t, node)) { T.next = node; return T; }}}} Abstractqueuedsynchronizer has two main methods: the A

Multithreaded programming also brings some security issues while improving program performance, producing unpredictable results. The reason for this is that the sequence of operations in each thread in multiple threads is unpredictable, and the resource operations shared by each thread are likely to interact with each other. For example, statistics on the number of accesses to a page, the value of an int type is accumulated, each thread accepts the user request will be added to the int type. The

the concurrent libraries and frameworks in the JAVA field that are currently quite awesome. Of course, you will also be particularly careful with the use of locks, release visibility, activity, performance, and testing. This book covers a wide range of contents, and cannot be completely digested at once. The example is representative and targeted. It is worth reading this book again when you face

threads are created in the code above, there can be only one thread executing concurrently. The semaphore method Semaphore (int permits) accepts an integer number that represents the number of licenses available. Semaphore (10) indicates that 10 threads are allowed to obtain a license, that is, the maximum number of concurrent is 10. Semaphore is also very simple to use, first the thread uses the semaphore acquire () method to obtain a license, and then call the release () method to return the

least bring up a lot of interest. The translation of this book is obscure. It is not a level problem if you try to understand it without a hard head, it is hard to imagine that it took 10 hours to complete the book again. In fact, after reading this book, you should be able to understand the concurrent libraries and frameworks in the JAVA field that are currently quite awesome. Of course, you will also be

One what is a thread A modern operating system creates a process for a program when it is running. For example, when you start a Java program, the operating system creates a Java process. Thread concept is defined on the basis of process, thread is the smallest unit that modern operating system can dispatch, it is included in the process, it is the actual operation unit of the journey. A thread refers to a

Java employment training course, read notes, Training Course The java employment training course is the first book I studied java in college and also a textbook for professional courses in college. Thanks to this experience, I ha

Java multithreading and concurrency model lock, java multithreading Model This is a long article that summarizes Java multi-threaded development. This article introduces the synchronized keyword from the beginning of Java, and discusses