mastering concurrency programming with java 8

-load-use and assign-store-write became two indivisible atomic operations.Although there is still a vacuum between use and assign, it is possible that the variables will be read by other threads, but the values of the main memory variables and any working memory variables are equal at any point in time. This feature causes the volatile variable to be unsuitable for operations that depend on the current value, such as self-increment.So depending on the visibility of the characteristics of volatil

: Public class insertdata { privatenew Object (); Public void Insert (thread thread) { synchronized (object) { } } publicsynchronizedvoid insert1 (thread thread) { } public void insert2 (thread thread) { }}The bytecode obtained from the anti-compilation can be seen, synchronized code block actually more than the Monitorenter and monitorexit two instructions. When the monitorenter instruction executes, the lock

mode) to get a good resultII. When the state is increased from one to multiple states, and the variables are not independent of each other, have a certain connection, and access to a resource at the same time, do not use the atomic class, the concept of locking2.Java High concurrency Programming: (Just simple knowledge of understanding, jdk1.5 new version of ato

Java concurrency programming: blocking queuesIn the previous articles, we discussed the synchronization container (Hashtable, Vector), and also discussed the concurrent containers (Concurrenthashmap, copyonwritearraylist), which are very convenient for us to write multi-threaded program. Today we are going to discuss another class of containers: blocking queues.I

In "Java Concurrency Programming Combat"-"J.U.C": CLH queue lock mentioned, Aqs inside the CLH queue is a transformation of CLH synchronization lock. It is mainly reformed from two aspects: the structure of node and the mechanism of node waiting. In the structure, the head node and the tail node are introduced, they point to the head and tail of the queue respect

In "Java Concurrency Programming Combat"-"J.U.C": CLH queue lock mentioned, Aqs inside the CLH queue is a transformation of CLH synchronization lock.It is mainly reformed from two aspects: node structure and node waiting mechanism. In the structure, the head and tail nodes are introduced, respectively, they point to the head and tail of the queue, and the attempt

Java Concurrency Programming: Timer and TimerTask (reprint)The following content is reproduced from:http://blog.csdn.net/xieyuooo/article/details/8607220In fact, the timer is a scheduler, and TimerTask is just a implementation of the run method of a class, and the specific timertask need to be implemented by yourself, such as:Timer timer = new timer (); Timer.sch

first attempt to obtain the object's lock, if the lock is obtained, the lock counter is added 1, corresponding to the execution of the monitorexit instruction will reduce the lock counter 1, when the counter is 0 o'clock, the lock is released. Since the synchronized synchronization block is reentrant to the same thread, one thread can obtain the mutex of the same object multiple times, and the same, the corresponding number of times the mutex must be released in order to finally release the loc

other or modifying the container's threads to interfere with each other.Obviously, the underlying array is copied whenever the container is modified, which requires some overhead, especially if the container is large in size. The "Copy on write" container should be used only when the operation is far more than the modification operation. This guideline is a good description of many event notification systems:When you distribute notifications, you need to iterate through the registered listener

(); this.barrier = Barrier;this.name = name;} @Overridepublic void Run () {try {thread.sleep (New Random ()). Nextint (8)); SYSTEM.OUT.PRINTLN (name + "Ready ...");//The await method of barrier will wait until all participants have already raised the await method in this barrier. Barrier.await ();} catch (Interruptedexception e) {e.printstacktrace ();} CAtch (brokenbarrierexception e) {e.printstacktrace ();} SYSTEM.OUT.PRINTLN (name + "Starting!") ")

Synchronized is a keyword in Java that is called a built-in lock or monitor lock in concurrent programming. When you use it to decorate a method or a block of code, you can guarantee that at most one thread at a time executes the code.Java's built-in lock is equivalent to a mutex, where at most one thread can hold such a lock, the synchronous block of code protected by the lock is atomically executed, and m

Synchronized is a keyword in Java that is called a built-in lock or monitor lock in concurrent programming. When you use it to decorate a method or a block of code, you can guarantee that at most one thread at a time executes the code.Java's built-in lock is equivalent to a mutex, where at most one thread can hold such a lock, the synchronous block of code protected by the lock is atomically executed, and m

if(c = = 0) at return false; - intNEXTC = c-1; - if(Compareandsetstate (c, NEXTC)) - returnNEXTC = = 0; - } - } in}As can be seen from the sync source, Countdownlatch is based on the Aqs shared access and Release synchronization state mechanism implementation.Await ()1 // call Aqs to provide a shared-interrupt get synchronization state method. 2// If successful (state=0), continue execution of subsequent code; othe

threads in the thread pool is greater than corepoolsize, until the number of threads in the thread pool is not greater than corepoolsize, that is, when the number of threads in the thread pool is greater than corepoolsize. If a thread is idle for KeepAliveTime, it terminates until the number of threads in the thread pool does not exceed corepoolsize. However, if the Allowcorethreadtimeout (Boolean) method is called and the number of threads in the thread pool is not greater than corepoolsize, t

Understanding of the volatile keyword for Java concurrency programmingEach thread in Java has its own working memory, analogous to the Processor's cache, where the Thread's working memory holds a copy of the main memory of the variable used by that Thread. Thread read and write variables are directly in their own working memory, and when to refresh the data (refe

Ownership of the stateThe object encapsulates its state, owning the state ownership, which is the ability to change the state, and if the object's reference is published, it is not the ownership of the object's exclusive state, but the ownership of the shared state with the other;2. Instance closure　　Object A is enclosed in another object B, and the path to access object A is known to facilitate thread safety, and if the data is enclosed in an object, access to the data is done through methods,

Http://www.importnew.com/18126.htmlHttp://www.importnew.com/20566.htmlHttp://www.importnew.com/19745.html Original address: Java concurrency programming: voldatile keyword parsing Volatile this keyword may have been heard by many friends, and may have been used. Before Java 5, it was a controversial keywo

not depend on it. As a simple example: if you create a daemon thread in the main thread, when the main method finishes running, the daemon thread will die as well. The user thread does not, and the user thread runs until it finishes running. In the JVM, a garbage collector thread is the daemon thread.The thread class has a more commonly used static method, CurrentThread (), to get the current thread.The most of the methods in the thread class have been mentioned above, so how does a method call

method is also an obsolete method. Basic will not be used.Here are a few ways to relate to thread properties:1) getIdUsed to get the thread ID2) GetName and SetNameUsed to get or set the thread name.3) GetPriority and SetPriorityUsed to get and set thread priority.4) Setdaemon and IsdaemonUsed to set whether the thread is a daemon thread and whether the thread is a daemon thread.The difference between a daemon thread and a user thread is that the daemon relies on the thread that created it, and

mutable objects, you need to use synchronization not only when you publish an object, but also with synchronization every time you access the object to ensure the visibility of subsequent modifications. To safely share mutable objects, these objects must be securely published and must be thread-safe or protected by a lock.The publication requirements of an object depend on its variability: Immutable objects can be published by any mechanism. Fact immutable must be published in a se