rhel atomic

Nonatomic: Non-atomic access, no lock when assigning values to attributes, multi-thread concurrent access will improve performance. If this attribute is not added, both access methods are atomic transaction access by default. (Atomic is a thread protection technology used by objc. Basically, it is used to prevent reading by another thread when the write is not co

Done twiceCodeBoth Java and. Net were reviewed for about three hours. The biggest achievement is to separate the scheduling method from the atomic operation method. The scheduling method is generally a method that calls other methods to implement a function based on different situations. The scheduling method reflects the process. The atomic operation method is generally a method with a single func

This is part of the interlocked API introduced by Microsoft, but the atomic operation problem is mentioned in it. Although it should be only for Microsoft operating systems, I think all operating systems should be consistent. For a numeric operation that has the same or lower CPU bits and is aligned with bytes, the value assignment must be completed. After the assignment, the value must be assigned, after the value is obtained, it must be a value assi

1. Introduction Atom is intended to be "the smallest particle that cannot be further divided", and atomic operation is "one or more operations that cannot be interrupted ". It is a little complicated to implement atomic operations on a multi-processor. In this article, let's talk about how the Intel processor and Java implement atomic operations.2. Definition of

variable simultaneously using CAS, only one of the threads can update the value of the variable, and the other threads will fail. * However, the failed thread is not suspended, but is told to fail in this competition and can try again. * Because a thread does not block when it competes with CAS, it can decide whether to retry, or perform some recovery operations, or not take any action. */ Public classSimulatedcas {Private intvalue; Public synchronized intget () {returnvalue; } Public

Ext.: http://www.blogjava.net/xylz/archive/2010/07/01/324988.htmlStart with a relatively simple atomic (Java.util.concurrent is a queue-based contract and the queue, in many cases, uses the atomic operation, so begin here first). In many cases we just need a simple, efficient, thread-safe increment-decrement scheme. Note that there are three conditions: simple, which means that it is easier for programmers

The Java class library contains a number of useful "base module" classes. In general, we should prefer to reuse these existing classes instead of creating new ones. : Reuse can reduce development effort, develop risk (because existing classes are already tested), and maintenance costs. Sometimes, a thread-safe class can support all the operations we need, but more often, the existing class can only support most operations, and a new operation needs to be added without breaking the thread's secur

I haven't written any learning logs for a long time, and I don't know what I 've been busy with recently. I suddenly felt I should write something. The database's atomic operation was learned two or three months ago. It was suddenly used again today, so it must be recorded today, or it will be searched again next time. A common method for atomic operations is to implement data rollback. Using PHP to impleme

Import java. util. concurrent. atomic. atomicInteger; public class Counter {public static int count = 0; public static volatile int volatileCount = 0; public static AtomicInteger atomicCount = new AtomicInteger (0 ); public static byte [] lock = new byte [0]; public static int syCount = 0; public static void sleep (final int gap) {try {Thread. sleep (gap);} catch (InterruptedException e) {// TODO Auto-generated catch blocke. printStackTrace () ;}} pub

(); int next = current-1; if (Compareandset (current, next)) return next; }} public final int addandget (int. delta) {for (;;) {int current = get (); int next = current + Delta; if (Compareandset (current, next)) return next; }} public String toString () {return integer.tostring (get ()); } public int Intvalue () {return get (); } public Long Longvalue () {return (long) get (); } public float Floatvalue () {return (float) get (); } p

CAS operations can be divided into the following three steps: Step 1. Read the old value (that is, the value of the variable to be read from system memory, for example: reading the value of the variable i) Step 2. Novelty value (that is, the value read from memory operation, but the operation does not modify the value of the variable in memory, such as: i=i+1, this step is only i+1, no assignment, do not modify the memory i) Step 3. Two indivisible atomic