Atomicinteger Variable Learning

This is a example of how to use the AtomicInteger class of Java. Thejava.util.concurrent.atomic package provides very useful classes the support Lock-free and Thread-safe programming on Single variables. Among them, the AtomicInteger class is a wrapper class for a int value of allows it to be updated atomically. The class provides useful methods, some of which would be shown in the code snippet below.

The most common use of the was to AtomicInteger handle a counter that's accessed by different threads simultaneously. In order to see how the this works, we'll create and run both, each one Threads of which would access and update an AtomicInteger VARIAB Le, using its API methods. The basic methods used in the example is described in short:

Understanding: The most common usage of atomicinteger is as a counter between multiple threads.

• incrementAndGet()with API method, the value was incremented and its new value is returned.
• getAndIncrement()with API method, the value of is incremented, but it previous value is returned.
• addAndGet(int delta)with API method, the was delta added to the value and the new value are returned, whereas there is also a getAndAdd(int delta) method That's adds delta the value, but returns the previous value.
• With compareAndSet(int expect, int update) API method, the value was compared to expect the Param, and if they was equal, then the value was set update to the Param and is true returned.
• You can get the the, int long , float or value of the double AtomicInteger variable, using intValue() , longValue() , and floatValue() doubleValue() methods re Spectivelly.

 PackageCom.javacodegeeks.snippets.core;ImportJava.util.concurrent.atomic.AtomicInteger; Public classAtomicintegerexample {Private StaticAtomicinteger at =NewAtomicinteger (0); Static classMyrunnableImplementsRunnable {Private intMyCounter; Private intMyprevcounter; Private intmycounterplusfive; Private BooleanIsnine;  Public voidrun () {MyCounter=At.incrementandget (); System.out.println ("Thread" + thread.currentthread (). GetId () + "/Counter:" +myCounter); Myprevcounter=at.getandincrement (); System.out.println ("Thread" + thread.currentthread (). GetId () + "/Previous:" +myprevcounter); Mycounterplusfive= At.addandget (5); System.out.println ("Thread" + thread.currentthread (). GetId () + "/Plus Five:" +mycounterplusfive); Isnine= At.compareandset (9, 3); if(isnine) {System.out.println ("Thread" +Thread.CurrentThread (). GetId ()+ "/Value is equal to 9, so it is updated to" +At.intvalue ()); }        }    }     Public Static voidMain (string[] args) {Thread T1=NewThread (Newmyrunnable ()); Thread T2=NewThread (Newmyrunnable ());        T1.start ();    T2.start (); }}

If You run the example, you'll see that both threads can update the AtomicInteger variable atomically.

Thread 9  /counter:1  /counter:29/previous:29/plus five:9 9/val UE is equal to 9, so it is updated to 310/previous:310/plus five:8

Atomicinteger Variable Learning