原子操作是线性安全的,比如int i =1;
而i++不是,因为会有取i,+1,再赋值给i,可能会发生线程中的同步异步问题
所以提供了一个包,里面使得自增自减这些操作是安全得
package
multiplethread;
import
java.util.concurrent.atomic.AtomicInteger;
public
class
TestThread {
public
static
void
main(String[] args)
throws
InterruptedException {
AtomicInteger atomicI =
new
AtomicInteger();
int
i = atomicI.decrementAndGet();
int
j = atomicI.incrementAndGet();
int
k = atomicI.addAndGet(
3
);
}
}
—————————————————————————————————————————————————————————
Thread[] ts2 = new Thread[number];
for (int i = 0; i < number; i++) {
Thread t =new Thread(){
public void run(){
atomicValue.incrementAndGet();
}
};
t.start();
ts2[i] = t;
}
//等待这些线程全部结束
for (Thread t : ts2) {
try {
t.join();//用join(),来让这些线程全部结束
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
System.out.printf("%d个线程进行atomicValue.incrementAndGet();后,atomicValue的值变成:%d%n", number,atomicValue.intValue());
}
}