在实现java编程思想的小例子的时候发现运行结果不一样,书上的结果是先执行完优先级最高的才执行优先级低的,但是我的却没有先把优先级最高的线程执行完
代码如下:
package concurrency;
import java.util.concurrent.*;
public class SimplePriorities implements Runnable{
private int countDown = 5;
private int priority;
@SuppressWarnings("unused")
private volatile double d;
public SimplePriorities(int priority) {
this.priority = priority;
}
public String toString(){
return Thread.currentThread() + ": " + countDown;
}
@Override
public void run(){
Thread.currentThread().setPriority(priority);
while(true){
for(int i = 1; i < 100000; i++){
d += (Math.PI + Math.E) / (double)i;
if(i % 1000 == 0)
Thread.yield();
}
System.out.println(this);
if(--countDown == 0)
return;
}
}
public static void main(String[] args) {
ExecutorService exec = Executors.newCachedThreadPool();
for (int i = 0; i < 5; i++) {
exec.execute(new SimplePriorities(Thread.MIN_PRIORITY));
}
exec.execute(new SimplePriorities(Thread.MAX_PRIORITY));
exec.shutdown();
}
}
运行结果如下
Thread[pool-1-thread-6,10,main]: 5
Thread[pool-1-thread-6,10,main]: 4
Thread[pool-1-thread-4,1,main]: 5
Thread[pool-1-thread-3,1,main]: 5
Thread[pool-1-thread-1,1,main]: 5
Thread[pool-1-thread-2,1,main]: 5
Thread[pool-1-thread-6,10,main]: 3
Thread[pool-1-thread-5,1,main]: 5
Thread[pool-1-thread-6,10,main]: 2
Thread[pool-1-thread-6,10,main]: 1
Thread[pool-1-thread-4,1,main]: 4
Thread[pool-1-thread-1,1,main]: 4
Thread[pool-1-thread-3,1,main]: 4
Thread[pool-1-thread-2,1,main]: 4
Thread[pool-1-thread-5,1,main]: 4
Thread[pool-1-thread-4,1,main]: 3
Thread[pool-1-thread-2,1,main]: 3
Thread[pool-1-thread-1,1,main]: 3
Thread[pool-1-thread-3,1,main]: 3
Thread[pool-1-thread-5,1,main]: 3
Thread[pool-1-thread-3,1,main]: 2
Thread[pool-1-thread-2,1,main]: 2
Thread[pool-1-thread-4,1,main]: 2
Thread[pool-1-thread-1,1,main]: 2
Thread[pool-1-thread-5,1,main]: 2
Thread[pool-1-thread-3,1,main]: 1
Thread[pool-1-thread-4,1,main]: 1
Thread[pool-1-thread-2,1,main]: 1
Thread[pool-1-thread-1,1,main]: 1
Thread[pool-1-thread-5,1,main]: 1
求大神赐教!