Java 在线程对象上调用start时,线程上设置的优先级无效
我执行了以下代码:Java 在线程对象上调用start时,线程上设置的优先级无效,java,multithreading,Java,Multithreading,我执行了以下代码: public class TestMain extends Thread{ public static Runnable getRunnableObject(){ Runnable r = new Runnable(){ @Override public void run() { System.out.println("inside runnable");
public class TestMain extends Thread{
public static Runnable getRunnableObject(){
Runnable r = new Runnable(){
@Override
public void run() {
System.out.println("inside runnable");
}
};
return r;
}
public static void main(String args[]){
Thread t2 = new Thread(getRunnableObject());
// t2.start();
System.out.println("name "+t2.getName()+" id "+t2.getPriority()+" class "+t2.getClass()
+" priortity "+t2.getPriority()+" state "+t2.getState()+" alive/dead "+t2.isAlive());
System.out.println("runtime"+Runtime.getRuntime().availableProcessors());
t2.setPriority(MAX_PRIORITY);
System.out.println(t2.getPriority());
t2.setPriority(MIN_PRIORITY);
System.out.println(t2.getPriority());
t2.setPriority(NORM_PRIORITY);
System.out.println(t2.getPriority());
}
}
输出:
name Thread-0 id 5 class class java.lang.Thread priortity 5 state NEW alive/dead false
runtime4
10
1
5
现在我再次运行它,取消第22行的代码注释
产出2:
inside runnable
name Thread-0 id 5 class class java.lang.Thread priortity 5 state RUNNABLE alive/dead true
runtime4
5
5
5
当我在线程上调用start()时,您能告诉我为什么设置优先级不起作用吗?这是一个争用条件
当您试图设置t2
的优先级时,它已经死了。
如果将Runnable
更改为阻塞一段时间,如下所示:
Runnable r = new Runnable() {
@Override
public void run() {
System.out.println("inside runnable");
try {
Thread.sleep(100000);
} catch (InterruptedException e) {
//
}
}
}
然后你会得到10,1,5的相同序列。Ah。。我明白了。我还尝试在设置优先级和状态被打印为“新”之间打印状态。