我的代码基本上是这样的：
//in Main Thread: (myList is a volatile field)
myList = new ArrayList<myClass>();
Thread myThread = new Thread(new MyCustomRunnable(myList));
myThread.start();
//some lines of code NOT involving myList
myThread.join();
//myList appears empty here even though I can see that the list has been populated
//in the other thread
有这种现象的原因吗？就像我说的那样，我可以在调试器中看到已在被调用线程中填充了列表，但是这些更改未在join（）方法之后的调用者线程中出现。MyCustomRunnable也将ArrayList声明为由构造函数分配的易失字段。
更新：好的，我做了一个简单的程序，用一个简单的Integer替换了ArrayList，结果是一样的...
public class Threading {
private volatile static Integer i = 0;
public static void main(String[] args) throws InterruptedException {
Thread t = new Thread(new MyCustomRunnable(i));
t.start();
t.join();
System.out.println(i); //prints '0', I expected '1'
}
}
public class MyCustomRunnable implements Runnable {
private volatile Integer i;
public MyCustomRunnable(Integer i) {
this.i = i;
}
public void run() {
this.i = 1;
}
}
为什么在主线程中不更新Integer的值？
添加
public static void setI(int i) {
Threading.i = i;
}
到您的Threading类并在您的runnable中添加
public void run() {
this.i = 1;
Threading.setI(1);
}
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