【实践 -- 线程 VS 进程】 【多线程 扩展了 多进程的 概念 - 3级！！有图！ - OS -- Process -- Thread】【线程 -- 轻量级进程】【主进程 -- 主线程】

总结：
1、进程：进程是系统（进程的上一级抽象资源）的独立单元，拥有自己独立的地址空间（memory资源？？cpu时间片资源靠OS分配）。进程是动态的（运行中的，运行必然包含时间）程序。

四、 demo，注意共享的 int i

package ch16.mutli.thread;

public class FirstThread extends Thread{

    
    private volatile static int i;
    @Override
    public void run(){
//        setName("songxiaohu");
        for( ; i < 100; i++){
            System.out.println(getName() + " " + i);
        }
    }
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        for (; i < 100; i++) {
//            for (int i = 0; i < 100; i++) {
            System.out.println(Thread.currentThread().getName() + " " + i);
            if (i==20) {
                new FirstThread().start();
                new FirstThread().start();
            }
            
        }
    }

}

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