[Java 09 多线程] 线程是指一个进程在执行过程中可以产生更小的程序单元

p9 第九章 多线程
  进程是程序的一次性动态执行过程，它需要经历从代码加载，代码执行，到执行完毕的一个完整过程，这个过程也是进程本身从产生，发展到最终消亡的过程。多进程操作系统能同时运行多个进程（程序）。
  多线程是实现并发机制的一种有效手段。进程和线程一样，都是实现并发的一个基本单位。线程是比进程更小的执行单位，线程是在进程的基础上进行的进一步划分。所谓多线程是指一个进程在执行过程中可以产生更小的程序单元，这些更小的单元称为线程，这些线程同时存在，同时运行，一个进程可能包含了多个同时执行的线程。
  Java 中线程的实现
   一，继承 Thread 类
   二，Runnable 接口
   
   public class Thread extends Object implements Runnable
 (1), 线程的中断，合并，后台线程， 线程的休眠， 线程的优先级， 线程的礼让
 (2), 线程的同步 与 死锁
 (3), Object 类对线程的支持 -- 等待与唤醒
 (4), 线程的生命周期
 总结 ： Thread / Runnable  run() 方法

        在每一个线程创建和消亡之前，均会处于创建，就绪，运行，阻塞，终止 状态之一

TestThread1 入门

package com.qunar.basicJava.javase.p9thread;/** * Author: [e-mail]  Date: 14-5-20 14:17 */public class TestThread1 {    public static void main(String args[]) {        Runner1 r = new Runner1();        r.start();        // r.run();        // Thread t = new Thread(r);        // t.start();        for (int i = 0; i < 100; i++) {            System.out.println("Main Thread:------" + i);        }    }}// class Runner1 implements Runnable {class Runner1 extends Thread {    public void run() {        for (int i = 0; i < 100; i++) {            System.out.println("Runner1 :" + i);        }    }}// 马老师心得 ： 能使用接口，就尽量使用接口，别从　Thread 继承，因为缺少灵活性。

TestInterrupt 线程的中断

package com.qunar.basicJava.javase.p9thread;/** * Author: [e-mail]  Date: 14-5-20 14:19 */import java.util.*;public class TestInterrupt {    public static void main(String[] args) {        MyThread thread = new MyThread();        thread.start();        try {            Thread.sleep(10000);        } catch (InterruptedException e) {        }        thread.interrupt();    }}class MyThread extends Thread {    boolean flag = true;    public void run() {        while (flag) {            System.out.println("===" + new Date() + "===");            try {                sleep(1000);            } catch (InterruptedException e) {                return;            }        }    }}

TestJoin  线程的合并

package com.qunar.basicJava.javase.p9thread;/** * Author: [e-mail]  Date: 14-5-20 14:22 */public class TestJoin {    public static void main(String[] args) {        MyThread2 t1 = new MyThread2("abcde");        t1.start();        try {            t1.join();         // 合并线程，等待该线程结束，再恢复当前线程的执行        } catch (InterruptedException e) {        }        for (int i = 1; i <= 10; i++) {            System.out.println("i am main thread");        }    }}class MyThread2 extends Thread {    MyThread2(String s) {        super(s);    }    public void run() {        for (int i = 1; i <= 10; i++) {            System.out.println("i am " + this.getName());  // 线程名字            try {                sleep(1000);            } catch (InterruptedException e) {                return;            }        }    }}

TestYield 线程的礼让

package com.qunar.basicJava.javase.p9thread;/** * Author: [e-mail]  Date: 14-5-20 14:27 */public class TestYield {    public static void main(String[] args) {        MyThread3 t1 = new MyThread3("t1");        MyThread3 t2 = new MyThread3("t2");        t1.start();        t2.start();    }}class MyThread3 extends Thread {    MyThread3(String s) {        super(s);    }    public void run() {        for (int i = 1; i <= 30; i++) {            System.out.println(getName() + ": " + i);            if (i % 10 == 0) {                yield();     // 让出 CPU， 让当前线程进入队列等待            }        }    }}

TestSync 线程的同步

package com.qunar.basicJava.javase.p9thread;/** * Author: [e-mail]  Date: 14-5-20 14:40 */public class TestSync implements Runnable {    Timer timer = new Timer();    public static void main(String[] args) {        TestSync test = new TestSync();        Thread t1 = new Thread(test);        Thread t2 = new Thread(test);        t1.setName("t1");        t2.setName("t2");        t1.start();        t2.start();    }    public void run() {        timer.add(Thread.currentThread().getName());    }}class Timer {    private static int num = 0;    public synchronized void add(String name) { // 锁定当前对象资源        // synchronized (this) {        num++;        try {            Thread.sleep(1);        } catch (InterruptedException e) {        }        System.out.println(name + ", 你是第" + num + "个使用timer的线程");        // }    }}

Thread-05- 线程同步-生产者与消费者的经典问题

package com.bjsxt.chap9Thread;public class ProducerConsumer {    public static void main(String[] args) {        SyncStack ss = new SyncStack();        Producer p = new Producer(ss);        Consumer c = new Consumer(ss);        new Thread(p).start();        //new Thread(p).start();        //new Thread(p).start();        new Thread(c).start();    }}class WoTou {    int id;    WoTou(int id) {        this.id = id;    }    public String toString() {        return "WoTou : " + id;    }}class SyncStack {    int index = 0;    WoTou[] arrWT = new WoTou[6];    public synchronized void push(WoTou wt) {        while (index == arrWT.length) {            try {                this.wait();            } catch (InterruptedException e) {                e.printStackTrace();            }        }        this.notifyAll();        arrWT[index] = wt;        index++;    }    public synchronized WoTou pop() {        while (index == 0) {            try {                this.wait();            } catch (InterruptedException e) {                e.printStackTrace();            }        }        this.notifyAll();        index--;        return arrWT[index];    }}class Producer implements Runnable {    SyncStack ss = null;    Producer(SyncStack ss) {        this.ss = ss;    }    public void run() {        for (int i = 0; i < 20; i++) {            WoTou wt = new WoTou(i);            ss.push(wt);            System.out.println("生产了：" + wt);            try {                Thread.sleep((int) (Math.random() * 200));            } catch (InterruptedException e) {                e.printStackTrace();            }        }    }}class Consumer implements Runnable {    SyncStack ss = null;    Consumer(SyncStack ss) {        this.ss = ss;    }    public void run() {        for (int i = 0; i < 20; i++) {            WoTou wt = ss.pop();            System.out.println("消费了: " + wt);            try {                Thread.sleep((int) (Math.random() * 1000));            } catch (InterruptedException e) {                e.printStackTrace();            }        }    }}