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?????????

???????

???????????????????????Thread??start()???????????????????????Thread??stop()?????????????JDK1.2?????stop()?destroy()?suspend()?resume()????????????????????????????????????????

????????????????????????????????????????????

public class MyThread {
    public static boolean flag = true;
    public static void main(String[] args) throws InterruptedException {
        new Thread(() -> {
            int num = 0;
            while (flag) {
                try {
                    Thread.sleep(20);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                System.out.println(Thread.currentThread().getName() + ", num=" + (num++));
            }
        }).start();
        Thread.sleep(200);
        flag = false; // ????
    }
}

???????flag??????????????flag???false????????????????????????????????????????

??????

????????????????????????????????????????????????????????????????????????

Thread????setDaemon()?isDaemon()????????????????

public class MyThread {
    public static void main(String[] args) throws InterruptedException {
        Thread userThread = new Thread(() -> {
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            for (int i = 0; i < 10; i++) {
                System.out.println(Thread.currentThread().getName() + ", i=" + i);
            }
        }, "????");
        Thread daemonThread = new Thread(() -> {
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            for (int i = 0; i < 10; i++) {
                System.out.println(Thread.currentThread().getName() + ", i=" + i);
            }
        });
        daemonThread.setDaemon(true);
        daemonThread.start();
    }
}

????????????????????????????????????????????????????GC?????????????????????????????

volatile???

????????volatile??????????????????????????????????????????????????????????volatile????????????????????????????????????????

???????volatile???????

public class MyThread implements Runnable {
    private volatile int tickets = 5;
    @Override
    public void run() {
        synchronized (this) {
            while (this.tickets > 0) {
                System.out.println(Thread.currentThread().getName() + "????, tickets=" + this.tickets--);
            }
        }
    }
}
class ThreadDemo {
    public static void main(String[] args) {
        MyThread myThread = new MyThread();
        new Thread(myThread, "???A").start();
        new Thread(myThread, "???B").start();
        new Thread(myThread, "???C").start();
    }
}

???????tickets????volatile??????????????????????????????????????????????????????

?????????

????

????????????????????????????????????????????????????????0?-1?1?????

??????????

package com.lut.JavaPlus;
public class MyThread {
    public static void main(String[] args) {
        Resource resource = new Resource();
        SubThread subThread = new SubThread(resource);
        AddThread addThread = new AddThread(resource);
        new Thread(addThread, "????A").start();
        new Thread(addThread, "????B").start();
        new Thread(subThread, "????A").start();
        new Thread(subThread, "????B").start();
    }
}
class AddThread implements Runnable {
    private Resource resource;
    public AddThread(Resource resource) {
        this.resource = resource;
    }
    @Override
    public void run() {
        for (int i = 0; i < 50; i++) {
            try {
                this.resource.add();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}
class SubThread implements Runnable {
    private Resource resource;
    public SubThread(Resource resource) {
        this.resource = resource;
    }
    @Override
    public void run() {
        for (int i = 0; i < 50; i++) {
            try {
                this.resource.sub();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}
class Resource {
    private int num = 0;
    private boolean flag = true;
    public synchronized void add() throws Exception {
        if (this.flag == false) {
            super.wait();
        }
        Thread.sleep(100);
        this.num++;
        System.out.println("?????-" + Thread.currentThread().getName() + "? num=" + this.num);
        this.flag = false;
        super.notifyAll();
    }
    public synchronized void sub() throws Exception {
        if (this.flag == true) {
            super.wait();
        }
        Thread.sleep(200);
        this.num--;
        System.out.println("?????-" + Thread.currentThread().getName() + "? num=" + this.num);
        this.flag = true;
        super.notifyAll();
    }
}

??????add()?sub()????flag??????????????????????????????

????

?????????????????????????????????????????????????

??????????

package com.lut.JavaPlus;
public class MyThread {
    public static void main(String[] args) {
        Resource resource = new Resource();
        new Thread(new Producer(resource)).start();
        new Thread(new Consumer(resource)).start();
    }
}
class Producer implements Runnable {
    private Resource resource;
    public Producer(Resource resource) {
        this.resource = resource;
    }
    @Override
    public void run() {
        for (int i = 0; i < 50; i++) {
            try {
                this.resource.make();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}
class Consumer implements Runnable {
    private Resource resource;
    public Consumer(Resource resource) {
        this.resource = resource;
    }
    @Override
    public void run() {
        for (int i = 0; i < 50; i++) {
            try {
                this.resource.get();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}
class Computer {
    private static int count = 0;
    private String name;
    private double price;
    public Computer(String name, double price) {
        this.name = name;
        this.price = price;
        count++;
    }
    @Override
    public String toString() {
        return "?count=" + count + "-Computer{" +
                "name='" + name + '\'' +
                ", price=" + price +
                "}?";
    }
}
class Resource {
    private Computer computer;
    public synchronized void make() throws Exception {
        if (this.computer != null) {
            super.wait();
        }
        this.computer = new Computer("DELL", 3000);
        System.out.println("????:" + computer.toString());
        super.notifyAll();
    }
    public synchronized void get() throws Exception {
        if (this.computer == null) {
            super.wait();
        }
        System.out.println("????:" + computer.toString());
        this.computer = null;
        super.notifyAll();
    }
}

??????make()?get()????flag???????????????????????make()??????????get()?????????????

????

????????????????????????????????????????????????????????????????????????Callable?FutureTask????

??????????

public class MyThread {
    public static void main(String[] args) throws Exception {
        ThreadDemo threadDemo = new ThreadDemo();
        FutureTask
   
     taskA = new FutureTask<>(threadDemo);
        FutureTask
    
      taskB = new FutureTask<>(threadDemo);
        FutureTask
     
       taskC = new FutureTask<>(threadDemo);
        new Thread(taskA, "???A").start();
        new Thread(taskB, "???B").start();
        new Thread(taskC, "???C").start();
        System.out.println(taskA.get());
        System.out.println(taskB.get());
        System.out.println(taskC.get());
    }
}
class ThreadDemo implements Callable
      
        {
    private boolean flag = false;
    @Override
    public String call() throws Exception {
        synchronized (this) {
            if (this.flag == false) {
                this.flag = true;
                return Thread.currentThread().getName() + "?????";
            } else {
                return Thread.currentThread().getName() + "?????";
            }
        }
    }
}
      
     
    
   

??????Callable???????call()???????String???FutureTask??? Callable?????????get()?????????????????????????????????????????