线程

Posted 2021-05-19 FZZ98

线程

创建线程的方式

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;

public class CreateThread {
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        new Thread1().start();
        new Thread(new Thread2()).start();
        Future<Integer> future = new FutureTask<>(new Thread3());
        new Thread((Runnable) future).start();
        Integer integer = future.get();
        System.out.println(integer);
    }
}

class Thread1 extends Thread{
    @Override
    public void run() {
        System.out.println("thread1 run");
    }
}

class Thread2 implements Runnable{
    @Override
    public void run() {
        System.out.println("thread2 run");
    }
}

class Thread3 implements Callable<Integer>{
    final int i=100;
    @Override
    public Integer call() throws Exception {
        System.out.println("thread3 run");
        return i;
    }
}

ReentrantLock

import java.util.concurrent.locks.ReentrantLock;

public class LockDemo {

    public static void main(String[] args) {
        BuyTicket station = new BuyTicket();
        new Thread(station,"a").start();
        new Thread(station,"b").start();
        new Thread(station,"c").start();
    }

}

class BuyTicket implements Runnable{
    private int tickets = 10;

    private final ReentrantLock lock = new ReentrantLock();

    @Override
    public void run() {

        while(true){
            try{
                lock.lock();
                if (tickets>0){
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    System.out.println(tickets--);
                } else {
                    break;
                }
            } finally {
                lock.unlock();
            }

        }
    }
}

Synchronized

Sample 01

public class UnsafeStation {
    public static void main(String[] args) {
        Station station = new Station();
        new Thread(station,"Passenger No."+1).start();
        new Thread(station,"Passenger No."+2).start();
        new Thread(station,"Passenger No."+3).start();
    }
}

class Station implements Runnable{
    private int nums = 10;
    boolean flag = true;

    @Override
    public void run() {
        while(flag){
            try {
                buyTickets();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    private /*synchronized*/ void buyTickets() throws InterruptedException {
        synchronized (this){
            if (nums<=0){
                flag = false;
                System.out.println("tickets is run out.");
                return;
            }
            Thread.sleep(100);
            System.out.println(Thread.currentThread().getName()+" : buy the No."+(nums--)+" ticket.");
        }

    }
}

Sample 02

public class UnsafeBank {

    public static void main(String[] args) {
        Account account = new Account(100,"account");
        Drawing you = new Drawing(account,50,"a");
        Drawing wife = new Drawing(account,100,"b");
        you.start();
        wife.start();
    }
}

class Account{
    int save;
    String name;
    public Account(int save,String name){
        this.save=save;
        this.name=name;
    }
}

class Drawing extends Thread{

    Account account;
    int drawMoney;
    int nowMoney;

    public Drawing(Account account,int drawMoney,String name){
        super(name);
        this.account=account;
        this.drawMoney=drawMoney;
    }

    @Override
    public void run() {
        synchronized (account){
            if (account.save-drawMoney<0){
                System.out.println("money is not sufficient.");
                return;
            }
            try {
                Thread.sleep(1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            account.save-=drawMoney;
            nowMoney+=drawMoney;
            System.out.println(account.name+"\'s money is "+account.save);
            System.out.println(this.getName()+" now you have "+nowMoney+" in hand.");
        }

    }

}

Sample 03

public class UnsafeList {
    public static void main(String[] args) throws InterruptedException {
        ArrayList list = new ArrayList();
        for (int i = 0; i < 10000; i++) {
            new Thread(()->{
                synchronized (list){
                    list.add(Thread.currentThread().getName());
                }
            }).start();
        }
        Thread.sleep(5000);
        System.out.println(list.size());
    }

}

生产者消费者

管程法

public class TestPC1 {
    public static void main(String[] args) {
        SynContainer container = new SynContainer();
        new Producer(container).start();
        new Customer(container).start();
    }
}

class Chicken{
    int id;
    public Chicken(int id){
        this.id = id;
    }
}

class Producer extends Thread{
    SynContainer container;
    public Producer(SynContainer container){
        this.container=container;
    }

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            try {
                container.push(new Chicken((i+1)));
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

class Customer extends Thread{
    SynContainer container;
    public Customer(SynContainer container){
        this.container = container;
    }

    @Override
    public void run() {
        for (int i = 0; i < 100; i++) {
            try {
                Chicken pop = container.pop();
                System.out.println("consume no."+pop.id+" chicken.");
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

class SynContainer{

    Chicken[] chickens = new Chicken[10];
    int count=0;

    public synchronized void push(Chicken chicken) throws InterruptedException {
        if (count==chickens.length-1){
            this.wait();
        }
        chickens[count]=chicken;
        System.out.println("produce no."+chicken.id+" chicken.");
        count++;
        this.notifyAll();
    }

    public synchronized Chicken pop() throws InterruptedException {
        if (count==0){
            this.wait();
        }
        count--;
        Chicken chicken = chickens[count];
        this.notifyAll();
        return chicken;
    }

}

信号灯法

public class TestPC2 {
    public static void main(String[] args) {
        TV tv = new TV();
        new Player(tv).start();
        new Watcher(tv).start();
    }

}

class Player extends Thread{
    TV tv;
    public Player(TV tv){
        this.tv=tv;
    }

    @Override
    public void run() {
        for (int i = 0; i < 20; i++) {
            if (i%2==0){
                tv.play("super mario");
            } else {
                tv.play("dragon ball");
            }
        }
    }
}

class Watcher extends Thread{
    TV tv;
    public Watcher(TV tv){
        this.tv=tv;
    }
    
    @Override
    public void run() {
        for (int i = 0; i < 20; i++) {
            tv.watch();
        }
    }
}

class TV{
    
    String voice;
    boolean flag = true;
    
    public synchronized void play(String voice){
        if (!flag){
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        this.voice=voice;
        System.out.println("play "+voice);
        flag=!flag;
        notifyAll();
    }

    public synchronized void watch(){
        if (flag){
            try {
                wait();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
        System.out.println("watch "+voice);
        flag=!flag;
        notifyAll();
    }
}

线程池

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class TestPool {
    public static void main(String[] args) {
        ExecutorService service = Executors.newFixedThreadPool(10);
        service.execute(new MyThread());
        service.execute(new MyThread());
        service.execute(new MyThread());
        service.execute(new MyThread());
        service.shutdown();
    }
}

class MyThread implements Runnable{
    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName());
    }
}