线程通信

目前了解到的有三种情况
　　1.condition(await/signal)
　　2.object(wait/notify)
　　3.volatile

这里只对condition和object进行测试
================================================================================================================================

package com.meritdata.cloud.thirdsystemintegration.service;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class TestCondition {
    private Lock lock = new ReentrantLock();
    private Condition condition1 = lock.newCondition();
    private Condition condition2 = lock.newCondition();
    private Condition condition3 = lock.newCondition();

    private int index = 1;


    public void test1() {
        lock.lock();
        try {
            while (index != 1) {
                condition1.await();
            }
            index = 2;
            System.out.println(Thread.currentThread().getName());
            condition2.signal();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        } finally {
            lock.unlock();
        }
    }

    public void test2() {
        lock.lock();
        try {
            while (index != 2) {
                condition2.await();
            }
            index = 3;
            System.out.println(Thread.currentThread().getName());
            condition3.signal();
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            lock.unlock();
        }
    }


    public void test3() {
        lock.lock();
        try {
            while (index != 3) {
                condition3.await();
            }
            index = 1;
            System.out.println(Thread.currentThread().getName());
            condition1.signal();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        } finally {
            lock.unlock();
        }
    }

    public static void main(String[] args) {

        TestCondition test = new TestCondition();

        Thread thread1 = new Thread(() -> {
            for (int i = 0; i < 3; i++) {
                test.test1();
            }
        });
        Thread thread2 = new Thread(() -> {
            for (int i = 0; i < 3; i++) {
                test.test2();
            }
        });
        Thread thread3 = new Thread(() -> {
            for (int i = 0; i < 3; i++) {
                test.test3();
                System.out.println("================================");
            }
        });

        thread3.start();
        thread2.start();
        thread1.start();

    }
}

=============================================================================================================

package com.meritdata.cloud.thirdsystemintegration.service;

import com.google.common.collect.Lists;
import org.springframework.util.CollectionUtils;

import java.util.List;

public class TestCondition {


    private Object lock = new Object();

    private List<Integer> list = Lists.newArrayListWithCapacity(2);

    public void take() {
        synchronized (lock) {
            while (CollectionUtils.isEmpty(list)) {
                try {
                    System.out.println(Thread.currentThread().getName()+"take wait...");
                    lock.wait();
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
            list.remove(list.get(0));
            System.out.println(Thread.currentThread().getName()+"put signal...,list size:"+list.size());
            lock.notify();
        }
    }

    public void put() {
        synchronized (lock) {
            while (list.size() >= 2) {
                try {
                    System.out.println(Thread.currentThread().getName()+"put wait...");
                    lock.wait();
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
            list.add(1);
            System.out.println(Thread.currentThread().getName()+"take signal...,list size:"+list.size());
            lock.notify();
        }
    }

    public static void main(String[] args) {
        TestCondition condition = new TestCondition();
        Thread thread1 = new Thread(() -> {
            for (int i = 0; i < 2; i++) {
                condition.take();
            }
        });
        thread1.setName("take thread:");


        Thread thread2 = new Thread(() -> {
            for (int i = 0; i < 3; i++) {
                condition.put();
            }
        });
        thread2.setName("put thread:");
        thread1.start();
        thread2.start();
    }
}

}