Lock版的生产者消费者的实现及问题

Lock版的生产者消费者的实现及问题

方法功能对应

synchronized	Lock Condition
wait()	await()
notifyAll()	signalAll()

package com.example.juc;

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

public class TestLock {
    public static void main(String[] args) {

        A1 a = new A1();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                a.increase();
            }
        }, "A").start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                a.decrease();
            }
        }, "B").start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                a.increase();
            }
        }, "C").start();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                a.decrease();
            }
        }, "D").start();
    }

}

class A1 {
    private int num;
    Lock lock = new ReentrantLock();
    Condition condition = lock.newCondition();

    public void increase() {
        lock.lock();


        try {
            // 等待
            while (num != 0) {
                try {
                    condition.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            //
            System.out.println(Thread.currentThread().getName() + "-->" + ++num);
            condition.signalAll();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public void decrease() {
        lock.lock();
        try {
            // 等待
            while (num == 0) {
                try {
                    condition.await();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            //
            System.out.println(Thread.currentThread().getName() + "-->" + --num);
            condition.signalAll();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
}

A-->1
B-->0
A-->1
B-->0
A-->1
B-->0
A-->1
B-->0
A-->1
B-->0
A-->1
B-->0
A-->1
B-->0
A-->1
B-->0
A-->1
B-->0
A-->1
B-->0
C-->1
D-->0
C-->1
D-->0
C-->1
D-->0
C-->1
D-->0
C-->1
D-->0
C-->1
D-->0
C-->1
D-->0
C-->1
D-->0
C-->1
D-->0
C-->1
D-->0

问题：怎么让几个线程顺序执行呢？

package com.example.juc;

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

public class TestOrderLock {
    public static void main(String[] args) {
        Data data = new Data();
        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                data.printA();
            }
        }, "A").start();

        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                data.printB();
            }
        }, "B").start();

        new Thread(() -> {
            for (int i = 0; i < 10; i++) {
                data.printC();
            }
        }, "C").start();

    }
}

class Data {
    private Lock lock = new ReentrantLock();
    private Condition condition1 = lock.newCondition();
    private Condition condition2 = lock.newCondition();
    private Condition condition3 = lock.newCondition();
    private int num = 1;

    public void printA() {
        lock.lock();

        try {
            if (num != 1) {
                condition1.await();
            }
            System.out.println(Thread.currentThread().getName() + "->AAAAAAAAAA");
            num = 2;
            condition2.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }

    }

    public void printB() {
        lock.lock();

        try {
            if (num != 2) {
                condition2.await();
            }
            System.out.println(Thread.currentThread().getName() + "->BBBBBBBB");
            num = 3;
            condition3.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }

    }

    public void printC() {
        lock.lock();

        try {
            if (num != 3) {
                condition3.await();
            }
            System.out.println(Thread.currentThread().getName() + "->CCCCCCCCCCC");
            num = 1;
            condition1.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }

    }

}

A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC
A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC
A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC
A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC
A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC
A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC
A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC
A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC
A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC
A->AAAAAAAAAA
B->BBBBBBBB
C->CCCCCCCCCCC