線程通訊（一）

##底層業務線數據隔離

要求：子線程循環跑30次，暫停，然後跑到主線程40次，接着子線程循環跑30次，暫停，主線程跑40次
如此往復，一共交替50次

public class ThreadTest {

    private static Lock lock = new ReentrantLock();

    private static Condition chil_condition = lock.newCondition();

    private static Condition main_condition = lock.newCondition();

    private volatile static int sign = 0;

    public static void main(String[] args) throws  Exception{

        new Thread(()->{
            while (true){
                for(int i = 0;i<50;i++){
                    lock.lock();
                    try {
                        if(sign!=0){
                            chil_condition.await();
                        }
                        for(int j = 0;j<30;j++){
                            try {
                                Thread.sleep(40);
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                            System.out.println(String.format("子線程運行第%d輪第%d次",i,j));
                        }
                        sign=1;
                        main_condition.signal();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }finally {
                        lock.unlock();
                    }
                }
            }
        }).start();

        while (true){
            for(int i = 0;i<50;i++){
                lock.lock();
                if(sign==0){
                    main_condition.await();
                }
                for(int j = 0;j<40;j++){
                    Thread.sleep(40);
                    System.out.println(String.format("主線程運行第%d輪第%d次",i,j));
                }
                sign=0;
                chil_condition.signal();
                lock.unlock();
            }
        }
    }

}