Java线程同步Condition替代wait-notify

亦凉 2024-01-20 07:18 5阅读 0赞

## Java线程同步Condition替代wait-notify ##

package zhangphil.demo;
    
    import android.support.v7.app.AppCompatActivity;
    import android.os.Bundle;
    import android.view.View;
    
    import java.util.concurrent.TimeUnit;
    import java.util.concurrent.locks.Condition;
    import java.util.concurrent.locks.Lock;
    import java.util.concurrent.locks.ReentrantLock;
    
    public class MainActivity extends AppCompatActivity {
        private boolean flag = false;
    
        private Lock mLock = new ReentrantLock();
        private Condition mCondition = mLock.newCondition();
    
        //等待，加锁。
        private void await() throws Exception {
            mLock.lock();
            
            try {
                mCondition.await();
            } finally {
                mLock.unlock();
            }
        }
    
        //发送信号，解锁。
        private void signal() {
            mLock.lock();
            try {
                mCondition.signalAll();//或者 mCondition.signal();
            } finally {
                mLock.unlock();
            }
        }
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
    
            findViewById(R.id.change_flag).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    flag = !flag;
                    System.out.println(flag + "");
                }
            });
    
            findViewById(R.id.notify_all).setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    notify_all();
                }
            });
    
            t();
        }
    
        private void t() {
            new Thread(new Runnable() {
                @Override
                public void run() {
                    while (true) {
                        System.out.println(Thread.currentThread().getId() + "-" + System.currentTimeMillis());
    
                        try {
                            TimeUnit.SECONDS.sleep(2);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
    
                        if (flag) {
                            try {
                                await();
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                        }
                    }
                }
            }).start();
        }
    
        private void notify_all() {
            signal();
        }
    }