Android-线程同步

  1 package com.csizg.jniport;
  2 
  3 
  4 import java.util.ArrayList;
  5 import java.util.List;
  6 
  7 /**
  8  * 与芯片交互线程
  9  */
 10 public class SpiQueue implements Runnable {
 11 
 12     private static final String TAG = SpiQueue.class.getSimpleName();
 13 
 14     private static final byte INIT = 0;// 初始化
 15     private static final byte RUNNING = 1;// 执行中
 16     private static final byte WITING = 2;// 暂停等待中
 17     private static final byte DONE = 3;// 结束
 18 
 19     private byte state = INIT;// 执行状态
 20 
 21     private static SpiQueue spiQueue = null;
 22 
 23     private SpiQueue() {
 24 
 25     }
 26 
 27     public static SpiQueue getSpiQueue() {
 28         if (spiQueue == null) {
 29             spiQueue = new SpiQueue();
 30         }
 31         return spiQueue;
 32     }
 33 
 34     private Thread thread;
 35     private List<SpiTask> tasks = new ArrayList<>();
 36 
 37     @Override
 38     public void run() {
 39         state = RUNNING;
 40         while (state != DONE) {
 41             synchronized (this) {
 42                 SpiTask currentTask = getNextTask();
 43                 if (currentTask == null) {
 44                     System.out.println(TAG + "  run  " + "no task todo begin to waiting");
 45                     try {
 46                         state = WITING;
 47                         wait();
 48                     } catch (InterruptedException e) {
 49                         e.printStackTrace();
 50                     }
 51                 } else {
 52                     try {
 53                         Thread.sleep(10);
 54                     } catch (InterruptedException e) {
 55                         e.printStackTrace();
 56                     }
 57                     System.out.println(TAG + "  run  " + "currentTask = " + currentTask.toString());
 58                 }
 59             }
 60         }
 61 
 62     }
 63 
 64     private synchronized SpiTask getNextTask() {
 65         System.out.println(TAG + "  getNextTask  " + "tasks.size() = " + tasks.size());
 66         if (tasks.size() > 0) {
 67             SpiTask task = tasks.remove(0);
 68             return task;
 69         }
 70         return null;
 71     }
 72 
 73     public synchronized void addTask(SpiTask task) {
 74         System.out.println(TAG + "  addTask  " + "tasks.size() = " + tasks.size() + ", new task : " + task.getCode());
 75         if (state == DONE) {
 76             System.out.println(TAG + "  addTask  " + "Thread is DONE : task : " + task.getCode());
 77             return;
 78         }
 79         tasks.add(task);
 80         if (state != RUNNING) {
 81             synchronized (this) {
 82                 state = RUNNING;
 83                 System.out.println(TAG + "  addTask notifyAll ");
 84                 notifyAll();
 85             }
 86         }
 87     }
 88 
 89     public synchronized void start() {
 90         System.out.println(TAG + "   start   " + "state = " + state);
 91         if (state == RUNNING || state == WITING) {
 92             return;
 93         }
 94         state = INIT;
 95         // 运行本线程
 96         tasks.clear();
 97         if (thread != null) {
 98             thread.interrupt();
 99         }
100         thread = new Thread(this);
101         thread.start();
102     }
103 
104 
105     public synchronized void stop() {
106         state = DONE;
107         tasks.clear();
108         synchronized (this) {
109             notifyAll();
110         }
111     }
112 }