Javase-Concurrency

  1 import java.util.concurrent.ExecutorService;
  2 import java.util.concurrent.Executors;
  3 import java.util.concurrent.TimeUnit;
  4 import java.util.concurrent.locks.Lock;
  5 import java.util.concurrent.locks.ReentrantLock;
  6 
  7 
  8 public class SynchronizedTest {
  9     
 10     static class Run implements Runnable
 11     {
 12         private IncreaseThree it;
 13         private int times;
 14         
 15         public Run(IncreaseThree it, int times)
 16         {
 17             this.it = it;
 18             this.times = times;
 19         }
 20 
 21         @Override
 22         public void run() {
 23             for (int i = 0; i < times; i++)
 24             {
 25                 it.increaseThree();
 26             }
 27         }
 28         
 29     }
 30     
 31     public static void main(String[] args) throws InterruptedException
 32     {
 33         IncreaseThree it = new IncreaseThree();
 34         //it = new SynchronizedIncrease1();
 35         //it = new SynchronizedIncrease2();
 36         //it = new LockIncreaseThree();
 37         
 38         ExecutorService es = Executors.newCachedThreadPool();
 39         for (int i = 0; i < 10; i++)
 40             es.execute(new Run(it, 100));
 41         
 42         //等待子线程结束
 43         TimeUnit.SECONDS.sleep(1);
 44         
 45         if (it.getValue() != 3 * 10 * 100)
 46         {
 47             System.out.println("出现竞争:value=" + it.getValue());
 48         }
 49         else
 50         {
 51             System.out.println("未出现竞争:value=" + it.getValue());
 52         }
 53     }
 54 
 55 }
 56 
 57 class IncreaseThree
 58 {
 59     protected int value = 0;
 60     
 61     protected void increaseThree()
 62     {
 63         value++;
 64         //切换线程,增强效果
 65         Thread.yield();
 66         value++;
 67         Thread.yield();
 68         value++;
 69         Thread.yield();
 70     }
 71     
 72     public int getValue()
 73     {
 74         return value;
 75     }
 76 }
 77 
 78 class SynchronizedIncrease1 extends IncreaseThree
 79 {
 80     public void increaseThree()
 81     {
 82         synchronized(this)
 83         {
 84             value++;
 85             //切换线程,增强效果
 86             Thread.yield();
 87             value++;
 88             Thread.yield();
 89             value++;
 90             Thread.yield();
 91         }
 92     }
 93 }
 94 
 95 class SynchronizedIncrease2 extends IncreaseThree
 96 {
 97     public synchronized void increaseThree()
 98     {
 99         value++;
100         //切换线程,增强效果
101         Thread.yield();
102         value++;
103         Thread.yield();
104         value++;
105         Thread.yield();
106     }
107 }
108 
109 class LockIncreaseThree extends IncreaseThree
110 {
111     Lock lock = new ReentrantLock();
112     public void increaseThree()
113     {
114         lock.lock();
115         try
116         {
117         value++;
118         //切换线程,增强效果
119         Thread.yield();
120         value++;
121         Thread.yield();
122         value++;
123         Thread.yield();
124         }finally
125         {
126             lock.unlock();
127         }
128     }
129     
130 }

出现竞争:value=2997