java多线程：并发包中的信号量和计数栓的编程模型

Posted 2020-08-10

一：信号量的编程模型

 1 package com.yeepay.sxf.test.atomic.test;
 2 
 3 import java.util.concurrent.Semaphore;
 4 
 5 /**
 6  * 测试信号量
 7  * 相当于有一把可以控制并发量的锁。
 8  * 例如银行柜台，只有两个窗口。但三个人做业务，只允许同时有两个人能进行做业务
 9  * 
10  * 多线程
11  * @author sxf
12  *
13  */
14 public class TestSemaphore {
15     
16     public static void main(String[] args) {
17         //声明两个信号量
18         Semaphore semaphore=new Semaphore(2);
19         //有三个线程抢许可证（信号量）做业务
20         Person person1=new Person("sxf", semaphore);
21         Person person2=new Person("sxs", semaphore);
22         Person person3=new Person("ssy", semaphore);
23         //启动这三个线程工作（同时允许的并发量为2）
24         person1.start();
25         person2.start();
26         person3.start();
27     }
28 
29 }
30 
31 class Person extends Thread{
32     
33     /**
34      * 信号量（许可证）
35      */
36     private Semaphore semaphore;
37     /**
38      * 当前线程的名字
39      */
40     private String cname;
41     
42     public Person(String cname,Semaphore semaphore) {
43         this.cname=cname;
44         this.semaphore=semaphore;
45     }
46     
47 
48     @Override
49     public void run() {
50         System.out.println("Person.run(==>)"+getCname()+" is wating........");
51         try {
52             //获取许可证
53             semaphore.acquire();
54             System.out.println("Person.run()"+getCname()+" is doneing.......");
55             Thread.sleep(3000);
56             System.out.println("Person.run(==>)"+getCname()+"  is service done......");
57             //释放许可证
58             semaphore.release();
59         } catch (InterruptedException e) {
60             e.printStackTrace();
61         }
62     }
63 
64 
65     public Semaphore getSemaphore() {
66         return semaphore;
67     }
68 
69 
70     public void setSemaphore(Semaphore semaphore) {
71         this.semaphore = semaphore;
72     }
73 
74 
75     public String getCname() {
76         return cname;
77     }
78 
79 
80     public void setCname(String cname) {
81         this.cname = cname;
82     }
83 
84 
85     
86 
87 
88 
89 
90     
91     
92     
93 }

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一：计数栓的编程模型

 1 package com.yeepay.sxf.test.atomic.test;
 2 
 3 import java.util.concurrent.CountDownLatch;
 4 /**
 5  * 测试记数栓
 6  * 
 7  * 当记数栓定义的多个事件发生时候，才能执行任务
 8  * @author sxf
 9  *
10  */
11 public class TestCountDowanLatch {
12 
13     public static void main(String[] args) throws InterruptedException {
14         //定义三个事件的计数栓
15         CountDownLatch countDownLatch=new CountDownLatch(3);
16         //定义任务线程
17         Runer runer=new Runer("sxf", countDownLatch);
18         Runer runer2=new Runer("sxs", countDownLatch);
19         Runer runer3=new Runer("sxy", countDownLatch);
20         
21         //启动任务线程
22         runer.start();
23         runer2.start();
24         runer3.start();
25         
26         //住线程监控特定事件的发生次数
27         for(int i=0;i<3;i++){
28             Thread.sleep(3000);
29             System.out.println("TestCountDowanLatch.main(事件发生第【"+(i+1)+"】次");
30             if(i==2){
31                 System.out.println("TestCountDowanLatch.main(事件发生次数已经达标允许线程执行任务)");
32                 countDownLatch.countDown();
33             }
34             
35         }
36         
37     }
38 }
39 
40 
41 class Runer extends Thread{
42     /**
43      * 计数栓
44      */
45     private CountDownLatch countDownLatch;
46     
47     private String cname;
48     
49     public Runer(String cname,CountDownLatch countDownLatch) {
50         this.cname=cname;
51         this.countDownLatch=countDownLatch;
52     }
53 
54     @Override
55     public void run() {
56         try {
57             System.out.println("Runer.run()"+getName()+"  is await.............");
58             countDownLatch.await();
59             System.out.println("Runer.run()"+getName()+"  is doneing...........cname");
60             
61         } catch (InterruptedException e) {
62             // TODO Auto-generated catch block
63             e.printStackTrace();
64         }
65     }
66 
67     public CountDownLatch getCountDownLatch() {
68         return countDownLatch;
69     }
70 
71     public void setCountDownLatch(CountDownLatch countDownLatch) {
72         this.countDownLatch = countDownLatch;
73     }
74 
75     public String getCname() {
76         return cname;
77     }
78 
79     public void setCname(String cname) {
80         this.cname = cname;
81     }
82     
83     
84     
85 }

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