1. package Paradigms.List11.CommonStaticVariableResolvings;
2.  
3.  
4.  
5. public class IntCellDefault {
6.  
7.     public int getN(){
8.  
9.         return n;
10.  
11.     }
12.  
13.  
14.  
15.     public void setN(int n){
16.  
17.         this.n = n;
18.  
19.     }
20.  
21.  
22.  
23.     private int n = 0;
24.  
25. }
26.  
27.  
28.  
29. class Count extends Thread{
30.  
31.     static IntCellDefault n = new IntCellDefault();
32.  
33.  
34.  
35.     @Override
36.  
37.     public void run(){
38.  
39.         for (int i = 0; i < 200000; i++){
40.  
41.             int temp = n.getN();
42.  
43.             n.setN(temp+1);
44.  
45.         }
46.  
47.     }
48.  
49.  
50.  
51.     public static void main(String[] args){
52.  
53.         Count thread1 = new Count();
54.  
55.         Count thread2 = new Count();
56.  
57.         thread1.start();
58.  
59.         thread2.start();
60.  
61.         try{
62.  
63.             thread1.join();
64.  
65.             thread2.join();
66.  
67.         }catch(InterruptedException e){
68.  
69.             System.out.println(e.getStackTrace());
70.  
71.             System.out.println("Catched exception");
72.  
73.         }
74.  
75.         System.out.println("The value of n is " + n.getN());
76.  
77.     }
78.  
79.  
80.  
81.     // First of all thread1 and thread2 starts in various times
82.  
83.     // Secondly each thread makes a copy to their local caches
84.  
85.     // It implies that when thread1 modifies the static variable
86.  
87.     // The thread2 can contain old value of static variable
88.  
89.     // And will increase basing on old value
90.  
91.     // Then finally cause that the value of n.n has lower value then expected 400000
92.  
93.     //
94.  
95.     // Exception
96.  
97.     // InterruptedException is cought for the security because JVM can sometimes throw it
98.  
99.     // But common situation is when someone will call interrupt(przerwij) on this thread
100.  
101.     //
102.  
103.     // Join
104.  
105.     // Wait for this thread to die
106.  
107. }