1 /*
2  * Written by Doug Lea with assistance from members of JCP JSR-166
3  * Expert Group and released to the public domain, as explained at
4  * http://creativecommons.org/publicdomain/zero/1.0/
5  * Other contributors include Andrew Wright, Jeffrey Hayes,
6  * Pat Fisher, Mike Judd.
7  */
8 
9 package jsr166;
10 
11 import junit.framework.Test;
12 import junit.framework.TestSuite;
13 
14 public class ThreadLocalTest extends JSR166TestCase {
15     // android-note: Removed because the CTS runner does a bad job of
16     // retrying tests that have suite() declarations.
17     //
18     // public static void main(String[] args) {
19     //     main(suite(), args);
20     // }
21     // public static Test suite() {
22     //     return new TestSuite(ThreadLocalTest.class);
23     // }
24 
25     static ThreadLocal<Integer> tl = new ThreadLocal<Integer>() {
26             public Integer initialValue() {
27                 return one;
28             }
29         };
30 
31     static InheritableThreadLocal<Integer> itl =
32         new InheritableThreadLocal<Integer>() {
33             protected Integer initialValue() {
34                 return zero;
35             }
36 
37             protected Integer childValue(Integer parentValue) {
38                 return new Integer(parentValue.intValue() + 1);
39             }
40         };
41 
42     /**
43      * remove causes next access to return initial value
44      */
testRemove()45     public void testRemove() {
46         assertSame(tl.get(), one);
47         tl.set(two);
48         assertSame(tl.get(), two);
49         tl.remove();
50         assertSame(tl.get(), one);
51     }
52 
53     /**
54      * remove in InheritableThreadLocal causes next access to return
55      * initial value
56      */
testRemoveITL()57     public void testRemoveITL() {
58         assertSame(itl.get(), zero);
59         itl.set(two);
60         assertSame(itl.get(), two);
61         itl.remove();
62         assertSame(itl.get(), zero);
63     }
64 
65     private class ITLThread extends Thread {
66         final int[] x;
ITLThread(int[] array)67         ITLThread(int[] array) { x = array; }
run()68         public void run() {
69             Thread child = null;
70             if (itl.get().intValue() < x.length - 1) {
71                 child = new ITLThread(x);
72                 child.start();
73             }
74             Thread.yield();
75 
76             int threadId = itl.get().intValue();
77             for (int j = 0; j < threadId; j++) {
78                 x[threadId]++;
79                 Thread.yield();
80             }
81 
82             if (child != null) { // Wait for child (if any)
83                 try {
84                     child.join();
85                 } catch (InterruptedException e) {
86                     threadUnexpectedException(e);
87                 }
88             }
89         }
90     }
91 
92     /**
93      * InheritableThreadLocal propagates generic values.
94      */
testGenericITL()95     public void testGenericITL() throws InterruptedException {
96         final int threadCount = 10;
97         final int[] x = new int[threadCount];
98         Thread progenitor = new ITLThread(x);
99         progenitor.start();
100         progenitor.join();
101         for (int i = 0; i < threadCount; i++) {
102             assertEquals(i, x[i]);
103         }
104     }
105 }
106