Calin Juravle | 8f0d92b | 2013-08-01 17:26:00 +0100 | [diff] [blame] | 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.*; |
| 12 | import java.util.*; |
| 13 | import java.util.concurrent.CountDownLatch; |
| 14 | import static java.util.concurrent.TimeUnit.MILLISECONDS; |
| 15 | |
| 16 | public class CountDownLatchTest extends JSR166TestCase { |
| 17 | |
| 18 | /** |
| 19 | * negative constructor argument throws IAE |
| 20 | */ |
| 21 | public void testConstructor() { |
| 22 | try { |
| 23 | new CountDownLatch(-1); |
| 24 | shouldThrow(); |
| 25 | } catch (IllegalArgumentException success) {} |
| 26 | } |
| 27 | |
| 28 | /** |
| 29 | * getCount returns initial count and decreases after countDown |
| 30 | */ |
| 31 | public void testGetCount() { |
| 32 | final CountDownLatch l = new CountDownLatch(2); |
| 33 | assertEquals(2, l.getCount()); |
| 34 | l.countDown(); |
| 35 | assertEquals(1, l.getCount()); |
| 36 | } |
| 37 | |
| 38 | /** |
| 39 | * countDown decrements count when positive and has no effect when zero |
| 40 | */ |
| 41 | public void testCountDown() { |
| 42 | final CountDownLatch l = new CountDownLatch(1); |
| 43 | assertEquals(1, l.getCount()); |
| 44 | l.countDown(); |
| 45 | assertEquals(0, l.getCount()); |
| 46 | l.countDown(); |
| 47 | assertEquals(0, l.getCount()); |
| 48 | } |
| 49 | |
| 50 | /** |
| 51 | * await returns after countDown to zero, but not before |
| 52 | */ |
| 53 | public void testAwait() { |
| 54 | final CountDownLatch l = new CountDownLatch(2); |
| 55 | final CountDownLatch pleaseCountDown = new CountDownLatch(1); |
| 56 | |
| 57 | Thread t = newStartedThread(new CheckedRunnable() { |
| 58 | public void realRun() throws InterruptedException { |
| 59 | assertEquals(2, l.getCount()); |
| 60 | pleaseCountDown.countDown(); |
| 61 | l.await(); |
| 62 | assertEquals(0, l.getCount()); |
| 63 | }}); |
| 64 | |
| 65 | await(pleaseCountDown); |
| 66 | assertEquals(2, l.getCount()); |
| 67 | l.countDown(); |
| 68 | assertEquals(1, l.getCount()); |
| 69 | assertThreadStaysAlive(t); |
| 70 | l.countDown(); |
| 71 | assertEquals(0, l.getCount()); |
| 72 | awaitTermination(t); |
| 73 | } |
| 74 | |
| 75 | /** |
| 76 | * timed await returns after countDown to zero |
| 77 | */ |
| 78 | public void testTimedAwait() { |
| 79 | final CountDownLatch l = new CountDownLatch(2); |
| 80 | final CountDownLatch pleaseCountDown = new CountDownLatch(1); |
| 81 | |
| 82 | Thread t = newStartedThread(new CheckedRunnable() { |
| 83 | public void realRun() throws InterruptedException { |
| 84 | assertEquals(2, l.getCount()); |
| 85 | pleaseCountDown.countDown(); |
| 86 | assertTrue(l.await(LONG_DELAY_MS, MILLISECONDS)); |
| 87 | assertEquals(0, l.getCount()); |
| 88 | }}); |
| 89 | |
| 90 | await(pleaseCountDown); |
| 91 | assertEquals(2, l.getCount()); |
| 92 | l.countDown(); |
| 93 | assertEquals(1, l.getCount()); |
| 94 | assertThreadStaysAlive(t); |
| 95 | l.countDown(); |
| 96 | assertEquals(0, l.getCount()); |
| 97 | awaitTermination(t); |
| 98 | } |
| 99 | |
| 100 | /** |
| 101 | * await throws IE if interrupted before counted down |
| 102 | */ |
| 103 | public void testAwait_Interruptible() { |
| 104 | final CountDownLatch l = new CountDownLatch(1); |
| 105 | final CountDownLatch pleaseInterrupt = new CountDownLatch(1); |
| 106 | Thread t = newStartedThread(new CheckedRunnable() { |
| 107 | public void realRun() throws InterruptedException { |
| 108 | Thread.currentThread().interrupt(); |
| 109 | try { |
| 110 | l.await(); |
| 111 | shouldThrow(); |
| 112 | } catch (InterruptedException success) {} |
| 113 | assertFalse(Thread.interrupted()); |
| 114 | |
| 115 | pleaseInterrupt.countDown(); |
| 116 | try { |
| 117 | l.await(); |
| 118 | shouldThrow(); |
| 119 | } catch (InterruptedException success) {} |
| 120 | assertFalse(Thread.interrupted()); |
| 121 | |
| 122 | assertEquals(1, l.getCount()); |
| 123 | }}); |
| 124 | |
| 125 | await(pleaseInterrupt); |
| 126 | assertThreadStaysAlive(t); |
| 127 | t.interrupt(); |
| 128 | awaitTermination(t); |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * timed await throws IE if interrupted before counted down |
| 133 | */ |
| 134 | public void testTimedAwait_Interruptible() { |
| 135 | final CountDownLatch l = new CountDownLatch(1); |
| 136 | final CountDownLatch pleaseInterrupt = new CountDownLatch(1); |
| 137 | Thread t = newStartedThread(new CheckedRunnable() { |
| 138 | public void realRun() throws InterruptedException { |
| 139 | Thread.currentThread().interrupt(); |
| 140 | try { |
| 141 | l.await(LONG_DELAY_MS, MILLISECONDS); |
| 142 | shouldThrow(); |
| 143 | } catch (InterruptedException success) {} |
| 144 | assertFalse(Thread.interrupted()); |
| 145 | |
| 146 | pleaseInterrupt.countDown(); |
| 147 | try { |
| 148 | l.await(LONG_DELAY_MS, MILLISECONDS); |
| 149 | shouldThrow(); |
| 150 | } catch (InterruptedException success) {} |
| 151 | assertFalse(Thread.interrupted()); |
| 152 | |
| 153 | assertEquals(1, l.getCount()); |
| 154 | }}); |
| 155 | |
| 156 | await(pleaseInterrupt); |
| 157 | assertThreadStaysAlive(t); |
| 158 | t.interrupt(); |
| 159 | awaitTermination(t); |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * timed await times out if not counted down before timeout |
| 164 | */ |
| 165 | public void testAwaitTimeout() throws InterruptedException { |
| 166 | final CountDownLatch l = new CountDownLatch(1); |
| 167 | Thread t = newStartedThread(new CheckedRunnable() { |
| 168 | public void realRun() throws InterruptedException { |
| 169 | assertEquals(1, l.getCount()); |
| 170 | assertFalse(l.await(timeoutMillis(), MILLISECONDS)); |
| 171 | assertEquals(1, l.getCount()); |
| 172 | }}); |
| 173 | |
| 174 | awaitTermination(t); |
| 175 | assertEquals(1, l.getCount()); |
| 176 | } |
| 177 | |
| 178 | /** |
| 179 | * toString indicates current count |
| 180 | */ |
| 181 | public void testToString() { |
| 182 | CountDownLatch s = new CountDownLatch(2); |
| 183 | assertTrue(s.toString().contains("Count = 2")); |
| 184 | s.countDown(); |
| 185 | assertTrue(s.toString().contains("Count = 1")); |
| 186 | s.countDown(); |
| 187 | assertTrue(s.toString().contains("Count = 0")); |
| 188 | } |
| 189 | |
| 190 | } |