1 /*
2 * Copyright (c) 2005, 2008, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /*
25 * @test
26 * @bug 6207928 6328220 6378321 6625723
27 * @summary Recursive lock invariant sanity checks
28 * @library /lib/testlibrary/
29 * @author Martin Buchholz
30 */
31
32 import static java.util.concurrent.TimeUnit.MILLISECONDS;
33
34 import java.io.ByteArrayInputStream;
35 import java.io.ByteArrayOutputStream;
36 import java.io.IOException;
37 import java.io.InputStream;
38 import java.io.ObjectInputStream;
39 import java.io.ObjectOutputStream;
40 import java.util.Random;
41 import java.util.concurrent.CyclicBarrier;
42 import java.util.concurrent.ExecutorService;
43 import java.util.concurrent.Executors;
44 import java.util.concurrent.TimeUnit;
45 import java.util.concurrent.locks.Lock;
46 import java.util.concurrent.locks.ReentrantLock;
47 import java.util.concurrent.locks.ReentrantReadWriteLock;
48 import jdk.testlibrary.Utils;
49
50 // I am the Cownt, and I lahve to cownt.
51 public class Count {
52 static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000);
53 final Random rnd = new Random();
54
55 void lock(Lock lock) {
56 try {
57 switch (rnd.nextInt(4)) {
58 case 0: lock.lock(); break;
59 case 1: lock.lockInterruptibly(); break;
60 case 2: check(lock.tryLock()); break;
61 case 3: check(lock.tryLock(45, TimeUnit.MINUTES)); break;
62 }
63 } catch (Throwable t) { unexpected(t); }
64 }
65
66 void test(String[] args) throws Throwable {
67 for (boolean fair : new boolean[] { true, false })
68 for (boolean serialClone : new boolean[] { true, false }) {
69 testReentrantLocks(fair, serialClone);
70 testConcurrentReadLocks(fair, serialClone);
71 }
72 }
73
74 void testConcurrentReadLocks(final boolean fair,
75 final boolean serialClone) throws Throwable {
76 final int nThreads = 10;
77 final CyclicBarrier barrier = new CyclicBarrier(nThreads);
78 final ExecutorService es = Executors.newFixedThreadPool(nThreads);
79 final ReentrantReadWriteLock rwl = serialClone ?
80 serialClone(new ReentrantReadWriteLock(fair)) :
81 new ReentrantReadWriteLock(fair);
82 for (int i = 0; i < nThreads; i++) {
83 es.submit(new Runnable() { public void run() {
84 try {
85 int n = 5;
86 for (int i = 0; i < n; i++) {
87 barrier.await();
88 equal(rwl.getReadHoldCount(), i);
89 equal(rwl.getWriteHoldCount(), 0);
90 check(! rwl.isWriteLocked());
91 equal(rwl.getReadLockCount(), nThreads * i);
92 barrier.await();
93 lock(rwl.readLock());
94 }
95 for (int i = 0; i < n; i++) {
96 rwl.readLock().unlock();
97 barrier.await();
98 equal(rwl.getReadHoldCount(), n-i-1);
99 equal(rwl.getReadLockCount(), nThreads*(n-i-1));
100 equal(rwl.getWriteHoldCount(), 0);
101 check(! rwl.isWriteLocked());
102 barrier.await();
103 }
104 THROWS(IllegalMonitorStateException.class,
105 new F(){void f(){rwl.readLock().unlock();}},
106 new F(){void f(){rwl.writeLock().unlock();}});
107 barrier.await();
108 } catch (Throwable t) { unexpected(t); }}});}
109 es.shutdown();
110 check(es.awaitTermination(LONG_DELAY_MS, MILLISECONDS));
111 }
112
113 void testReentrantLocks(final boolean fair,
114 final boolean serialClone) throws Throwable {
115 final ReentrantLock rl = serialClone ?
116 serialClone(new ReentrantLock(fair)) :
117 new ReentrantLock(fair);
118 final ReentrantReadWriteLock rwl = serialClone ?
119 serialClone(new ReentrantReadWriteLock(fair)) :
120 new ReentrantReadWriteLock(fair);
121 final int depth = 10;
122 equal(rl.isFair(), fair);
123 equal(rwl.isFair(), fair);
124 check(! rl.isLocked());
125 check(! rwl.isWriteLocked());
126 check(! rl.isHeldByCurrentThread());
127 check(! rwl.isWriteLockedByCurrentThread());
128 check(! rwl.writeLock().isHeldByCurrentThread());
129
130 for (int i = 0; i < depth; i++) {
131 equal(rl.getHoldCount(), i);
132 equal(rwl.getReadLockCount(), i);
133 equal(rwl.getReadHoldCount(), i);
134 equal(rwl.getWriteHoldCount(), i);
135 equal(rwl.writeLock().getHoldCount(), i);
136 equal(rl.isLocked(), i > 0);
137 equal(rwl.isWriteLocked(), i > 0);
138 lock(rl);
139 lock(rwl.writeLock());
140 lock(rwl.readLock());
141 }
142
143 for (int i = depth; i > 0; i--) {
144 check(! rl.hasQueuedThreads());
145 check(! rwl.hasQueuedThreads());
146 check(! rl.hasQueuedThread(Thread.currentThread()));
147 check(! rwl.hasQueuedThread(Thread.currentThread()));
148 check(rl.isLocked());
149 check(rwl.isWriteLocked());
150 check(rl.isHeldByCurrentThread());
151 check(rwl.isWriteLockedByCurrentThread());
152 check(rwl.writeLock().isHeldByCurrentThread());
153 equal(rl.getQueueLength(), 0);
154 equal(rwl.getQueueLength(), 0);
155 equal(rwl.getReadLockCount(), i);
156 equal(rl.getHoldCount(), i);
157 equal(rwl.getReadHoldCount(), i);
158 equal(rwl.getWriteHoldCount(), i);
159 equal(rwl.writeLock().getHoldCount(), i);
160 rwl.readLock().unlock();
161 rwl.writeLock().unlock();
162 rl.unlock();
163 }
164 THROWS(IllegalMonitorStateException.class,
165 new F(){void f(){rl.unlock();}},
166 new F(){void f(){rwl.readLock().unlock();}},
167 new F(){void f(){rwl.writeLock().unlock();}});
168 }
169
170 //--------------------- Infrastructure ---------------------------
171 volatile int passed = 0, failed = 0;
172 void pass() {passed++;}
173 void fail() {failed++; Thread.dumpStack();}
174 void fail(String msg) {System.err.println(msg); fail();}
175 void unexpected(Throwable t) {failed++; t.printStackTrace();}
176 void check(boolean cond) {if (cond) pass(); else fail();}
177 void equal(Object x, Object y) {
178 if (x == null ? y == null : x.equals(y)) pass();
179 else fail(x + " not equal to " + y);}
180 public static void main(String[] args) throws Throwable {
181 new Count().instanceMain(args);}
182 void instanceMain(String[] args) throws Throwable {
183 try {test(args);} catch (Throwable t) {unexpected(t);}
184 System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
185 if (failed > 0) throw new AssertionError("Some tests failed");}
186 abstract class F {abstract void f() throws Throwable;}
187 void THROWS(Class<? extends Throwable> k, F... fs) {
188 for (F f : fs)
189 try {f.f(); fail("Expected " + k.getName() + " not thrown");}
190 catch (Throwable t) {
191 if (k.isAssignableFrom(t.getClass())) pass();
192 else unexpected(t);}}
193
194 static byte[] serializedForm(Object obj) {
195 try {
196 ByteArrayOutputStream baos = new ByteArrayOutputStream();
197 new ObjectOutputStream(baos).writeObject(obj);
198 return baos.toByteArray();
199 } catch (IOException e) { throw new RuntimeException(e); }}
200 static Object readObject(byte[] bytes)
201 throws IOException, ClassNotFoundException {
202 InputStream is = new ByteArrayInputStream(bytes);
203 return new ObjectInputStream(is).readObject();}
204 @SuppressWarnings("unchecked")
205 static <T> T serialClone(T obj) {
206 try { return (T) readObject(serializedForm(obj)); }
207 catch (Exception e) { throw new RuntimeException(e); }}
208 }