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
32import static java.util.concurrent.TimeUnit.MILLISECONDS;
33
34import java.io.ByteArrayInputStream;
35import java.io.ByteArrayOutputStream;
36import java.io.IOException;
37import java.io.InputStream;
38import java.io.ObjectInputStream;
39import java.io.ObjectOutputStream;
40import java.util.Random;
41import java.util.concurrent.CyclicBarrier;
42import java.util.concurrent.ExecutorService;
43import java.util.concurrent.Executors;
44import java.util.concurrent.TimeUnit;
45import java.util.concurrent.locks.Lock;
46import java.util.concurrent.locks.ReentrantLock;
47import java.util.concurrent.locks.ReentrantReadWriteLock;
48import jdk.testlibrary.Utils;
49
50// I am the Cownt, and I lahve to cownt.
51public 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}
209