/*
* Copyright (c) 2005, 2008, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* questions.
*/
/*
* @test
* @bug 6207928 6328220 6378321 6625723
* @summary Recursive lock invariant sanity checks
* @library /lib/testlibrary/
* @author Martin Buchholz
*/
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Random;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import jdk.testlibrary.Utils;
// I am the Cownt, and I lahve to cownt.
public class Count {
static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000);
final Random rnd = new Random();
void lock(Lock lock) {
try {
switch (rnd.nextInt(4)) {
case 0: lock.lock(); break;
case 1: lock.lockInterruptibly(); break;
case 2: check(lock.tryLock()); break;
case 3: check(lock.tryLock(45, TimeUnit.MINUTES)); break;
}
} catch (Throwable t) { unexpected(t); }
}
void test(String[] args) throws Throwable {
for (boolean fair : new boolean[] { true, false })
for (boolean serialClone : new boolean[] { true, false }) {
testReentrantLocks(fair, serialClone);
testConcurrentReadLocks(fair, serialClone);
}
}
void testConcurrentReadLocks(final boolean fair,
final boolean serialClone) throws Throwable {
final int nThreads = 10;
final CyclicBarrier barrier = new CyclicBarrier(nThreads);
final ExecutorService es = Executors.newFixedThreadPool(nThreads);
final ReentrantReadWriteLock rwl = serialClone ?
serialClone(new ReentrantReadWriteLock(fair)) :
new ReentrantReadWriteLock(fair);
for (int i = 0; i < nThreads; i++) {
es.submit(new Runnable() { public void run() {
try {
int n = 5;
for (int i = 0; i < n; i++) {
barrier.await();
equal(rwl.getReadHoldCount(), i);
equal(rwl.getWriteHoldCount(), 0);
check(! rwl.isWriteLocked());
equal(rwl.getReadLockCount(), nThreads * i);
barrier.await();
lock(rwl.readLock());
}
for (int i = 0; i < n; i++) {
rwl.readLock().unlock();
barrier.await();
equal(rwl.getReadHoldCount(), n-i-1);
equal(rwl.getReadLockCount(), nThreads*(n-i-1));
equal(rwl.getWriteHoldCount(), 0);
check(! rwl.isWriteLocked());
barrier.await();
}
THROWS(IllegalMonitorStateException.class,
new F(){void f(){rwl.readLock().unlock();}},
new F(){void f(){rwl.writeLock().unlock();}});
barrier.await();
} catch (Throwable t) { unexpected(t); }}});}
es.shutdown();
check(es.awaitTermination(LONG_DELAY_MS, MILLISECONDS));
}
void testReentrantLocks(final boolean fair,
final boolean serialClone) throws Throwable {
final ReentrantLock rl = serialClone ?
serialClone(new ReentrantLock(fair)) :
new ReentrantLock(fair);
final ReentrantReadWriteLock rwl = serialClone ?
serialClone(new ReentrantReadWriteLock(fair)) :
new ReentrantReadWriteLock(fair);
final int depth = 10;
equal(rl.isFair(), fair);
equal(rwl.isFair(), fair);
check(! rl.isLocked());
check(! rwl.isWriteLocked());
check(! rl.isHeldByCurrentThread());
check(! rwl.isWriteLockedByCurrentThread());
check(! rwl.writeLock().isHeldByCurrentThread());
for (int i = 0; i < depth; i++) {
equal(rl.getHoldCount(), i);
equal(rwl.getReadLockCount(), i);
equal(rwl.getReadHoldCount(), i);
equal(rwl.getWriteHoldCount(), i);
equal(rwl.writeLock().getHoldCount(), i);
equal(rl.isLocked(), i > 0);
equal(rwl.isWriteLocked(), i > 0);
lock(rl);
lock(rwl.writeLock());
lock(rwl.readLock());
}
for (int i = depth; i > 0; i--) {
check(! rl.hasQueuedThreads());
check(! rwl.hasQueuedThreads());
check(! rl.hasQueuedThread(Thread.currentThread()));
check(! rwl.hasQueuedThread(Thread.currentThread()));
check(rl.isLocked());
check(rwl.isWriteLocked());
check(rl.isHeldByCurrentThread());
check(rwl.isWriteLockedByCurrentThread());
check(rwl.writeLock().isHeldByCurrentThread());
equal(rl.getQueueLength(), 0);
equal(rwl.getQueueLength(), 0);
equal(rwl.getReadLockCount(), i);
equal(rl.getHoldCount(), i);
equal(rwl.getReadHoldCount(), i);
equal(rwl.getWriteHoldCount(), i);
equal(rwl.writeLock().getHoldCount(), i);
rwl.readLock().unlock();
rwl.writeLock().unlock();
rl.unlock();
}
THROWS(IllegalMonitorStateException.class,
new F(){void f(){rl.unlock();}},
new F(){void f(){rwl.readLock().unlock();}},
new F(){void f(){rwl.writeLock().unlock();}});
}
//--------------------- Infrastructure ---------------------------
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
public static void main(String[] args) throws Throwable {
new Count().instanceMain(args);}
void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
abstract class F {abstract void f() throws Throwable;}
void THROWS(Class<? extends Throwable> k, F... fs) {
for (F f : fs)
try {f.f(); fail("Expected " + k.getName() + " not thrown");}
catch (Throwable t) {
if (k.isAssignableFrom(t.getClass())) pass();
else unexpected(t);}}
static byte[] serializedForm(Object obj) {
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
new ObjectOutputStream(baos).writeObject(obj);
return baos.toByteArray();
} catch (IOException e) { throw new RuntimeException(e); }}
static Object readObject(byte[] bytes)
throws IOException, ClassNotFoundException {
InputStream is = new ByteArrayInputStream(bytes);
return new ObjectInputStream(is).readObject();}
@SuppressWarnings("unchecked")
static <T> T serialClone(T obj) {
try { return (T) readObject(serializedForm(obj)); }
catch (Exception e) { throw new RuntimeException(e); }}
}