/*
* Copyright (c) 2012, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/* @test
* @bug 6206780
* @summary Test that all public unsynchronized methods of StringBuffer are either directly or indirectly synchronized
*/
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* TestSynchronization tests whether synchronized methods calls on an object
* result in synchronized calls. Note that this may not test all cases desired.
* It only tests whether some synchronization has occurred on the object during
* the call chain, and can't tell whether the object was locked across all
* operations that have been performed on the object.
*/
public class TestSynchronization {
/**
* Define parameters used in methods of StringBuffer - admittedly a bit of
* hack but 'purpose-built' for StringBuffer. Something more general could
* probably be developed if the test needs to be more widely adopted.
* <p/>
* boolean char char[] int double float long Object CharSequence String
* StringBuffer StringBuilder
* <p/>
*/
private static final boolean BOOLEAN_VAL = true;
private static final char CHAR_VAL = 'x';
private static final char[] CHAR_ARRAY_VAL = {'c', 'h', 'a', 'r', 'a', 'r',
'r', 'a', 'y'};
private static final int INT_VAL = 1;
private static final double DOUBLE_VAL = 1.0d;
private static final float FLOAT_VAL = 1.0f;
private static final long LONG_VAL = 1L;
private static final Object OBJECT_VAL = new Object();
private static final String STRING_VAL = "String value";
private static final StringBuilder STRING_BUILDER_VAL =
new StringBuilder("StringBuilder value");
private static final StringBuffer STRING_BUFFER_VAL =
new StringBuffer("StringBuffer value");
private static final CharSequence[] CHAR_SEQUENCE_VAL = {STRING_VAL,
STRING_BUILDER_VAL, STRING_BUFFER_VAL};
public static void main(String... args) throws Exception {
// First, test the tester
testClass(MyTestClass.class, /*
* self-test
*/ true);
// Finally, test StringBuffer
testClass(StringBuffer.class, /*
* self-test
*/ false);
}
/**
* Test all the public, unsynchronized methods of the given class. If
* isSelfTest is true, this is a self-test to ensure that the test program
* itself is working correctly. Should help ensure correctness of this
* program if it changes.
* <p/>
* @param aClass - the class to test
* @param isSelfTest - true if this is the special self-test class
* @throws SecurityException
*/
private static void testClass(Class<?> aClass, boolean isSelfTest) throws
Exception {
// Get all unsynchronized public methods via reflection. We don't need
// to test synchronized methods. By definition. they are already doing
// the right thing.
List<Method> methods = Arrays.asList(aClass.getDeclaredMethods());
for (Method m : methods) {
// skip synthetic methods, like default interface methods and lambdas
if (m.isSynthetic()) {
continue;
}
int modifiers = m.getModifiers();
if (Modifier.isPublic(modifiers)
&& !Modifier.isSynchronized(modifiers)) {
try {
testMethod(aClass, m);
} catch (TestFailedException e) {
if (isSelfTest) {
String methodName = e.getMethod().getName();
switch (methodName) {
case "should_pass":
throw new RuntimeException(
"Test failed: self-test failed. The 'should_pass' method did not pass the synchronization test. Check the test code.");
case "should_fail":
break;
default:
throw new RuntimeException(
"Test failed: something is amiss with the test. A TestFailedException was generated on a call to "
+ methodName + " which we didn't expect to test in the first place.");
}
} else {
throw new RuntimeException("Test failed: the method "
+ e.getMethod().toString()
+ " should be synchronized, but isn't.");
}
}
}
}
}
private static void invokeMethod(Class<?> aClass, final Method m,
final Object[] args) throws TestFailedException, Exception {
//System.out.println( "Invoking " + m.toString() + " with parameters " + Arrays.toString(args));
final Constructor<?> objConstructor;
Object obj = null;
objConstructor = aClass.getConstructor(String.class);
obj = objConstructor.newInstance("LeftPalindrome-emordnilaP-thgiR");
// test method m for synchronization
if (!isSynchronized(m, obj, args)) {
throw new TestFailedException(m);
}
}
private static void testMethod(Class<?> aClass, Method m) throws
Exception {
/*
* Construct call with arguments of the correct type. Note that the
* values are somewhat irrelevant. If the call actually succeeds, it
* means we aren't synchronized and the test has failed.
*/
Class<?>[] pTypes = m.getParameterTypes();
List<Integer> charSequenceArgs = new ArrayList<>();
Object[] args = new Object[pTypes.length];
for (int i = 0; i < pTypes.length; i++) {
// determine the type and create the corresponding actual argument
Class<?> pType = pTypes[i];
if (pType.equals(boolean.class)) {
args[i] = BOOLEAN_VAL;
} else if (pType.equals(char.class)) {
args[i] = CHAR_VAL;
} else if (pType.equals(int.class)) {
args[i] = INT_VAL;
} else if (pType.equals(double.class)) {
args[i] = DOUBLE_VAL;
} else if (pType.equals(float.class)) {
args[i] = FLOAT_VAL;
} else if (pType.equals(long.class)) {
args[i] = LONG_VAL;
} else if (pType.equals(Object.class)) {
args[i] = OBJECT_VAL;
} else if (pType.equals(StringBuilder.class)) {
args[i] = STRING_BUILDER_VAL;
} else if (pType.equals(StringBuffer.class)) {
args[i] = STRING_BUFFER_VAL;
} else if (pType.equals(String.class)) {
args[i] = STRING_VAL;
} else if (pType.isArray() && pType.getComponentType().equals(char.class)) {
args[i] = CHAR_ARRAY_VAL;
} else if (pType.equals(CharSequence.class)) {
charSequenceArgs.add(new Integer(i));
} else {
throw new RuntimeException("Test Failed: not accounting for method call with parameter type of " + pType.getName() + " You must update the test.");
}
}
/*
* If there are no CharSequence args, we can simply invoke our method
* and test it
*/
if (charSequenceArgs.isEmpty()) {
invokeMethod(aClass, m, args);
} else {
/*
* Iterate through the different CharSequence types and invoke the
* method for each type.
*/
if (charSequenceArgs.size() > 1) {
throw new RuntimeException("Test Failed: the test cannot handle a method with multiple CharSequence arguments. You must update the test to handle the method "
+ m.toString());
}
for (int j = 0; j < CHAR_SEQUENCE_VAL.length; j++) {
args[charSequenceArgs.get(0)] = CHAR_SEQUENCE_VAL[j];
invokeMethod(aClass, m, args);
}
}
}
@SuppressWarnings("serial")
private static class TestFailedException extends Exception {
final Method m;
public Method getMethod() {
return m;
}
public TestFailedException(Method m) {
this.m = m;
}
}
static class InvokeTask implements Runnable {
private final Method m;
private final Object target;
private final Object[] args;
InvokeTask(Method m, Object target, Object... args) {
this.m = m;
this.target = target;
this.args = args;
}
@Override
public void run() {
try {
m.invoke(target, args);
} catch (IllegalAccessException | IllegalArgumentException |
InvocationTargetException e) {
e.printStackTrace();
}
}
}
/**
* isSynchronized tests whether the given method is synchronized or not by
* invoking it in a thread and testing the thread state after starting the
* thread
* <p/>
* @param m the method to test
* @param target the object the method is executed on
* @param args the arguments passed to the method
* @return true iff the method is synchronized
*/
private static boolean isSynchronized(Method m, Object target,
Object... args) {
Thread t = new Thread(new InvokeTask(m, target, args));
Boolean isSynchronized = null;
synchronized (target) {
t.start();
while (isSynchronized == null) {
switch (t.getState()) {
case NEW:
case RUNNABLE:
case WAITING:
case TIMED_WAITING:
Thread.yield();
break;
case BLOCKED:
isSynchronized = true;
break;
case TERMINATED:
isSynchronized = false;
break;
}
}
}
try {
t.join();
} catch (InterruptedException ex) {
ex.printStackTrace();
}
return isSynchronized;
}
/*
* This class is used to test the synchronization tester above. It has a
* method, should_pass, that is unsynchronized but calls a synchronized
* method. It has another method, should_fail, which isn't synchronized and
* doesn't call a synchronized method. The former should pass and the latter
* should fail.
*/
private static class MyTestClass {
@SuppressWarnings("unused")
public MyTestClass(String s) {
}
@SuppressWarnings("unused")
public void should_pass() {
// call sync method
sync_shouldnt_be_tested();
}
@SuppressWarnings("unused")
public void should_fail() {
}
public synchronized void sync_shouldnt_be_tested() {
}
}
}