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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.List;
/**
* Some finalizer tests.
*
* This only works if System.runFinalization() causes finalizers to run
* immediately or very soon.
*/
public class Main {
private static void snooze(int ms) {
try {
Thread.sleep(ms);
} catch (InterruptedException ie) {
System.out.println("Snooze: " + ie.getMessage());
}
}
public static WeakReference<FinalizerTest> makeRef() {
/*
* Make ft in another thread, so there is no danger of
* a conservative reference leaking onto the main thread's
* stack.
*/
final List<WeakReference<FinalizerTest>> wimp =
new ArrayList<WeakReference<FinalizerTest>>();
Thread t = new Thread() {
public void run() {
FinalizerTest ft = new FinalizerTest("wahoo");
wimp.add(new WeakReference<FinalizerTest>(ft));
ft = null;
}
};
t.start();
try {
t.join();
} catch (InterruptedException ie) {
throw new RuntimeException(ie);
}
return wimp.get(0);
}
public static String wimpString(final WeakReference<FinalizerTest> wimp) {
/*
* Do the work in another thread, so there is no danger of a
* conservative reference to ft leaking onto the main thread's
* stack.
*/
final String[] s = new String[1];
Thread t = new Thread() {
public void run() {
FinalizerTest ref = wimp.get();
if (ref != null) {
s[0] = ref.toString();
}
}
};
t.start();
try {
t.join();
} catch (InterruptedException ie) {
throw new RuntimeException(ie);
}
return s[0];
}
public static void main(String[] args) {
WeakReference<FinalizerTest> wimp = makeRef();
System.out.println("wimp: " + wimpString(wimp));
/* this will try to collect and finalize ft */
System.out.println("gc");
Runtime.getRuntime().gc();
System.out.println("wimp: " + wimpString(wimp));
System.out.println("finalize");
System.runFinalization();
System.out.println("wimp: " + wimpString(wimp));
System.out.println("sleep");
snooze(1000);
System.out.println("reborn: " + FinalizerTest.mReborn);
System.out.println("wimp: " + wimpString(wimp));
System.out.println("reset reborn");
Runtime.getRuntime().gc();
FinalizerTest.mReborn = FinalizerTest.mNothing;
System.out.println("gc + finalize");
System.gc();
System.runFinalization();
System.out.println("sleep");
snooze(1000);
System.out.println("reborn: " + FinalizerTest.mReborn);
System.out.println("wimp: " + wimpString(wimp));
// Test runFinalization with multiple objects.
runFinalizationTest();
}
static class FinalizeCounter {
public static final int maxCount = 1024;
public static boolean finalized[] = new boolean[maxCount];
private static Object finalizeLock = new Object();
private static volatile int finalizeCount = 0;
private int index;
static int getCount() {
return finalizeCount;
}
static void printNonFinalized() {
for (int i = 0; i < maxCount; ++i) {
if (!FinalizeCounter.finalized[i]) {
System.err.println("Element " + i + " was not finalized");
}
}
}
FinalizeCounter(int index) {
this.index = index;
}
protected void finalize() {
synchronized(finalizeLock) {
++finalizeCount;
finalized[index] = true;
}
}
}
private static void allocFinalizableObjects(int count) {
Object[] objs = new Object[count];
for (int i = 0; i < count; ++i) {
objs[i] = new FinalizeCounter(i);
}
}
private static void runFinalizationTest() {
allocFinalizableObjects(FinalizeCounter.maxCount);
Runtime.getRuntime().gc();
System.runFinalization();
System.out.println("Finalized " + FinalizeCounter.getCount() + " / " + FinalizeCounter.maxCount);
if (FinalizeCounter.getCount() != FinalizeCounter.maxCount) {
// Print out all the finalized elements.
FinalizeCounter.printNonFinalized();
// Try to sleep for a couple seconds to see if the objects became finalized after.
try {
java.lang.Thread.sleep(2000);
} catch (InterruptedException e) {
}
System.out.println("After sleep finalized " + FinalizeCounter.getCount() + " / " + FinalizeCounter.maxCount);
FinalizeCounter.printNonFinalized();
}
}
public static class FinalizerTest {
public static FinalizerTest mNothing = new FinalizerTest("nothing");
public static FinalizerTest mReborn = mNothing;
private final String message;
private boolean finalized = false;
public FinalizerTest(String message) {
this.message = message;
}
public String toString() {
return "[FinalizerTest message=" + message +
", finalized=" + finalized + "]";
}
protected void finalize() {
finalized = true;
mReborn = this;
}
}
}
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