undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/jdk/java/lang/ref/FinalizerHistogramTest.java

@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2015, 2025, 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.
+ */
+
+import jdk.test.whitebox.WhiteBox;
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.ReentrantLock;
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Field;
+
+/*
+ * @test
+ * @summary Unit test for FinalizerHistogram
+ * @modules java.base/java.lang.ref:open
+ * @library /test/lib
+ * @build jdk.test.whitebox.WhiteBox
+ * @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
+ * @run main/othervm
+ *      -Xbootclasspath/a:.
+ *      -XX:+UnlockDiagnosticVMOptions
+ *      -XX:+WhiteBoxAPI
+ *      FinalizerHistogramTest
+ */
+
+public class FinalizerHistogramTest {
+    static ReentrantLock lock = new ReentrantLock();
+    static final AtomicInteger initializedCount = new AtomicInteger(0);
+    static final int OBJECTS_COUNT = 1000;
+
+    static WhiteBox wb;
+
+    static class MyObject {
+        public MyObject() {
+            // Make sure object allocation/deallocation is not optimized out
+            initializedCount.incrementAndGet();
+        }
+
+        protected void finalize() {
+            // Trap the object in a finalization queue
+            lock.lock();
+        }
+    }
+
+    public static void main(String[] argvs) throws InterruptedException {
+        try {
+            lock.lock();
+            for(int i = 0; i < OBJECTS_COUNT; ++i) {
+                new MyObject();
+            }
+            System.out.println("Objects intialized: " + initializedCount.get());
+            wb = WhiteBox.getWhiteBox();
+            wb.fullGC();
+            boolean refProResult;
+            do {
+                refProResult = wb.waitForReferenceProcessing();
+                System.out.println("waitForReferenceProcessing returned: " + refProResult);
+            } while (refProResult);
+
+            Class<?> klass = Class.forName("java.lang.ref.FinalizerHistogram");
+
+            Method m = klass.getDeclaredMethod("getFinalizerHistogram");
+            m.setAccessible(true);
+            Object entries[] = (Object[]) m.invoke(null);
+
+            Class<?> entryKlass = Class.forName("java.lang.ref.FinalizerHistogram$Entry");
+            Field name = entryKlass.getDeclaredField("className");
+            name.setAccessible(true);
+            Field count = entryKlass.getDeclaredField("instanceCount");
+            count.setAccessible(true);
+
+            System.out.println("Unreachable instances waiting for finalization");
+            System.out.println("#instances  class name");
+            System.out.println("-----------------------");
+
+            boolean found = false;
+            for (Object entry : entries) {
+                Object e = entryKlass.cast(entry);
+                System.out.printf("%10d %s\n", count.get(e), name.get(e));
+                if (((String) name.get(e)).indexOf("MyObject") != -1 ) {
+                    found = true;
+                }
+            }
+
+            if (!found) {
+                throw new RuntimeException("MyObject is not found in test output");
+            }
+
+            System.out.println("Test PASSED");
+        } catch(Exception e) {
+           System.err.println("Test failed with " + e);
+           e.printStackTrace(System.err);
+           throw new RuntimeException("Test failed");
+        } finally {
+            lock.unlock();
+        }
+    }
+}