--- /dev/null	2020-03-17 11:31:50.000000000 -0700
+++ new/test/jdk/java/lang/invoke/defineHiddenClass/UnloadingTest.java	2020-03-17 11:31:49.000000000 -0700
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2020, 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
+ * @summary verify if the hidden class is unloaded when the class loader is GC'ed
+ * @library /test/lib/
+ * @build jdk.test.lib.util.ForceGC
+ * @run testng/othervm UnloadingTest
+ */
+
+import java.io.IOException;
+import java.lang.invoke.MethodHandles.Lookup;
+import java.lang.ref.Reference;
+import java.lang.ref.WeakReference;
+import java.lang.reflect.Method;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import jdk.test.lib.util.ForceGC;
+
+import jdk.test.lib.compiler.CompilerUtils;
+import jdk.test.lib.Utils;
+
+import org.testng.annotations.BeforeTest;
+import org.testng.annotations.Test;
+
+import static java.lang.invoke.MethodHandles.lookup;
+import static org.testng.Assert.*;
+
+public class UnloadingTest {
+    private static final Path CLASSES_DIR = Paths.get("classes");
+    private static byte[] hiddenClassBytes;
+
+    @BeforeTest
+    static void setup() throws IOException {
+        Path src = Paths.get(Utils.TEST_SRC, "src", "LookupHelper.java");
+        if (!CompilerUtils.compile(src, CLASSES_DIR)) {
+            throw new RuntimeException("Compilation of the test failed: " + src);
+        }
+
+        hiddenClassBytes = Files.readAllBytes(CLASSES_DIR.resolve("LookupHelper.class"));
+    }
+
+    /*
+     * Test that a hidden class is unloaded while the loader remains strongly reachable
+     */
+    @Test
+    public void unloadable() throws Exception {
+        TestLoader loader = new TestLoader();
+        Class<?> helper = Class.forName("LookupHelper", true, loader);
+        Method m = helper.getMethod("getLookup");
+        Lookup lookup = (Lookup)m.invoke(null);
+        HiddenClassUnloader unloader = new HiddenClassUnloader(lookup, false);
+        // the hidden class should be unloaded
+        unloader.unload();
+
+        // loader is strongly reachable
+        Reference.reachabilityFence(loader);
+    }
+
+    /*
+     * Test that a hidden class is not unloaded when the loader is strongly reachable
+     */
+    @Test
+    public void notUnloadable() throws Exception {
+        TestLoader loader = new TestLoader();
+        Class<?> helper = Class.forName("LookupHelper", true, loader);
+        Method m = helper.getMethod("getLookup");
+        Lookup lookup = (Lookup)m.invoke(null);
+        HiddenClassUnloader unloader = new HiddenClassUnloader(lookup, true);
+        assertFalse(unloader.tryUnload());      // hidden class is not unloaded
+    }
+
+    static class HiddenClassUnloader {
+        private final WeakReference<?> weakRef;
+        HiddenClassUnloader(Lookup lookup, boolean strong) throws Exception {
+            Class<?> hc;
+            if (strong) {
+                hc = lookup.defineHiddenClass(hiddenClassBytes, false, Lookup.ClassOption.STRONG).lookupClass();
+            } else {
+                hc = lookup.defineHiddenClass(hiddenClassBytes, false).lookupClass();
+            }
+            this.weakRef = new WeakReference<>(hc);
+            assertTrue(hc.getClassLoader() == lookup.lookupClass().getClassLoader());
+        }
+
+        void unload() {
+            // Force garbage collection to trigger unloading of class loader and native library
+            ForceGC gc = new ForceGC();
+            assertTrue(gc.await(() -> weakRef.get() == null));
+
+            if (weakRef.get() != null) {
+                throw new RuntimeException("loader " + " not unloaded!");
+            }
+        }
+
+        boolean tryUnload() {
+            ForceGC gc = new ForceGC();
+            return gc.await(() -> weakRef.get() == null);
+        }
+    }
+
+    static class TestLoader extends URLClassLoader {
+        static URL[] toURLs() {
+            try {
+                return new URL[] { CLASSES_DIR.toUri().toURL() };
+            } catch (MalformedURLException e) {
+                throw new Error(e);
+            }
+        }
+
+        static AtomicInteger counter = new AtomicInteger();
+        TestLoader() {
+            super("testloader-" + counter.addAndGet(1), toURLs(), ClassLoader.getSystemClassLoader());
+        }
+    }
+}