--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/ClassUnload/KeepAliveClass.java	Tue May 07 21:36:59 2013 +0200
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2013, 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 KeepAliveClass
+ * @summary This test case uses a java.lang.Class instance to keep a class alive.
+ * @library /testlibrary /testlibrary/whitebox /runtime/testlibrary
+ * @library classes
+ * @build KeepAliveClass test.Empty
+ * @build ClassUnloadCommon
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveClass
+ */
+
+import java.lang.ref.SoftReference;
+import sun.hotspot.WhiteBox;
+
+/**
+ * Test that verifies that classes are not unloaded when specific types of references are kept to them.
+ */
+public class KeepAliveClass {
+  private static final String className = "test.Empty";
+  private static final WhiteBox wb = WhiteBox.getWhiteBox();
+  public static Object escape = null;
+
+  public static void main(String... args) throws Exception {
+    ClassLoader cl = ClassUnloadCommon.newClassLoader();
+    Class<?> c = cl.loadClass(className);
+    Object o = c.newInstance();
+    o = null; cl = null;
+    escape = c;
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testClass (1) alive: " + isAlive);
+
+        ClassUnloadCommon.failIf(!isAlive, "should be alive");
+    }
+
+    ClassUnloadCommon.triggerUnloading();
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testClass (2) alive: " + isAlive);
+
+        ClassUnloadCommon.failIf(!isAlive, "should be alive");
+    }
+    c = null;
+    escape = null;
+    ClassUnloadCommon.triggerUnloading();
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testClass (3) alive: " + isAlive);
+        ClassUnloadCommon.failIf(isAlive, "should be unloaded");
+    }
+
+  }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/ClassUnload/KeepAliveClassLoader.java	Tue May 07 21:36:59 2013 +0200
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2013, 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 KeepAliveClassLoader
+ * @summary This test case uses a java.lang.ClassLoader instance to keep a class alive.
+ * @library /testlibrary /testlibrary/whitebox /runtime/testlibrary
+ * @library classes
+ * @build KeepAliveClassLoader test.Empty
+ * @build ClassUnloadCommon
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveClassLoader
+ */
+
+import sun.hotspot.WhiteBox;
+
+/**
+ * Test that verifies that classes are not unloaded when specific types of references are kept to them.
+ */
+public class KeepAliveClassLoader {
+  private static final String className = "test.Empty";
+  private static final WhiteBox wb = WhiteBox.getWhiteBox();
+  public static Object escape = null;
+
+
+  public static void main(String... args) throws Exception {
+    ClassLoader cl = ClassUnloadCommon.newClassLoader();
+    Class<?> c = cl.loadClass(className);
+    Object o = c.newInstance();
+    o = null; c = null;
+    escape = cl;
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testClassLoader (1) alive: " + isAlive);
+
+        ClassUnloadCommon.failIf(!isAlive, "should be alive");
+    }
+    ClassUnloadCommon.triggerUnloading();
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testClassLoader (2) alive: " + isAlive);
+
+        ClassUnloadCommon.failIf(!isAlive, "should be alive");
+    }
+    cl = null;
+    escape = null;
+    ClassUnloadCommon.triggerUnloading();
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testClassLoader (3) alive: " + isAlive);
+        ClassUnloadCommon.failIf(isAlive, "should be unloaded");
+    }
+
+  }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/ClassUnload/KeepAliveObject.java	Tue May 07 21:36:59 2013 +0200
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2013, 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 KeepAliveObject
+ * @summary This test case uses a class instance to keep the class alive.
+ * @library /testlibrary /testlibrary/whitebox /runtime/testlibrary
+ * @library classes
+ * @build KeepAliveObject test.Empty
+ * @build ClassUnloadCommon
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveObject
+ */
+
+import sun.hotspot.WhiteBox;
+
+/**
+ * Test that verifies that classes are not unloaded when specific types of references are kept to them.
+ */
+public class KeepAliveObject {
+  private static final String className = "test.Empty";
+  private static final WhiteBox wb = WhiteBox.getWhiteBox();
+  public static Object escape = null;
+
+  public static void main(String... args) throws Exception {
+    ClassLoader cl = ClassUnloadCommon.newClassLoader();
+    Class<?> c = cl.loadClass(className);
+    Object o = c.newInstance();
+    cl = null; c = null;
+    escape = o;
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testObject (1) alive: " + isAlive);
+
+        ClassUnloadCommon.failIf(!isAlive, "should be alive");
+    }
+
+    ClassUnloadCommon.triggerUnloading();
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testObject (2) alive: " + isAlive);
+
+        ClassUnloadCommon.failIf(!isAlive, "should be alive");
+    }
+    o = null;
+    escape = null;
+    ClassUnloadCommon.triggerUnloading();
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testObject (3) alive: " + isAlive);
+        ClassUnloadCommon.failIf(isAlive, "should be unloaded");
+    }
+
+  }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/ClassUnload/KeepAliveSoftReference.java	Tue May 07 21:36:59 2013 +0200
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2013, 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 KeepAliveSoftReference
+ * @summary This test case uses a java.lang.ref.SoftReference referencing a class instance to keep a class alive.
+ * @library /testlibrary /testlibrary/whitebox /runtime/testlibrary
+ * @library classes
+ * @build KeepAliveSoftReference test.Empty
+ * @build ClassUnloadCommon
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI KeepAliveSoftReference
+ */
+
+import java.lang.ref.SoftReference;
+import sun.hotspot.WhiteBox;
+
+/**
+ * Test that verifies that classes are not unloaded when specific types of references are kept to them.
+ */
+public class KeepAliveSoftReference {
+  private static final String className = "test.Empty";
+  private static final WhiteBox wb = WhiteBox.getWhiteBox();
+
+  public static void main(String... args) throws Exception {
+    ClassLoader cl = ClassUnloadCommon.newClassLoader();
+    Class<?> c = cl.loadClass(className);
+    Object o = c.newInstance();
+    SoftReference<Object> sr = new SoftReference(o);
+    o = null; c = null; cl = null;
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testSoftReference (1) alive: " + isAlive);
+        boolean cleared = (sr.get() == null);
+        boolean shouldBeAlive = !cleared;
+        ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive);
+    }
+
+    ClassUnloadCommon.triggerUnloading();
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testSoftReference (2) alive: " + isAlive);
+        boolean cleared = (sr.get() == null);
+        boolean shouldBeAlive = !cleared;
+        ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive);
+    }
+    sr.clear();
+    ClassUnloadCommon.triggerUnloading();
+
+    {
+        boolean isAlive = wb.isClassAlive(className);
+        System.out.println("testSoftReference (3) alive: " + isAlive);
+        boolean cleared = (sr.get() == null);
+        boolean shouldBeAlive = !cleared;
+        ClassUnloadCommon.failIf(isAlive != shouldBeAlive, "" + isAlive + " != " + shouldBeAlive);
+    }
+  }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/ClassUnload/UnloadTest.java	Tue May 07 21:36:59 2013 +0200
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2013, 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 UnloadTest
+ * @library /runtime/testlibrary /testlibrary /testlibrary/whitebox
+ * @library classes
+ * @build ClassUnloadCommon test.Empty
+ * @build UnloadTest
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -Xmn8m -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI UnloadTest
+ */
+import sun.hotspot.WhiteBox;
+
+/**
+ * Test that verifies that classes are unloaded when they are no longer reachable.
+ *
+ * The test creates a class loader, uses the loader to load a class and creates an instance
+ * of that class. The it nulls out all the references to the instance, class and class loader
+ * and tries to trigger class unloading. Then it verifies that the class is no longer
+ * loaded by the VM.
+ */
+public class UnloadTest {
+    private static String className = "test.Empty";
+
+    public static void main(String... args) throws Exception {
+       run();
+    }
+
+    private static void run() throws Exception {
+        final WhiteBox wb = WhiteBox.getWhiteBox();
+
+        ClassUnloadCommon.failIf(wb.isClassAlive(className), "is not expected to be alive yet");
+
+        ClassLoader cl = ClassUnloadCommon.newClassLoader();
+        Class<?> c = cl.loadClass(className);
+        Object o = c.newInstance();
+
+        ClassUnloadCommon.failIf(!wb.isClassAlive(className), "should be live here");
+
+        cl = null; c = null; o = null;
+        ClassUnloadCommon.triggerUnloading();
+        ClassUnloadCommon.failIf(wb.isClassAlive(className), "should have been unloaded");
+    }
+}
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/ClassUnload/classes/test/Empty.java	Tue May 07 21:36:59 2013 +0200
@@ -0,0 +1,5 @@
+package test;
+
+public class Empty {
+public String toString() { return "nothing"; }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/testlibrary/ClassUnloadCommon.java	Tue May 07 21:36:59 2013 +0200
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2013, 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 java.io.File;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+
+public class ClassUnloadCommon {
+    public static class TestFailure extends RuntimeException {
+        TestFailure(String msg) {
+            super(msg);
+        }
+    }
+
+    public static void failIf(boolean value, String msg) {
+        if (value) throw new TestFailure("Test failed: " + msg);
+    }
+
+    private static volatile Object dummy = null;
+    private static void allocateMemory(int kilobytes) {
+        ArrayList<byte[]> l = new ArrayList<>();
+        dummy = l;
+        for (int i = kilobytes; i > 0; i -= 1) {
+            l.add(new byte[1024]);
+        }
+        l = null;
+        dummy = null;
+    }
+
+    public static void triggerUnloading() {
+        allocateMemory(16 * 1024); // yg size is 8m with cms, force young collection
+        System.gc();
+    }
+
+    public static ClassLoader newClassLoader() {
+        try {
+            return new URLClassLoader(new URL[] {
+                Paths.get(System.getProperty("test.classes",".") + File.separatorChar + "classes").toUri().toURL(),
+            }, null);
+        } catch (MalformedURLException e){
+            throw new RuntimeException("Unexpected URL conversion failure", e);
+        }
+    }
+
+}