hotspot/test/runtime/ClassUnload/UnloadTest.java
changeset 17311 6ba3841cb7f9
child 25958 8dc85547d6d6
--- /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");
+    }
+}
+