1 /*
   2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @summary Verifies the behaviour of Unsafe.allocateInstance
  27  * @library /test/lib
  28  * @modules java.base/jdk.internal.misc
  29  *          java.management
  30  * @run main AllocateInstance
  31  */
  32 
  33 import jdk.test.lib.Utils;
  34 import jdk.internal.misc.Unsafe;
  35 import static jdk.test.lib.Asserts.*;
  36 
  37 public class AllocateInstance {
  38     static final Unsafe UNSAFE = Utils.getUnsafe();
  39 
  40     class TestClass {
  41         public boolean calledConstructor = false;
  42 
  43         public TestClass() {
  44             calledConstructor = true;
  45         }
  46     }
  47 
  48     static void testConstructorCall() throws InstantiationException {
  49         // allocateInstance() should not result in a call to the constructor
  50         TestClass tc = (TestClass)UNSAFE.allocateInstance(TestClass.class);
  51         assertFalse(tc.calledConstructor);
  52     }
  53 
  54     abstract class AbstractClass {
  55         public AbstractClass() {}
  56     }
  57 
  58     static void testAbstractClass() {
  59         try {
  60             AbstractClass ac = (AbstractClass) UNSAFE.allocateInstance(AbstractClass.class);
  61             throw new AssertionError("Should throw InstantiationException for an abstract class");
  62         } catch (InstantiationException e) {
  63             // Expected
  64         }
  65     }
  66 
  67     interface AnInterface {}
  68 
  69     static void testInterface() {
  70         try {
  71             AnInterface ai = (AnInterface) UNSAFE.allocateInstance(AnInterface.class);
  72             throw new AssertionError("Should throw InstantiationException for an interface");
  73         } catch (InstantiationException e) {
  74             // Expected
  75         }
  76     }
  77 
  78     public static void main(String args[]) throws Exception {
  79         for (int i = 0; i < 20_000; i++) {
  80             testConstructorCall();
  81             testAbstractClass();
  82             testInterface();
  83         }
  84     }
  85 }