1 /* 2 * Copyright (c) 2015, 2016, 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 * @requires vm.compMode != "Xcomp" 27 * @bug 8058897 28 * @library /test/lib 29 * @modules java.base/jdk.internal.misc 30 * java.management 31 * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:MallocMaxTestWords=100m Reallocate 32 */ 33 34 import jdk.test.lib.unsafe.UnsafeHelper; 35 import jdk.internal.misc.Unsafe; 36 import static jdk.test.lib.Asserts.*; 37 38 public class Reallocate { 39 public static void main(String args[]) throws Exception { 40 Unsafe unsafe = UnsafeHelper.getUnsafe(); 41 42 long address = unsafe.allocateMemory(1); 43 assertNotEquals(address, 0L); 44 45 // Make sure we reallocate correctly 46 unsafe.putByte(address, Byte.MAX_VALUE); 47 address = unsafe.reallocateMemory(address, 2); 48 assertNotEquals(address, 0L); 49 assertEquals(unsafe.getByte(address), Byte.MAX_VALUE); 50 51 // Reallocating with a 0 size should return a null pointer 52 address = unsafe.reallocateMemory(address, 0); 53 assertEquals(address, 0L); 54 55 // Reallocating with a null pointer should result in a normal allocation 56 address = unsafe.reallocateMemory(0L, 1); 57 assertNotEquals(address, 0L); 58 unsafe.putByte(address, Byte.MAX_VALUE); 59 assertEquals(unsafe.getByte(address), Byte.MAX_VALUE); 60 61 // Make sure we can throw an OOME when we fail to reallocate due to OOM 62 try { 63 unsafe.reallocateMemory(address, 100 * 1024 * 1024 * 8); 64 } catch (OutOfMemoryError e) { 65 // Expected 66 return; 67 } 68 throw new RuntimeException("Did not get expected OOM"); 69 } 70 }