instanceOop.hpp revision 1472:c18cbe5936b8
1/* 2 * Copyright (c) 1997, 2008, 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// An instanceOop is an instance of a Java Class 26// Evaluating "new HashTable()" will create an instanceOop. 27 28class instanceOopDesc : public oopDesc { 29 public: 30 // aligned header size. 31 static int header_size() { return sizeof(instanceOopDesc)/HeapWordSize; } 32 33 // If compressed, the offset of the fields of the instance may not be aligned. 34 static int base_offset_in_bytes() { 35 return UseCompressedOops ? 36 klass_gap_offset_in_bytes() : 37 sizeof(instanceOopDesc); 38 } 39 40 static bool contains_field_offset(int offset, int nonstatic_field_size) { 41 int base_in_bytes = base_offset_in_bytes(); 42 return (offset >= base_in_bytes && 43 (offset-base_in_bytes) < nonstatic_field_size * heapOopSize); 44 } 45}; 46