| /* |
| * Copyright (c) 1997, 2016, 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. |
| * |
| */ |
| |
| #ifndef SHARE_VM_OOPS_OBJARRAYOOP_HPP |
| #define SHARE_VM_OOPS_OBJARRAYOOP_HPP |
| |
| #include "gc/shared/specialized_oop_closures.hpp" |
| #include "oops/arrayOop.hpp" |
| #include "utilities/align.hpp" |
| |
| // An objArrayOop is an array containing oops. |
| // Evaluating "String arg[10]" will create an objArrayOop. |
| |
| class objArrayOopDesc : public arrayOopDesc { |
| friend class ObjArrayKlass; |
| friend class Runtime1; |
| friend class psPromotionManager; |
| friend class CSetMarkOopClosure; |
| friend class G1ParScanPartialArrayClosure; |
| |
| template <class T> T* obj_at_addr(int index) const { |
| assert(is_within_bounds(index), "index out of bounds"); |
| return &((T*)base())[index]; |
| } |
| |
| private: |
| // Give size of objArrayOop in HeapWords minus the header |
| static int array_size(int length) { |
| const uint OopsPerHeapWord = HeapWordSize/heapOopSize; |
| assert(OopsPerHeapWord >= 1 && (HeapWordSize % heapOopSize == 0), |
| "Else the following (new) computation would be in error"); |
| uint res = ((uint)length + OopsPerHeapWord - 1)/OopsPerHeapWord; |
| #ifdef ASSERT |
| // The old code is left in for sanity-checking; it'll |
| // go away pretty soon. XXX |
| // Without UseCompressedOops, this is simply: |
| // oop->length() * HeapWordsPerOop; |
| // With narrowOops, HeapWordsPerOop is 1/2 or equal 0 as an integer. |
| // The oop elements are aligned up to wordSize |
| const uint HeapWordsPerOop = heapOopSize/HeapWordSize; |
| uint old_res; |
| if (HeapWordsPerOop > 0) { |
| old_res = length * HeapWordsPerOop; |
| } else { |
| old_res = align_up((uint)length, OopsPerHeapWord)/OopsPerHeapWord; |
| } |
| assert(res == old_res, "Inconsistency between old and new."); |
| #endif // ASSERT |
| return res; |
| } |
| |
| public: |
| // Returns the offset of the first element. |
| static int base_offset_in_bytes() { |
| return arrayOopDesc::base_offset_in_bytes(T_OBJECT); |
| } |
| |
| // base is the address following the header. |
| HeapWord* base() const { return (HeapWord*) arrayOopDesc::base(T_OBJECT); } |
| |
| // Accessing |
| oop obj_at(int index) const; |
| |
| void inline obj_at_put(int index, oop value); |
| |
| oop atomic_compare_exchange_oop(int index, oop exchange_value, oop compare_value); |
| |
| // Sizing |
| static int header_size() { return arrayOopDesc::header_size(T_OBJECT); } |
| int object_size() { return object_size(length()); } |
| |
| static int object_size(int length) { |
| // This returns the object size in HeapWords. |
| uint asz = array_size(length); |
| uint osz = align_object_size(header_size() + asz); |
| assert(osz >= asz, "no overflow"); |
| assert((int)osz > 0, "no overflow"); |
| return (int)osz; |
| } |
| |
| // special iterators for index ranges, returns size of object |
| #define ObjArrayOop_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ |
| void oop_iterate_range(OopClosureType* blk, int start, int end); |
| |
| ALL_OOP_OOP_ITERATE_CLOSURES_1(ObjArrayOop_OOP_ITERATE_DECL) |
| ALL_OOP_OOP_ITERATE_CLOSURES_2(ObjArrayOop_OOP_ITERATE_DECL) |
| }; |
| |
| #endif // SHARE_VM_OOPS_OBJARRAYOOP_HPP |