1 /*
2 * Copyright (c) 2025, 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
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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.
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23 */
24
25 #ifndef SHARE_OOPS_REFARRAYOOP_HPP
26 #define SHARE_OOPS_REFARRAYOOP_HPP
27
28 #include "oops/arrayOop.hpp"
29 #include "utilities/align.hpp"
30
31 #include <type_traits>
32
33 class Klass;
34
35 // An refArrayOop is an array containing references (oops).
36 // Evaluating "String arg[10]" will create an refArrayOop.
37
38 class refArrayOopDesc : public arrayOopDesc {
39 friend class ArchiveHeapWriter;
40 friend class RefArrayKlass;
41 friend class Runtime1;
42 friend class psPromotionManager;
43 friend class CSetMarkWordClosure;
44 friend class Continuation;
45 template <typename T>
46 friend class RawOopWriter;
47
48 template <class T> T* obj_at_addr(int index) const;
49
50 template <class T>
51 static ptrdiff_t obj_at_offset(int index) {
52 return base_offset_in_bytes() + sizeof(T) * index;
53 }
54
55 public:
56 // Returns the offset of the first element.
57 static int base_offset_in_bytes() {
58 return arrayOopDesc::base_offset_in_bytes(T_OBJECT);
59 }
60
61 inline static refArrayOop cast(oop o);
62
63 // base is the address following the header.
64 inline HeapWord* base() const;
65
66 // Accessing
67 oop obj_at(int index) const;
68 oop obj_at(int index, TRAPS) const;
69
70 void obj_at_put(int index, oop value);
71 void obj_at_put(int index, oop value, TRAPS);
72
73 oop replace_if_null(int index, oop exchange_value);
74
75 // Sizing
76 size_t object_size() { return object_size(length()); }
77
78 static size_t object_size(int length) {
79 // This returns the object size in HeapWords.
80 size_t asz = (size_t)length * heapOopSize;
81 size_t size_words = heap_word_size(base_offset_in_bytes() + asz);
82 size_t osz = align_object_size(size_words);
83 assert(osz < max_jint, "no overflow");
84 return osz;
85 }
86
87 Klass* element_klass();
88
89 public:
90 // special iterators for index ranges, returns size of object
91 template <typename OopClosureType>
92 void oop_iterate_range(OopClosureType* blk, int start, int end);
93 };
94
95 // See similar requirement for oopDesc.
96 static_assert(std::is_trivially_default_constructible<refArrayOopDesc>::value, "required");
97
98 #endif // SHARE_OOPS_REFARRAYOOP_HPP