1 /*
2 * Copyright (c) 2000, 2024, 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 #ifndef SHARE_OOPS_ARRAY_HPP
26 #define SHARE_OOPS_ARRAY_HPP
27
28 #include "runtime/atomic.hpp"
29 #include "utilities/align.hpp"
30 #include "utilities/exceptions.hpp"
31 #include "utilities/globalDefinitions.hpp"
32 #include "utilities/ostream.hpp"
33
34 // Array for metadata allocation
35
36 template <typename T>
37 class Array: public MetaspaceObj {
38 friend class ArchiveBuilder;
39 friend class MetadataFactory;
40 friend class VMStructs;
41 friend class JVMCIVMStructs;
42 friend class MethodHandleCompiler; // special case
43 friend class WhiteBox;
44 friend class FieldInfoStream;
45 protected:
46 int _length; // the number of array elements
47 T _data[1]; // the array memory
48
49 void initialize(int length) {
50 _length = length;
51 }
52
53 private:
54 NONCOPYABLE(Array);
55
56 inline void* operator new(size_t size, ClassLoaderData* loader_data, int length, TRAPS) throw();
57
58 inline void* operator new(size_t size, ClassLoaderData* loader_data, int length) throw();
59
60 // Work-around -- see JDK-8331086
61 inline void* operator new(size_t size, int length, MEMFLAGS flags) throw();
62
63 static size_t byte_sizeof(int length, size_t elm_byte_size) {
64 return sizeof(Array<T>) + MAX2(length - 1, 0) * elm_byte_size;
65 }
66 static size_t byte_sizeof(int length) { return byte_sizeof(length, sizeof(T)); }
67
68 // WhiteBox API helper.
69 // Can't distinguish between array of length 0 and length 1,
70 // will always return 0 in those cases.
71 static int bytes_to_length(size_t bytes) {
72 assert(is_aligned(bytes, BytesPerWord), "Must be, for now");
73
74 if (sizeof(Array<T>) >= bytes) {
75 return 0;
76 }
77
78 size_t left = bytes - sizeof(Array<T>);
79 assert(is_aligned(left, sizeof(T)), "Must be");
80
81 size_t elements = left / sizeof(T);
82 assert(elements <= (size_t)INT_MAX, "number of elements " SIZE_FORMAT "doesn't fit into an int.", elements);
83
84 int length = (int)elements;
85
86 assert((size_t)size(length) * BytesPerWord == (size_t)bytes,
87 "Expected: " SIZE_FORMAT " got: " SIZE_FORMAT,
88 bytes, (size_t)size(length) * BytesPerWord);
89
90 return length;
91 }
92
93 explicit Array(int length) : _length(length) {
94 assert(length >= 0, "illegal length");
95 }
96
97 Array(int length, T init) : _length(length) {
98 assert(length >= 0, "illegal length");
99 for (int i = 0; i < length; i++) {
100 data()[i] = init;
101 }
102 }
103
104 public:
105
106 // standard operations
107 int length() const { return _length; }
108
109 T* data() {
110 return reinterpret_cast<T*>(
111 reinterpret_cast<char*>(this) + base_offset_in_bytes());
112 }
113
114 const T* data() const {
115 return reinterpret_cast<const T*>(
116 reinterpret_cast<const char*>(this) + base_offset_in_bytes());
117 }
118
119 bool is_empty() const { return length() == 0; }
120
121 int index_of(const T& x) const {
122 int i = length();
123 while (i-- > 0 && data()[i] != x) ;
124
125 return i;
126 }
127
128 // sort the array.
129 bool contains(const T& x) const { return index_of(x) >= 0; }
130
131 T at(int i) const { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return data()[i]; }
132 void at_put(const int i, const T& x) { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); data()[i] = x; }
133 T* adr_at(const int i) { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return &data()[i]; }
134 int find(const T& x) { return index_of(x); }
135
136 T at_acquire(const int i) { return Atomic::load_acquire(adr_at(i)); }
137 void release_at_put(int i, T x) { Atomic::release_store(adr_at(i), x); }
138
139 static int size(int length) {
140 size_t bytes = align_up(byte_sizeof(length), BytesPerWord);
141 size_t words = bytes / BytesPerWord;
142
143 assert(words <= INT_MAX, "Overflow: " SIZE_FORMAT, words);
144
145 return (int)words;
146 }
147 int size() {
148 return size(_length);
149 }
150
151 static int length_offset_in_bytes() { return (int) (offset_of(Array<T>, _length)); }
152 // Note, this offset don't have to be wordSize aligned.
153 static int base_offset_in_bytes() { return (int) (offset_of(Array<T>, _data)); };
154
155 // FIXME: How to handle this?
156 void print_value_on(outputStream* st) const {
157 st->print("Array<T>(" PTR_FORMAT ")", p2i(this));
158 }
159
160 #ifndef PRODUCT
161 void print(outputStream* st) {
162 for (int i = 0; i< _length; i++) {
163 st->print_cr("%d: " INTPTR_FORMAT, i, (intptr_t)at(i));
164 }
165 }
166 void print() { print(tty); }
167 #endif // PRODUCT
168 };
169
170
171 #endif // SHARE_OOPS_ARRAY_HPP