1 /*
2 * Copyright (c) 2000, 2019, 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 "memory/allocation.hpp"
29 #include "memory/metaspace.hpp"
30 #include "runtime/atomic.hpp"
31 #include "utilities/align.hpp"
32
33 // Array for metadata allocation
34
35 template <typename T>
36 class Array: public MetaspaceObj {
37 friend class MetadataFactory;
38 friend class MetaspaceShared;
39 friend class VMStructs;
40 friend class JVMCIVMStructs;
41 friend class MethodHandleCompiler; // special case
42 friend class WhiteBox;
43 protected:
44 int _length; // the number of array elements
45 T _data[1]; // the array memory
46
47 void initialize(int length) {
48 _length = length;
49 }
50
51 private:
52 // Turn off copy constructor and assignment operator.
53 Array(const Array<T>&);
54 void operator=(const Array<T>&);
55
56 void* operator new(size_t size, ClassLoaderData* loader_data, int length, TRAPS) throw() {
57 size_t word_size = Array::size(length);
58 return (void*) Metaspace::allocate(loader_data, word_size,
59 MetaspaceObj::array_type(sizeof(T)), THREAD);
60 }
61
62 static size_t byte_sizeof(int length, size_t elm_byte_size) {
63 return sizeof(Array<T>) + MAX2(length - 1, 0) * elm_byte_size;
64 }
65 static size_t byte_sizeof(int length) { return byte_sizeof(length, sizeof(T)); }
66
67 // WhiteBox API helper.
68 // Can't distinguish between array of length 0 and length 1,
69 // will always return 0 in those cases.
70 static int bytes_to_length(size_t bytes) {
71 assert(is_aligned(bytes, BytesPerWord), "Must be, for now");
72
73 if (sizeof(Array<T>) >= bytes) {
74 return 0;
75 }
76
77 size_t left = bytes - sizeof(Array<T>);
78 assert(is_aligned(left, sizeof(T)), "Must be");
79
80 size_t elements = left / sizeof(T);
81 assert(elements <= (size_t)INT_MAX, "number of elements " SIZE_FORMAT "doesn't fit into an int.", elements);
82
83 int length = (int)elements;
84
85 assert((size_t)size(length) * BytesPerWord == (size_t)bytes,
86 "Expected: " SIZE_FORMAT " got: " SIZE_FORMAT,
87 bytes, (size_t)size(length) * BytesPerWord);
88
89 return length;
90 }
91
92 explicit Array(int length) : _length(length) {
93 assert(length >= 0, "illegal length");
94 }
95
96 Array(int length, T init) : _length(length) {
97 assert(length >= 0, "illegal length");
98 for (int i = 0; i < length; i++) {
99 _data[i] = init;
100 }
101 }
102
103 public:
104
105 // standard operations
106 int length() const { return _length; }
107 T* data() { return _data; }
108 bool is_empty() const { return length() == 0; }
109
110 int index_of(const T& x) const {
111 int i = length();
112 while (i-- > 0 && _data[i] != x) ;
113
114 return i;
115 }
116
117 // sort the array.
118 bool contains(const T& x) const { return index_of(x) >= 0; }
119
120 T at(int i) const { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return _data[i]; }
121 void at_put(const int i, const T& x) { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); _data[i] = x; }
122 T* adr_at(const int i) { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return &_data[i]; }
123 int find(const T& x) { return index_of(x); }
124
125 T at_acquire(const int i) { return Atomic::load_acquire(adr_at(i)); }
126 void release_at_put(int i, T x) { Atomic::release_store(adr_at(i), x); }
127
128 static int size(int length) {
129 size_t bytes = align_up(byte_sizeof(length), BytesPerWord);
130 size_t words = bytes / BytesPerWord;
131
132 assert(words <= INT_MAX, "Overflow: " SIZE_FORMAT, words);
133
134 return (int)words;
135 }
136 int size() {
137 return size(_length);
138 }
139
140 static int length_offset_in_bytes() { return (int) (offset_of(Array<T>, _length)); }
141 // Note, this offset don't have to be wordSize aligned.
142 static int base_offset_in_bytes() { return (int) (offset_of(Array<T>, _data)); };
143
144 // FIXME: How to handle this?
145 void print_value_on(outputStream* st) const {
146 st->print("Array<T>(" INTPTR_FORMAT ")", p2i(this));
147 }
148
149 #ifndef PRODUCT
150 void print(outputStream* st) {
151 for (int i = 0; i< _length; i++) {
152 st->print_cr("%d: " INTPTR_FORMAT, i, (intptr_t)at(i));
153 }
154 }
155 void print() { print(tty); }
156 #endif // PRODUCT
157 };
158
159
160 #endif // SHARE_OOPS_ARRAY_HPP