1 /*
2 * Copyright (c) 2000, 2017, 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_VM_OOPS_ARRAY_HPP
26 #define SHARE_VM_OOPS_ARRAY_HPP
27
28 #include "memory/metaspace.hpp"
29 #include "utilities/align.hpp"
30
31 // Array for metadata allocation
32
33 template <typename T>
34 class Array: public MetaspaceObj {
35 friend class MetadataFactory;
36 friend class MetaspaceShared;
37 friend class VMStructs;
38 friend class JVMCIVMStructs;
39 friend class MethodHandleCompiler; // special case
40 friend class WhiteBox;
41 protected:
42 int _length; // the number of array elements
43 T _data[1]; // the array memory
44
45 void initialize(int length) {
46 _length = length;
47 }
48
49 private:
50 // Turn off copy constructor and assignment operator.
51 Array(const Array<T>&);
52 void operator=(const Array<T>&);
53
54 void* operator new(size_t size, ClassLoaderData* loader_data, int length, TRAPS) throw() {
55 size_t word_size = Array::size(length);
56 return (void*) Metaspace::allocate(loader_data, word_size,
57 MetaspaceObj::array_type(sizeof(T)), THREAD);
58 }
59
60 static size_t byte_sizeof(int length, size_t elm_byte_size) {
61 return sizeof(Array<T>) + MAX2(length - 1, 0) * elm_byte_size;
62 }
63 static size_t byte_sizeof(int length) { return byte_sizeof(length, sizeof(T)); }
64
65 // WhiteBox API helper.
66 // Can't distinguish between array of length 0 and length 1,
67 // will always return 0 in those cases.
68 static int bytes_to_length(size_t bytes) {
69 assert(is_aligned(bytes, BytesPerWord), "Must be, for now");
70
71 if (sizeof(Array<T>) >= bytes) {
72 return 0;
73 }
74
75 size_t left = bytes - sizeof(Array<T>);
76 assert(is_aligned(left, sizeof(T)), "Must be");
77
78 size_t elements = left / sizeof(T);
79 assert(elements <= (size_t)INT_MAX, "number of elements " SIZE_FORMAT "doesn't fit into an int.", elements);
80
81 int length = (int)elements;
82
83 assert((size_t)size(length) * BytesPerWord == (size_t)bytes,
84 "Expected: " SIZE_FORMAT " got: " SIZE_FORMAT,
85 bytes, (size_t)size(length) * BytesPerWord);
86
87 return length;
88 }
89
90 explicit Array(int length) : _length(length) {
91 assert(length >= 0, "illegal length");
92 }
93
94 Array(int length, T init) : _length(length) {
95 assert(length >= 0, "illegal length");
96 for (int i = 0; i < length; i++) {
97 _data[i] = init;
98 }
99 }
100
101 public:
102
103 // standard operations
104 int length() const { return _length; }
105 T* data() { return _data; }
106 bool is_empty() const { return length() == 0; }
107
108 int index_of(const T& x) const {
109 int i = length();
110 while (i-- > 0 && _data[i] != x) ;
111
112 return i;
113 }
114
115 // sort the array.
116 bool contains(const T& x) const { return index_of(x) >= 0; }
117
118 T at(int i) const { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return _data[i]; }
119 void at_put(const int i, const T& x) { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); _data[i] = x; }
120 T* adr_at(const int i) { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return &_data[i]; }
121 int find(const T& x) { return index_of(x); }
122
123 T at_acquire(const int which);
124 void release_at_put(int which, T contents);
125
126 static int size(int length) {
127 size_t bytes = align_up(byte_sizeof(length), BytesPerWord);
128 size_t words = bytes / BytesPerWord;
129
130 assert(words <= INT_MAX, "Overflow: " SIZE_FORMAT, words);
131
132 return (int)words;
133 }
134 int size() {
135 return size(_length);
136 }
137
138 static int length_offset_in_bytes() { return (int) (offset_of(Array<T>, _length)); }
139 // Note, this offset don't have to be wordSize aligned.
140 static int base_offset_in_bytes() { return (int) (offset_of(Array<T>, _data)); };
141
142 // FIXME: How to handle this?
143 void print_value_on(outputStream* st) const {
144 st->print("Array<T>(" INTPTR_FORMAT ")", p2i(this));
145 }
146
147 #ifndef PRODUCT
148 void print(outputStream* st) {
149 for (int i = 0; i< _length; i++) {
150 st->print_cr("%d: " INTPTR_FORMAT, i, (intptr_t)at(i));
151 }
152 }
153 void print() { print(tty); }
154 #endif // PRODUCT
155 };
156
157
158 #endif // SHARE_VM_OOPS_ARRAY_HPP