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