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/allocation.inline.hpp"
30 #include "memory/metaspace.hpp"
31 #include "runtime/orderAccess.hpp"
32 #include "utilities/align.hpp"
33
34 // Array for metadata allocation
35
36 template <typename T>
37 class Array: public MetaspaceObj {
38 friend class MetadataFactory;
39 friend class MetaspaceShared;
40 friend class VMStructs;
41 friend class JVMCIVMStructs;
42 friend class MethodHandleCompiler; // special case
43 friend class WhiteBox;
44 protected:
45 int _length; // the number of array elements
46 T _data[1]; // the array memory
47
48 void initialize(int length) {
49 _length = length;
50 }
51
52 private:
53 // Turn off copy constructor and assignment operator.
54 Array(const Array<T>&);
55 void operator=(const Array<T>&);
56
57 void* operator new(size_t size, ClassLoaderData* loader_data, int length, TRAPS) throw() {
58 size_t word_size = Array::size(length);
59 return (void*) Metaspace::allocate(loader_data, word_size,
60 MetaspaceObj::array_type(sizeof(T)), THREAD);
61 }
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 T* data() { return _data; }
109 bool is_empty() const { return length() == 0; }
110
111 int index_of(const T& x) const {
112 int i = length();
113 while (i-- > 0 && _data[i] != x) ;
114
115 return i;
116 }
117
118 // sort the array.
119 bool contains(const T& x) const { return index_of(x) >= 0; }
120
121 T at(int i) const { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return _data[i]; }
122 void at_put(const int i, const T& x) { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); _data[i] = x; }
123 T* adr_at(const int i) { assert(i >= 0 && i< _length, "oob: 0 <= %d < %d", i, _length); return &_data[i]; }
124 int find(const T& x) { return index_of(x); }
125
126 T at_acquire(const int which) { return OrderAccess::load_acquire(adr_at(which)); }
127 void release_at_put(int which, T contents) { OrderAccess::release_store(adr_at(which), contents); }
128
129 static int size(int length) {
130 size_t bytes = align_up(byte_sizeof(length), BytesPerWord);
131 size_t words = bytes / BytesPerWord;
132
133 assert(words <= INT_MAX, "Overflow: " SIZE_FORMAT, words);
134
135 return (int)words;
136 }
137 static int size(int length, int elm_byte_size) {
138 return align_up(byte_sizeof(length, elm_byte_size), BytesPerWord) / BytesPerWord;
139 }
140
141 int size() {
142 return size(_length);
143 }
144
145 static int length_offset_in_bytes() { return (int) (offset_of(Array<T>, _length)); }
146 // Note, this offset don't have to be wordSize aligned.
147 static int base_offset_in_bytes() { return (int) (offset_of(Array<T>, _data)); };
148
149 // FIXME: How to handle this?
150 void print_value_on(outputStream* st) const {
151 st->print("Array<T>(" INTPTR_FORMAT ")", p2i(this));
152 }
153
154 #ifndef PRODUCT
155 void print(outputStream* st) {
156 for (int i = 0; i< _length; i++) {
157 st->print_cr("%d: " INTPTR_FORMAT, i, (intptr_t)at(i));
158 }
159 }
160 void print() { print(tty); }
161 #endif // PRODUCT
162 };
163
164
165 #endif // SHARE_VM_OOPS_ARRAY_HPP