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