1 /*
2 * Copyright (c) 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26 package jdk.internal.foreign;
27
28 import jdk.internal.access.foreign.MemoryAddressProxy;
29 import jdk.internal.misc.Unsafe;
30
31 import jdk.incubator.foreign.MemoryAddress;
32 import jdk.incubator.foreign.MemorySegment;
33
34 import java.util.Objects;
35
36 /**
37 * This class provides an immutable implementation for the {@code MemoryAddress} interface. This class contains information
38 * about the segment this address is associated with, as well as an offset into such segment.
39 */
40 public final class MemoryAddressImpl implements MemoryAddress, MemoryAddressProxy {
41
42 private static final Unsafe UNSAFE = Unsafe.getUnsafe();
43
44 private final AbstractMemorySegmentImpl segment;
45 private final long offset;
46
47 public MemoryAddressImpl(long offset) {
48 this.segment = AbstractMemorySegmentImpl.NOTHING;
49 this.offset = offset;
50 }
51
52 public MemoryAddressImpl(AbstractMemorySegmentImpl segment, long offset) {
53 this.segment = Objects.requireNonNull(segment);
54 this.offset = offset;
55 }
56
57 // MemoryAddress methods
58
59 @Override
60 public long segmentOffset() {
61 if (segment() == null) {
62 throw new UnsupportedOperationException("Address does not have a segment");
63 }
64 return offset;
65 }
66
67 @Override
68 public long toRawLongValue() {
69 if (unsafeGetBase() != null) {
70 throw new UnsupportedOperationException("Not a native address");
71 }
72 return unsafeGetOffset();
73 }
74
75 @Override
76 public MemorySegment segment() {
77 return segment != AbstractMemorySegmentImpl.NOTHING ?
78 segment : null;
79 }
80
81 @Override
82 public MemoryAddress addOffset(long bytes) {
83 return new MemoryAddressImpl(segment, offset + bytes);
84 }
85
86 @Override
87 public MemoryAddress rebase(MemorySegment segment) {
88 AbstractMemorySegmentImpl segmentImpl = (AbstractMemorySegmentImpl)segment;
89 if (segmentImpl.base() != this.segment.base()) {
90 throw new IllegalArgumentException("Invalid rebase target: " + segment);
91 }
92 return new MemoryAddressImpl((AbstractMemorySegmentImpl)segment,
93 unsafeGetOffset() - ((MemoryAddressImpl)segment.baseAddress()).unsafeGetOffset());
94 }
95
96 // MemoryAddressProxy methods
97
98 public void checkAccess(long offset, long length, boolean readOnly) {
99 segment.checkRange(MemoryAddressProxy.addOffsets(this.offset, offset, this), length, !readOnly);
100 }
101
102 public long unsafeGetOffset() {
103 return segment.min() + offset;
104 }
105
106 public Object unsafeGetBase() {
107 return segment.base();
108 }
109
110 @Override
111 public boolean isSmall() {
112 return segment.isSmall();
113 }
114 // Object methods
115
116 @Override
117 public int hashCode() {
118 return Objects.hash(unsafeGetBase(), unsafeGetOffset());
119 }
120
121 @Override
122 public boolean equals(Object that) {
123 if (that instanceof MemoryAddressImpl) {
124 MemoryAddressImpl addr = (MemoryAddressImpl)that;
125 return Objects.equals(unsafeGetBase(), ((MemoryAddressImpl) that).unsafeGetBase()) &&
126 unsafeGetOffset() == addr.unsafeGetOffset();
127 } else {
128 return false;
129 }
130 }
131
132 @Override
133 public String toString() {
134 return "MemoryAddress{ region: " + segment + " offset=0x" + Long.toHexString(offset) + " }";
135 }
136 }