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 public static void copy(MemoryAddressImpl src, MemoryAddressImpl dst, long size) {
58 src.checkAccess(0, size, true);
59 dst.checkAccess(0, size, false);
60 //check disjoint
61 long offsetSrc = src.unsafeGetOffset();
62 long offsetDst = dst.unsafeGetOffset();
63 Object baseSrc = src.unsafeGetBase();
64 Object baseDst = dst.unsafeGetBase();
65 UNSAFE.copyMemory(baseSrc, offsetSrc, baseDst, offsetDst, size);
66 }
67
68 // MemoryAddress methods
69
70 @Override
71 public long segmentOffset() {
72 if (segment() == null) {
73 throw new UnsupportedOperationException("Address does not have a segment");
74 }
75 return offset;
76 }
77
78 @Override
79 public long toRawLongValue() {
80 if (unsafeGetBase() != null) {
81 throw new UnsupportedOperationException("Not a native address");
82 }
83 return unsafeGetOffset();
84 }
85
86 @Override
87 public MemorySegment segment() {
88 return segment != AbstractMemorySegmentImpl.NOTHING ?
89 segment : null;
90 }
91
92 @Override
93 public MemoryAddress addOffset(long bytes) {
94 return new MemoryAddressImpl(segment, offset + bytes);
95 }
96
97 @Override
98 public MemoryAddress rebase(MemorySegment segment) {
99 AbstractMemorySegmentImpl segmentImpl = (AbstractMemorySegmentImpl)segment;
100 if (segmentImpl.base() != this.segment.base()) {
101 throw new IllegalArgumentException("Invalid rebase target: " + segment);
102 }
103 return new MemoryAddressImpl((AbstractMemorySegmentImpl)segment,
104 unsafeGetOffset() - ((MemoryAddressImpl)segment.baseAddress()).unsafeGetOffset());
105 }
106
107 // MemoryAddressProxy methods
108
109 public void checkAccess(long offset, long length, boolean readOnly) {
110 segment.checkRange(MemoryAddressProxy.addOffsets(this.offset, offset, this), length, !readOnly);
111 }
112
113 public long unsafeGetOffset() {
114 return segment.min() + offset;
115 }
116
117 public Object unsafeGetBase() {
118 return segment.base();
119 }
120
121 @Override
122 public boolean isSmall() {
123 return segment.isSmall();
124 }
125 // Object methods
126
127 @Override
128 public int hashCode() {
129 return Objects.hash(unsafeGetBase(), unsafeGetOffset());
130 }
131
132 @Override
133 public boolean equals(Object that) {
134 if (that instanceof MemoryAddressImpl) {
135 MemoryAddressImpl addr = (MemoryAddressImpl)that;
136 return Objects.equals(unsafeGetBase(), ((MemoryAddressImpl) that).unsafeGetBase()) &&
137 unsafeGetOffset() == addr.unsafeGetOffset();
138 } else {
139 return false;
140 }
141 }
142
143 @Override
144 public String toString() {
145 return "MemoryAddress{ region: " + segment + " offset=0x" + Long.toHexString(offset) + " }";
146 }
147 }