rev 57826 : 8237521: Memory Access API fixes for 32-bit Reviewed-by: mcimadamore, dholmes
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 27 package jdk.internal.foreign; 28 29 import jdk.incubator.foreign.MemorySegment; 30 import jdk.internal.access.JavaNioAccess; 31 import jdk.internal.access.SharedSecrets; 32 import jdk.internal.access.foreign.UnmapperProxy; 33 import jdk.internal.misc.Unsafe; 34 import sun.nio.ch.FileChannelImpl; 35 import sun.security.action.GetBooleanAction; 36 37 import java.io.IOException; 38 import java.nio.ByteBuffer; 39 import java.nio.channels.FileChannel; 40 import java.nio.file.OpenOption; 41 import java.nio.file.Path; 42 import java.nio.file.StandardOpenOption; 43 import java.util.function.Supplier; 44 45 /** 46 * This class contains misc helper functions to support creation of memory segments. 47 */ 48 public final class Utils { 49 50 private static Unsafe unsafe = Unsafe.getUnsafe(); 51 52 // The maximum alignment supported by malloc - typically 16 on 64-bit platforms. 53 private final static long MAX_ALIGN = 16; 54 55 private static final JavaNioAccess javaNioAccess = SharedSecrets.getJavaNioAccess(); 56 57 private static final boolean skipZeroMemory = GetBooleanAction.privilegedGetProperty("jdk.internal.foreign.skipZeroMemory"); 58 59 public static long alignUp(long n, long alignment) { 60 return (n + alignment - 1) & -alignment; 61 } 62 63 public static long bitsToBytesOrThrow(long bits, Supplier<RuntimeException> exFactory) { 64 if (bits % 8 == 0) { 65 return bits / 8; 66 } else { 67 throw exFactory.get(); 68 } 69 } 70 71 // segment factories 72 73 public static MemorySegment makeNativeSegment(long bytesSize, long alignmentBytes) { 74 long alignedSize = bytesSize; 75 76 if (alignmentBytes > MAX_ALIGN) { 77 alignedSize = bytesSize + (alignmentBytes - 1); 78 } 79 80 long buf = unsafe.allocateMemory(alignedSize); 81 if (!skipZeroMemory) { 82 unsafe.setMemory(buf, alignedSize, (byte)0); 83 } 84 long alignedBuf = Utils.alignUp(buf, alignmentBytes); 85 MemoryScope scope = new MemoryScope(null, () -> unsafe.freeMemory(buf)); 86 MemorySegment segment = new MemorySegmentImpl(buf, null, alignedSize, 0, Thread.currentThread(), scope); 87 if (alignedBuf != buf) { 88 long delta = alignedBuf - buf; 89 segment = segment.asSlice(delta, bytesSize); 90 } 91 return segment; 92 } 93 94 public static MemorySegment makeArraySegment(byte[] arr) { 95 return makeArraySegment(arr, arr.length, Unsafe.ARRAY_BYTE_BASE_OFFSET, Unsafe.ARRAY_BYTE_INDEX_SCALE); 96 } 97 98 public static MemorySegment makeArraySegment(char[] arr) { 99 return makeArraySegment(arr, arr.length, Unsafe.ARRAY_CHAR_BASE_OFFSET, Unsafe.ARRAY_CHAR_INDEX_SCALE); 100 } 101 102 public static MemorySegment makeArraySegment(short[] arr) { 103 return makeArraySegment(arr, arr.length, Unsafe.ARRAY_SHORT_BASE_OFFSET, Unsafe.ARRAY_SHORT_INDEX_SCALE); 104 } 105 106 public static MemorySegment makeArraySegment(int[] arr) { 107 return makeArraySegment(arr, arr.length, Unsafe.ARRAY_INT_BASE_OFFSET, Unsafe.ARRAY_INT_INDEX_SCALE); 108 } 109 110 public static MemorySegment makeArraySegment(float[] arr) { 111 return makeArraySegment(arr, arr.length, Unsafe.ARRAY_FLOAT_BASE_OFFSET, Unsafe.ARRAY_FLOAT_INDEX_SCALE); 112 } 113 114 public static MemorySegment makeArraySegment(long[] arr) { 115 return makeArraySegment(arr, arr.length, Unsafe.ARRAY_LONG_BASE_OFFSET, Unsafe.ARRAY_LONG_INDEX_SCALE); 116 } 117 118 public static MemorySegment makeArraySegment(double[] arr) { 119 return makeArraySegment(arr, arr.length, Unsafe.ARRAY_DOUBLE_BASE_OFFSET, Unsafe.ARRAY_DOUBLE_INDEX_SCALE); 120 } 121 122 private static MemorySegment makeArraySegment(Object arr, int size, int base, int scale) { 123 MemoryScope scope = new MemoryScope(null, null); 124 return new MemorySegmentImpl(base, arr, size * scale, 0, Thread.currentThread(), scope); 125 } 126 127 public static MemorySegment makeBufferSegment(ByteBuffer bb) { 128 long bbAddress = javaNioAccess.getBufferAddress(bb); 129 Object base = javaNioAccess.getBufferBase(bb); 130 131 int pos = bb.position(); 132 int limit = bb.limit(); 133 134 MemoryScope bufferScope = new MemoryScope(bb, null); 135 return new MemorySegmentImpl(bbAddress + pos, base, limit - pos, 0, Thread.currentThread(), bufferScope); 136 } 137 138 // create and map a file into a fresh segment 139 public static MemorySegment makeMappedSegment(Path path, long bytesSize, FileChannel.MapMode mapMode) throws IOException { 140 if (bytesSize <= 0) throw new IllegalArgumentException("Requested bytes size must be > 0."); 141 try (FileChannelImpl channelImpl = (FileChannelImpl)FileChannel.open(path, openOptions(mapMode))) { 142 UnmapperProxy unmapperProxy = channelImpl.mapInternal(mapMode, 0L, bytesSize); 143 MemoryScope scope = new MemoryScope(null, unmapperProxy::unmap); 144 return new MemorySegmentImpl(unmapperProxy.address(), null, bytesSize, 0, Thread.currentThread(), scope); 145 } 146 } 147 148 private static OpenOption[] openOptions(FileChannel.MapMode mapMode) { 149 if (mapMode == FileChannel.MapMode.READ_ONLY) { 150 return new OpenOption[] { StandardOpenOption.READ }; 151 } else if (mapMode == FileChannel.MapMode.READ_WRITE || mapMode == FileChannel.MapMode.PRIVATE) { 152 return new OpenOption[] { StandardOpenOption.READ, StandardOpenOption.WRITE }; 153 } else { 154 throw new UnsupportedOperationException("Unsupported map mode: " + mapMode); 155 } 156 } 157 } --- EOF ---