/*
* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package jdk.internal.foreign;
import jdk.incubator.foreign.MemorySegment;
import jdk.internal.access.JavaNioAccess;
import jdk.internal.access.SharedSecrets;
import jdk.internal.access.foreign.UnmapperProxy;
import jdk.internal.misc.Unsafe;
import sun.nio.ch.FileChannelImpl;
import sun.security.action.GetBooleanAction;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.file.OpenOption;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.function.Supplier;
/**
* This class contains misc helper functions to support creation of memory segments.
*/
public final class Utils {
private static Unsafe unsafe = Unsafe.getUnsafe();
// The maximum alignment supported by malloc - typically 16 on 64-bit platforms.
private final static long MAX_ALIGN = 16;
private static final JavaNioAccess javaNioAccess = SharedSecrets.getJavaNioAccess();
private static final boolean skipZeroMemory = GetBooleanAction.privilegedGetProperty("jdk.internal.foreign.skipZeroMemory");
public static long alignUp(long n, long alignment) {
return (n + alignment - 1) & -alignment;
}
public static long bitsToBytesOrThrow(long bits, Supplier<RuntimeException> exFactory) {
if (bits % 8 == 0) {
return bits / 8;
} else {
throw exFactory.get();
}
}
// segment factories
public static MemorySegment makeNativeSegment(long bytesSize, long alignmentBytes) {
long alignedSize = bytesSize;
if (alignmentBytes > MAX_ALIGN) {
alignedSize = bytesSize + (alignmentBytes - 1);
}
long buf = unsafe.allocateMemory(alignedSize);
if (!skipZeroMemory) {
unsafe.setMemory(buf, alignedSize, (byte)0);
}
long alignedBuf = Utils.alignUp(buf, alignmentBytes);
MemoryScope scope = new MemoryScope(null, () -> unsafe.freeMemory(buf));
MemorySegment segment = new MemorySegmentImpl(buf, null, alignedSize, 0, Thread.currentThread(), scope);
if (alignedBuf != buf) {
long delta = alignedBuf - buf;
segment = segment.asSlice(delta, bytesSize);
}
return segment;
}
public static MemorySegment makeArraySegment(byte[] arr) {
return makeArraySegment(arr, arr.length, Unsafe.ARRAY_BYTE_BASE_OFFSET, Unsafe.ARRAY_BYTE_INDEX_SCALE);
}
public static MemorySegment makeArraySegment(char[] arr) {
return makeArraySegment(arr, arr.length, Unsafe.ARRAY_CHAR_BASE_OFFSET, Unsafe.ARRAY_CHAR_INDEX_SCALE);
}
public static MemorySegment makeArraySegment(short[] arr) {
return makeArraySegment(arr, arr.length, Unsafe.ARRAY_SHORT_BASE_OFFSET, Unsafe.ARRAY_SHORT_INDEX_SCALE);
}
public static MemorySegment makeArraySegment(int[] arr) {
return makeArraySegment(arr, arr.length, Unsafe.ARRAY_INT_BASE_OFFSET, Unsafe.ARRAY_INT_INDEX_SCALE);
}
public static MemorySegment makeArraySegment(float[] arr) {
return makeArraySegment(arr, arr.length, Unsafe.ARRAY_FLOAT_BASE_OFFSET, Unsafe.ARRAY_FLOAT_INDEX_SCALE);
}
public static MemorySegment makeArraySegment(long[] arr) {
return makeArraySegment(arr, arr.length, Unsafe.ARRAY_LONG_BASE_OFFSET, Unsafe.ARRAY_LONG_INDEX_SCALE);
}
public static MemorySegment makeArraySegment(double[] arr) {
return makeArraySegment(arr, arr.length, Unsafe.ARRAY_DOUBLE_BASE_OFFSET, Unsafe.ARRAY_DOUBLE_INDEX_SCALE);
}
private static MemorySegment makeArraySegment(Object arr, int size, int base, int scale) {
MemoryScope scope = new MemoryScope(null, null);
return new MemorySegmentImpl(base, arr, size * scale, 0, Thread.currentThread(), scope);
}
public static MemorySegment makeBufferSegment(ByteBuffer bb) {
long bbAddress = javaNioAccess.getBufferAddress(bb);
Object base = javaNioAccess.getBufferBase(bb);
int pos = bb.position();
int limit = bb.limit();
MemoryScope bufferScope = new MemoryScope(bb, null);
return new MemorySegmentImpl(bbAddress + pos, base, limit - pos, 0, Thread.currentThread(), bufferScope);
}
// create and map a file into a fresh segment
public static MemorySegment makeMappedSegment(Path path, long bytesSize, FileChannel.MapMode mapMode) throws IOException {
if (bytesSize <= 0) throw new IllegalArgumentException("Requested bytes size must be > 0.");
try (FileChannelImpl channelImpl = (FileChannelImpl)FileChannel.open(path, openOptions(mapMode))) {
UnmapperProxy unmapperProxy = channelImpl.mapInternal(mapMode, 0L, bytesSize);
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