JavaNioAccess.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.  Oracle designates this
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 * 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).
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package jdk.internal.access;

import jdk.internal.access.foreign.MemorySegmentProxy;
import jdk.internal.access.foreign.UnmapperProxy;
import jdk.internal.misc.ScopedMemoryAccess.Scope;
import jdk.internal.misc.VM.BufferPool;

import java.io.FileDescriptor;
import java.nio.Buffer;
import java.nio.ByteBuffer;

public interface JavaNioAccess {

    /**
     * Used by {@code jdk.internal.misc.VM}.
     */
    BufferPool getDirectBufferPool();

    /**
     * Constructs a direct ByteBuffer referring to the block of memory starting
     * at the given memory address and extending {@code cap} bytes.
     * The {@code ob} parameter is an arbitrary object that is attached
     * to the resulting buffer.
     * Used by {@code jdk.internal.foreignMemorySegmentImpl}.
     */
    ByteBuffer newDirectByteBuffer(long addr, int cap, Object obj, MemorySegmentProxy segment);

    /**
     * Constructs a mapped ByteBuffer referring to the block of memory starting
     * at the given memory address and extending {@code cap} bytes.
     * The {@code ob} parameter is an arbitrary object that is attached
     * to the resulting buffer. The {@code sync} and {@code fd} parameters of the mapped
     * buffer are derived from the {@code UnmapperProxy}.
     * Used by {@code jdk.internal.foreignMemorySegmentImpl}.
     */
    ByteBuffer newMappedByteBuffer(UnmapperProxy unmapperProxy, long addr, int cap, Object obj, MemorySegmentProxy segment);

    /**
     * Constructs an heap ByteBuffer with given backing array, offset, capacity and segment.
     * Used by {@code jdk.internal.foreignMemorySegmentImpl}.
     */
    ByteBuffer newHeapByteBuffer(byte[] hb, int offset, int capacity, MemorySegmentProxy segment);

    /**
     * Used by {@code jdk.internal.foreign.Utils}.
     */
    Object getBufferBase(ByteBuffer bb);

    /**
     * Used by {@code jdk.internal.foreign.Utils}.
     */
    long getBufferAddress(ByteBuffer bb);

    /**
     * Used by {@code jdk.internal.foreign.Utils}.
     */
    UnmapperProxy unmapper(ByteBuffer bb);

    /**
     * Used by {@code jdk.internal.foreign.AbstractMemorySegmentImpl} and byte buffer var handle views.
     */
    MemorySegmentProxy bufferSegment(Buffer buffer);

    /**
     * Used by I/O operations to make a buffer's resource scope non-closeable
     * (for the duration of the I/O operation) by acquiring a new resource
     * scope handle. Null is returned if the buffer has no scope, or
     * acquiring is not required to guarantee safety.
     */
    Scope.Handle acquireScope(Buffer buffer, boolean async);

    /**
     * Used by {@code jdk.internal.foreign.MappedMemorySegmentImpl} and byte buffer var handle views.
     */
    void force(FileDescriptor fd, long address, boolean isSync, long offset, long size);

    /**
     * Used by {@code jdk.internal.foreign.MappedMemorySegmentImpl} and byte buffer var handle views.
     */
    void load(long address, boolean isSync, long size);

    /**
     * Used by {@code jdk.internal.foreign.MappedMemorySegmentImpl}.
     */
    void unload(long address, boolean isSync, long size);

    /**
     * Used by {@code jdk.internal.foreign.MappedMemorySegmentImpl} and byte buffer var handle views.
     */
    boolean isLoaded(long address, boolean isSync, long size);

    /**
     * Used by {@code jdk.internal.foreign.NativeMemorySegmentImpl}.
     */
    void reserveMemory(long size, long cap);

    /**
     * Used by {@code jdk.internal.foreign.NativeMemorySegmentImpl}.
     */
    void unreserveMemory(long size, long cap);

    /**
     * Used by {@code jdk.internal.foreign.NativeMemorySegmentImpl}.
     */
    int pageSize();
}