--- old/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java	2019-12-09 18:15:15.563742032 +0000
+++ new/src/java.base/share/classes/jdk/internal/access/JavaNioAccess.java	2019-12-09 18:15:15.095733680 +0000
@@ -25,6 +25,8 @@
 
 package jdk.internal.access;
 
+import jdk.internal.access.foreign.MemorySegmentProxy;
+
 import java.nio.Buffer;
 import java.nio.ByteBuffer;
 
@@ -39,4 +41,34 @@
         long getMemoryUsed();
     }
     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 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 byte buffer var handle views.
+     */
+    void checkSegment(Buffer buffer);
 }