diff -r f280911d3427 -r 289000934908 src/java.base/share/classes/sun/nio/ch/NativeSocketAddress.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/sun/nio/ch/NativeSocketAddress.java	Sat Nov 30 16:21:19 2019 +0000
@@ -0,0 +1,213 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * 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.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.nio.ch;
+
+import java.net.Inet6Address;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.SocketException;
+import java.net.UnknownHostException;
+
+import jdk.internal.misc.Unsafe;
+import jdk.internal.util.ArraysSupport;
+
+/**
+ * A native socket address that is the union of struct sockaddr, struct sockaddr_in,
+ * and struct sockaddr_in6.
+ *
+ * This class is not thread safe.
+ */
+class NativeSocketAddress {
+    private static final Unsafe UNSAFE = Unsafe.getUnsafe();
+    private static final long ARRAY_BASE_OFFSET = UNSAFE.arrayBaseOffset(byte[].class);
+
+    private static final int AF_INET  = AFINET();
+    private static final int AF_INET6 = AFINET6();
+
+    private static final int SIZEOF_SOCKETADDRESS = sizeofSOCKETADDRESS();
+    private static final int SIZEOF_FAMILY        = sizeofFamily();
+    private static final int OFFSET_FAMILY        = offsetFamily();
+    private static final int OFFSET_SIN4_PORT     = offsetSin4Port();
+    private static final int OFFSET_SIN4_ADDR     = offsetSin4Addr();
+    private static final int OFFSET_SIN6_PORT     = offsetSin6Port();
+    private static final int OFFSET_SIN6_ADDR     = offsetSin6Addr();
+    private static final int OFFSET_SIN6_SCOPE_ID = offsetSin6ScopeId();
+
+    // SOCKETADDRESS
+    private final long address;
+
+    // cached copy of SOCKETADDRESS and the corresponding InetSocketAddress
+    private final long cachedSocketAddress;
+    private InetSocketAddress cachedInetSocketAddress;
+
+    NativeSocketAddress() {
+        // allocate 2 * SOCKETADDRESS
+        int size = SIZEOF_SOCKETADDRESS << 1;
+        long base = UNSAFE.allocateMemory(size);
+        UNSAFE.setMemory(base, size, (byte) 0);
+
+        this.address = base;
+        this.cachedSocketAddress = base + SIZEOF_SOCKETADDRESS;
+    }
+
+    long address() {
+        return address;
+    }
+
+    void free() {
+        UNSAFE.freeMemory(address);
+    }
+
+    /**
+     * Return an InetSocketAddress to represent the socket address in this buffer.
+     * @throws SocketException if the socket address is not AF_INET or AF_INET6
+     */
+    InetSocketAddress toInetSocketAddress() throws SocketException {
+        // return cached InetSocketAddress if the SOCKETADDRESS bytes match
+        if (cachedInetSocketAddress != null && mismatch() < 0) {
+            return cachedInetSocketAddress;
+        }
+
+        // decode SOCKETADDRESS to InetSocketAddress
+        int family = family();
+        if (family != AF_INET && family != AF_INET6)
+            throw new SocketException("Socket family not recognized");
+        var isa = new InetSocketAddress(address(family), port(family));
+
+        // copy SOCKETADDRESS and InetSocketAddress
+        UNSAFE.copyMemory(null, address, null, cachedSocketAddress, SIZEOF_SOCKETADDRESS);
+        this.cachedInetSocketAddress = isa;
+        return isa;
+    }
+
+    /**
+     * Find a mismatch between the SOCKETADDRESS structures stored at address
+     * and cachedSocketAddress.
+     * @return the byte offset of the first mismatch or -1 if no mismatch
+     */
+    private int mismatch() {
+        int i = ArraysSupport.vectorizedMismatch(null,
+                address,
+                null,
+                cachedSocketAddress,
+                SIZEOF_SOCKETADDRESS,
+                ArraysSupport.LOG2_ARRAY_BYTE_INDEX_SCALE);
+        if (i >= 0)
+            return i;
+        i = SIZEOF_SOCKETADDRESS - ~i;
+        for (; i < SIZEOF_SOCKETADDRESS; i++) {
+            if (UNSAFE.getByte(address + i) != UNSAFE.getByte(cachedSocketAddress + i)) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    @Override
+    public String toString() {
+        int family = family();
+        if (family == AF_INET || family == AF_INET6) {
+            return ((family == AF_INET) ? "AF_INET" : "AF_INET6")
+                    + ", address=" + address(family) + ", port=" + port(family);
+        } else {
+            return "<unknown>";
+        }
+    }
+
+    /**
+     * Return the value of the sa_family field.
+     */
+    private int family() {
+        if (SIZEOF_FAMILY == 1) {
+            return UNSAFE.getByte(address + OFFSET_FAMILY);
+        } else if (SIZEOF_FAMILY == 2) {
+            return UNSAFE.getShort(address + OFFSET_FAMILY);
+        } else {
+            throw new InternalError();
+        }
+    }
+
+    /**
+     * Return the value of the sin4_port or sin6_port field. These fields are
+     * stored in network order.
+     */
+    private int port(int family) {
+        byte b1, b2;
+        if (family == AF_INET) {
+            b1 = UNSAFE.getByte(address + OFFSET_SIN4_PORT);
+            b2 = UNSAFE.getByte(address + OFFSET_SIN4_PORT + 1);
+        } else {
+            b1 = UNSAFE.getByte(address + OFFSET_SIN6_PORT);
+            b2 = UNSAFE.getByte(address + OFFSET_SIN6_PORT + 1);
+        }
+        return (Byte.toUnsignedInt(b1) << 8) + Byte.toUnsignedInt(b2);
+    }
+
+    /**
+     * Return an InetAddress to represent the value of the address in the
+     * sin4_addr or sin6_addr fields.
+     */
+    private InetAddress address(int family) {
+        int len;
+        int offset;
+        int scope_id;
+        if (family == AF_INET) {
+            len = 4;
+            offset = OFFSET_SIN4_ADDR;
+            scope_id = 0;
+        } else {
+            len = 16;
+            offset = OFFSET_SIN6_ADDR;
+            scope_id = UNSAFE.getInt(address + OFFSET_SIN6_SCOPE_ID);
+        }
+        byte[] bytes = new byte[len];
+        UNSAFE.copyMemory(null, address + offset, bytes, ARRAY_BASE_OFFSET, len);
+        try {
+            if (scope_id == 0) {
+                return InetAddress.getByAddress(bytes);
+            } else {
+                return Inet6Address.getByAddress(null, bytes, scope_id);
+            }
+        } catch (UnknownHostException e) {
+            throw new InternalError(e);
+        }
+    }
+
+    private static native int AFINET();
+    private static native int AFINET6();
+    private static native int sizeofSOCKETADDRESS();
+    private static native int sizeofFamily();
+    private static native int offsetFamily();
+    private static native int offsetSin4Port();
+    private static native int offsetSin4Addr();
+    private static native int offsetSin6Port();
+    private static native int offsetSin6Addr();
+    private static native int offsetSin6ScopeId();
+
+    static {
+        IOUtil.load();
+    }
+}