--- a/src/java.base/share/classes/java/net/AbstractPlainSocketImpl.java	Fri Mar 01 18:28:44 2019 +0000
+++ b/src/java.base/share/classes/java/net/AbstractPlainSocketImpl.java	Sat Mar 02 11:44:38 2019 +0000
@@ -607,15 +607,10 @@
         }
     }
 
-    void reset() throws IOException {
-        if (fd != null) {
-            socketClose();
-        }
-        fd = null;
-        super.reset();
+    void reset() {
+        throw new InternalError("should not get here");
     }
 
-
     /**
      * Shutdown read-half of the socket connection;
      */

--- a/src/java.base/share/classes/java/net/ServerSocket.java	Fri Mar 01 18:28:44 2019 +0000
+++ b/src/java.base/share/classes/java/net/ServerSocket.java	Sat Mar 02 11:44:38 2019 +0000
@@ -576,6 +576,7 @@
         boolean completed = false;
         try {
             si.reset();
+            // custom SocketImpl may expect fd/address to be created
             si.fd = new FileDescriptor();
             si.address = new InetAddress();
             impl.accept(si);
@@ -599,19 +600,20 @@
     private void implAccept(SocketImpl si) throws IOException {
         assert !(si instanceof DelegatingSocketImpl);
 
-        // A non-platform SocketImpl cannot accept a connection with a platform
-        // SocketImpl
-        if (!(impl instanceof PlatformSocketImpl) && si instanceof PlatformSocketImpl) {
+        // A non-platform SocketImpl cannot accept a connection with a platform SocketImpl
+        if (!(impl instanceof PlatformSocketImpl) && (si instanceof PlatformSocketImpl)) {
             throw new IOException("An instance of " + impl.getClass() +
-                    " cannot accept a connection with an instance of " + si.getClass());
+                " cannot accept a connection with an instance of " + si.getClass());
         }
 
+        // accept a connection
         impl.accept(si);
 
+        // sanity check that the fields defined by SocketImpl have been set
         if (si instanceof PlatformSocketImpl) {
             var fd = si.fd;
-            if (fd == null || !fd.valid() || si.localport <= 0 ||
-                si.address == null || si.port <= 0) {
+            if (fd == null || !fd.valid() || si.localport <= 0
+                    || si.address == null || si.port <= 0) {
                 throw new IOException("Invalid accepted state:" + si);
             }
         }

--- a/src/java.base/share/classes/java/net/SocketImpl.java	Fri Mar 01 18:28:44 2019 +0000
+++ b/src/java.base/share/classes/java/net/SocketImpl.java	Sat Mar 02 11:44:38 2019 +0000
@@ -332,7 +332,8 @@
             ",port=" + getPort() + ",localport=" + getLocalPort()  + "]";
     }
 
-    void reset() throws IOException {
+    void reset() {
+        fd = null;
         address = null;
         port = 0;
         localport = 0;

--- a/src/java.base/share/classes/sun/nio/ch/NioSocketImpl.java	Fri Mar 01 18:28:44 2019 +0000
+++ b/src/java.base/share/classes/sun/nio/ch/NioSocketImpl.java	Sat Mar 02 11:44:38 2019 +0000
@@ -1173,9 +1173,6 @@
             ensureOpenAndConnected();
             if (!isInputClosed) {
                 Net.shutdown(fd, Net.SHUT_RD);
-                long reader = readerThread;
-                if (reader != 0)
-                    NativeThread.signal(reader);
                 isInputClosed = true;
             }
         }
@@ -1187,9 +1184,6 @@
             ensureOpenAndConnected();
             if (!isOutputClosed) {
                 Net.shutdown(fd, Net.SHUT_WR);
-                long writer = writerThread;
-                if (writer != 0)
-                    NativeThread.signal(writer);
                 isOutputClosed = true;
             }
         }
@@ -1288,15 +1282,6 @@
     }
 
     /**
-     * Returns the native file descriptor.
-     */
-    private static int fdVal(FileDescriptor fd) {
-        int fdVal = SharedSecrets.getJavaIOFileDescriptorAccess().get(fd);
-        assert fdVal == IOUtil.fdVal(fd);
-        return fdVal;
-    }
-
-    /**
      * Sets the SocketImpl fields to the given values.
      */
     private static void setSocketImplFields(SocketImpl si,