--- a/src/java.base/unix/classes/sun/nio/ch/NativeThread.java	Tue Apr 02 14:36:17 2019 +0100
+++ b/src/java.base/unix/classes/sun/nio/ch/NativeThread.java	Wed Apr 03 10:47:10 2019 +0100
@@ -25,6 +25,7 @@
 
 package sun.nio.ch;
 
+
 // Signalling operations on native threads
 //
 // On some operating systems (e.g., Linux), closing a channel while another
@@ -32,35 +33,23 @@
 // thread to be released.  This class provides access to the native threads
 // upon which Java threads are built, and defines a simple signal mechanism
 // that can be used to release a native thread from a blocking I/O operation.
+// On systems that do not require this type of signalling, the current() method
+// always returns -1 and the signal(long) method has no effect.
 
-import jdk.internal.access.JavaLangAccess;
-import jdk.internal.access.SharedSecrets;
 
 public class NativeThread {
-    private static final JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
 
-    /**
-     * Returns the current thread's ID.
-     */
-    public static long current() {
-        long tid = JLA.nativeTid();
-        if (tid == 0) {
-            tid = current0();
-            JLA.setNativeTid(tid);
-        }
-        return tid;
-    }
+    // Returns an opaque token representing the native thread underlying the
+    // invoking Java thread.  On systems that do not require signalling, this
+    // method always returns -1.
+    //
+    public static native long current();
 
-    /**
-     * Signals the given thread.
-     */
-    public static void signal(long tid) {
-        signal0(tid);
-    }
-
-    private static native long current0();
-
-    private static native void signal0(long tid);
+    // Signals the given native thread so as to release it from a blocking I/O
+    // operation.  On systems that do not require signalling, this method has
+    // no effect.
+    //
+    public static native void signal(long nt);
 
     private static native void init();