src/java.base/windows/classes/sun/nio/ch/NativeThread.java

@@ -23,49 +23,31 @@
   * questions.
   */
  
  package sun.nio.ch;
  
- 
- // Signalling operations on native threads
+ import java.util.concurrent.locks.LockSupport;
  
  public class NativeThread {
-     private static final long VIRTUAL_THREAD_ID = -1L;
- 
-     /**
-      * Returns the id of the current native thread if the platform can signal
-      * native threads, 0 if the platform can not signal native threads, or
-      * -1L if the current thread is a virtual thread.
-      */
-     public static long current() {
-         if (Thread.currentThread().isVirtual()) {
-             return VIRTUAL_THREAD_ID;
-         } else {
-             // no support for signalling threads on Windows
-             return 0;
-         }
-     }
+     private NativeThread() { }
  
      /**
-      * Signals the given native thread.
-      *
-      * @throws IllegalArgumentException if tid is not a token to a native thread
+      * Returns the Thread to signal the current thread or {@code null} if the current
+      * thread cannot be signalled.
       */
-     static void signal(long tid) {
-         throw new UnsupportedOperationException();
+     public static Thread threadToSignal() {
+         Thread thread = Thread.currentThread();
+         return thread.isVirtual() ? thread : null;
      }
  
      /**
-      * Returns true the tid is the id of a native thread.
+      * Signals the given thread.
+      * @throws UnsupportedOperationException is not supported
       */
-     static boolean isNativeThread(long tid) {
-         return false;
-     }
- 
-     /**
-      * Returns true if tid is -1L.
-      * @see #current()
-      */
-     static boolean isVirtualThread(long tid) {
-         return (tid == VIRTUAL_THREAD_ID);
+     public static void signal(Thread thread) {
+         if (thread.isVirtual()) {
+             LockSupport.unpark(thread);
+         } else {
+             throw new UnsupportedOperationException();
+         }
      }
  }