src/java.base/aix/classes/sun/nio/ch/DefaultPollerProvider.java

@@ -32,13 +32,17 @@
  class DefaultPollerProvider extends PollerProvider {
      DefaultPollerProvider() { }
  
      @Override
      Poller readPoller(boolean subPoller) throws IOException {
+         if (subPoller)
+             throw new UnsupportedOperationException();
          return new PollsetPoller(true);
      }
  
      @Override
      Poller writePoller(boolean subPoller) throws IOException {
+         if (subPoller)
+             throw new UnsupportedOperationException();
          return new PollsetPoller(false);
      }
  }