static bool isThreadRunnable_x(Thread t, StackTraceElement[] trace) {
  if (t.getState() != Thread.State.RUNNABLE) false;
  StackTraceElement e = first(trace);
  if (e == null) false; // Weird threads like "DestroyJavaVM"
  S s = e.getClassName() + "." + e.getMethodName();
  ret !eqOneOf(s,
    "java.net.SocketInputStream.socketRead0",
    "java.net.PlainSocketImpl.socketAccept");
}