// Hint to the underlying OS that a task switch would not be good.
// Void return because it's a hint and can fail.

void os::hint_no_preempt() {

  {- -------------------------------------------
  (1) schedctl_start() を呼んで, 
      カレントスレッドの time slice を増加させてくれるよう要請を出す.
      ---------------------------------------- -}

      schedctl_start(schedctl_init());
    }