def __notify_topmost(self):
    (priority, prioqueue) = self.__find_first_pending_queue()
    if prioqueue:
      cond = prioqueue[0]
      cond.notifyAll()
      if cond.shared:
        # Prevent further shared acquires from sneaking in while waiters are
        # notified
        self.__pending_shared.pop(priority, None)
Notifies topmost condition in queue of pending acquires.
dataset/ETHPy150Open ganeti/ganeti/lib/locking.py/SharedLock.__notify_topmost