ThreadPool WakeUpAllThreads behaviour

In ThreadPoolImpl.SubmitJob(...) function, after successfully pushed the job and before unlocking the mutex, it will wakeup all sleeping sub-threads when total_threads_limits_ has been shrinked (for example , 4 -> 2).
But when this situation happens, each "LastExcessiveThread" will wake up all sub-threads circularly until HasExcessiveThread() = == false. It leads that "WakeUpAllThreads() in Submit(...) is redundant". Is there any situation which can trigger the scene ?

Start at ThreadPoolImpl::SubmitJob(...) and trace WakeUpAllThreads(), LastExcessiveThread, and HasExcessiveThread() while checking the mutex and thread-limit shrink path. Reproduce or reason about the described circular wakeups, then determine whether Submit(...) can reach a redundant wakeup; done means the behavior and any necessary cleanup are covered by an appropriate test or documented conclusion.

Written by the indexing model from the issue text.