'Run \'start_thread\' listeners for the current thread.
If the current thread has already been seen, any \'start_thread\'
listeners will not be run again.'

def acquire_thread(self):

    thread_ident = get_thread_ident()
    if (thread_ident not in self.threads):
        i = (len(self.threads) + 1)
        self.threads[thread_ident] = i
        self.bus.publish('start_thread', i)
