apscheduler 为什么每次运行的线程名称都不一样？是不是会不断创建新的线程？

import  threading
from apscheduler.scheduler import Scheduler
schedudler = Scheduler(daemonic = False)

@schedudler.cron_schedule(second='*/10', minute='*', day_of_week='0-6', hour='7-21')
def send_toeflword():
    text = 'Hello World'
    print text
    print threading.current_thread().name
schedudler.start()

打印结果：

Hello World
Thread-1
Hello World
Thread-2
Hello World
Thread-3
Hello World
Thread-4
Hello World
Thread-5
Hello World
Thread-6
Hello World
Thread-7
Hello World
Thread-8
Hello World
Thread-9

---

sorry，看了下，好像前面的会自动销毁。