重新启动Python中的线程并检查异常

Question

我已经绘制出了一个流程图，我想遵循，但无法弄清楚如何执行此操作。目前我有以下几点。

t1是一个数据库插入脚本，不是cherrypy。

def main(): 
    thread = ThreadUrl(queue) 
    thread = thread() 
    thread.start() 
    cherrypy.config.update({'server.socket_host': '0.0.0.0', 
          'server.socket_port': 2970}) 
          #'server.thread_pool': 100}) 
    queue.join() 
    cherrypy.engine.start() 
    while True: 
     if thread.isAlive(): 
      try: 
       cherrypy.engine.start() 
      except Exception: 
       print ('Started cherrypy already.') 
      print ('I am alive.') 
     else: 
      try: 
       thread.exit() 
      except Exception: 
       print ('Already killed this thread.') 
      print ('I am dead.') 
      try: 
       cherrypy.engine.stop() 
      except Exception: 
       print ('Already stopped cherrypy.') 
      try: 
       thread.start() 
      except Exception: 
       print (sys.exc_info()[1]) 

if __name__ == '__main__': 
    main() 

Answer 1

你可以在一个字典创建一个状态表。每个节点将在执行其行动的功能，然后返回下一个状态，这样的事情：

def start_t1(): 
    # Start t1. 
    return "start cherrypy" 

def start_cherrypy(): 
    # Start Cherrypy. 
    return "is t1 alive?" 

def is_cherrypy_alive(): 
    # Check whether Cherrypy is alive. 
    if alive: 
     return "stop cherrypy" 
    return "start t1" 

actions = { 
    "start t1": start_t1, 
    "start cherrypy": start_cherrypy, 
    "is t1 alive?": is_t1_alive, 
    "is cherry pie alive?": is_cherrypy_alive, 
    ... 
} 

state = "start t1" 
while True: 
    state = actions[state]()