tornado--同步异步

同步：指两个或两个以上随时间变化的量在变化过程当中保持必定的相对关系 现象：有一个共同的时钟，按来的顺序一个一个处理

异步：双方不须要共同的时钟，也就是接收方不知道发送方何时发送，因此在发送的信息中就要有提示接收方开始接收的信息，如开始位，同时在结束时有中止位 现象：没有共同的时钟，不考虑顺序来了就处理 

 

四种异步：

import tornado.ioloop import tornado.web from data.table_1 import User from tornado.web import authenticated from pycket.session import SessionMixin import tornado.websocket from datetime import datetime import time import tornado.options import tornado.httpserver from tornado.options import define, options define('port',default=8000, help='run port', type=int) define('version', default=0.1, help='version', type=str) class BaseHandler(tornado.web.RequestHandler, SessionMixin): def get_current_user(self): # current_user = self.get_secure_cookie('ID')
        current_user = self.session.get('ID') if current_user: return current_user return None class AbcHandler(BaseHandler): def get(self): self.write('abc') import tornado.httpclient class SyncHandler(BaseHandler): def get(self): client = tornado.httpclient.HTTPClient()     # 同步HTTPClient
        response = client.fetch('http://127.0.0.1:8000/sync')  # 8000已经启动，去访问sync（至关于调用接口）
        print(response) self.write('----SyncHandler---') # 可能发生阻塞用异步
class CallbackHandler(BaseHandler): """ 1.经过回调函数实现异步 """ @tornado.web.asynchronous # 将请求变成长链接 def get(self): client = tornado.httpclient.AsyncHTTPClient()     # 异步AsyncHTTPClient
                                                # 阻塞完毕后调用 callback
        response = client.fetch('http://127.0.0.1:8000/sync', callback=self.on_response) print(response) self.write('OK'+'<br>') def on_response(self, response): print(response) self.write('----CallbackSyncHandler---') self.finish() # 回调结束，请求结束，响应到浏览器（不然浏览器一直等待状态）


import tornado.gen class GenHandler(BaseHandler): """ 2.经过协程实现异步 yield """ @tornado.web.asynchronous @tornado.gen.coroutine def get(self): client = tornado.httpclient.AsyncHTTPClient()     # 异步
        # 节省内存（暂停）
        response = yield tornado.gen.Task(client.fetch,'http://127.0.0.1:8000/sync') print(response) self.write('---gen----') class FuncHandler(BaseHandler): """ 3.经过协程实现异步 yield 调用函数 @tornado.gen.coroutine装饰函数（函数须要用到yield）""" @tornado.web.asynchronous @tornado.gen.coroutine def get(self): response = yield self.fun() print(response) self.write('---gen----') @tornado.gen.coroutine def fun(self): client = tornado.httpclient.AsyncHTTPClient()     # 异步
        response = yield tornado.gen.Task(client.fetch, 'http://127.0.0.1:8000/sync') raise tornado.gen.Return(response) from tornado.concurrent import run_on_executor from concurrent.futures import ThreadPoolExecutor # （它是由thread模块封装的（建立线程的模块）） import requests class ExeHandler(BaseHandler): """ 4.经过协程实现异步 yield 调用函数 @run_on_executor装饰函数（函数不用yield） 须要下载requests 和futures""" executor = ThreadPoolExecutor() # 当发生阻塞时，可以建立一个新的线程来执行阻塞的任务(多线程) @tornado.web.asynchronous @tornado.gen.coroutine def get(self): response = yield self.fun() print(response) self.write('---exe----') @run_on_executor def fun(self): response = requests.get( 'http://127.0.0.1:8000/sync') return response application = tornado.web.Application( handlers=[ (r"/sync", SyncHandler), (r"/abc", AbcHandler), (r"/callback", CallbackHandler), (r"/gen", GenHandler), (r"/func", FuncHandler), (r"/exe", ExeHandler), ], cookie_secret='haha', debug=True ) if __name__ == '__main__': tornado.options.parse_command_line() # 获取命令行的参数 --port=1040 就能使用这个参数
    print(options.port) print(options.version) http_server = tornado.httpserver.HTTPServer(application) application.listen(options.port) tornado.ioloop.IOLoop.instance().start()