[记录]python的简单协程框架(回调+时间循环+select)
# -*- coding: utf-8 -*- # @Time : 2018/12/15 18:55 # @File : coroutine.py #一个简单的 Coroutine 框架 import socket # on top of TCP import time from selectors import DefaultSelector, EVENT_WRITE, EVENT_READ # select: System Call -----> watch the readiness of a unix-file(socket) i/o # only socket is possible in Windows # non-blocking socket selector = DefaultSelector() class Future: # ~=Promise, return the caller scope a promise # about something in the future def __init__(self): self.callbacks = [] def resolve(self): # on future event callback for func in self.callbacks: func() class Task: # responsible for calling next() on generators # in charge of the async functions def __init__(self, gen, eventLoop): self.gen = gen self.step() def step(self): # go to next step/next yield try: f = next(self.gen) f.callbacks.append(self.step) except StopIteration as e: # Task is finished eventLoop.n_task -= 1 class EventLoop: def __init__(self): self.n_task = 0 def add_task(self, generator): self.n_task += 1 Task(generator, self) def start(self): while self.n_task > 0: events = selector.select() for event, mask in events: f = event.data f.resolve() def pause(s, event): f = Future() selector.register(s.fileno(), event, data=f) yield f # pause this function def resume(s): selector.unregister(s.fileno()) def async_await(s, event): yield from pause(s, event) resume(s) def async_get(path): s = socket.socket() s.setblocking(False) try: s.connect(('localhost', 3000)) except BlockingIOError as e: print(e) yield from async_await(s, EVENT_WRITE) request = 'GET %s HTTP/1.0\r\n\r\n' % path s.send(request.encode()) totalReceived = [] while True: yield from async_await(s, EVENT_READ) received = s.recv(1000) if received: totalReceived.append(received) else: body = (b''.join(totalReceived)).decode() print('--------------------------------------') print(body) print('--------------------------------------', 'Byte Received:', len(body), '\n\n') return if __name__ == '__main__': start = time.time() eventLoop = EventLoop() for i in range(50): eventLoop.add_task(async_get('/super-slow')) eventLoop.start() print('%.1f sec' % (time.time() - start))