eventlet如何绿化pyserial最好
问题
pyserial访问windows中的串口,如何绿化?不阻塞协程? 效率最高? 绿化毫无疑问要借用tpool.execute.
代码该如何实现才最佳呢?
方法一: 直接recv
直接recv,会阻塞协程
缺点: 协程被阻塞,程序不可用
方法二: tpool+in_waiting判断
import serial from eventlet import tpool class SerialSocket(serial.Serial): def recv(self): # 读完 if self.in_waiting: return tpool.execute(self.read, self.in_waiting) return data def listen_message(): ss = SerialSocket("com10") buffer = b'' while True: data = ss.recv() if data is not None: buffer +=data
缺点: cpu利用率较高
方法三: tpool+in_waiting判断+sleep
import serial from eventlet import tpool, sleep class SerialSocket(serial.Serial): def recv(self): # 读完 if self.in_waiting: return tpool.execute(self.read, self.in_waiting) return data def listen_message(): ss = SerialSocket("com10") buffer = b'' while True: data = ss.recv() if data is not None: buffer +=data else: sleep(0.01)
缺点: 满足大部分需求, 对时间要求比较敏感的程序,还是不行,多了0.01秒
方法四(完美):tpool+in_waiting判断+read(1)阻塞
利用serial的read()阻塞特性,加上tpool线程,最终线程阻塞转换成协程阻塞
import serial from eventlet import tpool class SerialSocket(serial.Serial): def recv(self): # 等待 data = tpool.execute(self.read, 1) # 读完 while self.in_waiting: data += tpool.execute(self.read, self.in_waiting) return data def listen_message(): ss = SerialSocket("com10") buffer = b'' while True: g = evenlet.spawn(ss.recv) data = g.wait() buffer +=data