Pyserial和asyncio

Question

試圖在Windows機器上使用pyserial和asyncio。

受https://stackoverflow.com/a/27927704/1629704啓發我的代碼不斷地觀看傳入數據的串行端口。

# This coroutine is added as a task to the event loop. 
@asyncio.coroutine 
def get_from_serial_port(self): 
    while 1: 
     serial_data = yield from self.get_byte_async() 
     <doing other stuff with serial_data> 

# The method which gets executed in the executor 
def get_byte(self): 
    data = self.s.read(1) 
    time.sleep(0.5) 
    tst = self.s.read(self.s.inWaiting()) 
    data += tst 
    return data 

# Runs blocking function in executor, yielding the result 
@asyncio.coroutine 
def get_byte_async(self): 
    with concurrent.futures.ThreadPoolExecutor(max_workers=1) as executor: 
     res = yield from self.loop.run_in_executor(executor, self.get_byte) 
     return res 

串行數據返回後。在while循環中調用協程get_byte_async以創建新的執行程序。我總是學會創建一個新的線程是昂貴的，所以我覺得我應該採取另一種方法，但我不知道如何做到這一點。 我一直在閱讀這篇文章https://hackernoon.com/threaded-asynchronous-magic-and-how-to-wield-it-bba9ed602c32#.964j4a5s7

我想我需要在另一個線程中讀取串口。但是如何讓串行數據返回到「主」循環？

Answer 1

您可以使用默認的執行，並用asyncio lock鎖定訪問get_byte：

async def get_byte_async(self): 
    async with self.lock: 
     return await self.loop.run_in_executor(None, self.get_byte) 

或者乾脆一次創建自己的遺囑執行人：

async def get_byte_async(self): 
    if self.executor is None: 
     self.executor = concurrent.futures.ThreadPoolExecutor(max_workers=1) 
    return await self.loop.run_in_executor(self.executor, self.get_byte)