我想使用异步调用的loop.run_in_executor方法在Executor中启动一个阻塞函数,然后稍后取消它,但这似乎对我不起作用。
以下是代码:
import asyncio
import time
from concurrent.futures import ThreadPoolExecutor
def blocking_func(seconds_to_block):
for i in range(seconds_to_block):
print('blocking {}/{}'.format(i, seconds_to_block))
time.sleep(1)
print('done blocking {}'.format(seconds_to_block))
@asyncio.coroutine
def non_blocking_func(seconds):
for i in range(seconds):
print('yielding {}/{}'.format(i, seconds))
yield from asyncio.sleep(1)
print('done non blocking {}'.format(seconds))
@asyncio.coroutine
def main():
non_blocking_futures = [non_blocking_func(x) for x in range(1, 4)]
blocking_future = loop.run_in_executor(None, blocking_func, 5)
print('wait a few seconds!')
yield from asyncio.sleep(1.5)
blocking_future.cancel()
yield from asyncio.wait(non_blocking_futures)
loop = asyncio.get_event_loop()
executor = ThreadPoolExecutor(max_workers=1)
loop.set_default_executor(executor)
asyncio.async(main())
loop.run_forever()
我期望上述代码只允许阻塞函数输出:
blocking 0/5
blocking 1/5
然后查看非阻塞函数的输出,但是实际上阻塞的future仍会继续执行,即使我已经取消了。
这种情况可能吗?还有其他方法可以解决吗?
谢谢
编辑:关于使用asyncio运行阻塞和非阻塞代码的更多讨论:如何使用asyncio与阻塞和非阻塞代码进行交互