我想知道python3.6和asyncio的并发性是如何工作的。我的理解是,当解释器执行await
语句时,它会将其留在那里,直到等待过程完成,然后继续执行另一个协同程序任务。但我在下面的代码中看到的并不是这样。程序同步运行,逐个执行任务。在
我的理解和实现代码有什么问题?在
import asyncio
import time
async def myWorker(lock, i):
print("Attempting to attain lock {}".format(i))
# acquire lock
with await lock:
# run critical section of code
print("Currently Locked")
time.sleep(10)
# our worker releases lock at this point
print("Unlocked Critical Section")
async def main():
# instantiate our lock
lock = asyncio.Lock()
# await the execution of 2 myWorker coroutines
# each with our same lock instance passed in
# await asyncio.wait([myWorker(lock), myWorker(lock)])
tasks = []
for i in range(0, 100):
tasks.append(asyncio.ensure_future(myWorker(lock, i)))
await asyncio.wait(tasks)
# Start up a simple loop and run our main function
# until it is complete
loop = asyncio.get_event_loop()
loop.run_until_complete(main())
print("All Tasks Completed")
loop.close()
asyncio使用一个循环来运行所有东西,
await
将把控制权交还给循环,这样它就可以安排下一个要运行的协同程序。在在异步协同例程中调用一个阻塞调用,如
time.sleep
,会阻塞整个事件循环,从而破坏使用asynciao的目的。在将
time.sleep(10)
更改为await asyncio.sleep(10)
,代码的行为将如您所期望的那样。在相关问题 更多 >
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