On 2024-03-22 1:23 PM, Frank Millman via Python-list wrote:
On 2024-03-22 12:09 PM, Frank Millman via Python-list wrote:
I am no expert. However, I do have something similar in my app, and it
works.
I do not use 'await future', I use 'asyncio.wait_for(future)'.
I tested it and it did not work.
I am not sure, but I think the problem is that you have a mixture of
blocking and non-blocking functions.
Here is a version that works. However, it is a bit different, so I don't
know if it fits your use case.
I have replaced the threads with background asyncio tasks.
I have replaced instances of queue.Queue with asyncio.Queue.
Frank
===============================================
import asyncio
in_queue = asyncio.Queue()
out_queue = asyncio.Queue()
async def worker():
print("worker started running")
while True:
future = await in_queue.get()
print(f"worker got future: {future}")
await asyncio.sleep(5)
print("worker sleeped")
await out_queue.put(future)
async def finalizer():
print("finalizer started running")
while True:
future = await out_queue.get()
print(f"finalizer got future: {future}")
future.set_result("completed")
print("finalizer set result")
async def main():
asyncio.create_task(worker()) # start a background task
asyncio.create_task(finalizer()) # ditto
future = asyncio.get_event_loop().create_future()
await in_queue.put(future)
print(f"main put future: {future}")
result = await asyncio.wait_for(future, timeout=None)
print(result)
if __name__ == "__main__":
# loop = asyncio.get_event_loop()
# loop.run_until_complete(main())
# this is the preferred way to start an asyncio app
asyncio.run(main())
One more point.
If I change 'await asyncio.wait_for(future, timeout=None)' back to your
original 'await future', it still works.
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