对 coroutine.__await__() 调用 next 为什么会导致重复进入 Future.__await__()

import types from typing import Any, Awaitable @types.coroutine def _async_yield(obj): return (yield obj) async def gather(*aws: Awaitable[Any], return_exceptions: bool = False): result_array: list[Any] = [None for _ in range(len(aws))] done, pending = [], [*aws] while pending: for i, awaitable in enumerate(aws): if awaitable in done: continue try: next(awaitable.__await__()) await _async_yield(None) except StopIteration as exc: result_array[i] = exc.value done.append(awaitable) pending.remove(awaitable) except BaseException as exc: if not return_exceptions: raise result_array[i] = exc done.append(awaitable) pending.remove(awaitable) return result_array async def test_wait(): async def a(): return 1 async def b(): import asyncio await asyncio.sleep(0) return 2 async def c(): import asyncio await asyncio.sleep(1) return 3 return await gather(a(), b(), c(), asyncio.create_task(c())) if __name__ == "__main__": import asyncio print(asyncio.run(test_wait())) 

报错所处的位置：

 # asyncio/futures.py line 281 def __await__(self): if not self.done(): self._asyncio_future_blocking = True yield self # This tells Task to wait for completion. if not self.done(): raise RuntimeError("await wasn't used with future") return self.result() # May raise too.