New submission from Vladimir Matveev <desco...@gmail.com>:
https://bugs.python.org/issue41756 has introduced PyIter_Send as a common entrypoint for sending values however currently fast path that does not use StopIteration exception is only available for generators/coroutines. It would be quite nice if this machinery was extensible and other types (both internal and 3rd party) could opt-in into using exception-free way of returning values without needing to update the implementation of PyIter_Send. One way of solving this is adding a new slot with a signature that matches PyIter_Send. With it: - it should be possible to implement this slot for coroutines/generators and remove special casing for them in PyIter_Send - provide implementation for this slot for internal types (i.e. FutureIter in _asynciomodule.c) - results of this experiment can be found below - enable external native extensions to provide efficient implementation of coroutines (i.e. Cython could benefit from it) Microbenchmark to demonstrate the difference of accessing the value of fulfiled Future without and with dedicated slot: ``` import asyncio import time N = 100000000 async def run(): fut = asyncio.Future() fut.set_result(42) t0 = time.time() for _ in range(N): await fut t1 = time.time() print(f"Time: {t1 - t0} s") asyncio.run(run()) ``` Time: 8.365560054779053 s - without the slot Time: 5.799655914306641 s - with the slot ---------- components: Interpreter Core messages: 378999 nosy: v2m priority: normal severity: normal status: open title: Add dedicated slot for sending values versions: Python 3.10 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue42085> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
