Reusing connections and asyncio tasks

[briskweb]

• GINO version: 0.8.2
• Python version: 3.7.3
• asyncpg version: 0.18.3
• aiocontextvars version: 0.2.2

Description

When I have a reusing connection and create new tasks, the tasks inherit the same reusing connection, which may result in a conflict.

I would expect that you can only reuse connections from the same task and new tasks have no reusing connection on their stacks in the beginning. Is it possible to have this behavior?

What I Did

Here is a small example showing the problem. It throws
asyncpg.exceptions._base.InterfaceError: cannot perform operation: another operation is in progress.

from gino import Gino
import asyncio

db = Gino()


async def main():
    await db.set_bind('postgresql+asyncpg://...')
    async with db.acquire(reuse=True) as con:
        t1 = asyncio.create_task(test())
        t2 = asyncio.create_task(test2())
        await asyncio.gather(t1, t2)


async def test():
    print(await db.scalar("SELECT pg_sleep(10)"))


async def test2():
    print(await db.scalar("SELECT pg_backend_pid()"))

asyncio.run(main())

[fantix]

This would work:

from aiocontextvars import Context

...

    async with db.acquire(reuse=True) as con:
        t1 = Context().run(asyncio.create_task, test())
        t2 = Context().run(asyncio.create_task, test2())

[wwwjfy]

Closing due to inactivity. Feel free to reopen.