python 3.6异步aioodbc阻塞

我希望将aioodbc与异步信号一起用于将行插入数据库。下面将向目标数据库中写入一些行,但似乎在sempahore周围锁定。 value + 1。关于如何重新编写这个或解决块/争用的任何建议?

表定义:

create table async_testing (
    insert_id int null
)

异步代码:

import asyncio
import aioodbc

loop = asyncio.get_event_loop()

async def odbc_insert_worker(semaphore, value, conn):
    await semaphore.acquire()
    print("Acquire Semaphore")
    async with conn.cursor() as cur:
        await cur.execute('INSERT INTO async_testing VALUES (?)', value)
    print("Release Semaphore")
    semaphore.release()

async def db_main(loop, values):
    dsn="foo"

    values = list(values)
    db_semaphore = asyncio.Semaphore(value=15)

    async with aioodbc.create_pool(dsn=dsn, loop=loop, autocommit=True) as pool:
        async with pool.acquire() as conn:
            tasks = [odbc_insert_worker(db_semaphore, value, conn) for value in values]
            await asyncio.gather(*tasks)

fmt_vals = range(0,1000)

loop.run_until_complete(db_main(loop, fmt_vals))