db and asynchrony. how to combine?-CodePudding

The problem is that the database does not have time to be processed and there is a call on the second circle. How to make the database processing happen and the cycle goes on. asynchronously

async def send_mes_to_users(client):
    async with client:
        user = 'userrrrrrrrr'
        try:
            if db.check_invited(name_table=table, user_name=user) != "TRUE":
                await client.send_message(entity=user, message=message)
                db.add_invited(name_table=table, user=user) #??????????
                print(f'Sent: @{user}')

        except errors.BadRequestError as e:
            print(f'Error: {e}')


async def main():
    await asyncio.gather(
        send_mes_to_users(TelegramClient('user1', api_id, api_hash)),
        send_mes_to_users(TelegramClient('user2', api_id, api_hash)),
    )


asyncio.run(main())

CodePudding user response：

You are running two tasks at the same time (with gather). You're likely to run into a race condition. If you need to synchronize a "critical section", consider using an asyncio.Lock:

db_lock = asyncio.Lock()

async def send_mes_to_users(client):
    async with client:
        user = 'userrrrrrrrr'
        try:
            async with db_lock:
                # everything inside here is protected under 'db_lock'
                # the lock can only be acquired once (so this section can't run concurrently)
                if db.check_invited(name_table=table, user_name=user) != "TRUE":
                    await client.send_message(entity=user, message=message)
                    db.add_invited(name_table=table, user=user) #??????????
                    print(f'Sent: @{user}')

        except errors.BadRequestError as e:
            print(f'Error: {e}')


async def main():
    await asyncio.gather(
        send_mes_to_users(TelegramClient('user1', api_id, api_hash)),
        send_mes_to_users(TelegramClient('user2', api_id, api_hash)),
    )


asyncio.run(main())

CodePudding user response：

you want the second Task to not send do userrrrr as its marked as invited? then you need to update database before awaiting send_message, as this passes control to the second task, which then checks for already invited userrrrr, and it´s not as it´s awaiting sending.