Как остановить асинхронный код

import asyncio
from asyncio import Semaphore
 
import aiohttp
 
 
async def parser(session, semaphore, link_item):  # , stop_event, owner_id, link_count
    await semaphore.acquire()
    # код парсера
    semaphore.release()
    
async def gahter():
    semaphore = Semaphore(20)
    tasks = []
    # stop_event = asyncio.Event()
    connector = aiohttp.TCPConnector(limit=20)
    # connector = aiohttp.TCPConnector()
    async with aiohttp.ClientSession(connector=connector) as session:  # ,  trust_env=True
        for link_count, link in enumerate(links_item):
            task = asyncio.create_task(parser(session, semaphore, link))
            tasks.append(task)
        await asyncio.gather(*tasks)
        # await stop_event.wait()
        
def main():
    # asyncio.get_event_loop().run_until_complete(gahter())
    asyncio.new_event_loop().run_until_complete(gahter())

import asyncio
from asyncio import Semaphore
from random import randint
 
 
async def parser(semaphore: Semaphore, item):
    async with semaphore:
        num = randint(30, 60)
        print(f'item {item}, sleeping for {num} seconds')
        await asyncio.sleep(num)
 
async def main():
    semaphore = Semaphore(3)
    links_item = [1, 2, 3, 4, 5]
    tasks = []
 
    for _, link in enumerate(links_item):
        task = asyncio.create_task(parser(semaphore, link))
        tasks.append(task)
    
    for _ in range(5):
        await asyncio.sleep(2)
 
        random_stop = randint(1, 5)
 
        print('Generated:', random_stop)
        if random_stop == 3:
            print("Lucky 3, stopping all tasks")
            for t in tasks:
                t.cancel()
            break
    
    await asyncio.wait(tasks)
    
 
loop = asyncio.get_event_loop()
loop.run_until_complete(main())