Потоки и процессы

import time
from concurrent.futures import ThreadPoolExecutor, as_completed

def load(name):
    delays = {"slow": 0.30, "fast": 0.05, "mid": 0.15}
    time.sleep(delays[name])
    return name

with ThreadPoolExecutor(max_workers=3) as ex:
    futures = [ex.submit(load, name) for name in ["slow", "fast", "mid"]]
    result = [future.result() for future in as_completed(futures)]
print(result)

from threading import Lock

lock_a = Lock()
lock_b = Lock()

def work():
    pass

def first():
    with lock_a:
        with lock_b:
            work()

def second():
    with lock_b:
        with lock_a:
            work()

from multiprocessing import Process

value = []
def worker():
    value.append(1)

if __name__ == "__main__":
    p = Process(target=worker)
    p.start(); p.join()
    print(value)

from threading import Barrier, Thread

counter = 0
barrier = Barrier(2)

def add_once():
    global counter
    current = counter
    barrier.wait()
    counter = current + 1

threads = [Thread(target=add_once) for _ in range(2)]
for thread in threads:
    thread.start()
for thread in threads:
    thread.join()
print(counter)