listing_6_12.py

"""
Захват и освобождение блокировки
"""
from multiprocessing import Process, Value


def increment_value(shared_int: Value) -> None:
    # shared_int.get_lock().acquire()
    # shared_int.value += 1
    # shared_int.get_lock().release()

    # Use context manager:
    with shared_int.get_lock():
        shared_int.value += 1


if __name__ == "__main__":
    for _ in range(100):
        integer = Value("i", 0)
        procs = [
            Process(target=increment_value, args=(integer,)),
            Process(target=increment_value, args=(integer,)),
        ]

        [p.start() for p in procs]
        [p.join() for p in procs]

        print(f"{integer.value=}")
        assert integer.value == 2