跨进程修改Numpy数据 基于multiprocessing.shared_memory

multiprocessing.shared_memory Python3.8新特性
官方文档

import numpy as np
from multiprocessing import shared_memory
from multiprocessing import Process
from multiprocessing.managers import SharedMemoryManager


def change(name):
    a = np.array([0, 0, 0, 0, 0, 0])
    existing_shm = shared_memory.SharedMemory(name=name)
    b = np.ndarray((6,), dtype=np.int64, buffer=existing_shm.buf)
    b[:] = a[:]
    print("changed")


def show(name):
    existing_shm = shared_memory.SharedMemory(name=name)
    b = np.ndarray((6,), dtype=np.int64, buffer=existing_shm.buf)
    print(b)


if __name__ == '__main__':
    smm = SharedMemoryManager()
    smm.start()
    a = np.array([1, 1, 2, 3, 5, 8])
    sm = smm.SharedMemory(a.nbytes)
    b = np.ndarray(a.shape, dtype=a.dtype, buffer=sm.buf)
    b[:] = a[:]
    print(b)
    p1 = Process(target=change, args=(sm.name,))
    p2 = Process(target=show, args=(sm.name,))
    p1.start()
    p1.join()
    print(b)