在3个进程之间写入(+lock)/读取文件的Python脚本

import os
import multiprocessing
import fcntl

def write_file(filename, content):
    with open(filename, 'a') as file:
        fcntl.flock(file, fcntl.LOCK_EX)  # 获取文件锁
        file.write(content)
        fcntl.flock(file, fcntl.LOCK_UN)  # 释放文件锁

def read_file(filename):
    with open(filename, 'r') as file:
        fcntl.flock(file, fcntl.LOCK_SH)  # 获取文件共享锁
        content = file.read()
        fcntl.flock(file, fcntl.LOCK_UN)  # 释放文件锁
    return content

if __name__ == '__main__':
    filename = 'data.txt'
    content = 'Hello, World!\n'

    # 创建3个进程
    processes = []
    for _ in range(3):
        p = multiprocessing.Process(target=write_file, args=(filename, content))
        processes.append(p)
        p.start()

    for p in processes:
        p.join()

    result = read_file(filename)
    print(result)