使用multiprocessing无法修改嵌套对象中的数据

我正在开发一个个人项目，包含嵌套对象结构：比如World包含多个Environment，每个Environment又包含多个People。我需要把People类中动态变化的属性，逐层传递到Environment类、World类，最终在主程序中展示结果。目前用multiprocessing来运行每个People对象，实现属性的动态修改。

下面是简化后的问题代码：Type1实例化Type2，Type2会修改自身值，Type1希望根据Type2的变化更新自身值，但Type1无法感知到Type2的修改。我试过multiprocessing模块里的locks、manager、values、queues以及syncmanagers，都没解决问题。想问是不是有忽略的关键点？或者有没有更合适的程序结构来实现需求？

我的预期是：Type1根据自身和Type2的change()方法，把特定数据类型的值更新为Type2对应的最新值。

原始代码示例 #

import multiprocessing
import time


class Type1:
    def __init__(self) -> None:
        self.array =[]
        self.dict = {}
        self.text = ""
        self.number = 0
        self.process_dict = {}
        self.type2_dict = {}
        self.num = 0
    
    def start(self):
            new_type = Type2()
            p = multiprocessing.Process(target=new_type.change)
            self.process_dict[f"type2{self.num}"] = p
            self.type2_dict[f"type2{self.num}"] = new_type
            self.num += 1
            p.start()
        
    def stop(self):
        while len(self.process_dict) > 0:
            _, process = self.process_dict.popitem()
            process.terminate()
            process.join()

    
    def change(self):
        self.array, self.dict, self.text, self.number = self.type2_dict[f"type2{self.num-1}"].get_data()
            
    def print(self):
        print(self.array)
        print(self.dict)
        print(self.text)
        print(self.number)
        print(self.process_dict)
        
        
        
class Type2:
    def __init__(self) -> None:
        self.array =[]
        self.dict = {}
        self.text = "Hello"
        self.number = 0
    
    def change(self):
        while True:
            self.array = [6,7,8,9,10]
            self.dict = {"d":4,"e":5,"f":6}
            self.text = "Goodbye"
            self.number += 1
            print("Type2 changed")
        
    def get_data(self):
        return self.array, self.dict, self.text, self.number
        
        
if __name__ == "__main__":
    t = Type1()
    t.start()
    time.sleep(2)
    print("\n\nType1 After Start:")
    t.change()
    t.print()
    t.stop()
    print("\n\nType1 After Finish:")
    t.print()
    print("Type1 stopped")

使用Manager后的代码示例（存在问题） #

根据建议尝试使用manager后，修改dict时出现None类型，说明不同进程间的shared_var未正确共享。

import multiprocessing
import time


class Type1:
    def __init__(self, array, dict, text, number) -> None:
        self.array = array
        self.dict = dict
        self.text = text
        self.number = number
        self.process_dict = {}
        self.type2_dict = {}
        self.num = 0
    
    def start(self):
            new_type = Type2(self.array, self.dict, self.text, self.number)
            p = multiprocessing.Process(target=new_type.change, args=(self.dict,))
            self.process_dict[f"type2{self.num}"] = p
            self.type2_dict[f"type2{self.num}"] = new_type
            self.num += 1
            p.start()
        
    def stop(self):
        while len(self.process_dict) > 0:
            _, process = self.process_dict.popitem()
            process.terminate()
            process.join()

    
    def change(self):
        self.array, self.dict, self.text, self.number = self.type2_dict[f"type2{self.num-1}"].get_data()
            
    def print(self):
        print(self.array.value)
        print(self.dict.value)
        print(self.text.value)
        print(self.number.value)
        print(self.process_dict)
        
        
        
class Type2:
    def __init__(self, array, dict, text, number) -> None:
        self.array = array
        self.dict = dict
        self.text = text
        self.number = number
    
    def change(self, shared_var):
        while True:
            self.array = [6,7,8,9,10]
            self.text = "Goodbye"
            self.number = 1
            self.dict = shared_var
            # increase each number in the dictionary by 1
            for key in self.dict.keys():
                self.dict[key] += 1
            # shared_var = self.dict
            # print("Type2 changed")
            time.sleep(0.01)
        
    def get_data(self):
        return self.array, self.dict, self.text, self.number
        
        
if __name__ == "__main__":
    manager = multiprocessing.Manager()
    array = manager.list([1,2,3,4,5])
    dict = manager.dict({"a":1,"b":2,"c":3})
    text = manager.Value("s", "Hello")
    number = manager.Value("i", 0)
    t = Type1(array, dict, text, number)
    t.start()
    print("\n\nType1 After Start:")
    t.change()
    t.print()
    time.sleep(2)
    t.stop()
    print("\n\nType1 After Finish:")
    t.print()
    print("Type1 stopped")

内容的提问来源于stack exchange，提问作者Icen