Question

我需要与“ multiprocessing”库并行运行多个类函数，但无法找到针对特定问题的指南或答案。我的问题是只有第一个进程正在启动（或者正在运行，我不知道确切的区别）。

为说明问题，我设置了以下示例：

import multiprocessing
import time

class parallel_printer(multiprocessing.Process):

    def __init__(self, freq_0, freq_1, freq_2):
        self.freq_0 = freq_0
        self.freq_1 = freq_1
        self.freq_2 = freq_2

    def print_0(self):
        while True:    
            now = time.localtime()
            if now.tm_sec % self.freq_0 == 0:
                print('printer 0')
                time.sleep(1.0)

    def print_1(self):
        while True:    
            now = time.localtime()
            if now.tm_sec % self.freq_1 == 0:
                print('printer 1')
                time.sleep(1.0)

    def print_2(self):
        while True:    
            now = time.localtime()
            if now.tm_sec % self.freq_2 == 0:
                print('printer 2')
                time.sleep(1.0)

    def start_printer(self):

        p_0 = multiprocessing.Process(target = self.print_0())
        p_1 = multiprocessing.Process(target = self.print_1())
        p_2 = multiprocessing.Process(target = self.print_2())

        p_0.start()
        p_1.start()
        p_2.start()


class Tester(object):

    def __init__(self):        

        self.freq_0 = 3
        self.freq_1 = 7
        self.freq_2 = 11

        self.parallel_printer = parallel_printer(self.freq_0, self.freq_1, self.freq_2)

    def start_Tester(self):
        self.parallel_printer.start_printer()


if __name__ == '__main__':
tester = Tester()
tester.start_Tester()

Answer 1

正如您在multiprocessing.Process的Python文档中可以看到的那样，您需要为target参数传递“调用对象”。

您的代码应如下所示：

p_0 = multiprocessing.Process(target=self.print_0)
p_1 = multiprocessing.Process(target=self.print_1)
p_2 = multiprocessing.Process(target=self.print_2)

如果您写的是self.print_0()而不是self.print_0，则说明您没有传递调用对象，而是调用函数并传递了返回值。

使用多处理库在同一个类中运行并发进程

1 个答案: