确认对多处理模块的理解以及如何启动线程

Question

您好我不确定我是否理解多处理模块并希望寻求建议。我正在审查此处http://revista.python.org.ar/1/html-en/PET-1-processing.pdf中的无痛并发示例。以下是我正在测试的代码。

import multiprocessing
import time

x = 4
y = 6

def f1(x,y):

    x = x+y
    print 'F1:', x


def f2(x,y):
    y = x-y
    print 'F2:', y


def main():
    print "Starting main program"
    hilo1 = multiprocessing.Process(target=f1, args=(x,y))
    hilo2 = multiprocessing.Process(target=f2, args=(x,y))
    print "Launching threads"
    hilo1.start()
    hilo2.start()
    hilo1.join()
    hilo2.join()
    print "Both threads finished"
    print "Ending program"
    print "X:", x, "Y:", y


if __name__=='__main__':
    main()

输出结果为：

Starting main program
Launching threads
Both threads finished
Ending program
X: 4 Y: 6

我期待更接近的事情：

Starting main program
Launching threads
F1: 10
F2: -2
Both threads finished
Ending program
X: 4 Y: 6

这是我将main（）更改为：

时的输出

def main():
    print "Starting main program"
    hilo1 = f1(x,y)
    hilo2 = f2(x,y)
    print "Launching threads"
    print "Both threads finished"
    print "Ending program"
    print "X:", x, "Y:", y

多处理线程是否正在运行？检查每个函数是否使用多处理运行的最佳方法是什么？