multiprocessing.Pool 似乎可以在 Windows 中工作，但不能在 ubuntu 中工作?

Something is very fishy and I am very thankful for any kind of help you guys can offer.

代码:

import multiprocessing as mp
import scipy as sp
import scipy.stats as spstat
import pylab

def testfunc(x0, N):
    print 'working with x0 = %s' % x0
    x = [x0]
    for i in xrange(1,N):
        x.append(spstat.norm.rvs(size = 1)) # stupid appending to make it slower
        if i % 10000 == 0:
            print 'x0 = %s, i = %s' % (x0, i)
    return sp.array(x)

def testfuncParallel(fargs):
    return testfunc(*fargs)


# Define Number of tasks.
nTasks = 4
N = 100000

if __name__ == '__main__':

    """
    Try number 1. Using multiprocessing.Pool together with Pool.map_async
    """
    pool = mp.Pool(processes = nTasks) # I have 12 threads (six cores) available so I am suprised that it does not get access to nTasks = 4 amount of workers

    # Define tasks:
    tasks = [(x, n) for x, n in enumerate(nTasks*[N])] # nTasks different tasks

    # Compute parallel: async - asynchronically, i.e. not necessary in order.
    result = pool.map_async(testfuncParallel, tasks)

    pool.close() # These are needed if map_async is used
    pool.join()

    # Get results:
    sim = sp.zeros((N, nTasks)) 

    for nn, res in enumerate(result.get()):    
        sim[:, nn] = res

    pylab.figure()
    for i in xrange(nTasks):
        pylab.subplot(nTasks,1, i + 1)
        pylab.plot(sim[:, i])

    pylab.show()

提前致谢.

真诚地，马蒂亚斯

解决方案

更新: 原来这与 matplotlib 或后端无关，而是与一般多处理相关的错误有关.我们已经为 Wing 版本 4.0.4+ 修复了这个问题.解决方法是不在子进程中执行的代码中设置断点.