multiprocessing.Array summing issue
===

So I have this program that basically sums arrays. I used multiprocessing because the program has to analyze 700,000 or so lines. Below I made a small script that illustrates the issue I am having 

    import multiprocessing as mp
    import numpy as np
    import ctypes
    
    t = range(100000)
    
    list_1 = np.zeros((10))
    
    for i in t:
        list_1 += np.array([1]*10)
    
    list_t = mp.Array(ctypes.c_double, 10)
    list_2 = np.ctypeslib.as_array(list_t.get_obj())
    list_2 = list_2.reshape(10)
    
    # No copy was made
    assert list_2.base.base is list_t.get_obj()
    
    
    def proc(x):
        global list_2
        list_2 += np.array([1]*10)
    
    if __name__ == '__main__':
        pool = mp.Pool(processes = 6)
        pool.map(proc,t)

The output of which:

    In [2]: list_1
    Out[2]: 
    array([ 100000.,  100000.,  100000.,  100000.,  100000.,  100000.,
            100000.,  100000.,  100000.,  100000.])
    
    In [3]: list_2
    Out[3]: 
    array([ 55828.,  65441.,  99300.,  68068.,  78774.,  78514.,  82393.,
            83446.,  82854.,  86987.])

Clearly I wanted both arrays to be like list_1. What is going on here?