title: The expected results were not obtained (np.frombuffer)
body: <pre><code>from multiprocessing import Array
  from ctypes import c_double
  import numpy as np
  from joblib import Parallel, delayed
  
  
  def f(a):
      for i in range(len(a)):
          a[i] = -a[i]
          print(a[i])
  
  
  if __name__ == '__main__':
      arr = Array(c_double,
                  range(10),
                  lock=False)
      arr = np.frombuffer(arr)
      arr = arr.reshape((len(arr), 1))
  
      Parallel(n_jobs=2)(delayed(f)(arr) for j in range(1))
  
      print(arr[:])
  </code></pre>
  <p>The expected value is negative, but the result is really the initial value. Can you help me? Thank you!</p>