Process Array

http://xiaorui.cc/2016/05/10/%E6%BA%90%E7%A0%81%E5%88%86%E6%9E%90multiprocessing%E7%9A%84value-array%E5%85%B1%E4%BA%AB%E5%86%85%E5%AD%98%E5%8E%9F%E7%90%86/

https://docs.python.org/2/library/ctypes.html

http://baike.baidu.com/view/1499209.htm