python 锁 多进程

参考：

http://www.cnblogs.com/huxi/archive/2010/06/26/1765808.html

http://linhs.blog.51cto.com/370259/126180

http://www.cnblogs.com/holbrook/archive/2012/03/04/2378947.html

http://www.360doc.com/content/11/0802/16/2902158_137445842.shtml

http://www.360doc.com/content/11/0802/16/2902158_137451084.shtml

http://www.ibm.com/developerworks/cn/linux/l-parse-memory-dumps/

http://www.cnblogs.com/dkblog/archive/2011/03/14/1983250.html

http://www.chenqing.org/2013/06/python-gil-1.html

http://blog.csdn.net/lianxiang_biancheng/article/details/7907776