线程安全_百度百科
http://baike.baidu.com/link?url=8THdYvUL3v-oPTugD2FviO8nh-66-k9uQsC5oNuX6-x4783aF_ABZDaY-SeMDRLzj3uLtlvpHXz5FtdhdRdu4a
IBM Knowledge Center - i5/OS: Multithreaded applications
http://www.ibm.com/support/knowledgecenter/en/ssw_ibm_i_72/rzahw/rzahwovepo.htm
原文：http://www.cnblogs.com/pegasus923/p/5554565.html