标签：
1. Technical Q&A QA1398
Mach Absolute Time Units
https://developer.apple.com/library/mac/qa/qa1398/_index.html
2. Kernel Programming Guide
https://developer.apple.com/library/mac/documentation/darwin/conceptual/kernelprogramming/services/services.html
标签：
原文地址：http://www.cnblogs.com/cwgk/p/3382033.html
