Author:YTC Mail:recessburton@gmail.com Created Time: 2015.4.27
Author:Guodong, 2015/08/19
This program implements a tree-based time synchronization algorithm. In detail, every
By default the sink is 1 of depth and its parent is 0
And we always assume the sink (root) has a perfect clock, that is, we have not yet time-synchronized the root according to an external clock, like UTC.