add random
Merge branch 'master' into base
 add unittest for timer
 .
 .
 .
 add comments
 .
 use closure
 .
fixbug in unittest
 .
 add new ut
 add unittest
Merge branch 'third_party'
Merge branch 'master' into base
task1: pseudo random 重新实现
task2: 通用 loop
 add new unittest for pseudo random
 move guid to base
 remove guid