The VTDAPI provides the following services:
VTDAPI_Begin_Min_Int_Period
VTDAPI_End_Min_Int_Period
VTDAPI_Get_Int_Period
VTDAPI_Get_Sys_Time
VTDAPI_Get_System_Time_Selector
VTDAPI_Get_Version
VTDAPI_Start_User_Timer
VTDAPI_Stop_User_Timer
VTDAPI_Timer_Start
VTDAPI_Timer_Stop