This function executes "RDTSC" (Opcode : 0F 31) instruction with thread affinity mask.
"RDTSC" : Loads the current value of the processor’s timestamp counter into the EDX:EAX registers.
BOOL RdtscTx(
PDWORD eax,
PDWORD edx,
DWORD_PTR threadAffinityMask
);
If the function succeeds, the return value is TRUE.
If the function fails, the return value is FALSE.
You can check whether "RDTSC" instruction is supported on your system with IsTsc.