rlm@1: // CPerfTimer - a simple Win32 performance counter wrapper
rlm@1: // by Dean Wyant dwyant@mindspring.com
rlm@1: 
rlm@1: #include "stdafx.h"
rlm@1: #include "PerfTimer.h"
rlm@1: 
rlm@1: // Declare and initialize static member vars that get set only once and never change
rlm@1: __int64 CPerfTimer::m_Freq = 0; 
rlm@1: __int64 CPerfTimer::m_Adjust = 0; 
rlm@1: 
rlm@1: // All functions defined inline for speed. After all, the performance counter is 
rlm@1: // supposed to be able to time very short events fairly accurately.
rlm@1: 
rlm@1: 
rlm@1: 
rlm@1: BOOL CPerfTimer::IsSupported()
rlm@1: { // Returns FALSE if performance counter not supported.
rlm@1: 	// Call after constructing at least one CPerfTimer
rlm@1: 	return (m_Freq > 1);
rlm@1: }
rlm@1: 
rlm@1: const double CPerfTimer::Resolution()   
rlm@1: { // Returns timer resolution in seconds
rlm@1: 	return 1.0/(double)m_Freq; 
rlm@1: }
rlm@1: 
rlm@1: const double CPerfTimer::Resolutionms() 
rlm@1: { // Returns timer resolution in milliseconds
rlm@1: 	return 1000.0/(double)m_Freq; 
rlm@1: }
rlm@1: 
rlm@1: const double CPerfTimer::Resolutionus() 
rlm@1: { // Returns timer resolution in microseconds
rlm@1: 	return 1000000.0/(double)m_Freq; 
rlm@1: }