Mercurial > vba-linux
annotate src/win32/PerfTimer.cpp @ 1:f9f4f1b99eed
importing src directory
| author | Robert McIntyre <rlm@mit.edu> |
|---|---|
| date | Sat, 03 Mar 2012 10:31:27 -0600 |
| parents | |
| children |
| rev | line source |
|---|---|
| rlm@1 | 1 // CPerfTimer - a simple Win32 performance counter wrapper |
| rlm@1 | 2 // by Dean Wyant dwyant@mindspring.com |
| rlm@1 | 3 |
| rlm@1 | 4 #include "stdafx.h" |
| rlm@1 | 5 #include "PerfTimer.h" |
| rlm@1 | 6 |
| rlm@1 | 7 // Declare and initialize static member vars that get set only once and never change |
| rlm@1 | 8 __int64 CPerfTimer::m_Freq = 0; |
| rlm@1 | 9 __int64 CPerfTimer::m_Adjust = 0; |
| rlm@1 | 10 |
| rlm@1 | 11 // All functions defined inline for speed. After all, the performance counter is |
| rlm@1 | 12 // supposed to be able to time very short events fairly accurately. |
| rlm@1 | 13 |
| rlm@1 | 14 |
| rlm@1 | 15 |
| rlm@1 | 16 BOOL CPerfTimer::IsSupported() |
| rlm@1 | 17 { // Returns FALSE if performance counter not supported. |
| rlm@1 | 18 // Call after constructing at least one CPerfTimer |
| rlm@1 | 19 return (m_Freq > 1); |
| rlm@1 | 20 } |
| rlm@1 | 21 |
| rlm@1 | 22 const double CPerfTimer::Resolution() |
| rlm@1 | 23 { // Returns timer resolution in seconds |
| rlm@1 | 24 return 1.0/(double)m_Freq; |
| rlm@1 | 25 } |
| rlm@1 | 26 |
| rlm@1 | 27 const double CPerfTimer::Resolutionms() |
| rlm@1 | 28 { // Returns timer resolution in milliseconds |
| rlm@1 | 29 return 1000.0/(double)m_Freq; |
| rlm@1 | 30 } |
| rlm@1 | 31 |
| rlm@1 | 32 const double CPerfTimer::Resolutionus() |
| rlm@1 | 33 { // Returns timer resolution in microseconds |
| rlm@1 | 34 return 1000000.0/(double)m_Freq; |
| rlm@1 | 35 } |