[2015] | 1 | // ===========================================================================
|
---|
| 2 | // (C) 1999 Vienna University of Technology
|
---|
| 3 | // ===========================================================================
|
---|
| 4 | // NAME: RDTSCTimer
|
---|
| 5 | // TYPE: c++ code
|
---|
| 6 | // PROJECT: Urban Viz/yare (yet another rendering engine)
|
---|
| 7 | // CONTENT: Very accurate timer for Win32 systems
|
---|
| 8 | // (uses QueryPerformanceCounter, usually microseconds)
|
---|
| 9 | // VERSION: 0.1
|
---|
| 10 | // ===========================================================================
|
---|
| 11 | // AUTHORS: mw Michael Wimmer
|
---|
| 12 | // ===========================================================================
|
---|
| 13 | // HISTORY:
|
---|
| 14 | //
|
---|
| 15 | // 15-jul-99 14:00:00 mw created
|
---|
| 16 | // ===========================================================================
|
---|
| 17 | // $Header: /usr/local/cvsyare/cvsyare/src/yareutils/RDTSCTimer.cpp,v 1.2 2005/03/07 17:32:09 wimmer Exp $
|
---|
| 18 | // ===========================================================================
|
---|
| 19 |
|
---|
| 20 | #ifdef WIN32
|
---|
| 21 |
|
---|
| 22 | #include "RDTSCTimer.h"
|
---|
| 23 |
|
---|
| 24 | #include "merror.h"
|
---|
| 25 |
|
---|
| 26 |
|
---|
| 27 | // ---------------------------------------------------------------------------
|
---|
| 28 | // class RDTSCTimer implementation
|
---|
| 29 | // ---------------------------------------------------------------------------
|
---|
| 30 |
|
---|
| 31 | LARGE_INTEGER RDTSCTimer::frequency = {0,1};
|
---|
| 32 | bool RDTSCTimer::isinitialized = false;
|
---|
| 33 | bool RDTSCTimer::available = false;
|
---|
| 34 |
|
---|
| 35 | // this retrieves the timer frequency - will be called by constructor
|
---|
| 36 | void RDTSCTimer::InitClass(bool verbose)
|
---|
| 37 | {
|
---|
| 38 | isinitialized = true;
|
---|
| 39 | available = true;
|
---|
| 40 |
|
---|
| 41 | if (verbose)
|
---|
| 42 | OUT1(("Calibrating RDTSC-Timer at real-time priority...."));
|
---|
| 43 |
|
---|
| 44 | // Increase process class
|
---|
| 45 | HANDLE hProcess = GetCurrentProcess();
|
---|
| 46 | DWORD iPriorityClass = GetPriorityClass(hProcess);
|
---|
| 47 | ASM_ELSE(iPriorityClass, "couldnt change priority class")
|
---|
| 48 | SetPriorityClass(hProcess, REALTIME_PRIORITY_CLASS);
|
---|
| 49 |
|
---|
| 50 | // Increase thread priority
|
---|
| 51 | HANDLE hThread = GetCurrentThread();
|
---|
| 52 | DWORD iPriority = GetThreadPriority(hThread);
|
---|
| 53 | ASM_ELSE(iPriority != THREAD_PRIORITY_ERROR_RETURN, "couldnt change thread priority")
|
---|
| 54 | SetThreadPriority(hThread, THREAD_PRIORITY_TIME_CRITICAL);
|
---|
| 55 |
|
---|
| 56 |
|
---|
| 57 | // Measure CPU frequency
|
---|
| 58 | LARGE_INTEGER PerfFreq;
|
---|
| 59 | LARGE_INTEGER calStart, calEnd;
|
---|
| 60 | LARGE_INTEGER perfStart, perfEnd;
|
---|
| 61 |
|
---|
| 62 | // warmup
|
---|
| 63 | RDTSC(calStart);
|
---|
| 64 | RDTSC(calStart);
|
---|
| 65 | RDTSC(calStart);
|
---|
| 66 |
|
---|
| 67 | ASM_RET( QueryPerformanceFrequency( &PerfFreq ), "QueryPerformanceCounter not available for calibrating!");
|
---|
| 68 | QueryPerformanceCounter( &perfStart );
|
---|
| 69 | RDTSC(calStart);
|
---|
| 70 | LARGE_INTEGER endmark; endmark.QuadPart = perfStart.QuadPart + PerfFreq.QuadPart;
|
---|
| 71 | do {
|
---|
| 72 | QueryPerformanceCounter( &perfEnd );
|
---|
| 73 | } while (perfEnd.QuadPart < endmark.QuadPart);
|
---|
| 74 | RDTSC(calEnd);
|
---|
| 75 |
|
---|
| 76 |
|
---|
| 77 | // number of Bench cycles counted
|
---|
| 78 | LARGE_INTEGER perfcounts; perfcounts.QuadPart = perfEnd.QuadPart - perfStart.QuadPart;
|
---|
| 79 | // number of RDTSC cycles counted
|
---|
| 80 | LARGE_INTEGER calcounts; calcounts.QuadPart = calEnd.QuadPart - calStart.QuadPart;
|
---|
| 81 | // note: this might overflow if processor is over 6GHz:
|
---|
| 82 | unsigned __int64 temp = calcounts.QuadPart * PerfFreq.QuadPart;
|
---|
| 83 | frequency.QuadPart = temp / perfcounts.QuadPart;
|
---|
| 84 |
|
---|
| 85 | //if (verbose)
|
---|
| 86 | // OUT1( SV(perfcounts.LowPart)<<SV(calcounts.LowPart)<<SV(calcounts.HighPart)<<SV(PerfFreq.LowPart));
|
---|
| 87 |
|
---|
| 88 | //
|
---|
| 89 | // Number of calibration loops
|
---|
| 90 | //
|
---|
| 91 | #define CALIBRATION_LOOPS 50000
|
---|
| 92 |
|
---|
| 93 | ///--- measure overhead of different calling conventions
|
---|
| 94 |
|
---|
| 95 | ULONG i;
|
---|
| 96 |
|
---|
| 97 | //-- Start/Elapsed overhead
|
---|
| 98 |
|
---|
| 99 | RDTSCTimer mytimer2;
|
---|
| 100 | RDTSC(calStart);
|
---|
| 101 | for( i = 0; i < CALIBRATION_LOOPS; i++ ) {
|
---|
| 102 | PERF_ENTRY(mytimer2);
|
---|
| 103 | PERF_EXIT(mytimer2);
|
---|
| 104 | }
|
---|
| 105 | RDTSC(calEnd);
|
---|
| 106 |
|
---|
| 107 | LARGE_INTEGER CalEntryExitCycles, CalCountedCycles;
|
---|
| 108 | CalEntryExitCycles.QuadPart = (calEnd.QuadPart - calStart.QuadPart)/CALIBRATION_LOOPS;
|
---|
| 109 | CalCountedCycles.QuadPart = mytimer2.total_count.QuadPart / CALIBRATION_LOOPS;
|
---|
| 110 |
|
---|
| 111 |
|
---|
| 112 | /* RDTSCTimer mytimer;
|
---|
| 113 | RDTSC(calStart);
|
---|
| 114 | for( i = 0; i < CALIBRATION_LOOPS; i++ ) {
|
---|
| 115 | mytimer.Start();
|
---|
| 116 | mytimer.Elapsed();
|
---|
| 117 | }
|
---|
| 118 | RDTSC(calEnd);
|
---|
| 119 |
|
---|
| 120 | LARGE_INTEGER CalStartElapsedCycles;
|
---|
| 121 | CalStartElapsedCycles.QuadPart = (calEnd.QuadPart - calStart.QuadPart)/CALIBRATION_LOOPS;
|
---|
| 122 |
|
---|
| 123 |
|
---|
| 124 | RDTSCTimer mytimer3;
|
---|
| 125 | RDTSC(calStart);
|
---|
| 126 | for( i = 0; i < CALIBRATION_LOOPS; i++ ) {
|
---|
| 127 | mytimer3.Entry();
|
---|
| 128 | mytimer3.Exit();
|
---|
| 129 | }
|
---|
| 130 | RDTSC(calEnd);
|
---|
| 131 |
|
---|
| 132 | LARGE_INTEGER CalEntryExitCycles2, CalCountedCycles2;
|
---|
| 133 | CalEntryExitCycles2.QuadPart = (calEnd.QuadPart - calStart.QuadPart)/CALIBRATION_LOOPS;
|
---|
| 134 | CalCountedCycles2.QuadPart = mytimer3.total_count.QuadPart / CALIBRATION_LOOPS;
|
---|
| 135 | */
|
---|
| 136 |
|
---|
| 137 | RDTSC(calStart);
|
---|
| 138 | for( i = 0; i < CALIBRATION_LOOPS; i++ ) {
|
---|
| 139 | QueryPerformanceCounter( &perfStart );
|
---|
| 140 | QueryPerformanceCounter( &perfStart );
|
---|
| 141 | }
|
---|
| 142 | RDTSC(calEnd);
|
---|
| 143 |
|
---|
| 144 | LARGE_INTEGER PerfEntryExitCycles;
|
---|
| 145 | PerfEntryExitCycles.QuadPart = (calEnd.QuadPart - calStart.QuadPart)/CALIBRATION_LOOPS;
|
---|
| 146 |
|
---|
| 147 | // Restore thread and process priority
|
---|
| 148 | if (iPriority != THREAD_PRIORITY_ERROR_RETURN)
|
---|
| 149 | SetThreadPriority(hThread, iPriority);
|
---|
| 150 |
|
---|
| 151 | if (iPriorityClass)
|
---|
| 152 | SetPriorityClass(hProcess, iPriorityClass);
|
---|
| 153 |
|
---|
| 154 |
|
---|
| 155 | if (verbose)
|
---|
| 156 | {
|
---|
| 157 | OUT2("RDTSC frequency: " << frequency.LowPart << ", QueryPerformanceCounter frequency: " << PerfFreq.LowPart);
|
---|
| 158 | OUT2("Overhead for timer calls in clock cycles:");
|
---|
| 159 | //OUT2(CalStartElapsedCycles.LowPart << " for timer.start;timer.elapsed;");
|
---|
| 160 | OUT2(CalEntryExitCycles.LowPart << " for PERF_ENTRY/PERF_EXIT, cycles counted per call: " << CalCountedCycles.LowPart);
|
---|
| 161 | //OUT2(CalEntryExitCycles2.LowPart << " for Entry()/Exit(), cycles counted per call: " << CalCountedCycles2.LowPart);
|
---|
| 162 | OUT2(PerfEntryExitCycles.LowPart << " for QueryPerformanceCounter twice");
|
---|
| 163 | }
|
---|
| 164 | }
|
---|
| 165 |
|
---|
| 166 | /// returns the frequency
|
---|
| 167 | double RDTSCTimer::GetFrequency(bool verbose)
|
---|
| 168 | {
|
---|
| 169 | if (!isinitialized)
|
---|
| 170 | InitClass(verbose);
|
---|
| 171 |
|
---|
| 172 | return (double)frequency.QuadPart;
|
---|
| 173 | }
|
---|
| 174 |
|
---|
| 175 | #endif // WIN32
|
---|