OpenSceneGraph/include/osg/Timer
2001-09-22 02:42:08 +00:00

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#ifndef OSG_TIMER
#define OSG_TIMER 1
#include <osg/Export>
namespace osg {
#ifdef WIN32
typedef __int64 Timer_t;
#elif defined(__linux) || defined(__FreeBSD__)
typedef unsigned long long Timer_t;
#elif defined(__sgi)
typedef unsigned long long Timer_t;
#elif defined(unix)
typedef unsigned long long Timer_t;
#else
#include <ctime>
typedef std::clock_t Timer_t;
#endif
/** A high resolution, low latency time stamper.*/
class SG_EXPORT Timer {
public:
Timer();
~Timer() {}
inline Timer_t tick();
inline double delta_s( Timer_t t1, Timer_t t2 ) const { return (double)(t2 - t1)*_secsPerClick; }
inline double delta_m( Timer_t t1, Timer_t t2 ) const { return delta_s(t1,t2)*1e3; }
inline double delta_u( Timer_t t1, Timer_t t2 ) const { return delta_s(t1,t2)*1e6; }
inline double delta_n( Timer_t t1, Timer_t t2 ) const { return delta_s(t1,t2)*1e9; }
private :
double _secsPerClick;
bool _useStandardClock;
#ifdef __sgi
unsigned long* _clockAddress;
int _cycleCntrSize;
static unsigned long _dummy;
#endif
};
#ifdef WIN32
#include <time.h>
#pragma optimize("",off)
inline Timer_t Timer::tick( void )
{
if (_useStandardClock) return clock();
volatile Timer_t ts;
volatile unsigned int HighPart;
volatile unsigned int LowPart;
_asm
{
xor eax, eax // Used when QueryPerformanceCounter()
xor edx, edx // not supported or minimal overhead
_emit 0x0f // desired
_emit 0x31 //
mov HighPart,edx
mov LowPart,eax
}
//ts = LowPart | HighPart >> 32;
*((unsigned int*)&ts) = LowPart;
*((unsigned int*)&ts+1) = HighPart;
return ts;
}
#pragma optimize("",on)
#elif defined(__linux) || defined(__FreeBSD__)
#include <sys/time.h>
#define CLK(x) __asm__ volatile (".byte 0x0f, 0x31" : "=A" (x))
inline Timer_t Timer::tick()
{
if (_useStandardClock)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return ((osg::Timer_t)tv.tv_sec)*1000000+(osg::Timer_t)tv.tv_usec;
}
else
{
Timer_t x;CLK(x);return x;
}
}
#elif defined(__sgi)
#include <sys/time.h>
inline Timer_t Timer::tick()
{
if (_useStandardClock)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return ((osg::Timer_t)tv.tv_sec)*1000000+(osg::Timer_t)tv.tv_usec;
}
else
{
return *_sgiClockAddress;
}
}
#elif defined(unix)
#include <sys/time.h>
inline Timer_t Timer::tick()
{
struct timeval tv;
gettimeofday(&tv, NULL);
return ((osg::Timer_t)tv.tv_sec)*1000000+(osg::Timer_t)tv.tv_usec;
}
#else
// no choice, always use std::clock()
inline Timer_t Timer::tick( void ) { return std::clock(); }
#endif
};
#endif