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| /*
* Author: David Robert Nadeau
* Site: http://NadeauSoftware.com/
* License: Creative Commons Attribution 3.0 Unported License
* http://creativecommons.org/licenses/by/3.0/deed.en_US
*/
#if defined(_WIN32)
#include <Windows.h>
#elif defined(__unix__) || defined(__unix) || defined(unix) || (defined(__APPLE__) && defined(__MACH__))
#include <unistd.h> /* POSIX flags */
#include <time.h> /* clock_gettime(), time() */
#include <sys/time.h> /* gethrtime(), gettimeofday() */
#if defined(__MACH__) && defined(__APPLE__)
#include <mach/mach.h>
#include <mach/mach_time.h>
#endif
#else
#error "Unable to define getRealTime( ) for an unknown OS."
#endif
/**
* Returns the real time, in seconds, or -1.0 if an error occurred.
*
* Time is measured since an arbitrary and OS-dependent start time.
* The returned real time is only useful for computing an elapsed time
* between two calls to this function.
*/
double getRealTime()
{
#if defined(_WIN32)
FILETIME tm;
ULONGLONG t;
#if defined(NTDDI_WIN8) && NTDDI_VERSION >= NTDDI_WIN8
/* Windows 8, Windows Server 2012 and later. ---------------- */
GetSystemTimePreciseAsFileTime( &tm );
#else
/* Windows 2000 and later. ---------------------------------- */
GetSystemTimeAsFileTime( &tm );
#endif
t = ((ULONGLONG)tm.dwHighDateTime << 32) | (ULONGLONG)tm.dwLowDateTime;
return (double)t / 10000000.0;
#elif (defined(__hpux) || defined(hpux)) || ((defined(__sun__) || defined(__sun) || defined(sun)) && (defined(__SVR4) || defined(__svr4__)))
/* HP-UX, Solaris. ------------------------------------------ */
return (double)gethrtime( ) / 1000000000.0;
#elif defined(__MACH__) && defined(__APPLE__)
/* OSX. ----------------------------------------------------- */
static double timeConvert = 0.0;
if ( timeConvert == 0.0 )
{
mach_timebase_info_data_t timeBase;
(void)mach_timebase_info( &timeBase );
timeConvert = (double)timeBase.numer / (double)timeBase.denom / 1000000000.0;
}
return (double)mach_absolute_time( ) * timeConvert;
#elif defined(_POSIX_VERSION)
/* POSIX. --------------------------------------------------- */
#if defined(_POSIX_TIMERS) && (_POSIX_TIMERS > 0)
{
struct timespec ts;
#if defined(CLOCK_MONOTONIC_PRECISE)
/* BSD. --------------------------------------------- */
const clockid_t id = CLOCK_MONOTONIC_PRECISE;
#elif defined(CLOCK_MONOTONIC_RAW)
/* Linux. ------------------------------------------- */
const clockid_t id = CLOCK_MONOTONIC_RAW;
#elif defined(CLOCK_HIGHRES)
/* Solaris. ----------------------------------------- */
const clockid_t id = CLOCK_HIGHRES;
#elif defined(CLOCK_MONOTONIC)
/* AIX, BSD, Linux, POSIX, Solaris. ----------------- */
const clockid_t id = CLOCK_MONOTONIC;
#elif defined(CLOCK_REALTIME)
/* AIX, BSD, HP-UX, Linux, POSIX. ------------------- */
const clockid_t id = CLOCK_REALTIME;
#else
const clockid_t id = (clockid_t)-1; /* Unknown. */
#endif /* CLOCK_* */
if ( id != (clockid_t)-1 && clock_gettime( id, &ts ) != -1 )
return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0;
/* Fall thru. */
}
#endif /* _POSIX_TIMERS */
/* AIX, BSD, Cygwin, HP-UX, Linux, OSX, POSIX, Solaris. ----- */
struct timeval tm;
gettimeofday( &tm, NULL );
return (double)tm.tv_sec + (double)tm.tv_usec / 1000000.0;
#else
return -1.0; /* Failed. */
#endif
} |
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