timerc

/****************************************************************************
 *                              ArtraCFD                                    *
 *                          <By Huangrui Mo>                                *
 * Copyright (C) Huangrui Mo <huangrui.mo@gmail.com>                        *
 * This file is part of ArtraCFD.                                           *
 * ArtraCFD is free software: you can redistribute it and/or modify it      *
 * under the terms of the GNU General Public License as published by        *
 * the Free Software Foundation, either version 3 of the License, or        *
 * (at your option) any later version.                                      *
 ****************************************************************************/
/****************************************************************************
 * Required Header Files
 ****************************************************************************/
#include "timer.h"

#if defined(_WIN32)
#include <Windows.h>

#elif defined(__unix__) || defined(__unix) || defined(unix) || (defined(__APPLE__) && defined(__MACH__))
/* enable POSIX definitions according to std version */
#if __STDC_VERSION__ >= 199901L
#define _XOPEN_SOURCE 600 /* 600: POSIX 2004; 700: POSIX 2008 */
#else
#define _XOPEN_SOURCE 500 /* 500: POSIX 1995 */
#endif
#include <unistd.h> /* enable POSIX flags */
#include <time.h> /* enable clock_gettime(), time() */
#include <sys/time.h> /* enable gethrtime(), gettimeofday() */

#if defined(__APPLE__) && defined(__MACH__)
#include <mach/mach.h>
#include <mach/mach_time.h>
#endif

#else
#error "cannot define timer for an unknown OS..."
#endif
/****************************************************************************
 * Function definitions
 ****************************************************************************/
/*
 * Adapted from getRealTime.c by David Robert Nadeau
 */
double GetTime(void)
{
#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(__APPLE__) && defined(__MACH__)
    /* OSX */
    mach_timebase_info_data_t timeBase;
    (void)mach_timebase_info(&timeBase);
    return ((double)(timeBase.numer) / (double)(timeBase.denom)) *
        ((double)(mach_absolute_time()) / 1000000000.0);

#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
        /* Unknown */
        const clockid_t id = (clockid_t) - 1;
#endif 
        if ((id != (clockid_t) - 1) && (clock_gettime(id, &ts) != -1)) {
            return (double)(ts.tv_sec) + (double)(ts.tv_nsec) / 1000000000.0;
        }
        /* Fall through */
    }
#endif
    /* 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
}
/* a good practice: end file with a newline */