CTicTac.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#include "base-precomp.h"  // Precompiled headers

#include <mrpt/config.h>

#ifdef MRPT_OS_WINDOWS
#include <windows.h>
#include <mrpt/utils/utils_defs.h>
#else
#include <sys/time.h>
#endif

#include <mrpt/utils/CTicTac.h>
#include <cstring>

// For Windows: get the common code out of CTicTac so it's only run once!
#ifdef MRPT_OS_WINDOWS
struct AuxWindowsTicTac
{
        static AuxWindowsTicTac& GetInstance()
        {
                static AuxWindowsTicTac obj;
                return obj;
        }

        double dbl_period;

   private:
        LARGE_INTEGER m_freq;

        AuxWindowsTicTac() : dbl_period(.0)
        {
                QueryPerformanceFrequency(&m_freq);
                ASSERTMSG_(
                        m_freq.QuadPart != 0, "Error getting QueryPerformanceFrequency()");
                dbl_period = 1.0 / static_cast<double>(m_freq.QuadPart);
        }
};

#endif

using namespace mrpt::utils;

// Macros for easy access to memory with the correct types:
#ifdef MRPT_OS_WINDOWS
#define LARGE_INTEGER_NUMS reinterpret_cast<LARGE_INTEGER*>(largeInts)
#else
#define TIMEVAL_NUMS reinterpret_cast<struct timeval*>(largeInts)
#endif

/*---------------------------------------------------------------
                                                Constructor
 ---------------------------------------------------------------*/
CTicTac::CTicTac()
{
        ::memset(largeInts, 0, sizeof(largeInts));

#ifdef MRPT_OS_WINDOWS
        static_assert(
                sizeof(largeInts) >= 2 * sizeof(LARGE_INTEGER),
                "sizeof(LARGE_INTEGER) failed!");
#else
        static_assert(
                sizeof(largeInts) > 2 * sizeof(struct timeval),
                "sizeof(struct timeval) failed!");
#endif
        Tic();
}

/*---------------------------------------------------------------
                                                Tic
        Starts the stopwatch
 ---------------------------------------------------------------*/
void CTicTac::Tic()
{
#ifdef MRPT_OS_WINDOWS
        LARGE_INTEGER* l = LARGE_INTEGER_NUMS;
        QueryPerformanceCounter(&l[0]);
#else
        struct timeval* ts = TIMEVAL_NUMS;
        gettimeofday(&ts[0], nullptr);
#endif
}

/*---------------------------------------------------------------
                                                Tac
   Stop. Returns ellapsed time in seconds
 ---------------------------------------------------------------*/
double CTicTac::Tac()
{
#ifdef MRPT_OS_WINDOWS
        LARGE_INTEGER* l = LARGE_INTEGER_NUMS;
        QueryPerformanceCounter(&l[1]);
        return (l[1].QuadPart - l[0].QuadPart) *
                   AuxWindowsTicTac::GetInstance().dbl_period;
#else
        struct timeval* ts = TIMEVAL_NUMS;
        gettimeofday(&ts[1], nullptr);
        return (ts[1].tv_sec - ts[0].tv_sec) +
                   1e-6 * (ts[1].tv_usec - ts[0].tv_usec);
#endif
}