Timer.h

#ifndef TIMER_H
#define TIMER_H

#ifdef _MSC_VER

// Define this if you want to enable the high resolution timer on Windows
#define USE_WIN_MSEC_TIMER

#ifdef USE_WIN_MSEC_TIMER
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#else
#include <time.h>
#endif

/// Simple timer.
///
///     @author Mario Valle - Swiss National Supercomputing Centre (CSCS)
///     @date 2010-08-31 (initial version)
///     @version 1.1
///
class Timer {
public:
  /// Constructor
  ///
  Timer() : mDelta(0) {
#ifdef USE_WIN_MSEC_TIMER
    QueryPerformanceFrequency(&mFreq);
#endif
    start();
  }

  /// Start the timer
  ///
  void start(void) {
#ifndef USE_WIN_MSEC_TIMER
    time(&mStartTime);
#else
    QueryPerformanceCounter(&mStartTime);
#endif
  }

  /// Stop the timer
  ///
  /// @return The elapsed time in milliseconds
  ///
  time_t stop(void) {
#ifndef USE_WIN_MSEC_TIMER
    mDelta = (time(NULL) - mStartTime) * 1000L;
#else
    LARGE_INTEGER end_time_w;
    QueryPerformanceCounter(&end_time_w);

    mDelta = static_cast<time_t>(
        ((end_time_w.QuadPart - mStartTime.QuadPart) * 1000) / mFreq.QuadPart);
#endif
    return mDelta;
  }

  /// Return the elapsed time (after a start/stop cycle)
  ///
  /// @return The elapsed time in milliseconds
  ///
  time_t get(void) const { return mDelta; }

private:
#ifndef USE_WIN_MSEC_TIMER
  time_t mStartTime; ///< The start time
#else
  LARGE_INTEGER mFreq;      ///< The timer frequency
  LARGE_INTEGER mStartTime; ///< The start time
#endif
  time_t mDelta; ///< The elapsed time in milliseconds
};

#else

#include <sys/time.h> // gettimeofday

/// Simple timer
///
///     @author Mario Valle - Swiss National Supercomputing Centre (CSCS)
///     @date 2010-08-31 (initial version)
///     @version 1.1
///
class Timer {
public:
  /// Constructor
  ///
  Timer() : mDelta(0) { start(); }

  /// Start the timer
  ///
  void start(void) { gettimeofday(&mStartTime, NULL); }

  /// Stop the timer
  ///
  /// @return The elapsed time in milliseconds
  ///
  time_t stop(void) {
    struct timeval end_time;
    gettimeofday(&end_time, NULL);

    mDelta = end_time.tv_sec * 1000000L + end_time.tv_usec;
    mDelta -= mStartTime.tv_sec * 1000000L + mStartTime.tv_usec;
    mDelta /= 1000L;

    return mDelta;
  }

  /// Return the elapsed time (after a start/stop cycle)
  ///
  /// @return The elapsed time in milliseconds
  ///
  time_t get(void) const { return mDelta; }

private:
  struct timeval mStartTime; ///< The start time
  time_t mDelta;             ///< The elapsed time in milliseconds
};

#endif
#endif