CPUTimer.cpp

#include "MantidKernel/CPUTimer.h"
#include "MantidKernel/System.h"
#include <ctime>
#include <sstream>
#include <iomanip>

namespace Mantid
{
namespace Kernel
{


  //----------------------------------------------------------------------------------------------
  /** Constructor
   */
  CPUTimer::CPUTimer()
  {
    // Record the starting time
    reset();
  }
    
  //----------------------------------------------------------------------------------------------
  /** Destructor
   */
  CPUTimer::~CPUTimer()
  {
  }
  

  /// Explicitly reset the timer.
  void CPUTimer::reset()
  {
  #ifdef _WIN32
  #else /* linux & mac */
    m_start = clock();
  #endif
    m_wallClockTime.reset();
  }

  /** Calculate the elapsed CPU time, reseting the timer if specified
   *
   * @param doReset :: true to reset the timer
   * @return time in CPU seconds
   */
  float CPUTimer::elapsedCPU(bool doReset)
  {
    float retval = 0;
  #ifdef _WIN32
    UNUSED_ARG(doReset);
  #else /* linux & mac */
    clock_t end = clock();
    retval = ((float)(end - m_start)) / CLOCKS_PER_SEC;
    if (doReset) this->reset();
  #endif
    return retval;
  }


  /** Calculate the elapsed wall-clock time, reseting the timer if specified
   *
   * @param doReset :: true to reset the timer
   * @return wall-clock time, in seconds
   */
  float CPUTimer::elapsedWallClock(bool doReset)
  {
    float retVal = m_wallClockTime.elapsed(false);
    if (doReset) this->reset();
    return retVal;
  }


  /** Return the fraction of the CPU used (CPUTime/wall-clock time).
   * This can be > 1 on multi-CPU systems.
   *
   * @param doReset :: true to reset both timers
   * @return
   */
  float CPUTimer::CPUfraction(bool doReset)
  {
    // Get the wall-clock time without resetting.
    double wallTime = m_wallClockTime.elapsed(false);
    double cpuTime = elapsedCPU(false);
    if (doReset) this->reset();
    return static_cast<float>((cpuTime / wallTime));
  }



  /// Convert the elapsed time (without reseting) to a string.
  std::string CPUTimer::str()
  {
    std::stringstream buffer;
    buffer << std::fixed  << std::setw(7) << std::setprecision(4) << m_wallClockTime.elapsed_no_reset() << " s, CPU " << std::setprecision(2) << this->CPUfraction(false);
    this->reset();
    return buffer.str();
  }

  /// Convenience function to provide for easier debug printing.
  std::ostream& operator<<(std::ostream& out, CPUTimer& obj)
  {
    out << obj.str();
    return out;
  }


} // namespace Mantid
} // namespace Kernel