migration C#, Java, C++ (day 10), chrono, time, exceptions

I have mentioned speed quite often. Let’s measure it now!

It is remarkable that C# is dealing with exceptions faster than C++. The code execution is amazing. Anyway, when it comes to thrown exceptions (rarely happens in practice), then C++ is more than 20x faster. I knew how to build in the exceptions to see a difference. I was astonished that C++ was beyond belief compared to C# thrown exceptions. For further study follow these links:
Exceptions part 1
Exceptions part 2
Exceptions part 3

Time, Benchmark and Co.

using System;
using System.Diagnostics;

namespace DemoApp {
   public class Benchmark {

      void Benchmark1() {
         for (int i = 0; i < 1000; i++) { Console.Write("*"); }
         Console.WriteLine();
      } //

      void Benchmark2() {
         for (int i = 0; i < 1000; i++) {
            try { Console.Write("*"); }
            catch (Exception ex) { Console.WriteLine(ex.Message); }
         }
         Console.WriteLine();
      } //

      void Benchmark3() {
         for (int i = 0; i < 1000; i++) {
            try { Console.Write("*"); throw new Exception("OMG"); }
            catch (Exception ex) { }
         }
         Console.WriteLine();
      } //

      void Benchmark4b() { Console.Write("*"); throw new Exception("OMG"); }
      void Benchmark4a() {
         for (int i = 0; i < 1000; i++) {
            try { Benchmark4b(); }
            catch (Exception ex) { }
         }
         Console.WriteLine();
      } //

      public class StopWatch {
         Stopwatch _Stopwatch = new Stopwatch();

         public void start() { _Stopwatch.Start(); }
         public void stop() {
            _Stopwatch.Stop();
            long lElapsedTicks = _Stopwatch.ElapsedTicks;
            long lTicksPerSecond = Stopwatch.Frequency;
            double lMilliseconds = 1000.0 * (double)lElapsedTicks / (double)lTicksPerSecond;
            Console.WriteLine(lMilliseconds + " ms ");
            _Stopwatch.Start();
         }
      };


      public void test() {
         DateTime lNow1 = DateTime.Now; // current time
         DateTime lNow2 = DateTime.Now.AddSeconds(2.0); // current time plus 2 seconds
         double lSince1970 = DateTime.Now.Subtract(new DateTime(1970, 1, 1)).TotalSeconds;  // Seconds since 1 Jan 1970  

         Console.WriteLine("Current local time and date: " + DateTime.Now.ToString("dd MMM yyyy, HH:mm:ss"));
         Console.WriteLine("1/" + Stopwatch.Frequency);  // eg. 1/1,000,000,000 == 1ns

         // Benchmark
         DateTime lStart = DateTime.Now;
         Benchmark1();
         DateTime lEnd = DateTime.Now;
         TimeSpan lDuration = lEnd - lStart;
         Console.WriteLine("Time passed ms: " + lDuration.TotalMilliseconds);

         // Benchmarks: let's get more precise now
         StopWatch lStopwatch = new StopWatch();
         lStopwatch.start();
         Console.Write("Benchmark1:"); Benchmark1(); lStopwatch.stop();
         Console.Write("Benchmark2:"); Benchmark2(); lStopwatch.stop();
         Console.Write("Benchmark3:"); Benchmark3(); lStopwatch.stop();
         Console.Write("Benchmark4:"); Benchmark4a(); lStopwatch.stop();

         Console.ReadKey();
      } //

   } // class
} // namespace

example output:
Current local time and date: 12 Mar 2014, 21:35:46
1/3122812
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
****************************************
Time passed ms: 62.0035
Benchmark1:*********************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
***************************************************
63.3714101265142 ms
Benchmark2:*********************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
***************************************************
133.177405492229 ms
Benchmark3:*********************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
***************************************************
6450.41872517462 ms
Benchmark4:*********************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
***************************************************
13223.9343899024 ms

#include <iostream>
#include <chrono>
#include <time.h>
#include <string>

using namespace std;
using namespace std::chrono;

void Benchmark1() {
  for (int i = 0; i < 1000; i++) { cout << "*"; }
  cout << endl;
} //

void Benchmark2() {
  for (int i = 0; i < 1000; i++) {
    try { cout << "*"; }
    catch (exception &ex) { cout << ex.what() << endl; }
  }
  cout << endl;
} //

void Benchmark3() {
  for (int i = 0; i < 1000; i++) {
    try { cout << "*"; throw exception("OMG"); }
    catch (exception &ex) {}
  }
  cout << endl;
} //

void Benchmark4b(){ cout << "*"; throw exception("OMG"); }
void Benchmark4a() {
  for (int i = 0; i < 1000; i++) {
    try { Benchmark4b(); }
    catch (exception &ex) {}
  }
  cout << endl;
} //

class Stopwatch {
  high_resolution_clock _Clock;
  high_resolution_clock::time_point _From;

public:
  void start() { _From = _Clock.now(); }
  void stop() {
    high_resolution_clock::time_point lNow = _Clock.now();
    high_resolution_clock::duration lDuration = lNow - _From;
    intmax_t lNum = high_resolution_clock::period::num;
    intmax_t lDen = high_resolution_clock::period::den;
    double lMilliseconds = 1000.0 * lDuration.count() * (double)lNum / (double)lDen;
    cout << lMilliseconds << " ms " << endl;
    _From = _Clock.now();
  }
};


int main() {
  system_clock c1;  // system clock changes will have an impact
  steady_clock c2;  // independent from system clock changes
  high_resolution_clock c3;

  system_clock::time_point lTimePoint = system_clock::now();
  cout << lTimePoint.time_since_epoch().count() << endl;
  lTimePoint = lTimePoint + seconds(2);
  cout << lTimePoint.time_since_epoch().count() << endl;
  
  time_t lRawTime;
  struct tm lLocalTime;
  const int lTimeStringLength = 50;
  char lTimeString[lTimeStringLength];
  bool b1 = (time(&lRawTime) != -1);                 // Seconds since 1 Jan 1970
  bool b2 = (localtime_s(&lLocalTime, &lRawTime) == 0); // Convert to local time
  bool b3 = (asctime_s(lTimeString, lTimeStringLength, &lLocalTime) == 0); // convert to string

  if (b1 && b2 && b3) cout << "Current local time and date: " << lTimeString << endl;
  else cerr << "Error, cannot get current time." << endl;
    
  ratio<1, 10> r1; // 1/10
  ratio<2, 10> r2; // 2/10
  cout << r1.num << "/" << r1.den << endl;  // 1/10
  cout << r2.num << "/" << r2.den << endl;  // 1/5
  cout << system_clock::period::num << "/" << system_clock::period::den << endl;  // eg. 1/1,000,000,000 == 1ns
  
  microseconds micros(1234);       // 1,234 microseconds
  cout << micros.count() << endl;  // 1,234
  nanoseconds ns = micros;         // 1,234,000 nanoseconds, no loss
  cout << ns.count() << endl;      // 1,234,000
  milliseconds ms = duration_cast<milliseconds>(micros); // 1 millisecond, precision loss => duration_cast required
  micros += ms;
  cout << micros.count() << endl;  // 2,234

  // Benchmark
  steady_clock::time_point lStart = steady_clock::now();
  Benchmark1();
  steady_clock::time_point lEnd = steady_clock::now();
  steady_clock::duration lDuration = lEnd - lStart;
  if (lDuration == steady_clock::duration::zero()) cout << "no time has passed" << endl;
  cout << duration_cast<milliseconds>(lDuration).count() << endl;

  // Benchmarks: let's get more precise now
  Stopwatch lStopwatch;
  lStopwatch.start();
  cout << "Benchmark1:"; Benchmark1(); lStopwatch.stop();
  cout << "Benchmark2:"; Benchmark2(); lStopwatch.stop();
  cout << "Benchmark3:"; Benchmark3(); lStopwatch.stop();
  cout << "Benchmark4:"; Benchmark4a(); lStopwatch.stop();

  cin.get();
  return 0;
} //

example output:
13946584250282411
13946584270282411
Current local time and date: Wed Mar 12 21:07:05 2014

1/10
1/5
1/10000000
1234
1234000
2234
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
****************************************
80
Benchmark1:*********************************************************************
********************************************************************************
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***************************************************
86.0049 ms
Benchmark2:*********************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
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***************************************************
84.0048 ms
Benchmark3:*********************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
***************************************************
311.018 ms
Benchmark4:*********************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
********************************************************************************
***************************************************
306.017 ms

package DemoApp;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.logging.Level;
import java.util.logging.Logger;

 public class Benchmark {

  private void Benchmark1() {
     for (int i = 0; i < 1000; i++) System.out.print("*");
     System.out.println();
  } //

  private void Benchmark2() {
    for (int i = 0; i < 1000; i++) {
      try { System.out.print("*"); }
      catch (RuntimeException ex) { System.out.println(ex.getMessage()); }
     }
    System.out.println();
  } //

  private void Benchmark3() {
     for (int i = 0; i < 1000; i++) {
        try {
          System.out.print("*");
          throw new RuntimeException("OMG");
        }
        catch (RuntimeException ex) { }
     }
     System.out.println();
  } //

  private void Benchmark4b() {
    System.out.print("*");
    throw new RuntimeException("OMG");
  } //
  private void Benchmark4a() {
     for (int i = 0; i < 1000; i++) {
        try { Benchmark4b(); }
        catch (RuntimeException ex) { }
     }
     System.out.println();
  } //

  public static class StopWatch {
    private long _Start = System.nanoTime();       
    private long _Stop = System.nanoTime();

    public final void start() {
      _Start = System.nanoTime();
    }
    public final void stop() {
        _Stop = System.nanoTime();
        long lElapsedTicks = _Stop - _Start;          
        double lMilliseconds = lElapsedTicks / 1000000.0;
        System.out.println(lMilliseconds + " ms ");
        _Start = System.nanoTime();
     }
  } // class

  public final void test() {
    Calendar lNow1 = Calendar.getInstance();  // current time
    Calendar lNow2 = Calendar.getInstance();
    lNow2.add(Calendar.SECOND, 2);  // current time plus 2 seconds
    double lSince1970 = System.currentTimeMillis() / 1000.0; // Seconds since 1 Jan 1970      
    SimpleDateFormat lFormat = new SimpleDateFormat("dd MMM yyyy, HH:mm:ss");
    System.out.print("Current local time and date: ");
    System.out.println(lFormat.format(Calendar.getInstance().getTime()));

    // Benchmark
    Calendar lStart = Calendar.getInstance();
    Benchmark1();
    Calendar lEnd = Calendar.getInstance();       
    long lDuration = lEnd.getTimeInMillis() - lStart.getTimeInMillis();
    System.out.println("Time passed ms: " + lDuration);

    // Benchmarks: let's get more precise now
    StopWatch lStopwatch = new StopWatch();
    lStopwatch.start();
    System.out.print("Benchmark1:"); Benchmark1(); lStopwatch.stop();
    System.out.print("Benchmark2:"); Benchmark2(); lStopwatch.stop();
    System.out.print("Benchmark3:"); Benchmark3(); lStopwatch.stop();
    System.out.print("Benchmark4:"); Benchmark4a();lStopwatch.stop();

    try {
      System.in.read();
    } catch (IOException ex) {
      Logger.getLogger(Benchmark.class.getName()).log(Level.SEVERE, null, ex);
    }
  } // 

  public static void main(String[] args) {
    Benchmark lBenchmark = new Benchmark();
    lBenchmark.test();
  } //
  
} // class

example output:
Current local time and date: 09 May 2014, 18:03:20
****************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************
Time passed ms: 16
Benchmark1:****************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************
18.10766 ms
Benchmark2:****************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************
14.703688 ms
Benchmark3:****************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************
25.99924 ms
Benchmark4:****************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************
49.451426 ms