Develop Reference

Running Timers in the Background c# Console

Wondering if there's a way to have a timer running in the background of a project that can be accessed if the user inputs a certain thing. At the moment this doesn't work
Timer t = new Timer(Program.TimerCallback, null, 0, 1000);
if (Console.ReadLine() == "i")
{
TimeSpan time = TimeSpan.FromSeconds(Program.seconds);
string str = time.ToString(#"mm\:ss");
Console.WriteLine("Time :" + str);
}
public static void TimerCallback(object o)
{
seconds +=1;
}
I used to have to code above within the Callback but then I couldn't do anything while it was running the timer. Thanks for any help

If I understand correctly, you don't actually need a timer:
DateTime startTime = DateTime.Now; // Just have a reference time
if (Console.ReadLine() == "i")
{
TimeSpan time = DateTime.Now - startTime; // Compute difference between "now" and "then"
string str = time.ToString(#"mm\:ss");
Console.WriteLine("Time :" + str);
}
should do the trick.
Subtracting two DateTimes like this gives you a TimeSpan: DateTime.Subtraction Operator
If you need better precision, you can make use of the StopWatch class, which also has a little more convenient API:
Stopwatch stopWatch = new Stopwatch();
stopWatch.Start();
if (Console.ReadLine() == "i")
{
TimeSpan time = stopWatch.Elapsed;
string str = time.ToString(#"mm\:ss");
Console.WriteLine("Time :" + str);
}
BUT do not think you can do (micro-)benchmarks with this. If you intend to do so, consider Benchmark.NET (not affiliated).

c# Measure the time between the various functions

I want to measure the time between fucnctions+ get the total time
I now that there is Stopwatch but what I know is that I can only get the time between start and stop with Elapsed , so on that way I can get the total time.
How can I get the time between functions? for ex. :
Stopwatch s= new Stopwatch();
s.Start();
Function1();
//here I want get the time of function1
Function2();
//here I want get the time of function2
Function3();
//here I want get the time of function3
//here I want get the time of total time
s.Stop();
If I restart the stopwatch between the function I will not have the total time.
I don't want to apply more than 1 stopwatch
What can I do?

You can retrieve the elapsed time from the Stopwatch as you go:
Stopwatch s= new Stopwatch();
s.Start();
Function1();
var timeF1 = s.Elapsed;
Function2();
var timeF2 = s.Elapsed-timeF1;
Function3();
var timeF3 = s.Elapsed-timeF2-timeF1;
s.Stop();
//here I want get the time of total time
var timeTotal = s.Elapsed;

You could make yourself a small helper that stops it for you and returns you the elapsed times:
using System;
using System.Threading;
using System.Diagnostics;
public class Program
{
// measures a given lambdas run time - you can call any
// other function by StopFunc( () => ......... ) and supply
// your function call instead of ........
public static TimeSpan StopFunc(Action act)
{
var watch = Stopwatch.StartNew();
act?.Invoke(); // call the function
watch.Stop();
return watch.Elapsed;
}
static void Fast() { Thread.Sleep(100); }
static void Slow() { Thread.Sleep(2000); }
public static void Main()
{
// this calls the "to be measured function"
// via lambda and prints the time needed
Console.WriteLine("Slow took: " + StopFunc( () => Slow()));
Console.WriteLine("Fast took: " + StopFunc( () => Fast()));
}
}
Output:
Slow took: 00:00:02.0024322
Fast took: 00:00:00.1099702
The StopFunc takes an Action which you supply by a lambda ( () => YourFuncToCall() ) - it is just for measurements though.

Here is a class I've used in the past that may be useful to you. It provides a simple abstraction over the Stopwatch class which allows you to keep your code as free as possible of boiler plate code needed to do the timing. This makes it easier to read and easier to remove at a later stage.
public class StopwatchWrapper : IDisposable
{
private bool disposed = false;
private Stopwatch _overallStopwatch;
private List<long> _increments;
public StopwatchWrapper()
{
_overallStopwatch = Stopwatch.StartNew();
_increments = new List<long>();
}
public void Reset()
{
_increments.Clear();
_overallStopwatch.Restart();
}
public long ElapsedMilliseconds
{
get
{
_overallStopwatch.Stop();
var elapsed = _overallStopwatch.ElapsedMilliseconds;
_increments.Add(elapsed);
_overallStopwatch.Start();
return elapsed;
}
}
public long OverallMilliseconds
{
get
{
return _increments.Sum();
}
}
protected virtual void Dispose(bool disposing)
{
if (!disposed)
{
if (disposing)
{
if (_overallStopwatch != null)
{
_overallStopwatch.Stop();
}
}
disposed = true;
}
}
public void Dispose()
{
Dispose(true);
}
}
You could use it in your scenario as follows:
using (var sw = new StopwatchWrapper())
{
Function1();
//here I want get the time of function1
Console.WriteLine($"{sw.ElapsedMilliseconds}ms");
Function2();
//here I want get the time of function2
Console.WriteLine($"{sw.ElapsedMilliseconds}ms");
Function3();
//here I want get the time of function3
Console.WriteLine($"{sw.ElapsedMilliseconds}ms");
//here I want get the time of total time
Console.WriteLine($"{sw.OverallMilliseconds}ms");
}

More efficient way of implementing a countdown timer/clock?

I'm writing a small lap counter for slot car races as a little home project. I want to implement a countdown timer, which I've done with the following as a test:
private Thread countdownThread;
private delegate void UpdateTimer(string update);
UpdateTimer ut;
public LapCounterForm()
{
InitializeComponent();
//...
ut += updateTimer;
countdownThread = new Thread(new ThreadStart(startCountdown));
}
private void startCountdown()
{
Process.GetCurrentProcess().ProcessorAffinity = new IntPtr(1);
Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;
Thread.CurrentThread.Priority = ThreadPriority.AboveNormal;
System.Diagnostics.Stopwatch stopwatch = new Stopwatch();
long time = 0;
stopwatch.Start();
while (stopwatch.ElapsedMilliseconds <= 5000)
{
time = 5000 - stopwatch.ElapsedMilliseconds;
TimeSpan ts = TimeSpan.FromMilliseconds(time);
ut(ts.Minutes.ToString().PadLeft(2, '0') + ":" + ts.Seconds.ToString().PadLeft(2, '0') + ":" + ts.Milliseconds.ToString().PadLeft(3, '0'));
}
}
private void updateTimer(string text)
{
if (this.InvokeRequired)
{
this.Invoke(new Action<String>(ut), new object[] { text });
}
else
{
lblCountdownClock.Text = text;
}
}
When I start my thread, it works. I get my 5 second countdown like I want, but I can see that I'm using a lot of CPU in the process (12% of my 8 thread i7 2600k).
I figure I can reduce this load a lot by only updating the UI every 10 milliseconds instead of every millisecond, but I have no idea how to do such, other than using if(time % 10 == 0) before making the TimeSpan and updating the UI but I suspect that will be just as inefficient thanks to the while loop.
Am I reinventing the wheel? I'd like my timer to be as accurate as possible (at least for the slot car lap time recordings, perhaps the UI does not need to be updated so often).
EDIT: I tried commenting out the actual string manipulation and UI update as suggested in the comments. Now when I start my thread my entire UI hangs until the thread exits and I still get 12% CPU usage. I suspect that while loop is eating up a lot of CPU time.
Update: I went with the multimedia timer (here) posted by Kohanz as well as Daniel's answer. I no longer use another thread at all, I just make one of those timer objects and have a tick event handler calculating the time between clicking the start button and the tick event. I can even set the period for my ticks to 1ms so I get my cool looking countdown, and it's apparently using 0% CPU :) I'm quite happy with this.

Dont, just DONT go down this road. You are completely thinking of this in the wrong way. You are basically forcing your thread to freeze for no benefit.
Basically any game works this way: you have an update loop, and whenever that triggers you do neccessary stuff. So for instance if you want to know how much time, you ask some kind of "timer" how much has passed since something happened
Here's a much better way to handle this:
class MyStopwatch {
private DateTime _startTime;
private DateTime _stopTime;
public void start() {
_running = true;
_startTime = DateTime.Now;
}
public void stop() {
_stopTime = DateTime.Now;
_running = false;
}
public double getTimePassed() {
if(_running) {
return (DateTime.Now - _startTime).TotalMilliseconds;
} else {
return (_stopTime - _startTime).TotalMilliseconds;
}
}
}

A bit after the fact, but this shows a way in which you might achieve what you need:
public class LapTimer : IDisposable
{
private readonly System.Diagnostics.Stopwatch _stopWatch = new System.Diagnostics.Stopwatch();
private readonly ConcurrentDictionary<string, List<TimeSpan>> _carLapTimes = new ConcurrentDictionary<string, List<TimeSpan>>();
private readonly Action<TimeSpan> _countdownReportingDelegate;
private readonly TimeSpan _countdownReportingInterval;
private System.Threading.Timer _countDownTimer;
private TimeSpan _countdownTo = TimeSpan.FromSeconds(5);
public LapTimer(TimeSpan countdownReportingInterval, Action<TimeSpan> countdownReporter)
{
_countdownReportingInterval = countdownReportingInterval;
_countdownReportingDelegate = countdownReporter;
}
public void StartRace(TimeSpan countdownTo)
{
_carLapTimes.Clear();
_stopWatch.Restart();
_countdownTo = countdownTo;
_countDownTimer = new System.Threading.Timer(this.CountdownTimerCallback, null, _countdownReportingInterval, _countdownReportingInterval);
}
public void RaceComplete()
{
_stopWatch.Stop();
_countDownTimer.Dispose();
_countDownTimer = null;
}
public void CarCompletedLap(string carId)
{
var elapsed = _stopWatch.Elapsed;
_carLapTimes.AddOrUpdate(carId, new List<TimeSpan>(new[] { elapsed }), (k, list) => { list.Add(elapsed); return list; });
}
public IEnumerable<TimeSpan> GetLapTimesForCar(string carId)
{
List<TimeSpan> lapTimes = null;
if (_carLapTimes.TryGetValue(carId, out lapTimes))
{
yield return lapTimes[0];
for (int i = 1; i < lapTimes.Count; i++)
yield return lapTimes[i] - lapTimes[i - 1];
}
yield break;
}
private void CountdownTimerCallback(object state)
{
if (_countdownReportingDelegate != null)
_countdownReportingDelegate(_countdownTo - _stopWatch.Elapsed);
}
public void Dispose()
{
if (_countDownTimer != null)
{
_countDownTimer.Dispose();
_countDownTimer = null;
}
}
}
class Program
{
public static void Main(params string[] args)
{
using (var lapTimer = new LapTimer(TimeSpan.FromMilliseconds(100), remaining => Console.WriteLine(remaining)))
{
lapTimer.StartRace(TimeSpan.FromSeconds(5));
System.Threading.Thread.Sleep(2000);
lapTimer.RaceComplete();
}
Console.ReadLine();
}
}

Time elapse computation in milliseconds C#

I need to time the execution of a code sequence written in C#. Using DateTime.Now I get incorrect values for the millisecond field.
For example:
int start_time, elapsed_time;
start_time = DateTime.Now.Millisecond;
for(int i = 0; i < N_ITER; i++) {
// cpu intensive sequence
}
elapsed_time = DateTime.Now.Millisecond - start_time;
elapsed_time gives negative values.
How may I replace DateTime in order to obtain the actual value of the elapsed time?

using System.Diagnostics;
//...
var stopwatch = new Stopwatch();
stopwatch.Start();
for (int i = 0; i < N_ITER; i++) {
// cpu intensive sequence
}
stopwatch.Stop();
elapsed_time = stopwatch.ElapsedMilliseconds;

Answer EDITED based on comments
This answer is only trying to count the total elapsed Milliseconds between two times, where the times are derived directly from DateTime.Now. As per the conversation, it's understood that DateTime.Now is vulnerable to outside influences. Hence the best solution would be to use the Stopwatch class. Here's a link that better explains (IMO) and discusses the performance between DateTimeNow, DateTime.Ticks, StopWatch.
Original Answer
The way you cast it into a int is the issue. You need better casting and extra elements :)
This may looks simple compared to an efficient timer. But it works:
DateTime startTime, endTime;
startTime = DateTime.Now;
//do your work
endTime = DateTime.Now;
Double elapsedMillisecs = ((TimeSpan)(endTime - startTime)).TotalMilliseconds;
There is a reference on the web, you may want to check out as well.

You're looking for the Stopwatch class. It is specifically designed to bring back high-accuracy time measurements.
var stopwatch = new Stopwatch();
stopwatch.Start();
for (int i = 0; i < N_ITER; i++)
{
// cpu intensive sequence
}
stopwatch.Stop();
var elapsed = stopwatch.ElapsedMilliseconds;

Stopwatch there are examples in the URL
https://learn.microsoft.com/en-us/dotnet/api/system.diagnostics.stopwatch?view=netframework-4.8
using System.Diagnostics;
//...
Stopwatch watch = new Stopwatch();
watch.Start();
// here the complex program.
//...
watch.Stop();
TimeSpan timeSpan = watch.Elapsed;
Console.WriteLine("Time: {0}h {1}m {2}s {3}ms", timeSpan.Hours, timeSpan.Minutes,
timeSpan.Seconds, timeSpan.Milliseconds);

DateTime.Millisecond just returns the millisecond fraction of the second, from 0-999. You would need to take the rest of the datetime into consideration when doing timings.
However, you should look at using the StopWatch class for these kinds of performance timings.

This works for me:
var lapsedTime = DateTime.Now.Subtract(beginTime).TotalMilliseconds;

Here is what I used to obtain the time for a simple computation:
class Program
{
static void Main(string[] args)
{
Decimal p = 0.00001m;
Decimal i = 0m;
DateTime start = new DateTime();
DateTime stop = new DateTime();
for (i = p; i <= 5; i = i + p)
{
Console.WriteLine("result is: " + i);
if (i==p) start = DateTime.Now;
if (i==5) stop = DateTime.Now;
}
Console.WriteLine("Time to compute: " + (stop-start));
}
}

Exact time measurement for performance testing [duplicate]

This question already has answers here:
How to measure code performance in .NET?
(18 answers)
Closed 9 years ago.
What is the most exact way of seeing how long something, for example a method call, took in code?
The easiest and quickest I would guess is this:
DateTime start = DateTime.Now;
{
// Do some work
}
TimeSpan timeItTook = DateTime.Now - start;
But how exact is this? Are there better ways?

A better way is to use the Stopwatch class:
using System.Diagnostics;
// ...
Stopwatch sw = new Stopwatch();
sw.Start();
// ...
sw.Stop();
Console.WriteLine("Elapsed={0}",sw.Elapsed);

As others have said, Stopwatch is a good class to use here. You can wrap it in a helpful method:
public static TimeSpan Time(Action action)
{
Stopwatch stopwatch = Stopwatch.StartNew();
action();
stopwatch.Stop();
return stopwatch.Elapsed;
}
(Note the use of Stopwatch.StartNew(). I prefer this to creating a Stopwatch and then calling Start() in terms of simplicity.) Obviously this incurs the hit of invoking a delegate, but in the vast majority of cases that won't be relevant. You'd then write:
TimeSpan time = StopwatchUtil.Time(() =>
{
// Do some work
});
You could even make an ITimer interface for this, with implementations of StopwatchTimer, CpuTimer etc where available.

As others said, Stopwatch should be the right tool for this. There can be few improvements made to it though, see this thread specifically: Benchmarking small code samples in C#, can this implementation be improved?.
I have seen some useful tips by Thomas Maierhofer here
Basically his code looks like:
//prevent the JIT Compiler from optimizing Fkt calls away
long seed = Environment.TickCount;
//use the second Core/Processor for the test
Process.GetCurrentProcess().ProcessorAffinity = new IntPtr(2);
//prevent "Normal" Processes from interrupting Threads
Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;
//prevent "Normal" Threads from interrupting this thread
Thread.CurrentThread.Priority = ThreadPriority.Highest;
//warm up
method();
var stopwatch = new Stopwatch()
for (int i = 0; i < repetitions; i++)
{
stopwatch.Reset();
stopwatch.Start();
for (int j = 0; j < iterations; j++)
method();
stopwatch.Stop();
print stopwatch.Elapsed.TotalMilliseconds;
}
Another approach is to rely on Process.TotalProcessTime to measure how long the CPU has been kept busy running the very code/process, as shown here This can reflect more real scenario since no other process affects the measurement. It does something like:
var start = Process.GetCurrentProcess().TotalProcessorTime;
method();
var stop = Process.GetCurrentProcess().TotalProcessorTime;
print (end - begin).TotalMilliseconds;
A naked, detailed implementation of the samething can be found here.
I wrote a helper class to perform both in an easy to use manner:
public class Clock
{
interface IStopwatch
{
bool IsRunning { get; }
TimeSpan Elapsed { get; }
void Start();
void Stop();
void Reset();
}
class TimeWatch : IStopwatch
{
Stopwatch stopwatch = new Stopwatch();
public TimeSpan Elapsed
{
get { return stopwatch.Elapsed; }
}
public bool IsRunning
{
get { return stopwatch.IsRunning; }
}
public TimeWatch()
{
if (!Stopwatch.IsHighResolution)
throw new NotSupportedException("Your hardware doesn't support high resolution counter");
//prevent the JIT Compiler from optimizing Fkt calls away
long seed = Environment.TickCount;
//use the second Core/Processor for the test
Process.GetCurrentProcess().ProcessorAffinity = new IntPtr(2);
//prevent "Normal" Processes from interrupting Threads
Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;
//prevent "Normal" Threads from interrupting this thread
Thread.CurrentThread.Priority = ThreadPriority.Highest;
}
public void Start()
{
stopwatch.Start();
}
public void Stop()
{
stopwatch.Stop();
}
public void Reset()
{
stopwatch.Reset();
}
}
class CpuWatch : IStopwatch
{
TimeSpan startTime;
TimeSpan endTime;
bool isRunning;
public TimeSpan Elapsed
{
get
{
if (IsRunning)
throw new NotImplementedException("Getting elapsed span while watch is running is not implemented");
return endTime - startTime;
}
}
public bool IsRunning
{
get { return isRunning; }
}
public void Start()
{
startTime = Process.GetCurrentProcess().TotalProcessorTime;
isRunning = true;
}
public void Stop()
{
endTime = Process.GetCurrentProcess().TotalProcessorTime;
isRunning = false;
}
public void Reset()
{
startTime = TimeSpan.Zero;
endTime = TimeSpan.Zero;
}
}
public static void BenchmarkTime(Action action, int iterations = 10000)
{
Benchmark<TimeWatch>(action, iterations);
}
static void Benchmark<T>(Action action, int iterations) where T : IStopwatch, new()
{
//clean Garbage
GC.Collect();
//wait for the finalizer queue to empty
GC.WaitForPendingFinalizers();
//clean Garbage
GC.Collect();
//warm up
action();
var stopwatch = new T();
var timings = new double[5];
for (int i = 0; i < timings.Length; i++)
{
stopwatch.Reset();
stopwatch.Start();
for (int j = 0; j < iterations; j++)
action();
stopwatch.Stop();
timings[i] = stopwatch.Elapsed.TotalMilliseconds;
print timings[i];
}
print "normalized mean: " + timings.NormalizedMean().ToString();
}
public static void BenchmarkCpu(Action action, int iterations = 10000)
{
Benchmark<CpuWatch>(action, iterations);
}
}
Just call
Clock.BenchmarkTime(() =>
{
//code
}, 10000000);
or
Clock.BenchmarkCpu(() =>
{
//code
}, 10000000);
The last part of the Clock is the tricky part. If you want to display the final timing, its up to you to choose what sort of timing you want. I wrote an extension method NormalizedMean which gives you the mean of the read timings discarding the noise. I mean I calculate the the deviation of each timing from the actual mean, and then I discard the values which was farer (only the slower ones) from the mean of deviation (called absolute deviation; note that its not the often heard standard deviation), and finally return the mean of remaining values. This means, for instance, if timed values are { 1, 2, 3, 2, 100 } (in ms or whatever), it discards 100, and returns the mean of { 1, 2, 3, 2 } which is 2. Or if timings are { 240, 220, 200, 220, 220, 270 }, it discards 270, and returns the mean of { 240, 220, 200, 220, 220 } which is 220.
public static double NormalizedMean(this ICollection<double> values)
{
if (values.Count == 0)
return double.NaN;
var deviations = values.Deviations().ToArray();
var meanDeviation = deviations.Sum(t => Math.Abs(t.Item2)) / values.Count;
return deviations.Where(t => t.Item2 > 0 || Math.Abs(t.Item2) <= meanDeviation).Average(t => t.Item1);
}
public static IEnumerable<Tuple<double, double>> Deviations(this ICollection<double> values)
{
if (values.Count == 0)
yield break;
var avg = values.Average();
foreach (var d in values)
yield return Tuple.Create(d, avg - d);
}

Use the Stopwatch class

System.Diagnostics.Stopwatch is designed for this task.

Stopwatch is fine, but loop the work 10^6 times, then divide by 10^6.
You'll get a lot more precision.

I'm using this:
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(myUrl);
System.Diagnostics.Stopwatch timer = new Stopwatch();
timer.Start();
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
statusCode = response.StatusCode.ToString();
response.Close();
timer.Stop();