TStopwatch.Elapsed

[dummzeuch 1505]

I must be doing something wrong here:

var
  Stopwatch: TStopwatch;
begin
  Stopwatch.Start;
  sleep(3000);
  Stopwatch.Stop;
  m_Result.Lines.Add(format('Took %.3f seconds', [Stopwatch.Elapsed.TotalSeconds]));
end;

The result is "-130847749795,796 seconds", I was, of course, expecting something around 3.

What am I missing?

[dummzeuch 1505]

Ouch! Forget it: I didn't reset the stopwatch first:

var
  Stopwatch: TStopwatch;
begin
  Stopwatch.Reset; //<<<--- this was missing
  Stopwatch.Start;
  sleep(3000);
  Stopwatch.Stop;
  m_Result.Lines.Add(format('Took %.3f seconds', [Stopwatch.Elapsed.TotalSeconds]));
end;

 

Edited May 30, 2020 by dummzeuch

[MarkShark 27]

I always do Stopwatch := TStopwatch.StartNew;  On a side note I wonder if the new managed records thing could make your original one work (which I would prefer.)

[dummzeuch 1505]

18 minutes ago, MarkShark said:

On a side note I wonder if the new managed records thing could make your original one work (which I would prefer.)

Yes, I'm sure it could.

[Leif Uneus 43]

Use StopWatch := TStopWatch.Create  to initialize a new TStopWatch value in a stopped condition or StopWatch := TStopWatch.StartNew to return a started stopwatch. See http://docwiki.embarcadero.com/Libraries/Rio/en/System.Diagnostics.TStopwatch.Create

[David Heffernan 2345]

4 hours ago, Leif Uneus said:

StopWatch := TStopWatch.StartNew

is all you need

[Anders Melander 1782]

24 minutes ago, David Heffernan said:

is all you need 

I would think RTFM is all he needs:

Quote

TStopwatch is not a class but still requires explicit initialization. Call the StartNew or Create method to initialize a TStopwatch value.

 

[dummzeuch 1505]

What i don't need are snide remarks like this.

[David Heffernan 2345]

I don't think RTFM is the right way to say it. But I trust you make a mental note to check the documentation another time.

 

I mean, the way the message was delivered was clumsy, but the thrust of the message is valid.

 

 

[dummzeuch 1505]

One of the bad habits I have picked up over the years is not looking into the documentation. The only reason I can give is that the documentation was so bad for some time that the time it took usually was wasted. Since documentation has become much better (but is still far from perfect, especially some of the examples), this no longer applies though.

[David Heffernan 2345]

1 hour ago, dummzeuch said:

One of the bad habits I have picked up over the years is not looking into the documentation. The only reason I can give is that the documentation was so bad for some time that the time it took usually was wasted. Since documentation has become much better (but is still far from perfect, especially some of the examples), this no longer applies though.

I think it is often the case that documentation for Delphi is added sometime after the code is released. Documentation for mature parts of the libs is often reasonable. Not so much for newly released libs. 

 

I think this is a really poor way to develop libs though. I routinely find design issues when I am writing documentation. If you write the documentation after you release then you'll find those issues after the consumers have started using the libs. 

[Mark- 29]

37 minutes ago, David Heffernan said:

I routinely find design issues when I am writing documentation.

Same here plus, I can verify all the design and functionality goals are achieved.

In some cases I write the documentation before the code. Especially when the goal is stated in one line but contains many facets.