pyscripter

If you have a look at the posted file, this is what I tried to do. Please have a go if you have the time.

Absolutely right. This is why I am passing the challenge to people like you, with much deeper knowledge than mine. I would very much hope that @Primož Gabrijelčičfor instance, has a go at providing a solution, since he has faced the very same issue in OmniThreadLibrary.

The following code program ThreadOSError; {$APPTYPE CONSOLE} uses System.SysUtils, System.Classes; begin Assert(GetLastError=0); TThread.CreateAnonymousThread(procedure begin try CheckOSError(GetLastError); except On E: Exception do WriteLn(E.Message); end; end).Start; ReadLn; end. produces the following output in 10.3,3 in Windows. System Error. Code: 87. The parameter is incorrect Same is true whichever way you run Thread code. Is this a known issue? Any idea why the OS error is raised?

Let me thank again everyone that responded. You said that the error-code is thread specific, this is not the way to check whether a specific API call failed etc., things I fully agree with, but which I knew already. My post just made an observation. Whenever you run code in a thread, GetLastError always returns 87 which corresponds to a call with invalid parameters, The original post asked two questions: Was this a known fact? More importantly why? In other words, what is the API call that sets this error? Even if it is inconsequential, and I believe it is, I had the curiosity to find out. I don't think I got an answer to these questions.

@Anders Melander @Lars FosdalSo you do not think this OS error is the result of Delphi making a call to an OS (Windows) function with invalid parameters.

@Der schöne GüntherI am not sure about the relevance of your quote. No matter what your thread code is or how you run it (by inheriting from TThread, creating an anonymous thread or whatever), something results in an OS error 87 (it is always the same code) that corresponds to "parameter is incorrect". This OS error has been raised before your thread code has started running. And this has nothing to do with the return code of a thread. This is a problem because if you do any OS stuff in your thread code, and then you want to check whether an error was raised using CheckOSError, an exception will be raised. A workaround would be to always start your thread code with the statement: SetLastError(0);

His legacy lives on through people like me using his code...

If you want type inference then add a new method: function SmartPtr<T>.Value: T; begin if FGuard <> nil then Result := FGuard.Value else Result := nil; end; Then you can write: var Bob := SmartPtr<TTalking>(TTalking.Create('Bob')).Value; slightly more elegant than having three times TTalking on the same line.

Funnily enough some of the most popular languages today, Python, JavaScript R and Ruby are single-threaded and you have to go out-of-your-way to use more than one cores.

I was not aware of that. It is certainly wrong now.

I finally got to the bottom of this issue and I have a simple fix. See https://quality.embarcadero.com/browse/RSP-28200 Please test and vote for it.

I revisited this thread and tested the code below: program Project1; {$APPTYPE CONSOLE} {$R *.res} uses System.SysUtils, System.Threading, System.Diagnostics; var SW:TStopWatch; type TThreadPoolStatsHelper = record helper for TThreadPoolStats function Formatted: string; end; function TThreadPoolStatsHelper.Formatted: string; begin Result := Format('Worker: %2d, Min: %2d, Max: %2d, Idle: %2d, Retired: %2d, Suspended: %2d, CPU(Avg): %3d, CPU: %3d', [self.WorkerThreadCount, self.MinLimitWorkerThreadCount, self.MaxLimitWorkerThreadCount, self.IdleWorkerThreadCount, self.RetiredWorkerThreadCount, self.ThreadSuspended, self.AverageCPUUsage, self.CurrentCPUUsage]); end; procedure Load; begin TParallel.For(0, 99999999, procedure(i: Integer) var T:Single; begin T:=Sin(i/PI); end); end; begin try Writeln('PPL Test ---------------'); Writeln('Before: '+ TThreadPoolStats.Current.Formatted); SW:=TStopWatch.StartNew; Load; Writeln('Finished in '+SW.Elapsed.ToString); Sleep(1000); Writeln('After: '+TThreadPoolStats.Current.Formatted); except on E: Exception do Writeln(E.ClassName, ': ', E.Message); end; ReadLn; end. This is the output 32-bits PPL Test --------------- Before: Worker: 0, Min: 8, Max: 200, Idle: 0, Retired: 0, Suspended: 0, CPU(Avg): 0, CPU: 0 Finished in 00:00:00.7620933 After: Worker: 8, Min: 8, Max: 200, Idle: 7, Retired: 0, Suspended: 0, CPU(Avg): 8, CPU: 15 64-bits PPL Test --------------- Before: Worker: 0, Min: 8, Max: 200, Idle: 0, Retired: 0, Suspended: 0, CPU(Avg): 0, CPU: 0 Finished in 00:00:14.0655228 After: Worker: 8, Min: 8, Max: 200, Idle: 7, Retired: 0, Suspended: 0, CPU(Avg): 85, CPU: 1 Can anyone explain the huge difference in times? (it was consistent over many runs).

Yes you are right...

Oh I get it. sin is highly optimized in 32-bits but apparently not in 64-bits.

I was looking at an old blog post by Barry Kelly. In particular the function: function TLocation.FieldRef(const name: string): TLocation; var f: TRttiField; begin if FType is TRttiRecordType then begin f := FType.GetField(name); Result.FLocation := PByte(FLocation) + f.Offset; Result.FType := f.FieldType; end else if FType is TRttiInstanceType then begin f := FType.GetField(name); Result.FLocation := PPByte(FLocation)^ + f.Offset; Result.FType := f.FieldType; end else raise Exception.CreateFmt('Field reference applied to type %s, which is not a record or class', [FType.Name]); end; I am puzzled by the line: Result.FLocation := PPByte(FLocation)^ + f.Offset; If Flocation is an object (FType is TRttiInstance type) and I am having a record field inside the object, the Result.FLocation should be PByte(FLocation) + f.offset, i.e. the same as for FType is TRttiRecord. Barry Kelly is probably the guy that wrote the Rtti stuff, so he knows what he is talking about. What I am missing?

@Attila Kovacs Thanks I missed that. Now I get it. The key is in class function TLocation.FromValue(C: TRttiContext; const AValue: TValue): TLocation; begin Result.FType := C.GetType(AValue.TypeInfo); Result.FLocation := AValue.GetReferenceToRawData; end; If AValue contains an object, Flocation would a pointer to a pointer. That was not the case in my testing. He could do the dereferencing in this function of course.

Another free one is at https://github.com/ekot1/DelphiSVG/commits/master

GetProperty(Name).PropertyType.Handle

https://github.com/ase379/gpprofile2017 A revamped version of the good old instrumenting profiler by @Primož Gabrijelčič.

I can confirm that the workaround worked.

I have just been told that this is a reported bug with Catalina 10.15.4. and there is a workaround I am going to try. @Dave NottageHow come this did not affect you?

@Dave NottageThanks for responding I am in Delphi 10.3.3. Here is what I see in verbose mode when I select Add New SDK as above and then press OK. The -version -skd happens while the dialog is showing. Nothing seems to happen when I press OK. Do I need to download the SDK in the Mac? The XCode version is 11.4.

@Dave NottageThanks for responding I am in Delphi 10.3.3. Here is what I see in verbose mode when I select Add New SDK as above and then press OK. The -version -skd happens while the dialog is showing. Nothing seems to happen when I press OK. Do I need to download the SDK in the Mac? The XCode version is 11.4.

You can add an extension method if you wish to do that using a class helper. (Low as well).