[Lazarus] Mutlithreaded Dll Callback crashes my Application

[Maik Wojcieszak]

Hi,

What exactly does this

System.IsMultiThread := true;

do ?

If I use external threads with my thread creation callback it works fine 
with
System.IsMultiThread := false;
If I set it to true the app crashes when creating the first threads.
If I use the suggested initialisation with the dummy thread it works 
too, but with
System.IsMultiThread := true;

Thanks in advance,
Maik


José Mejuto schrieb:
> Hello Lazarus-List,
>
> Wednesday, August 25, 2010, 10:05:32 PM, you wrote:
>
>   
>>> In Delphi setting IsMultithread to true is a must to use non TThread
>>> threads. Taken from Embarcadero QA:
>>>       
> SB> FPC is not Delphi and in this regard those two differ.
>
> Ok, I quoted Delphi just as a side note, and the reason I included it
> in the message. In fact there is some routines here and there that
> checks isMultiThread in order to perform or not locks. Of course, if
> heap is not properly initialized... ;)
>
>   
>>> Also the one thread creation is only for Unix systems, win32 does not
>>> have this problem since a lot of time.
>>>       
> SB> Windows DOES have this problem.
>
> In that case I misunderstood a quite recent message in fpc mailing
> list, my apologizes.
>
>   
>>> On the other hand, if Unix needs one thread creation then it should be
>>> automagically done in the initialization section of cthreads, do not ?
>>>       
> SB> This might indeed be a solution.
>
> If windows have the same problem, threading system should be
> initialized in... somewhere automagically as windows multithread is
> always present.
>
>