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Windows Threads

Today I tried to create a thread using Windows API. I always thought that there are no problems. But it turned out that I can not do anything. I can not even use the MESSAGE in the thread procedure. The application always crashes.

Below is the code that creates a new thread and simply increases the value of a variable. It works.

 PROGRAM
 MAP
    MODULE('WinAPI')
      CreateThread(LONG,LONG,LONG,LONG,LONG,LONG),ULONG,PASCAL,NAME('CreateThread')
      memcpy(LONG,LONG,LONG),LONG,RAW,NAME('_memcpy'),PROC
    END
    TThreadProc(LONG lpParameter),PASCAL
 END

Window WINDOW('Caption'),AT(,,129,115),FONT('MS Sans Serif',8,,FONT:regular),GRAY
       BUTTON('Start thread'),AT(4,4,81,18),USE(?OkButton),DEFAULT
       BUTTON('Show results'),AT(4,30,81,18),USE(?CancelButton)
     END

ThreadID LONG
Param    LONG
hThread  ULONG
 CODE
 OPEN(Window)
 DISPLAY
 ACCEPT
    CASE ACCEPTED()
    OF ?OkButton
       hThread = CreateThread(0,0,ADDRESS(TThreadProc),ADDRESS(Param),0,0)
       MESSAGE('Thread handle: ' & hThread)
    OF ?CancelButton
       MESSAGE('Param: ' & Param)
    END
 END

TThreadProc PROCEDURE(LONG lpParameter)
loc:Var LONG
 CODE
 ! MESSAGE('Enter TThreadProc') crashed
 LOOP
    loc:Var += 1
    memcpy(lpParameter,ADDRESS(loc:Var),4)
 END

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