[fpc-pascal] Re: Code conversion question - alloc and dealloc memory

[Michael Van Canneyt]

On Thu, 15 Oct 2009, Graeme Geldenhuys wrote:

> On 15/10/2009, Graeme Geldenhuys <graemeg.lists at gmail.com> wrote:
>>
>>  ------------------------
>>  function AllocateMemory( const Size: longint ): pointer;
>>
>>  procedure DeallocateMemory( Var P: pointer );
>
> OK, I managed to convert those two functions to the following.. it now
> compiles under my 64bit FPC.
>
> -----------------------------
> function AllocateMemory( const Size: ValUInt ): pointer;
> begin
>  GetMem( Result, size + sizeof( Size ) );
>  PtrUInt(Result^) := Size;
>  inc( Result, sizeof( Size ) );
> end;
>
> procedure DeallocateMemory( Var P: pointer );
> var
>  Size: ValUInt;
> begin
>  if P = nil then
>    exit;
>
>  dec( P, sizeof( size ) );
>  Size := ValUInt(P^);
>  FreeMem( P, Size + sizeof( Size ) );
>  P := nil;
> end;
> -----------------------------
>
> But based on Florian's reply, I assume I don't need to bother using
> these methods, because FreeMem() will automatically know much much
> memory to deallocate.

Yes.

Michael.