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Changing pointors value - A solution : Structure

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Changing pointors value - A solution : Structure

Posted: Wed Aug 15, 2007 8:59 pm
by Ollivier
When I code this:

Code: Select all

*pointor = allocatememory(4096)

*photoX = procedureLambda(*pointor)
*movieY = procedureLambda(*pointor)
*stringZ = procedureLambda(*pointor)
...procedureLambda fills step by step allocated memory pointed by *pointor.

When this allocated memory is full, there is a big problem cause I want to reallocate memory but the start pointor changed.

Code: Select all

*pointor2 = reallocatememory(8192)
If *pointor = *pointor2
  Debug "I am very happy!"
Else
  Debug "I loose all my pointors cause *PhotoX, *movieY and *StringZ become FALSE!"
EndIf
I try to update pointors.
First time, declaring all my pointors like procedure declarations.

Code: Select all

*PointorsBegin
*photoX
*movieY
*stringZ
*PointorsEnd
Second time, updating pointors values in a For...Next, like that:

Code: Select all

      *NewArea = AllocateMemory(NewSize)
      Shift.L = *NewArea - *OldArea
      For i = @*PointorsBegin + 4 To @*PointeursEnd - 4 Step 4
             PokeL(i, PeekL(i) + Shift)
      Next
But now, I see pointors adress doesn't depend of its place in the source code but depends of... it's name!!! :shock:

I suppose it's alphabetical...

Why does the compiler do it??? Useless...

Re: Updating any used pointors - Rendez-vous with a big bord

Posted: Wed Aug 15, 2007 9:46 pm
by tinman
Why not? There is nothing to say what order the compiler puts variables in memory, unlike e.g. C.

Variables inside functions, however, are on the stack in the order they are declared (i.e. first is at lowest address).

If you are really bothered about having them in order at a global scope you could create a structure:

Code: Select all

Structure MyPointers
*photoX
*movieY
*stringZ
EndStructure

*pointor = allocatememory(4096)
Define.MyPointers ptrs
ptrs\photoX = procedureLambda(*pointor) 
ptrs\movieY = procedureLambda(*pointor) 
ptrs\stringZ = procedureLambda(*pointor) 

*NewArea = AllocateMemory(NewSize)
Shift.L = *NewArea - *pointor 
For i = OffsetOf(ptrs\photoX) To OffsetOf(ptrs\stringZ) Step 4
    PokeL(i, PeekL(i) + Shift)
Next
Or use an array of pointers.

Posted: Wed Aug 15, 2007 10:05 pm
by Ollivier
Yes! :D :D

The structure : very good idea. The solution is elegant!

But I want to keep simplicity of syntax.
(Excuse me: it's french. See then main part)

Code: Select all

; CONVENTION

; Suite=
; Zone mémoire constituée d'une succession de valeurs contigües

; Descripteur=
; >> Quad (LONG * 2) décrivant un ensemble
; >> Contient deux Longs : le type et l'attribut 


; _________________________________________________________________________
; STE | Suite des Types d'Ensemble
; SAE | Suite des Attributs d'Ensemble
; TE  | Table des descripteurs d'Ensembles (Regroupant la STE et la SAE)
; ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

; _________________________________________________________________________
; CONVENTION DES TYPES DE DESCRIPTEUR
; ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
; ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
; Code type      Attribut
; _________________________________________________________________________
; $00 00 00 00 | Inexistant (libre)
;              |
; $01 00 00 00 | Pointeur vers un descripteur d'ensemble dans la TE
; $01 00 00 01 | Variable de type LONG
; $01 00 00 02 | Variable de type FLOAT
; $01 00 00 03 | Pointeur vers une variable de type STRING (Avec terminal 0)
;              |

; $01 01 00 00 | Pointeur de donnée non définie
; $01 01 00 10 | {Pointeur vers une zone mémoire}
; $01 01 00 12 | Idem constituée de pointeurs de donnée non définie
; $01 01 00 13 | Idem constituée de pointeurs vers la TE
;              | 
; $01 02 00 00 | Pointeur de code non défini
;              |
; $01 03 00 00 | Pointeur non défini
;              |
; ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
#Descript  = $01000000
#VarLong   = $01000001
#VarFloat  = $01000002
#VarString = $01000003

; _________________________________________________________________________
; QED.L | Quantité d'Ensembles Disponibles (64, par défaut)
; *STE  | Adresse de la STE
; *SAE  | Adresse de la SAE
; ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
      
      Global QED.L = 64
      Global SHI.L = QED << 2
      Global *SAE
      Global *STE      
      
Procedure CreerTE()
      *SAE = AllocateMemory(QED << 3)
      *STE = *SAE + SHI
EndProcedure

Procedure ModifTE(NouvelleQED.L)
      *NouvelleSAE = AllocateMemory(NouvelleQED << 3)
      *NouvelleSTE = *NouvelleSAE + (NouvelleQED << 2)
      Shift.L = *NouvelleSAE - *SAE
      For i = @*PointeursDebut + 4 To @*PointeursFin - 4 Step 4
            Debug PeekL(i)
            ;PokeL(i, PeekL(i) + Shift)
      Next
      If NouvelleQED > QED
            CopyMemory(*SAE, *NouvelleSAE, SHI)
            CopyMemory(*STE, *NouvelleSTE, SHI)
      Else
            CopyMemory(*SAE, *NouvelleSAE, NouvelleQED << 2)
            CopyMemory(*STE, *NouvelleSTE, NouvelleQED << 2)
      EndIf
      FreeMemory(*SAE)
      *SAE = *NouvelleSAE
      *STE = *NouvelleSTE
      QED = NouvelleQED
      SHI = QED << 2
EndProcedure

Procedure.L InexistTE()
Recherche:
      ! xor   eax,  eax
      ! mov   edi,  dword [p_STE]
      ! mov   ecx,  dword [v_QED]
      ! cld
      ! repne scasd
      ! jnz   l_introuvable
      ! mov   eax,  edi
      ! sub   eax,  4
      ProcedureReturn
introuvable:
      MessageRequester("TE pleine!", "La TE va passer à " + Str(QED << 1) + " éléments !")
      ModifTE(QED << 1)
      Goto Recherche
EndProcedure

Procedure Reg(*Adr, Type.L, *Var)
      PokeL(*Adr + SHI, Type)
      PokeL(*Adr, PeekL(*Var) )
EndProcedure

Procedure Def(Type.L, *Var)    
      *Adr = InexistTE() - SHI
      Reg(*Adr, Type, *Var)
      ProcedureReturn *Adr
EndProcedure
      
Procedure.L DetType(*Adr)
      Type.L = PeekL(*Adr + SHI)
      ProcedureReturn Type
EndProcedure

Procedure.L DetAttr(*Adr)
      Attr.L = PeekL(*Adr)
      ProcedureReturn Attr
EndProcedure

Procedure DefS(String.S)
      LString.L = Len(String) + 1             ; Calcule la quantité à traiter
      *Ptr = AllocateMemory(LString)          ; Alloue la mémoire correspondante
      *Adr = Def(#VarString, @*Ptr)           ; Définit la chaîne
      CopyMemory(@String, *Ptr, LString)      ; Transfert la chaîne
      ProcedureReturn *Adr                  ; Retourne l'adresse de l'ensemble
EndProcedure

Procedure.S DetS(*Adr)
      *Ptr = PeekL(*Adr)
      LString = MemorySize(*Ptr)
      String.S = Space(LString)
      CopyMemory(*Ptr, @String, LString)
      ProcedureReturn String
EndProcedure
      
Procedure DefF(Float.F)
      *Adr = Def(#VarFloat, @Float)
      ProcedureReturn *Adr
EndProcedure

Procedure.F DetF(*Adr)
      Float.F = PeekF(*Adr)
      ProcedureReturn Float
EndProcedure
      
Procedure DefL(Long.L)
      *Adr = Def(#VarLong, @Long)
      ProcedureReturn *Adr
EndProcedure

Procedure.L DetL(*Adr)
      Long.L = PeekL(*Adr)
      ProcedureReturn Long
EndProcedure
      




;***********************      
      ;MAIN PART
;***********************      
      
      
      CreerTE()

      *x = DefS("Hello")
      *z = DefS("Good bye")
      *y = DefF(29.9)
      *t = DefF(30.1)
      *a = DefL(29)
      *b = DefL(31)
      
      Debug "(" + DetS(*x) + ")"
      Debug "(" + DetS(*z) + ")"
      Debug StrF(DetF(*y) )
      Debug StrF(DetF(*t) )
      Debug PeekL(*a)
      Debug PeekL(*b)
Your answer helped me to find an other solution with arrays. A modification who won't reach the 'user' (other programmer really):
add area memory and store the start pointors (no used by user) in an array!

Thanks! Really!

Posted: Thu Aug 16, 2007 1:30 am
by Ollivier
I become crazy with these arrays!

Finally, it's your first solution : the structures...

Posted: Thu Aug 16, 2007 10:55 am
by tinman
Glad to hear it, although I realised this morning that the code I copied and pasted from your original message will not work. It would need to be something like this to work correctly:

Code: Select all

Structure MyPointers 
*photoX 
*movieY 
*stringZ 
EndStructure 

*pointor = allocatememory(4096) 
Define.MyPointers ptrs 
ptrs\photoX = procedureLambda(*pointor) 
ptrs\movieY = procedureLambda(*pointor) 
ptrs\stringZ = procedureLambda(*pointor) 

*NewArea = AllocateMemory(NewSize) 
Shift.L = *NewArea - *pointor 
For i = @ptrs\photoX To @ptrs\stringZ Step 4 
    PokeL(i, PeekL(i) + Shift) 
Next

Posted: Thu Aug 16, 2007 5:40 pm
by Ollivier
After reflexion, I can't use structures.

Replacing expression:

Code: Select all

*group
by:

Code: Select all

p\group
It's not the real problem. Your solution is very good. Your code shifting automatically values of each pointor is good too. (Excuse me, I didn't see error in your first code, cause I hadn't the time to check it) But adding structure header for each new pointor, it's too!

I think my memory architecture choice will be using fragmented memory. This technic will be allow me to keep my pointors. If I meet new problems, your solution will be used. Cause your last code is exact.

Thank you!
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