unit uTICSharedMemory;

{$mode ObjFPC}{$H+}

interface

uses
  Windows;

type

  { TTICSharedMemory }

  TTICSharedMemory = class
  private
    FPointer:   Pointer;
    FLastError: DWord;
    FHandle:    THandle;
    procedure FreeHandle;
  public
    // AName = l'identifiant du fichier partagé en mémoire
    // ASize = la taille totale des données partagées
    constructor Create(AName: PChar; ASize: integer);
    
    destructor Destroy; override;
    property LastError: DWord read FLastError;

   // Pointer = l'adresse de la donnée partagée
    property Pointer: pointer read FPointer;
  end;

implementation

{ TTICSharedMemory }

procedure TTICSharedMemory.FreeHandle;
begin
  if FHandle <> 0 then
  begin
    CloseHandle(FHandle);
    FHandle := 0;
  end;
end;

constructor TTICSharedMemory.Create(AName: PChar; ASize: integer);
begin
  FHandle    := CreateFileMapping(INVALID_HANDLE_VALUE, nil, PAGE_READWRITE,
    0, ASize, AName);
  FLastError := GetLastError;

  if FHandle > 0 then
  begin
    FPointer := MapViewOfFile(FHandle, FILE_MAP_WRITE, 0, 0, 0);
    if not assigned(FPointer) then FreeHandle;
  end;
end;

destructor TTICSharedMemory.Destroy;
begin
  if assigned(FPointer) then
  begin
    UnmapViewOfFile(FPointer);
    FPointer := nil;
  end;
  FreeHandle;
  inherited;
end;

end.