le Garbage Collector de delphi
Bonjour
avez vous testé la methode qui suit de liberation ?
(Tiré de http://www.delphi3000.com/articles/article_2888.asp?SK=
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| unit GarbageCollector;
interface
type
ISafeGuard = type IUnknown;
// Use the Guard function to instantiate the object!
function Guard(Obj : TObject; out SafeGuard : ISafeGuard) : TObject;
implementation
type
TSafeGuard = class(TInterfacedObject, ISafeGuard)
private
FObj : TObject;
public
constructor Create(Obj : TObject);
destructor Destroy; override;
end;
constructor TSafeGuard.Create(Obj : TObject);
begin
FObj := Obj;
end;
destructor TSafeGuard.Destroy;
begin
if Assigned(FObj) then
begin
FObj.Free;
FObj := nil;
end;
inherited Destroy;
end;
function Guard(Obj : TObject; out SafeGuard : ISafeGuard) : TObject;
begin
Result := Obj;
SafeGuard := TSafeGuard.Create(Obj); // Create the proxy obj.
end;
end. |
Pour creer un objet on fait ainsi
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|
var obj : TMyObj;
SafeGuard : ISafeGuard;
obj := TMyObj(Guard(TMyObj.Create, SafeGuard));
TMyObj descend TObject |
example:
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|
{$APPTYPE CONSOLE}
program Test;
uses GarbageCollector;
{ --- Test class --- }
type
TTest = class(TObject)
public
constructor Create;
destructor Destroy; override;
procedure Test;
end;
{ ---- Test members --- }
constructor TTest.Create;
begin
WriteLn('Create()');
end;
destructor TTest.Destroy;
begin
WriteLn('Destroy()');
inherited;
end;
procedure TTest.Test;
begin
WriteLn('Test()');
end;
{ ---- End Of Test members --- }
{ ---- Test Procedure --- }
procedure TestProc;
var SafeGuard : ISafeGuard;
obj : TTest;
begin
obj := TTest(Guard(obj.Create, SafeGuard)); // Create!
obj.Test;
{ Notice that we are not explicitlly destroying the object here! }
end;
{ ---- End Of Test Procedure --- }
begin
TestProc;
end. |
Est ce efficace ?
