NewLC - LEAVE and TRAP, part II: NewL and NewLC - Comments

Re: LEAVE and TRAP, part II: NewL and NewLC

murthy — Sat, 22 Sep 2007 14:07:09 +0200

If a function leaves at constructL() , You are thinking that it does not have any reference. But we are pushing the " self " into the CleanupStack before calling the constructL therefore it can be popped and destroyed.

LEAVE and TRAP, part II: NewL and NewLC

Anonymous — Tue, 13 Mar 2007 07:44:03 +0100

Better late than never. This is wonderful explanation for such a confusing and fundamental topic on Symbian. Great work.

LEAVE and TRAP, part II: NewL and NewLC

Anonymous — Fri, 27 Oct 2006 07:44:15 +0200

Wht will happen if function leaves at ConstructL(),.......and before return self of NewLC().

CleanUpStackPopAndDestroy(),............would be poping and destroying a NULL object.Can anybody explain??

LEAVE and TRAP, part II: NewL and NewLC

krishnaramram — Tue, 24 Oct 2006 15:44:01 +0200

EXPORT_C CUser* CUser::NewLC( MUserStateObserver* aObserver ) CUser* self = new (ELeave) CUser( aObserver ); CleanupStack::PushL(self); self->ConstructL(); return self;

Suppose in my function i have:

CUser *ptrMyUser = CUSer::NewLC(/*SomeObserver*/); MyUser->SomeFunction(); CleanUpStack::PopAndDestroy(ptrMyUser);

what would happen if ConstructL( )leaves?? "return self" the next statement would not execute and "ptrMyUser" object would be NULL.PopAndDestroy(ptrMyUser)would pop and destroy an object pointed by ptrMyUser which is NUll pointer.

We still have a pointer pushed to cleanupstack, but which has not been poped and destroyed.So in such scenario are we not leaving a pointer on clean up stack???

Please clarify.

LEAVE and TRAP, part II: NewL and NewLC

rosfranborges — Fri, 23 Jul 2004 09:49:05 +0200

Some additional definitions about object contruction (class instantiation) on Symbian, the object creation method formerly named "two-phase construction", and the NewL and NewLC static methods...