NewLC - Cleanup support for ResetAndDestroy() - Comments

> Cleanup support for ResetAndDestroy()

Artem — Sat, 17 Jun 2006 15:28:28 +0200

Here is an example of a built-in CleanupResetAndDestroyPushL

> Cleanup support for ResetAndDestroy()

Anonymous — Tue, 04 Oct 2005 11:33:18 +0200

Actually there is an entire implementation of this already provided in Symbian 7.0s in the mmf\common\mmfcontrollerpluginresolver.h class

No I don't kno why it was put there and I know the some of the guys in Symbian that wrote the MMF module!

> Cleanup support for ResetAndDestroy()

tOtE — Wed, 27 Oct 2004 21:02:56 +0200

That's a great solution, I like it! To support this feature, you either have to use cleanup items or TRAP the first leave. And I agree that TRAPping is much more expensive and, on the other hand, using TCleanupItem is much nicer. Cool.

> Cleanup support for ResetAndDestroy()

Anonymous — Thu, 21 Oct 2004 11:46:54 +0200

There is a subtle flaw in this, in that if the first line of the CleanupResetAndDestroyPushL method leaves then the array does not get cleaned up.

All the standard clean up stack functions guarantee that they take ownership of the object passed in. To do this they make sure that there is always at least one spare slot on the clean up stack. If a call to CleanupStack::PushL or CleanupClosePushL (or others) uses the last available slot, the stack will allocate more memory, which could cause a leave, which is why all the xxxPushL functions can leave. If a leave occurs, the object that was pushed on is destroyed along with the rest of the clean up items on the stack. Doing any kind of leaving operation in a CleanupResetAndDestroyPushL style function before the item is on the clean up stack is unsafe.

> Cleanup support for ResetAndDestroy()

Anonymous — Tue, 19 Oct 2004 09:24:47 +0200

Actually there is Symbian API support for this kind of behaviour.

Implement a cleanup method taking a TAny* parameter like void CleanupArray(TAny* aObj); and inside that method cast the aObj to correct array type and then call ResetAndDestroy().

To use the cleanup method push a TCleanupItem to the cleanup stack: RPointerArray<CMyType>* list = new RPointerArray<CMyType>( 1 ); CleanupStack::PushL(TCleanupItem(CleanupArray, list)); //... CleanupStack::PopAndDestroy();

Cleanup support for ResetAndDestroy()

mdahlbom — Mon, 18 Oct 2004 21:54:35 +0200

Need to perform ResetAndDestroy() for a list upon leave/a call to CleanupStack::PopAndDestroy()? Here's how.