size of CPbkContactEngine object

[ruchirvasavada]

Hi...

I am having some memory leak in my app and I fear that the object of CPbkContactEngine is acting as one of the potential memory leaks. The object is created as follows :

CPbkContactEngine *contactEngine = CPbkContactEngine::NewL();

If I put heap memory check before and after this statement, I can see around 55KB of mem allocation on heap.

At the end of the function I call the destructor of the class by using delete operator, and again check the heap memory but the memory previoulsy allocated doesnt get de-allocated.

Does anyone have any idea..??

Ruchir

[ruchaitu]

Obviously, there will be a difference in heap mem usage becoz you have created a new object,
what is more troubling is mem difference even after deleting the object,
can you give more details about what operations did you perform between
from object creation and object deletion.
then it will be easy to diagnise.
regards,
- kc.

[ruchirvasavada]

Dear KC,

Thanks for the reply!

This is what I am doing in my app :

1) there is a function which takes any number entered by user
2) find, if the entry for that number is available in local contacts
3) if match is found, then retrieve the name of the contact number
4) now dial the number displaying that name in GUI
5) if match is not found then display the number in GUI and no name

now, if we talk in terms of coding,

1) CPbkContactEngine *contactEngine = CPbkContactEngine::NewL();
-> initialise the contact engine

2) CContactIdArray* matches = contactEngine->MatchPhoneNumberL(*number, len_number);
-> find all the matches found for the number that returns an array, as can be seen

3) CPbkContactItem* item = contactEngine->OpenContactL((*matches)[0]);
-> pick up the first entry from the array of matched items

4) TPbkContactItemField* field = item->FindField(EPbkFieldIdFirstName);
-> pick up the name from the item.

5) finally return the name that was retrieved.

I have taken utmost care of destroying all the HBufCs that are used.

Before exiting the function, I am resetting the CContactIdArray object and then calling CleanupStack::PopAndDestroy(), which will call the desturctor, and finally deleting the CPbkContactEngine object. In-between I am also deleting the item & field objects.

Looking forward for your suggestions..

Thanks,
Ruchir

[ruchaitu]

well, if the item and engine are deleted then who is leaking the mem,
are you gettting a alloc panic or you are checking memory with macros.

if your code is not under a Non diclosure agreement, \
can you paste the code here, i mean you already pasted it, i didnt see the deletion and 'pop and destroy' code any where, so just assuming that few more lines needs to be posted.

also, search the internet there are quite a few docs available which have more than one way of solving mem leaks. like finding out who exactly leaked it.

cheers,
-kc

[ruchirvasavada]

Thanks for reply...

Actually the code is not to be disclosed... and so would not be able to put much part of it, but as far as destruction is concerned, I have used CleanupStack::PopAndDestroy() calls at the end of the functions, like :

CleanupStack::PopAndDestroy(contactEngine);
CleanupStack::PopAndDestroy(phoneNumberToLookup);
CleanupStack::PopAndDestroy(eightBitTemp);

One thing that is attracting me is, the size that gets allocated for the first time is as much as 55K and then if I come to this function the next time onwards, the size would be around two pages (2*4096).

I dont get any Panic, as far as I am within the heap size limit. I have used User::RHeap().Size() call to know the heap size after almost every allocation and deallocation (supposed to be ) code..

Thanks
Ruchir

[ruchaitu]

No Alloc Panics

then i cannot say whether there is any leak or not?

1. get Heap size
2. execute ur code
3. get Heap size again.

If you are saying that mem is leaked becoz heap size in step 1 and step 2 does not match, then we need to check whether your code is allocating mem for any member variables or not.

There can be a situation where heap size in above case differs frm 1 and 2, but the extra mem is deallocated some where else.

If the above said case is not correct then only one option left.

comment the entire code,
uncomment one by one, i mean firt uncomment the
creation and deletion of contact object
and so on....

check heap size in every step...and lets see whether this will uncover the problem or not.

- kc

[teemukurppa]

If you don't get ALLOC panics, then your code is quite likely safe.

HEAP size checks in your code can indicate leak, even if there is not, because calls to library functions can allocate and initialize some app-framework level singletons that are released only when app is closed.

[ruchirvasavada]

Oh... i c... that's interesting behaviour.... Thanks for sharing that...

[ntb]

I've faced the same problems. After a few try, i found out that CPbkContactEngine::Static() works perfectly, without memory leak.

[zhangjunhua]

I've faced the same problems. After a few try, i found out that CPbkContactEngine::Static() works perfectly, without memory leak.

but CPbkContactEngine::Static() return null,why?Can you tell me ?