Problem in OCI_CollFree()

[weexp]

Hi vrogier,
When I use function OCI_CollFree(), I find it does not work well. I check the source code, in the file
collection.c : line 147:
/* free data element /
if (coll->elem)
{
coll->elem->hstate = OCI_OBJECT_FETCHED_DIRTY;
OCI_ElemFree(coll->elem);
coll->elem = NULL;
}
I guess the coll handle only free one elem, not free all elem in the collection, it may lead to memory leak.
I write some sample code like this:
OCI_Object GEOMETRY = NULL;
OCI_TypeInfo* obj_type = OCI_TypeInfoGet(connection, "MDSYS.SDO_GEOMETRY", OCI_TIF_TYPE);
OCI_TypeInfo* coll_type = OCI_TypeInfoGet(connection, "MDSYS.SDO_ORDINATE_ARRAY", OCI_TIF_TYPE);
while(1)
{
OCI_Coll* sdo_ordinate_array = OCI_CollCreate(coll_type);
OCI_CollFree(sdo_ordinate_array);
}

   Memory leak happens.
  I suggest the source code maybe modify like this:
    /* free data element */

for(int i = 0; i < OCI_CollGetSize(coll); ++i)
{
OCI_Elem elem = OCI_CollGetElem(coll,i);
if (elem)
{
elem ->hstate = OCI_OBJECT_FETCHED_DIRTY;
OCI_ElemFree(elem);
elem = NULL;
}
}

[vrogier]

Hi,

Can you provide a working sample code that demonstrate the leak ?

Thanks

[weexp]

My test Code just like this:
void testOcilib(std::string db_url, std::string user_name, std::string pass_word, std::string TableName)
{

OCI_Connection* connection = 0;
OCI_Transaction* transaction = 0;
OCI_Statement* statement = 0;
OCI_Resultset* results = 0;

int isSus = OCI_Initialize(0, 0, OCI_ENV_CONTEXT);
connection = OCI_ConnectionCreate(db_url.c_str(), user_name.c_str(), pass_word.c_str(), OCI_SESSION_DEFAULT);
transaction = OCI_TransactionCreate(connection, 1, OCI_TRS_NEW, 0);
statement = OCI_StatementCreate(connection);

OCI_TypeInfo* obj_type = OCI_TypeInfoGet(connection, "MDSYS.SDO_GEOMETRY", OCI_TIF_TYPE);
OCI_TypeInfo* coll_type = OCI_TypeInfoGet(connection, "MDSYS.SDO_ORDINATE_ARRAY", OCI_TIF_TYPE);
while(1)
{
    OCI_Coll* sdo_ordinate_array = OCI_CollCreate(coll_type);
    OCI_CollFree(sdo_ordinate_array);
}
//transaction
if (0 != transaction)
{
    OCI_TransactionFree(transaction);
    transaction = 0;
}
//statement
if (0 != statement)
{
    OCI_StatementFree(statement);
    statement = 0;
}
//connection
if (0 != connection)
{
    OCI_ConnectionFree(connection);
    connection = 0;
}
OCI_Cleanup();

return ;

}

VS2010 platform, oracle 11g, OCI_CHARSET_ANSI

[vrogier]

Thanks.

I will check the issue asap

[vrogier]

Hi,

There is no memroy leak but rather memory retention (the memory is freed when calling OCI_Cleanup().
When the collection is freed, OCILIB call the oracle method OCIObjectFree() on the collection handle with the flag OCI_OBJECTFREE_NONULL.
The OCI client is maintaining a local cache of objects. with your code, it seems that is does not reuse previously allocated object as it should. Replacing the flag OCI_OBJECTFREE_NONULL by OCI_OBJECTFREE_FORCE forces the cleanup of the object instead of maintaining it in the cache.
And you code sample runs with constant memory.
I will study the impact of changing the flag and may commit it if there is no issue with it.

Regards,

Vincent

[vrogier]

In fact, after having checked again Oracle documentation, it appears that OCILIB should not use the flag OCI_OBJECTFREE_NONULL but rather pass OCI_DEFAULT. Nothing to do with OCI_OBJECTFREE_FORCE.
With OCI_OBJECTFREE_NONULL , the object indicator structure is not freed !

i will commit a fix for that these evening !

[vrogier]

Fix committed :)