OGR uses reference counting for some object to manage the life cycle of objects as well as to decrease OGR memory requirements.
In particular SpatialReferenceSystems? are reference counted. While reference counting is consistent in OGRProj4CT, namely
OGRSpatialReference are deleted when counter falls below 1, in OGRGeometry eg. OGRGeometry::~OGRGeometry and OGRGeometry::assignSpatialReference a counter is released without checking if OGRSpatialReference should be deleted. This may
result in memory leak.
SAMPLE FIX/WORKAROUND:
The quick fix is to check if reference counter falls below 1 and eventually delete the object eg.
OGRGeometry::~OGRGeometry()
{
if( poSRS != NULL )
{
if ( poSRS->Dereference() <= 0 )
delete poSRS;
}
}
However, a better way to manage reference counted objects is to use consistently in GDAL
intrusive smart pointers.
If the dependency on boost libraries is accepted, then I propose to use boost::instrusive_ptr
(http://www.boost.org/libs/smart_ptr/intrusive_ptr.html). If this dependency is for some reason
undesirable, then a
simple template (boost::instrusive_ptr is 273 lines long) for such pointers can be written. I strongly
recommend such
technique, as this is simple way to avoid related with reference counted memory management.
