[gdal-dev] GetSpatialRef, OGRSpatialReference and memory leaks ?

[Andrew C Aitchison]

On Sat, 1 Aug 2020, Andrew Bell wrote:

Thanks for the hint.
I had assumed that the caller was taking responsibility for it.

> Seems like it would depend on what you're doing with the pointer after you
> return it.
>
> On Sat, Aug 1, 2020, 5:50 AM Andrew C Aitchison <andrew at aitchison.me.uk>
> wrote:
>
>>
>> I would like to define GetSpatialRef() for my raster driver as something
>> like:
>>
>>      const OGRSpatialReference* GetSpatialRef() const override {
>>          OGRSpatialReference* poSRS = new OGRSpatialReference();
>>          if (poSRS->importFromEPSGA(27700)!=OGRERR_NONE)
>>          {
>>              delete poSRS;
>>              poSRS = nullptr;
>>          }
>>          return poSRS;
>>      }
>>
>> Unfortunately, valgrid reports that this leaks in the "new"
>> on the line
>>     OGRSpatialReference* poSRS = new OGRSpatialReference();
>>
>> On the other hand,
>>
>>      const OGRSpatialReference* GetSpatialRef() const override {
>>          return new OGRSpatialReference("EPSG:27700");
>>      }
>>
>> is no better:
>> ==117785==
>> ==117785== HEAP SUMMARY:
>> ==117785==     in use at exit: 5,764 bytes in 24 blocks
>> ==117785==   total heap usage: 7,363 allocs, 7,339 frees, 1,213,218 bytes
>> allocated
>> ==117785==
>> ==117785== Searching for pointers to 24 not-freed blocks
>> ==117785== Checked 3,635,216 bytes
>> ==117785==
>> ==117785== 596 (16 direct, 580 indirect) bytes in 1 blocks are definitely
>> lost in loss record 14 of 16
>> ==117785==    at 0x483BE63: operator new(unsigned long)
>> (vg_replace_malloc.c:344)
>> ==117785==    by 0x5E1D765: VRCDataset::GetSpatialRef() const (VRC.h:154)
>> ==117785==    by 0x4ED723A: GDALInfo (gdalinfo_lib.cpp:333)
>> ==117785==    by 0x10954D: main (gdalinfo_bin.cpp:213)
>> ==117785==
>> ==117785== 596 (16 direct, 580 indirect) bytes in 1 blocks are definitely
>> lost in loss record 15 of 16
>> ==117785==    at 0x483BE63: operator new(unsigned long)
>> (vg_replace_malloc.c:344)
>> ==117785==    by 0x5E1D765: VRCDataset::GetSpatialRef() const (VRC.h:154)
>> ==117785==    by 0x4ED9203: GDALInfo (gdalinfo_lib.cpp:578)
>> ==117785==    by 0x10954D: main (gdalinfo_bin.cpp:213)
>> ==117785==
>> ==117785== LEAK SUMMARY:
>> ==117785==    definitely lost: 32 bytes in 2 blocks
>> ==117785==    indirectly lost: 1,160 bytes in 10 blocks
>> ==117785==      possibly lost: 0 bytes in 0 blocks
>> ==117785==    still reachable: 4,572 bytes in 12 blocks
>> ==117785==         suppressed: 0 bytes in 0 blocks
>>
>> This is with both gdal 3.0.4 and 3.1.2 on Ubunto 20.04.
>>
>> --
>> Andrew C. Aitchison                                     Kendal, UK
>>                         andrew at aitchison.me.uk
>> _______________________________________________
>> gdal-dev mailing list
>> gdal-dev at lists.osgeo.org
>> https://lists.osgeo.org/mailman/listinfo/gdal-dev
>

-- 
Andrew C. Aitchison					Kendal, UK
 			andrew at aitchison.me.uk