Memory leak in TiffAppendPageFromGdPictureImage?

[MarkoZ]

Hi,

I'm using latest version of GdPicture. This is the code that's causing problems.

Code: Select all

        private void ConvertToTiff(byte[] dokument)
        {
            GdPicturePDF gdPdf = new GdPicturePDF();
            GdPictureImaging gdImaging = new GdPictureImaging();
            gdPdf.LoadFromStream(new MemoryStream(dokument));

            int multipageTifID = 0;
            for (int pageNr = 1; pageNr <= gdPdf.GetPageCount(); pageNr++)
            {
                gdPdf.SelectPage(pageNr);
                int pageImageID = gdPdf.RenderPageToGdPictureImageEx(100, false, System.Drawing.Imaging.PixelFormat.Format16bppGrayScale);
                if (pageImageID == 0)
                {
                    throw new Exception("Napaka v GdPictureImaging: " + gdPdf.GetStat().ToString());
                }

                if (multipageTifID == 0)
                {
                    multipageTifID = gdImaging.TiffCreateMultiPageFromGdPictureImage(pageImageID);
                    if (multipageTifID == 0)
                    {
                        throw new Exception("Napaka v GdPictureImaging: " + gdImaging.GetStat().ToString());
                    }
                }
                else
                {
                    GdPictureStatus status = gdImaging.TiffAppendPageFromGdPictureImage(multipageTifID, pageImageID);
                    if (status != GdPictureStatus.OK)
                    {
                        throw new Exception("Napaka v GdPictureImaging: " + status.ToString());
                    }
                }

                gdImaging.ReleaseGdPictureImage(pageImageID);
            }
            gdImaging.ReleaseGdPictureImage(multipageTifID);
            gdPdf.CloseDocument();
        }

Even after releasing entire generated tiff image GdPicture is still holding some memory. Only way to release it is ClearGdPicture function, but that also kills anything else still in use elsewhere, so that's not a viable solution.

[Loïc]

Hello,

The only memory leak I can find in your code is the non disposed MemoryStream. Despite the Garbage Collector can take care to invoke the Dispose method, I suggest you to call it by yourself when you are done with the object. Or simply use the using statement like this:

Code: Select all

            using (MemoryStream ms = new MemoryStream(dokument))
            {
                gdPdf.LoadFromStream(ms);

                int multipageTifID = 0;
                for (int pageNr = 1; pageNr <= gdPdf.GetPageCount(); pageNr++)
                {
                    gdPdf.SelectPage(pageNr);
                    int pageImageID = gdPdf.RenderPageToGdPictureImageEx(100, false, System.Drawing.Imaging.PixelFormat.Format16bppGrayScale);
                    if (pageImageID == 0)
                    {
                        throw new Exception("Napaka v GdPictureImaging: " + gdPdf.GetStat().ToString());
                    }

                    if (multipageTifID == 0)
                    {
                        multipageTifID = gdImaging.TiffCreateMultiPageFromGdPictureImage(pageImageID);
                        if (multipageTifID == 0)
                        {
                            throw new Exception("Napaka v GdPictureImaging: " + gdImaging.GetStat().ToString());
                        }
                    }
                    else
                    {
                        GdPictureStatus status = gdImaging.TiffAppendPageFromGdPictureImage(multipageTifID, pageImageID);
                        if (status != GdPictureStatus.OK)
                        {
                            throw new Exception("Napaka v GdPictureImaging: " + status.ToString());
                        }
                    }

                    gdImaging.ReleaseGdPictureImage(pageImageID);
                }
                gdImaging.ReleaseGdPictureImage(multipageTifID);
                gdPdf.CloseDocument();
            }

[MarkoZ]

Hello,

I've just tried disposing memory stream manually, but nothing changed. When converting 700 page PDF (~6 MB in size) document, application still holds 300 MB of memory when function returns.

Only way, that I've found, to release that memory is ClearGdPicture function. I'm fairly certain that TiffAppendPageFromGdPictureImage is the cause of this problem, because if I comment it out, problem disappears.

[Loïc]

Hello,

When converting 700 page PDF (~6 MB in size) document, application still holds 300 MB of memory when function returns.

OK. If you start 10 time the same process do you have 3000 of memory used ?

If yes, we have a memory leak in GdPicture.NET. If no, this is a typical garbage collector behavior. Just call the GC.Collect() to recover the unused memory.

Kind regards,

Loïc

[MarkoZ]

Hello,

calling GC.Collect() did release the memory. Thanks for your help.