[vtkusers] Wrong way of handing a time-dependent dataset? Memory leaks...

[Michael Jackson]

You need to clean up your memory allocations. Basically the simple  
rule is this:

EVERY time you use the static ::New() method to create a vtk object,  
when you are finished with the object you need to call the ::Delete()  
method on the object to release the memory. In your case I would try  
something like the following:


int totalTimeSteps = 100;
for (int t = 0; t < totalTimeSteps; ++t)
{
   vtkXMLUnstructuredGridReader* reader =  
vtkXMLUnstructuredGridReader::New();
   std::ostringstream ostr;
   ostr<<i;
   std::string s = ostr.str();
   std::string ansysFilename = "sph_"+s+".vtu";

   reader->SetFileName (ansysFilename.c_str());
   reader->Update();
   vtkUnstructuredGrid* grid = reader->getOutput();

   // Process the unstructured grid data


   // Clean up the memory
   grid::Delete();
   reader::Delete();
}

There is also the vtkSmartPointer<> template class that you can use.  
This offers the ability to clean itself up when it goes out of scope.

The above will not leak memory in the loop.
_________________________________________________________
Mike Jackson                  mike.jackson at bluequartz.net
BlueQuartz Software                    www.bluequartz.net
Principal Software Engineer                  Dayton, Ohio



On Feb 14, 2009, at 10:32 AM, Alessandro A. Bellina wrote:

> Hello All,
>
> First let me start by giving you my system info:
> --
> MacOS Intel Based
> VTK 5.0.3
> I don't have 5.2 because I get endianness errors while trying to  
> compile.
> --
>
> I need the ability to probe spatial points a time-dependent dataset
> and output a scalar value as an array to be later analyzed in Matlab.
>
> My data is originally stored as an XMLUnstructuredGrid.
>
> I start by loading the data using vtkXMLUnstructredGridReader I do
> this in a function that looks like this:
>
> //int i: the current time step to load. Files are named: "sph_1.vtu,
> sph_2.vtu, ..."
> void LoadFile (vtkXMLUnstructuredGridReader*, int i){
> 	vtkXMLUnstructuredGridReader *dataSet=  
> vtkXMLUnstructuredGridReader::New();
> 	std::ostringstream ostr;
> 	ostr<<i;
> 	std::string s = ostr.str();
> 	
> 	std::string ansysFilename = "sph_"+s+".vtu";
>
> 	//vtkUnstructuredGridReader for data (src)
> 	dataSet->SetFileName (ansysFilename.c_str());
> 	dataSet->Update();
> 	
> 	return dataSet;
> }
>
> I call this function in a loop that goes from time step = 0 to
> time_step = N, where N is a number on the order of 1,000. I also pass
> it through a probeFilter with a vtkFloatArray that has the coordinates
> of the spatial points I am interested in.
>
> About half way through, I get a vtk malloc error. Could it be because
> I am reading each one of these files and not clearing them? I am just
> loading the next file that comes along (not knowing how VTK is
> handling this under the hood).
>
> Any help would be greatly appreciated,
>
> Alessandro
>
> -- 
> Alessandro A. Bellina
>
> Graduate Student
> Bioacoustics Research Laboratory
> Electrical and Computer Engineering
> University of Illinois at Urbana-Champaign
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