[mvoss]

hi,

this is concerning the very general question about how to find a hanging pointer.
I am working on a MultiRegion-Solver, so i was starting from chtMultiRegionsFoam.

I followed the pattern in the solver
by addressing the pointers first with the appropriate size of the meshRegion with

PtrList<basicPsiThermo> thermoFluid(fluidRegions.size());

and then setting the pointerlists to the IOobjects by e.g.

 
Info<< "    Adding to KFluid\n" << endl;
                KFluid.set
                (
                    i,
                    new volScalarField
                    (
                        IOobject
                        (
                            "K",
                            runTime.timeName(),
                            fluidRegions[i],
                            IOobject::NO_READ,
                            IOobject::NO_WRITE
                        ),
                        thermoFluid[i].Cp()*thermoFluid[i].alpha()
                    )
                );

and finally use the local-"region"-variables in the normal manner.

fvScalarMatrix tEqn
        (
            -fvm::laplacian(K, T)
        );
        tEqn.relax();
        TEqnResidual = tEqn.solve().initialResidual();

Then i added the "solve"-part by including some working header-files.
The code is compiling but i am receiving an ERROR about: hanging pointer, cannot dereference .

So. How to solve this since there are plenty of pointers.
Is there a way to find the "bad" one? I just need some general advice where to search or how to look at that problem ... and maybe solving it the next time on my own.

Thanks in advance...

neewbie

[l_r_mcglashan]

When I had that error it was always because I got the range of a 'for' loop incorrect and I was trying to access an element in the pointer list that didn't exist. I would check the rangess of the loops you have in your program.

[mvoss]

hi,
thanks a lot. I did as you said and ended up in deleting EVERYTHING not necessary ... i´ve made a similar mistake by commenting over more than one line. took me a while to riddle that one out.

neewbie

[shanvach]

Hi all,

I have been getting this error while my running twoPhaseEulerFoam code. I have added a file called scalarTransport.H that solves for Scalar Transport Equation in addition to solving of the phases.

My scalarTransport.H is as follows:

dimensionedScalar dimen 
( 
"dimen", 
dimensionSet(0,0,1,0,0,0,0), 
scalar(1.0) 
); 
dimensionedScalar dimen1 
( 
"dimen1", 
dimensionSet(0,0,-1,0,0,0,0), 
scalar(1.0) 
); 
volTensorField grU_2 = (fvc::grad(U2))*dimen;
volScalarField sc = grU_2 && (grU_2 + grU_2.T());
const scalar a  = 4e-6;

dimensionedScalar dir_ste 
( 
"dir_ste", 
dimensionSet(0,0,2,0,0,0,0), 
scalar(1.0) 
); 
//const scalar a  = 4e-6;
const scalar K = 1;
volScalarField dsid = 0.7*.3*a*a*sc*alpha2*alpha2*dir_ste*dimen1*dimen1;
const scalar dbr = (1.380648e-23)*300/(6*3.142*(1.5e-3)*(4e-6));
volScalarField dbro = ((1.0-alpha2)/(1+0.95*alpha2))*(dbr/K);

volScalarField dnp = (dsid + dbro)*DT; 

		
fvScalarMatrix scalarEqn
             
 (
   		
  fvm::ddt(psi)             
 		
+ fvm::div(phi2,psi)        
 		
- fvm::laplacian(dnp,psi) 
		
);
 

  scalarEqn.solve();

The code compiles correctly but gives the following error at runtime.

--> FOAM FATAL ERROR: 
hanging pointer at index 0 (size 3), cannot dereference

    From function const T& Foam::UPtrList<T>::operator[](Foam::label) const [with T = Foam::fvPatchField<double>; Foam::label = int]
    in file /usr/local/apps/OpenFOAM/gcc482-v1706/OpenFOAM-v1706/src/OpenFOAM/lnInclude/UPtrListI.H at line 107.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::error::abort() at ??:?
#2  Foam::UPtrList<Foam::fvPatchField<double> >::operator[](int) const at ??:?
#3  Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>::Boundary::Boundary(Foam::DimensionedField<double, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>::Boundary const&) at ??:?
#4  Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>::GeometricField(Foam::IOobject const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:?
#5  ? at ??:?
#6  __libc_start_main in "/lib64/libc.so.6"
#7  ? at ??:?

How do I rectify this?
Your help in this matter is greatly appreciated.

Thanks and Regards,
Shantanu

[farzadmech]

Dear Shantanu
did you find the answer for your question?



thanks,
Farzad

[wanghongjie]

Originally Posted by farzadmech

Dear Shantanu
did you find the answer for your question?



thanks,
Farzad

Did you find the answer for the same question?

Thanks!

[XinXin]

Hi Matthias, Did you find the answer for the same question?