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Data Race Condition while using AddElementMatrixSymmetric
5 years 3 months ago #1363
by jhauser
Data Race Condition while using AddElementMatrixSymmetric was created by jhauser
I am still working on the implementation of the assembling in tensor product spaces. For that I need the local mass matrix of HCurl-functions. My resulting matrix seems mostly right, but there are a few entries that are wrong. It changes each time which entries are influenced. The error only occurs when I use a python script with python3. If I use the interface of jupyter notebook, my matrix is correct.
The local matices seem to be correct therefore I guess that it is a problem with AddElementMatrixSymmetric or rather a data race condition in IterateElements.
How can I slove it?
The code with this problem is as follows:
The local matices seem to be correct therefore I guess that it is a problem with AddElementMatrixSymmetric or rather a data race condition in IterateElements.
How can I slove it?
The code with this problem is as follows:
Code:
template<int Dy>
void CalcElementMatrix_tpy(const FiniteElement & fely,
const ElementTransformation &eltrans_y, LocalHeap & lhy,
FlatMatrix<double> elmaty)
{
const HCurlFiniteElement<Dy> & fely_cast =
dynamic_cast<const HCurlFiniteElement<Dy>&>(fely);
ELEMENT_TYPE eltypey = fely_cast.ElementType();
int ndy = fely_cast.GetNDof();
const IntegrationRule & ir_voly =
SelectIntegrationRule (eltypey, 2*fely_cast.Order());
MatrixFixWidth<Dy,double> shapey(ndy);
elmaty = 0.0;
for (int l = 0; l < ir_voly.Size(); l++)
{
HeapReset hr(lhy);
const MappedIntegrationPoint<Dy,Dy> sip(ir_voly[l], eltrans_y);
BaseMappedIntegrationPoint & mip = eltrans_y(ir_voly[l], lhy);
fely_cast.CalcMappedShape (mip, shapey);
elmaty += ir_voly[l].Weight() *sip.GetMeasure()* shapey * Trans (shapey);
}
}
...
shared_ptr<GridFunction> MyMaxwellAssemble(shared_ptr<FESpace> fes_in,
shared_ptr<CoefficientFunction> f_coef)
{
......
IterateElements(*fes_y, VOL, lhy, [&] (FESpace::Element ely, LocalHeap &lhy)
{
const ElementTransformation& eltrans_y = ma_y->GetTrafo(ely, lhy);
const FiniteElement& fely = fes_y->GetFE(ely,lhy);
FlatArray<DofId> dofsy = ely.GetDofs();
FlatMatrix<> elmat_fesy(dofsy.Size(),lhy);
CalcElementMatrix_tpy<2>(fely,eltrans_y,lhy,elmat_fesy);
maty->AddElementMatrixSymmetric(dofsy,elmat_fesy);
});
....
}
- christopher
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5 years 3 months ago #1364
by christopher
Replied by christopher on topic Data Race Condition while using AddElementMatrixSymmetric
Hi,
Do you use a standard HCurl space? IterateElements uses the coloring of the finite element space to decide which elements can be assembled at the same time.
Best
Christopher
Do you use a standard HCurl space? IterateElements uses the coloring of the finite element space to decide which elements can be assembled at the same time.
Best
Christopher
5 years 3 months ago - 5 years 3 months ago #1365
by jhauser
Replied by jhauser on topic Data Race Condition while using AddElementMatrixSymmetric
Yes, I use the standard HCurl space:
Code:
meshx = Mesh(unit_square.GenerateMesh(maxh=0.5))
fesx = HCurl(meshx,order=1)
Last edit: 5 years 3 months ago by jhauser.
5 years 3 months ago #1366
by joachim
Replied by joachim on topic Data Race Condition while using AddElementMatrixSymmetric
Hi,
Are you using the TaskManager ?
If not, IterateElements is not parallel anyway.
If yes, what happens without ?
Is the x-space or the y-space the HCurl ? The C++ part and the python part look inconsistent.
Your code snipped looks reasonable. It's difficult to help with this information. Maybe you can upload a full example producing this random results.
Joachim
Are you using the TaskManager ?
If not, IterateElements is not parallel anyway.
If yes, what happens without ?
Is the x-space or the y-space the HCurl ? The C++ part and the python part look inconsistent.
Your code snipped looks reasonable. It's difficult to help with this information. Maybe you can upload a full example producing this random results.
Joachim
5 years 3 months ago #1367
by jhauser
Replied by jhauser on topic Data Race Condition while using AddElementMatrixSymmetric
No, I do not parallelize it. That's why I have no clue what's the real problem.
Here a shortened version of my code, which still produces the error on my computer:
I am currently working in the ml-ngs file system. The two files which I've attached, I put into /1_Basic/4_utility_functions. The following lines I added in utility_function.hpp (in /1_Basic/4_utility_functions):
and added
in myngspy.cpp (in /1_Basic) to the list of exported functions in the end of the file. Of course I added "4_utility_functions/myMaxAssembling_small.cpp" in CMakeLists.txt to "add_ngsolve_python_module" as well.
Here a shortened version of my code, which still produces the error on my computer:
I am currently working in the ml-ngs file system. The two files which I've attached, I put into /1_Basic/4_utility_functions. The following lines I added in utility_function.hpp (in /1_Basic/4_utility_functions):
Code:
namespace mymaxassembleSMALL
{
void MyMaxwellAssemble_small(shared_ptr<FESpace> fes_in,
shared_ptr<CoefficientFunction> eps_coef,
shared_ptr<CoefficientFunction> mu_coef,
shared_ptr<CoefficientFunction> f_coef);
}
Code:
m.def("MyMaxwellAssembleSMALL", &mymaxassembleSMALL::MyMaxwellAssemble_small);
Attachments:
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