Hi Adán,
Unfortunately using STL vectors will probably not work as they are not
guaranteed to have any particular memory layout, and MPI requires a
contiguous allocation of memory.
This is a problem that has been studied and there was recently a paper
published about one way to solve it (http://dx.doi.org/10.1007/11846802_39).
Hope this helps,
Tim
On Monday 23 October 2006 02:51 pm, Adán Cosgaya wrote:
> Hi,
>
> I am trying to scatterv/gatherv an stl vector of vectors, but it doesn't
> seem to work, but if I try to do it using a 2d array, it works fine, is
> there anything special in the way the memory is allocated in the case of
> stl vectors, that is making it not to work correctly?.
>
> Here is my piece of code
> tmpSkyMatrix[size][d]
> vector <vector<int> > PointsTmp (size, vector<int>(d)); //allocate space in
> the vector of vectors
> ....//do some computation
>
> //with a 2d matrix works fine
> MPI_Gatherv(skyMatrix, localSkySize, MPI::INT, tmpSkyMatrix, receiveCount,
> disp, MPI::INT, ROOT, MPI_COMM_WORLD);
>
> //with a vector of vector crashes
> MPI_Gatherv(&localSkyline[0][0], localSkySize, MPI::INT, &PointsTmp[0][0],
> receiveCount, disp, MPI::INT, ROOT, MPI_COMM_WORLD);
>
> In case you wonder why I rather use an stl vector, it is because my
> computation is making use of some stl algorithms, I just need to send the
> resulting data accross the processor, but this data is stored in a vector
> of vectors, and is very costly, to load that data into a 2d array, then
> receive it, and load it in a vector of vectors again to do some other
> processing.
>
> Thanks in advance
|
