Fix error when mpi::wait_all is called with data of type std::vector

[vincentchabannes]

Hi boost developers.
After to have upgraded my boost version to 1.69 and I have this error :

communicator.hpp:1914: static optional<boost::mpi::status> boost::mpi::request::handle_dynamic_primitive_array_irecv(boost::mpi::request *, boost::mpi::request::request_action) [T = int, A = std::allocator<int>]: Assertion `_check_result == MPI_SUCCESS' failed.

The issue can be reproduce with this code :

mpi::communicator comm;
int rank = comm.rank();
std::vector<int> data;
std::vector< mpi::request> reqs;
if ( rank == 0 )
{
    for ( int i=0;i<10;++i )
        data.push_back( i );
    reqs.push_back( comm.isend(1, 0, data) );
}
else if ( rank == 1 )
{
    reqs.push_back( comm.irecv(0, 0, data) );
}
mpi::wait_all( reqs.begin(), reqs.end() );

if ( rank == 1 )
{
     for ( int i=0;i<data.size();++i )
         std::cout << data[i] << "\n";
}

It seems that the bug appears from Bugfix/vectors mix 62 #66 .

My fix is just to replace MPI_PACKED by get_mpi_datatype() (only with test() method, it was good with wait() method)

[aminiussi]

Ok, I need to add a test for that one.
Thanks!

[aminiussi]

@vincentchabannes Also, I'm assuming you are ok with the license ?

[aminiussi]

@vincentchabannes also, just as a performance issue, sending a vector is two communication process, as vector are not assumed to have a known size (depending on your configuration, it can rely on MPI_Probes which can speed things up).

[vincentchabannes]

thanks @aminiussi.
And ok with the license.