Valgrind complaint when using Boost MPI

[dongryel@…]

I am using the latest Boost library (version 1.45.0) on Ubuntu. I have built Boost from the source using the bjam.

boost::mpi::all_reduce uses boost::mpi::broadcast which seems to generate annoying invalid write errors under valgrind. The problem points to the line 47 in boost/mpi/detail/packed_oprimitive.hpp in const std::size_t &size() const function. I changed the function to:

const std::size_t& size() const {

const_cast<std::size_t &>(size_) = buffer_.size(); return size_;

}

and the valgrind complaint seems to be gone. Const_cast seems less than ideal, but it fixes the problem.

[dongryel@…]

Actually, this does not solve the problem. I did not notice that the mutable keyword was already present for size_ member.

[Matthias Troyer]

Is this still present? If so, do you have a test case that we can try to reproduce?