id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
5292	boost::mpi::scatterv and boost::mpi::gatherv added	Júlio Hoffimann <julio.hoffimann@…>	Matthias Troyer	"Two more collective operations for Boost.MPI. I made the headers completely based on the existent one: scatter.hpp and gather.hpp

""common use versions"" was added too, for those cases where the great buffer is stored contiguously at the root process.

The ""common use version"" of gatherv needs a warning in the docs: Since the process send it's own buffer size and nothing more, all sizes will be gathered before the real call. I don't know if this is tolerable, you have the decision.

Other doubt about gatherv implementation: I did switch to the packed_archive_send() / packed_archive_recv() communication, i tried to figure out the difference in send an archive or send using communicator::send when dealing with non-MPI types, but without success. boost::mpi::scatter uses the first and boost::mpi::gather uses the second. Anyway,the snippet of code is commented if you want to switch back.

I'm sending a Main.cpp file with the simple tests i made, comment or uncomment the prototypes in pairs: scatterv / gatherv.

To see the results in a separate terminal for each process, this is a possible way:


'''mpicxx Main.cpp -o test &&
echo 107 > input.txt &&
mpirun -np 4 xterm -e ./test'''
"	Patches	new	To Be Determined	mpi	Boost 1.45.0	Not Applicable		collective operations	troyer@…