Define error/failure behavior in MPI_INIT/FINALIZE

[wesbland]

Problem

Errors before or during MPI_INIT may kill the entire application, which makes initializing MPI a possibly risky proposition in a mixed-mode application.

Proposal

This proposal defines clearly what should happen when a failure occurs during and before MPI_INIT,
and during and after MPI_FINALIZE. The behavior can be controlled by setting a launch info key (mpi_initial_errhandler) during MPI_COMM_SPAWN or mpiexec.

Slide deck used during the forum presentation

Changes to the Text

There are short changes in Chapter 8, detailed in the pull request: https://github.com/mpi-forum/mpi-standard/pull/50

Impact on Implementations

Implementations can largely continue operating as before, but are now able to provide better error notification during initialization and finalization, if desired.

A new mpiexec parameter and a new predefined info key must be supported.

Impact on Users

The users will have the option to get more information about initialization and finalization through the return codes of MPI_INIT and MPI_FINALIZE. Users may call MPI_INIT without fearing crashing the entire application, given a high quality implementation.

References

Pull Request - https://github.com/mpi-forum/mpi-standard/pull/50