CoArray Fortran Framework of Efficient Interfaces to Network Environments

Caffeine is a parallel runtime library that aims to support Fortran compilers with a programming-model-agnostic application interface to various communication libraries. Current work is on supporting the Parallel Runtime Interface for Fortran (PRIF) with the GASNet-EX exascale-ready networking middleware. Future plans include support for an alternative Message Passing Interface (MPI) back end.

The install.sh script uses the following packages:

• Fortran and C compilers
• GASNet-EX exascale networking middleware
• Fortran package manager fpm
• pkg-config
• realpath
• make

The script will invoke these if present in a user's PATH. If not present, the script will ask permission to use Homebrew to install the relevant package.

Caffeine leverages the following non-parallel features of Fortran to simplify the writing of a portable, compact runtime-library that supports Fortran's parallel features:

[1] This feature simplifies development but is not essential to the package

[2] This feature is used to support only co_reduce and might become optional in a future release.

git clone https://github.com/BerkeleyLab/caffeine.git
cd caffeine
./install.sh
export GASNET_PSHM_NODES=8
FC=<Fortran-compiler-path> CC=<C-compiler-path> CXX=<C++-compiler-path> ./build/run-fpm.sh run --example hello

./build/run-fpm.sh test

Damian Rouson, Dan Bonachea.
"Caffeine: CoArray Fortran Framework of Efficient Interfaces to Network Environments",
Proceedings of the Eighth Annual Workshop on the LLVM Compiler Infrastructure in HPC (LLVM-HPC2022), November 2022.
Paper: https://doi.org/10.25344/S4459B
Talk Slides

Damian Rouson, Brad Richardson, Dan Bonachea, Katherine Rasmussen.
"Parallel Runtime Interface for Fortran (PRIF) Design Document, Revision 0.2",
Lawrence Berkeley National Laboratory Technical Report (LBNL-2001563), December 2023.
https://doi.org/10.25344/S4DG6S

One of our continuous integration (CI) scripts generates up-to-date Caffeine documentation using ford. The CI script also deploys the generated documentation to the our GitHub Pages site. Alternatively, generate HTML documentation locally using ford as follows:

ford doc-generator.md

Open doc/html/index.html in a web browser.

The Computer Languages and Systems Software (CLaSS) Group at Berkeley Lab has developed Caffeine development on funding from the Exascale Computing Project (ECP) and the Stewardship for Programming Systems and Tools (S4PST) project.

See LICENSE.txt for usage terms and conditions.