Virtual Workshop Held by STE||AR Group

The SC16-001 Advanced Parallel Programming in C++ workshop was held on 7/25 as part of USNCCM16. Patrick Diehl, Hartmut Kaiser, and Steven R. Brandt of CCT/LSU were the instructors and organizers for this virtual event. Participation was very good, with 28 national and international attendees!

In the tutorial, participants learned how to use C++17 functions and objects to write straightforward yet fully parallized code without external tools, such as OpenMP. The team used Jupyter Notebooks with the Cling extension for C++ to walk attendees step-by-step through creating a fully parallized one-dimensional finite element code.

In the second half of the tutorial, the team demonstrated how users can employ nearly the same syntax to distribute these codes across a cluster. They used the HPX library to provide the support needed to manage a distributed application. 

The work-shop was very well received and will be offered again next year!

HPX’s Season of Docs 2021

By Rachitt Shah

HPX was recently selected to be part of Google’s Season of Docs (GSoD), a program designed to improve the documentation of open source software, as well as being a Google Summer of Code organization.

GSoD aims to cover and create the documentation gaps faced by organizations due to various reasons, alongside giving technical writers an avenue to showcase their skills.

I will be helping in the organization and update of the prior documentation to make it into a more navigable and to provide a user-friendly structure, which many users have had issues with using the current documentation. I will work closely with the HPX team and our users to collect feedback, find user pain-points, and improve preexisting docs, which mainly comprise of the build instructions.

Alongside, I would create a “design document” containing guidelines for how to add new content to the documentation: tips on how to structure new sections, general guidelines on what sort of content should be presented in what chapters, etc. The project may also include content rearrangement and a change of hierarchy, if the users find it is needed. 

I am currently working on a timeline and action items and researching about the possible shift to another documentation platform.

I am reachable at rachitt01@gmail.com or on the IRC as rachitt_shah, please contact me to suggest changes to the documentation or to provide feedback. We can always benefit from your ideas.

About me, I’m an undergrad studying electronics as my major, and I’m a casual sport programmer as well. I’ve been a product manager and venture capital intern in the past, and done Google Summer of Code with OpenAstronomy.

HPX 1.5.1 Released!

We have just released HPX 1.5.1. This patch release fixes problems found in the 1.5.0 release. It contains the following changes:

  • Removes restriction on suspending runtime with multiple localities, users are now responsible for synchronizing work between localities before suspending.
  • Fixes several compilation problems and warnings.
  • Adds notes in the documentation explaining how to cite HPX.


Download the release from our releases page or by checking our the 1.5.1 tag. Please see our release notes for a full list of fixed issues and merged pull requests.


If you have any questions, comments, or exploits to report you can reach us on IRC (#ste||ar on freenode), on the matrix hpx channel, or email us at hpx-users. We depend on your input!

HPX 1.5.0 Released!

Make sure to read our release notes for a full list of changes as they contain important information on deprecations and breaking changes.

Thank you to everyone in the STE||AR Group and all the volunteers who have provided fixes, opened issues, and improved the documentation.

Download the release from our releases page.

The highlights of this release are:

  • We continued with the modularization. This results in the deprecation of several headers which have been moved to a different location while better matching the standard ones, we encourage you to update your includes to the new header location as soon as possible as it will be removed in a couple of releases. Here is the link to the headers you should refer to the public API.
  • We adapted several algorithms to be C++20 conformant and added hpx::stable_sort.
  • We have refactored the CMake target, you can now link directly to HPX::hpx (link additionally to HPX::wrap_main to have your main() to be used as the first HPX thread).
  • HPX now requires a C++14 compatible compiler and the standard is set by default to C++14.

If you have any questions, comments, or exploits to report you can reach us on IRC (#ste||ar on freenode), on the matrix hpx channel, or email us at hpx-users. We depend on your input!

GSoD Final Report

By Rebecca Stobaugh.

We’ve reached the end of Google’s Season of Docs, and we’ve accomplished a lot in the past three months. My initial proposal was to work on three sections of the manual, and we have far exceeded our goal, managing to make changes to twelve different sections of the documentation. The majority of the work I’ve done has consisted of cleaning up grammatical errors and improving sentence structure. I have also added a style guide to the wiki, which should help standardize future changes to the documentation. The style guide can be found in the “HPX Source Code Structure and Coding Standards” wiki document under the section “Documentation Style Guide”. For a complete list of my pull requests during Season of Docs, please see here. To view my changes to the wiki, please see here.

HPX 1.3.0 Released!

The STE||AR Group is proud to announce the release of HPX 1.3.0! This release focuses on performance and stability improvements. Make sure to read the full release notes to see all new and breaking changes. Thank you once again to everyone in the STE||AR Group and all the volunteers who have provided fixes, opened issues, and improved documentation.

Download the release from our download page, or GitHub page.

HPX documentation now uses Sphinx

With the release of HPX 1.2.0 we moved from a Boostbook-based documentation system to Sphinx. The latest documentation is now hosted on GitHub pages and can be found here.

There were multiple reasons for moving to a Sphinx-based documentation setup:

  • Modern look: the Boostbook-based documentation used awkward, non-responsive styling
  • Search: Sphinx natively supports search which makes it much faster to find what you’re looking for in the documentation
  • Table of contents in sidebar: this also helps navigating the documentation more easily
  • More familiar markup with reStructuredText

While the above are mostly visual reasons for moving to Sphinx, we used the opportunity to restructure the documentation at the same time. The first page of the documentation now tries to guide new and old users to sections that they might be interested in. For new users there is a quick start guide since we know that starting out with HPX can often be a big hurdle (to help with that there are also HPX packages available on Fedora). Our examples have been labeled with what you will learn by reading through the examples. For more advanced users the comprehensive manual has been restructured in a more logical way to start from getting and building HPX, to writing single-node HPX applications, multi-node HPX applications, and finally to optimizing and debugging applications. We’ve also added a new section for developers getting started with HPX. A less noticeable feature is that we link key concepts to our terminology page. Next time you see a term you haven’t seen before you’ll hopefully be able to just click the word to get an explanation.

We hope you enjoy the new documentation and would love to hear your feedback on it!

HPX meets Fedora

With the release of HPX 1.2.0, we added support of HPX to the offical Fedora updates-testing repository. Following packages are available on Fedora 28/29

We provide HPX compiled with the GNU compiler collection, with the OpenMPI compiler, and the MPICH compiler.  The hpx-devel packages contains the header files and he hpx-*-examples package contains all the examples compiled with the respective compiler.  The purpose of these packages is educational and we hope to lower the entrance point to experiment with HPX. For performance measurements we recommend to compile HPX on the used hardware.