STE||AR Spotlight: Patrick Diehl

Patrick Diehl is a research scientist here in the STE||AR Group at CCT – LSU. He is definitely one of our most active members!  In addition to his extensive research activities and numerous publications, Patrick also teaches in the LSU Math Department and has organized several workshops and events.

Before joining LSU, Patrick was a postdoctoral fellow at the Laboratory for Multiscale Mechanics at Polytechnique Montreal. He received his diploma in computer science at the University of Stuttgart and his Ph.D. in Applied Mathematics from the university of Bonn.

Patrick created and hosted the virtual CAIRO colloquium series in the Spring.  Speakers from across the country, and even internationally, joined to discuss various AI (artificial intelligence) topics.  The series was an overall success and will continue in the Fall.

Patrick is the liaison for universities in Louisiana for the Texas and Louisiana section of the Society for Applied and Industrial Mathematics (SIAM). He is a topic editor for the Journal for Open Source Software (JOSS) for computational fracture mechanics, applied mathematics, C++, asynchronous and task-based programming.

Patrick also cohosts a podcast – FLOSS For Science – with episodes that showcase free, libre and open source software uses in science with the aim to advocate for the usage of Open Source software in academia and higher education.

Patrick’s main research interests are:

Computational engineering with the focus on peridynamic material models for the application in solids, like glassy or composite materials

High performance computing, especially the asynchronous many task system (ATM), e.g. the C++ standard library for parallelism and concurrency (HPX) for large heterogeneous computations.

In addition, Patrick has a deep interest in the usage of Open Source software to enhance the openness of Science. With respect to teaching, he is interested to develop tools to easily introduce C++ and parallel computing to non-computer science students.

Patrick lives in Baton Rouge with his wife Sylvia and their young daughter Ava.  Aside from all the great work he does at LSU, he’s an active family man and enjoys trips to the park and gymnastics lessons for Ava.  Some of their favorite activities are enjoying the local Cajun food and visiting the amazing BREC parks.

Important: IRC channel change

Because of the growing problems with Freenode we have decided to move our IRC channel to a different network. Please /join #ste||ar at Libra.Chat (irc:// If you are using the Matrix bridge to IRC, you can join #ste|| through Matrix.

HPX 1.6.0 Released!

The STE||AR Group is proud to announce the release of HPX 1.6.0! HPX is an implementation of the C++ standard library for parallelism and concurrency on an efficient user-level threading runtime, with extensions for distributed computing.

This release continues the focus on C++20 conformance with multiple new algorithms adapted to be C++20 conformant and becoming customization point objects (CPOs). We have added experimental support for HIP, allowing existing CUDA features to now be compiled with hipcc and run on AMD GPUs as well. We have also continued improving the performance of the parallel executors, and added an experimental fork-join executor. The full list of improvements, fixes, and breaking changes can be found in the release notes.

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.

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 accepted for Google Season of Docs 2019

This year Google is organizing for the first time Google Season of Docs (GSoD). Like Google Summer of Code (GSoC) the program aims to match motivated people with interesting open source projects that are looking for volunteer contributions. GSoD, however, aims to improve open source project documentation, which often tends to get less attention than the code itself. We recognize this all too well in the HPX project. For this reason, we decided to apply for GSoD and can now proudly announce that HPX has been selected as one of 50 projects participating in this year’s GSoD!

This means that we are now looking for motivated people to help us improve our documentation. If you have some prior experience with technical writing, and are interested in working together with us on making the documentation of a cutting edge open source C++ library the best possible guide for new and experienced users, this is your chance. You can read more about the program on the official GSoD home page. We’ve provided a few project ideas on our wiki, but you can also come up with your own. Our current documentation can be found here.

The deadline for technical writer applications is June 28. Come talk to us about your ideas and your application on our mailing list, IRC, or Slack. We’d love to hear from you!

GSoC 18: Final Documentation for a C++ run time replacement

By Nikunj Gupta

A C++ Runtime Replacement


A user can make use of the HPX functionality only after initializing the HPX Runtime System. To initialize the user has to call thehpx::init function with valid parameters and an entry point for the HPX runtime system (defaulting tohpx_main if none provided).

My GSoC project was to integrate the HPX runtime system with C++ runtime system i.e. to make all HPX features directly available from int main. To give a clear picture, this was already pre-implemented using a C++ macro #define main hpx_startup::user_main. This method, however, is not robust and can result in unexpected errors. The project, therefore, involved researching various ways to integrate the two seamlessly and make sure it is robust at the same time. I was able to integrate the runtime systems for machines running Linux or Mac OSX.

Google Summer of Code Statistics

After the Google Mentor Summit, we started to gather some statistics about our participation in Google Summer of Code. In Summer 2014, we were first time accepted as an organization.  Figure 1 shows that since our first year we have increased the number of students mentored from two to six. Unfortunately, with an more students, the odd of a student failing the program increased. In 2017 we started to analyze the pull requests of our students. Here, we counted the open pull request at the last day of GSoC and the closed one one day later. In 2018 we started to analyze the ammount of applications we received .We also analyzed the amount of students per country of residence and continent of residence.

GSoC 2016 Wrap-up

This summer the STE||AR Group was proud to mentor four students through Google’s Summer of Code program. These students worked on a variety of projects which helped improve our software, HPX. This Library is a distributed C++ runtime system which supports a standards compliant API and helps users to scale their applications across thousands of machines. The improvements that

Welcome to the STE||AR Group’s New Site!

The STE||AR Group is an international collaboration of researchers who are committed to making applications scalable on today’s and tomorrow’s machines.  We want this website to provide a platform to support and promote our work.  Here you can find a community of researchers who are interested in sharing and building upon the best ideas in HPC.  We strongly believe that the best way to spread these ideas is to have them applied in real applications by an active user base.  The Libraries page provides links to software developed by our researchers for anyone to download and try out.  Please look at the library descriptions and see if any of this software applies to you!

In addition to providing demonstrations of our current work, we would like to also share and coordinate the direction of our group’s research.  We hope that by explicitly stating what we are currently working on and what we hope to work on we can entice internal and external collaboration. These collaborations are mutually beneficial as the pressure to fulfill new needs will improve everyone’s software.  Feel free to peruse our research interest on the Research page and see where you could fit into the mix.

Finally, we hope to use this site to distribute news and updates of the happenings of this group.  Please come back here to read about recent releases, publications, and conferences that  we are involved with.  If you are interested in our work or just have a few questions, please contact us at: or visit our IRC channel #ste||ar on Freenode.  We would love to exchange our ideas with you!