Stackless Multi-Threading for Embedded Systems

Programming support for multi-threaded applications on embedded microcontroller platforms has attracted a considerable amount of research attention in the recent years. This paper is focused on this problem, and presents UnStacked C, a source-to-source transformation that can translate multithreaded programs written in C into stackless continuations. The transformation can support legacy code by not requiring any changes to application code; only the underlying threading library needs modifications. We describe the details of UnStacked C in the context of the TinyOS operating system for wireless sensor network applications. We present a modified implementation of the TOSThreads library for TinyOS, and show how existing applications programmed using TOSThreads can be automatically transformed to use stackless threads with only modifications in the build process. By eliminating the need to allocate individual thread stacks and by supporting lazy thread preemption, UnStacked C enables a considerable saving of memory used and power consumed, respectively

Stackless Multi-Threading for Embedded Systems

Programming support for multi-threaded applications on embedded microcontroller platforms has attracted a considerable amount of research attention in the recent years. This paper is focused on this problem, and presents UnStacked C, a source-to-source transformation that can translate multithreaded programs written in C into stackless continuations. The transformation can support legacy code by not requiring any changes to application code; only the underlying threading library needs modifications. We describe the details of UnStacked C in the context of the TinyOS operating system for wireless sensor network applications. We present a modified implementation of the TOSThreads library for TinyOS, and show how existing applications programmed using TOSThreads can be automatically transformed to use stackless threads with only modifications in the build process. By eliminating the need to allocate individual thread stacks and by supporting lazy thread preemption, UnStacked C enables a considerable saving of memory used and power consumed, respectively

A Review of Lightweight Thread Approaches for High Performance Computing

High-level, directive-based solutions are becoming the programming models (PMs) of the multi/many-core architectures. Several solutions relying on operating system (OS) threads perfectly work with a moderate number of cores. However, exascale systems will spawn hundreds of thousands of threads in order to exploit their massive parallel architectures and thus conventional OS threads are too heavy for that purpose. Several lightweight thread (LWT) libraries have recently appeared offering lighter mechanisms to tackle massive concurrency. In order to examine the suitability of LWTs in high-level runtimes, we develop a set of microbenchmarks consisting of commonly-found patterns in current parallel codes. Moreover, we study the semantics offered by some LWT libraries in order to expose the similarities between different LWT application programming interfaces. This study reveals that a reduced set of LWT functions can be sufficient to cover the common parallel code patterns andthat those LWT libraries perform better than OS threads-based solutions in cases where task and nested parallelism are becoming more popular with new architectures.The researchers from the Universitat Jaume I de Castelló were supported by project TIN2014-53495-R of the MINECO, the Generalitat Valenciana fellowship programme Vali+d 2015, and FEDER. This work was partially supported by the U.S. Dept. of Energy, Office of Science, Office of Advanced Scientific Computing Research (SC-21), under contract DEAC02-06CH11357. We gratefully acknowledge the computing resources provided and operated by the Joint Laboratory for System Evaluation (JLSE) at Argonne National Laboratory.Peer ReviewedPostprint (author's final draft

Simplifying Embedded System Development Through Whole-Program Compilers

As embedded systems embrace ever more complicated microcontrollers, they present both new capability and new complexity. To simplify their development, some lessons of computer application development will translate with additional work. This thesis offers one such translation. It shows how whole-program compilers - those that broadly analyze a program\u27s entire source code - can achieve performance gains and remove faults in embedded system applications. In so doing, this yields a novel stackless threading system named UnStacked C. UnStacked C enables cooperative multithreading without the risk of stack overflows in embedded system applications. We also propose a novel preemption system called Lazy Preemption. Unstacked C with Lazy Preemption enables stackless preemptive multithreading in embedded systems. These remove the possibility of thread stack overflows, but also significantly reduces the memory required for multithreading in embedded system

RIOT: One OS to Rule Them All in the IoT

The Internet of Things (IoT) embodies a wide spectrum of machines ranging from sensors powered by 8-bits microcontrollers, to devices powered by processors roughly equivalent to those found in entry-level smartphones. Neither traditional operating systems (OS) currently running on internet hosts, nor typical OS for sensor networks are capable to fulfill all at once the diverse requirements of such a wide range of devices. Hence, in order to avoid redundant developments and maintenance costs of IoT products, a novel, unifying type of OS is needed. The following analyzes requirements such an OS should fulfill, and introduces RIOT, a new OS satisfying these demands

Analysis of threading libraries for high performance computing

© 2020 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] With the appearance of multi-/many core machines, applications and runtime systems have evolved in order to exploit the new on-node concurrency brought by new software paradigms. POSIX threads (Pthreads) was widely-adopted for that purpose and it remains as the most used threading solution in current hardware. Lightweight thread (LWT) libraries emerged as an alternative offering lighter mechanisms to tackle the massive concurrency of current hardware. In this article, we analyze in detail the most representative threading libraries including Pthread- and LWT-based solutions. In addition, to examine the suitability of LWTs for different use cases, we develop a set of microbenchmarks consisting of OpenMP patterns commonly found in current parallel codes, and we compare the results using threading libraries and OpenMP implementations. Moreover, we study the semantics offered by threading libraries in order to expose the similarities among different LWT application programming interfaces and their advantages over Pthreads. This article exposes that LWT libraries outperform solutions based on operating system threads when tasks and nested parallelism are required.The researchers from the Universitat Jaume I and Universitat Politecnica de Valencia were supported by project TIN2014-53495-R of the MINECO and FEDER, and the Generalitat Valenciana fellowship programme Vali+d 2015. Antonio J. Pena is financed by the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie Grant No. 749516. This work was partially supported by the U.S. Department of Energy, Office of Science, Office of Advanced Scientific Computing Research (SC-21), under contract DE-AC02-06CH11357.Castelló, A.; Mayo Gual, R.; Seo, S.; Balaji, P.; Quintana Ortí, ES.; Peña, AJ. (2020). Analysis of threading libraries for high performance computing. IEEE Transactions on Computers. 69(9):1279-1292. https://doi.org/10.1109/TC.2020.2970706S1279129269

Towards Python-based Domain-specific Languages for Self-reconfigurable Modular Robotics Research

This paper explores the role of operating system and high-level languages in the development of software and domain-specific languages (DSLs) for self-reconfigurable robotics. We review some of the current trends in self-reconfigurable robotics and describe the development of a software system for ATRON II which utilizes Linux and Python to significantly improve software abstraction and portability while providing some basic features which could prove useful when using Python, either stand-alone or via a DSL, on a self-reconfigurable robot system. These features include transparent socket communication, module identification, easy software transfer and reliable module-to-module communication. The end result is a software platform for modular robots that where appropriate builds on existing work in operating systems, virtual machines, middleware and high-level languages.Comment: Presented at DSLRob 2011 (arXiv:1212.3308

OS for the IoT - Goals, Challenges, and Solutions

International audienceThe Internet of Things embodies a wide spectrum of machines ranging from sensors powered by 8-bit microcontrollers to devices powered by processors roughly equivalent to those found in entry-level smartphones. Neither traditional operating systems (OS) currently running on Internet hosts, nor typical OS for sensor networks are capable to fulfill all at once the diverse requirements of such a wide range of devices. Hence, in order to avoid redundant developments and maintenance costs of IoT products, a novel, unifying type of OS is needed. The following analyzes requirements such an OS should fulfill and introduces RIOT, an OS satisfying these demands

RIOT: One OS to Rule Them All in the IoT

The Internet of Things (IoT) embodies a wide spectrum of machines ranging from sensors powered by 8-bits microcontrollers, to devices powered by processors roughly equivalent to those found in entry-level smartphones. Neither traditional operating systems (OS) currently running on internet hosts, nor typical OS for sensor networks are capable to fulfill all at once the diverse requirements of such a wide range of devices. Hence, in order to avoid redundant developments and maintenance costs of IoT products, a novel, unifying type of OS is needed. The following analyzes requirements such an OS should fulfill, and introduces RIOT, a new OS satisfying these demands