CPC: programming with a massive number of lightweight threads

Threads are a convenient and modular abstraction for writing concurrent programs, but often fairly expensive. The standard alternative to threads, event-loop programming, allows much lighter units of concurrency, but leads to code that is difficult to write and even harder to understand. Continuation Passing C (CPC) is a translator that converts a program written in threaded style into a program written with events and native system threads, at the programmer's choice. Together with two undergraduate students, we taught ourselves how to program in CPC by writing Hekate, a massively concurrent network server designed to efficiently handle tens of thousands of simultaneously connected peers. In this paper, we describe a number of programming idioms that we learnt while writing Hekate; while some of these idioms are specific to CPC, many should be applicable to other programming systems with sufficiently cheap threads.Comment: To appear in PLACES'1

Implementation of RTOS to the WSN node

Bezdrátové senzorické sieťe zväčša používajú `event-driven` operačné systémy. Táto práca diskutuje výhody nevýhody použitia RTOS v bezdrátových senzorických sieťach. Najvhodnejší RTOS je vybratý a sú podniknuté všetky kroky aby bolo možne demonštrovať schopnosť mikrokontrolérov Gecko od EnergyMicro prevádzkovať tento RTOS s nízkou spotrebou energie a demonštrovať jednoduchú bezdrátovú komunikáciu s Atmel AT86RF212 rádiami.Wireless sensors networks mostly use event-driven OSes. This works discusses pros and cons of using RTOS in wirless sensors networks. A most appropriate RTOS is chosen and all necessary steps are undergone to demonstrate EnergyMicro Gecko MCU's ability to run the RTOS with low energy consumption and demonstrate wireless simple communication with Atmel AT86RF212 radios.

Automatic Verification of Message-Based Device Drivers

We develop a practical solution to the problem of automatic verification of the interface between device drivers and the OS. Our solution relies on a combination of improved driver architecture and verification tools. It supports drivers written in C and can be implemented in any existing OS, which sets it apart from previous proposals for verification-friendly drivers. Our Linux-based evaluation shows that this methodology amplifies the power of existing verification tools in detecting driver bugs, making it possible to verify properties beyond the reach of traditional techniques.Comment: In Proceedings SSV 2012, arXiv:1211.587

EbbRT: a framework for building per-application library operating systems

Efficient use of high speed hardware requires operating system components be customized to the application work- load. Our general purpose operating systems are ill-suited for this task. We present EbbRT, a framework for constructing per-application library operating systems for cloud applications. The primary objective of EbbRT is to enable high-performance in a tractable and maintainable fashion. This paper describes the design and implementation of EbbRT, and evaluates its ability to improve the performance of common cloud applications. The evaluation of the EbbRT prototype demonstrates memcached, run within a VM, can outperform memcached run on an unvirtualized Linux. The prototype evaluation also demonstrates an 14% performance improvement of a V8 JavaScript engine benchmark, and a node.js webserver that achieves a 50% reduction in 99th percentile latency compared to it run on Linux

Alaska Army National Guard Construction Planning Process Improvement

A Project Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE in Project ManagementThe Alaska Army National Guard (AKARNG) is a jointly funded agency run under a cooperative agreement between the federal and state governments. Recognized as a state agency, the AKARNG reports to the governor for domestic response and trains for federal missions. With this relationship, the AKARNG receives funds from the National Guard Bureau (NGB) and the Alaska State Legislature for the execution of construction projects. Under the cooperative agreement, the AKARNG follows state procedures and uses the Alaska Department of Transportation and Public Facilities (ADOT/PF) to manage projects. The AKARNG Construction and Facilities Maintenance Officer (CFMO) ensures federal oversight of all AKARNG facilities. This project looks at the relationship between the AKARNG CFMO and ADOT/PF as they collaborate and plan construction projects for the AKARNG. The primary deliverables for this project are a current state swim lane chart (SLC) with written description and an improved state SLC with a written description. The goal of this project is to offer the AKARNG a roadmap for process improvement. The current and improved SLCs were produced by conducting research and engaging with stakeholders through interviews and questionnaires. Stakeholders were engaged throughout and offered quality oversight of the deliverables. The improved state SLC incorporated regulatory compliance and previously omitted policy requirements. When necessary, the improved state SLC included the addition or subtraction of steps to add value to the process. This project delivered the AKARNG a scalable depiction of their construction planning process and recommendations for improvement.Title Page / Table of Contents / List of Exhibits / List of Appendices / Project Management / Project Execution / Project Outcomes / Future Research and Project Conclusions / Appendice

User interface development and software environments : the Chiron-1 system

User interface development systems for software environments have to cope with the broad, extensible and dynamic character of such environments, must support internal and external integration, and should enable various software development strategies. The Chiron-1 system adapts and extends key ideas from current research in user interface development systems to address the particular demands of software environments. Important Chiron-1 concepts are: separation of concerns, dynamism, and open architecture. We discuss the requirements on such user interface development systems, present the Chiron-1 architecture and a scenario of its usage, detail the concepts it embodies, and report on its design and prototype implementation

EbbRT: a customizable operating system for cloud applications

Efficient use of hardware requires operating system components be customized to the application workload. Our general purpose operating systems are ill-suited for this task. We present Genesis, a new operating system that enables per-application customizations for cloud applications. Genesis achieves this through a novel heterogeneous distributed structure, a partitioned object model, and an event-driven execution environment. This paper describes the design and prototype implementation of Genesis, and evaluates its ability to improve the performance of common cloud applications. The evaluation of the Genesis prototype demonstrates memcached, run within a VM, can outperform memcached run on an unvirtualized Linux. The prototype evaluation also demonstrates an 14% performance improvement of a V8 JavaScript engine benchmark, and a node.js webserver that achieves a 50% reduction in 99th percentile latency compared to it run on Linux

Continuation-Passing C: compiling threads to events through continuations

In this paper, we introduce Continuation Passing C (CPC), a programming language for concurrent systems in which native and cooperative threads are unified and presented to the programmer as a single abstraction. The CPC compiler uses a compilation technique, based on the CPS transform, that yields efficient code and an extremely lightweight representation for contexts. We provide a proof of the correctness of our compilation scheme. We show in particular that lambda-lifting, a common compilation technique for functional languages, is also correct in an imperative language like C, under some conditions enforced by the CPC compiler. The current CPC compiler is mature enough to write substantial programs such as Hekate, a highly concurrent BitTorrent seeder. Our benchmark results show that CPC is as efficient, while using significantly less space, as the most efficient thread libraries available.Comment: Higher-Order and Symbolic Computation (2012). arXiv admin note: substantial text overlap with arXiv:1202.324

Research in software allocation for advanced manned mission communications and tracking systems

An assessment of the planned processing hardware and software/firmware for the Communications and Tracking System of the Space Station Freedom (SSF) was performed. The intent of the assessment was to determine the optimum distribution of software/firmware in the processing hardware for maximum throughput with minimum required memory. As a product of the assessment process an assessment methodology was to be developed that could be used for similar assessments of future manned spacecraft system designs. The assessment process was hampered by changing requirements for the Space Station. As a result, the initial objective of determining the optimum software/firmware allocation was not fulfilled, but several useful conclusions and recommendations resulted from the assessment. It was concluded that the assessment process would not be completely successful for a system with changing requirements. It was also concluded that memory requirements and hardware requirements were being modified to fit as a consequence of the change process, and although throughput could not be quantitized, potential problem areas could be identified. Finally, inherent flexibility of the system design was essential for the success of a system design with changing requirements. Recommendations resulting from the assessment included development of common software for some embedded controller functions, reduction of embedded processor requirements by hardwiring some Orbital Replacement Units (ORUs) to make better use of processor capabilities, and improvement in communications between software development personnel to enhance the integration process. Lastly, a critical observation was made regarding the software integration tasks did not appear to be addressed in the design process to the degree necessary for successful satisfaction of the system requirements