Control flow based cost analysis for P4

The networking industry is currently undergoing a steady trend of softwarization. Yet, network engineers suffer from the lack of software development tools that support programming of new protocols. We are creating a cost analysis tool for the P4 programming language, that automatically verifies whether the developed program meets soft deadline requirements imposed by the network. In this paper, we present an approach to estimate the average execution time of P4 program based on control flow graphs. Our approach takes into consideration that many of the parts of P4 are implementation-defined: required information can be added in through incremental refinement, while missing information is handled by falling back to less precise defaults. We illustrate application of this approach to a P4 protocol in two case studies: we use it to examine the effect of a compiler optimization in the deparse stage, and to show how it enables cost modelling complex lookup table implementations. Finally, we assess future research tasks to be completed before the tool is ready for real-world usage.

Scheduling in Real Time System

Scheduling of real time tasks are very important aspect in systems as processes should complete its task at a specific time. There is a need of high energy efficiency and low response time in large data stream so for this energy efficient resources and optimized frameworks are needed. Both hard real time and mixed critically systems are targeted. Soft deadline can be handled while hard deadlines are difficult to cater. Different algorithms are used to schedule tasks like rate monotonic, earliest deadline first, deadline monotonic etc.

Breakthroughs, Deadlines, and Self-Reported Progress: Contracting for Multistage Projects

We study the optimal incentive scheme for a multistage project in which the agent privately observes intermediate progress. The optimal contract involves a soft deadline wherein the principal guarantees funding up to a certain date—if the agent reports progress at that date, then the principal gives him a relatively short hard deadline to complete the project—if progress is not reported at that date, then a probationary phase begins in which the project is randomly terminated at a constant rate until progress is reported. We explore several variants of the model with implications for optimal project design. In particular, we show that the principal benefits by imposing a small cost on the agent for submitting a progress report or by making the first stage of the project somewhat “harder” than the second. (JEL D82, D86, G32)

A Mixed Scheduling Algorithm about Hard Periodic and Soft Aperiodic Real-Time Tasks on Heterogeneous Multiprocessor

This paper studies the problem about scheduling composition of periodic real-time tasks and aperiodic soft real-time tasks in heterogeneous multiprocessor environment. It analyzes the response time of each task in periodic real-time task set and the influence factor about the response time of aperiodic soft real-time task. We use a new mixed scheduling algorithm--UEDF and Task-Centric with Slack Defragmentation algorithm (TCSD) to schedule hybrid task set which consist of the periodic real-time tasks and aperiodic soft real-time tasks. It can improve the timeliness of aperiodic soft real-time tasks response, so the ratio of aperiodic tasks to meet soft deadline will increase.

A Method for Simultaneously Satisfying Important Constraints and Dependencies for Many Different Types of Processes in Embedded Real-Time Systems

In most embedded, real-time applications, processes need to satisfy various important constraints and dependencies, such as release times, offsets, precedence relations, and exclusion relations. Embedded, real-time systems with high assurance requirements often must execute many different types of processes with such constraints and dependencies. Some of the processes may be periodic and some of them may be asynchronous. Some of the processes may have hard deadlines and some of them may have soft deadlines. For some of the processes, especially the hard real-time processes, complete knowledge about their characteristics can and must be acquired before run-time. For other processes, prior knowledge of their worst case computation time and their data requirements may not be available. It is important for many embedded real-time systems to be able to simultaneously satisfy as many important constraints and dependencies as possible for as many different types of processes as possible. In this paper, we discuss what types of important constraints and dependencies can be satisfied among what types of processes. We also present a method which guarantees that, for every process, no matter whether it is periodic or asynchronous, and no matter whether it has a hard deadline or a soft deadline, as long as the characteristics of that process are known before run-time, then that process will be guaranteed to be completed before predetermined time limits, while simultaneously satisfying many important constraints and dependencies with other processes.