scholarly journals Improving the performance of fragments of computer code with high time costs based on parallel programming technologies

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Artem Zainetdinov ◽  
Oleg Rudzeyt ◽  
Anton Nedyak
Keyword(s):  
Programming Languages ◽  
Execution Time ◽  
Computer Code ◽  
Real Time Systems ◽  
Total Execution Time ◽  
C Language ◽  
Sequential Execution ◽  
The Moment ◽  
Time Systems ◽  
Processor Cores

This article describes the process of converting the program from single-threaded to multithreaded mode. The influence of the number of threads of execution on the total execution time of the code. The problem of spending much time to run programs solved by incremental parallelization when the code is designed for sequential execution, are added to the parallelizing directives. Are similar libraries for working with threads in other programming languages and the advantages of OpenMP over other libraries. Considered a model of parallelizing OpenMP directives, which is time-consuming to run the snippet in multi-threaded mode. The article also presents example code implemented using the C++ language, which built the parallelizing directives of OpenMP. In this model, the estimated execution time of a code snippet of a program with different number of threads. The study showed that with increasing the number of threads the run time is significantly reduced on the average in 1,5–2 times. This happens until the moment when the number of threads will be equal to the number of processor cores. If the number of threads becomes greater than the number of processor cores, the execution time of the program remains virtually unchanged. Are the OpenMP library allows to significantly shorten the program, which can be critical for works of real-time systems, to reduce the time of creating multithreaded applications is simple inserts directives of the library, to reduce the number of errors made by the programmer in the course of working with multi-threaded applications.

scholarly journals Tropical Fourier–Motzkin elimination, with an application to real-time verification

2014 ◽  
Vol 24 (05) ◽  
pp. 569-607 ◽  
Author(s):  
Xavier Allamigeon ◽  
Uli Fahrenberg ◽  
Stéphane Gaubert ◽  
Ricardo D. Katz ◽  
Axel Legay
Keyword(s):  
Real Time ◽  
Execution Time ◽  
Timed Automata ◽  
Real Time Systems ◽  
Total Execution Time ◽  
Exponential Bound ◽  
Geometrical Properties ◽  
Strict Inequalities ◽  
Time Systems ◽  
Mean Payoff

We introduce a generalization of tropical polyhedra able to express both strict and non-strict inequalities. Such inequalities are handled by means of a semiring of germs (encoding infinitesimal perturbations). We develop a tropical analogue of Fourier–Motzkin elimination from which we derive geometrical properties of these polyhedra. In particular, we show that they coincide with the tropically convex union of (non-necessarily closed) cells that are convex both classically and tropically. We also prove that the redundant inequalities produced when performing successive elimination steps can be dynamically deleted by reduction to mean payoff game problems. As a complement, we provide a coarser (polynomial time) deletion procedure which is enough to arrive at a simply exponential bound for the total execution time. These algorithms are illustrated by an application to real-time systems (reachability analysis of timed automata).

scholarly journals A Comparative Analysis of Looping Structures: Comparison of ‘While’ Loop and ‘Do-While’ Loop in the C++ Language

2019 ◽  
pp. 1-5
Author(s):  
P. Shouthiri ◽  
N. Thushika
Keyword(s):  
Comparative Analysis ◽  
Programming Languages ◽  
Execution Time ◽  
Total Execution Time ◽  
C Language ◽  
The Difference ◽  
The Given ◽  
Number Of Iterations

Looping is one of the fundamental logical instructions used for repeating a block of statements. All programming languages are used looping structures to simplify the programs. Loops are supported by all modern programming languages, though their implementations and syntax may differ. This paper compares the two types of looping structures while and do-while using the compile time and runtime of the given programs to improve the efficiency of the programs. It is found that for small number of iterations while is efficient in runtime and do-while is efficient in compile time, the difference in total execution time may not be considerable. But given any large number of iterations, the difference is noticeable.

Real-time MLton: A Standard ML runtime for real-time functional programs

2021 ◽  
Vol 31 ◽  
Author(s):  
BHARGAV SHIVKUMAR ◽  
JEFFREY MURPHY ◽  
LUKASZ ZIAREK
Keyword(s):  
Programming Languages ◽  
Real Time ◽  
Concurrency Control ◽  
General Purpose ◽  
Functional Languages ◽  
Control Mechanisms ◽  
Real Time Systems ◽  
Functional Programming Languages ◽  
Standard Ml ◽  
Time Systems

Abstract There is a growing interest in leveraging functional programming languages in real-time and embedded contexts. Functional languages are appealing as many are strictly typed, amenable to formal methods, have limited mutation, and have simple but powerful concurrency control mechanisms. Although there have been many recent proposals for specialized domain-specific languages for embedded and real-time systems, there has been relatively little progress on adapting more general purpose functional languages for programming embedded and real-time systems. In this paper, we present our current work on leveraging Standard ML (SML) in the embedded and real-time domains. Specifically, we detail our experiences in modifying MLton, a whole-program optimizing compiler for SML, for use in such contexts. We focus primarily on the language runtime, reworking the threading subsystem, object model, and garbage collector. We provide preliminary results over a radar-based aircraft collision detector ported to SML.

Use of Measurements in Worst-Case Execution Time Estimation for Real-Time Systems

2021 ◽  
Author(s):  
Jessica Junia Santillo Costa ◽  
Romulo Silva de Oliveira ◽  
Luis Fernando Arcaro
Keyword(s):  
Real Time ◽  
Execution Time ◽  
Time Estimation ◽  
Real Time Systems ◽  
Worst Case ◽  
Worst Case Execution Time ◽  
Time Systems

scholarly journals Worst-case execution-time analysis for embedded real-time systems

2003 ◽  
Vol 4 (4) ◽  
pp. 437-455 ◽  
Author(s):  
Jakob Engblom ◽  
Andreas Ermedahl ◽  
Mikael Sjödin ◽  
Jan Gustafsson ◽  
Hans Hansson
Keyword(s):  
Real Time ◽  
Execution Time ◽  
Real Time Systems ◽  
Time Analysis ◽  
Worst Case ◽  
Worst Case Execution Time ◽  
Time Systems

Interactive WCET Prediction with Warning for Timeout Risk

2017 ◽  
Vol 31 (05) ◽  
pp. 1750012 ◽  
Author(s):  
Fanqi Meng ◽  
Xiaohong Su ◽  
Zhaoyang Qu
Keyword(s):  
Execution Time ◽  
Control Flow ◽  
Real Time Systems ◽  
Wcet Analysis ◽  
Running Speed ◽  
Worst Case ◽  
Worst Case Execution Time ◽  
Level Model ◽  
Hard Real Time ◽  
Time Systems

Worst case execution time (WCET) analysis is essential for exposing timeliness defects when developing hard real-time systems. However, it is too late to fix timeliness defects cheaply since developers generally perform WCET analysis in a final verification phase. To help developers quickly identify real timeliness defects in an early programming phase, a novel interactive WCET prediction with warning for timeout risk is proposed. The novelty is that the approach not only fast estimates WCET based on a control flow tree (CFT), but also assesses the estimated WCET with a trusted level by a lightweight false path analysis. According to the trusted levels, corresponding warnings will be triggered once the estimated WCET exceeds a preset safe threshold. Hence developers can identify real timeliness defects more timely and efficiently. To this end, we first analyze the reasons of the overestimation of CFT-based WCET calculation; then we propose a trusted level model of timeout risks; for recognizing the structural patterns of timeout risks, we develop a risk data counting algorithm; and we also give some tactics for applying our approach more effectively. Experimental results show that our approach has almost the same running speed compared with the fast and interactive WCET analysis, but it saves more time in identifying real timeliness defects.

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