DOCSLIB.ORG

Jbse-Manual Documentation Release Latest

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Jbse-Manual Documentation Release Latest jbse-manual Documentation Release latest Pietro Braione Aug 25, 2021 Contents 1 About this book 1 1.1 What is JBSE?..............................................1 1.2 Who is the author of this book?.....................................1 1.3 Where do I find this book?........................................1 2 Introduction 3 2.1 Software analysis.............................................3 2.2 What is symbolic execution?.......................................4 2.3 Symbolic execution with objects as inputs................................ 10 3 Getting started with JBSE 17 3.1 Obtaining and installing JBSE...................................... 17 3.2 A basic example............................................. 17 3.3 Assertions and assumptions....................................... 22 4 Using JBSE 25 4.1 The symbolic execution classes..................................... 25 4.2 Creating a symbolic executor...................................... 25 i ii CHAPTER 1 About this book This book teaches you how to install, use and modify JBSE, an open source framework for the analysis of Java programs. 1.1 What is JBSE? JBSE is the Java Bytecode Symbolic Executor. Basically, it is a special-purpose Java Virtual Machine written in Java that can be used for program analysis and automated test generation. The homepage of JBSE is at https://pietrobraione. github.io/jbse/ and its Github repository is at https://github.com/pietrobraione/jbse. 1.2 Who is the author of this book? The author of this book is the main maintainer of JBSE, Pietro Braione. You can contact me via email at [email protected]. 1.3 Where do I find this book? This book is available on Github. Its repository is https://github.com/pietrobraione/jbse-manual. The book is written in reStructuredText and is published on readthedocs at https://jbse-manual.readthedocs.io. 1 jbse-manual Documentation, Release latest 2 Chapter 1. About this book CHAPTER 2 Introduction Welcome. Let me introduce you to JBSE and explain what it is and what it can do. JBSE is a special-purpose Java Virtual Machine (JVM). As you may know, a JVM is what is necessary to execute a program written in the programming languages Java, Scala, Clojure, Groovy, and many others. To be more precise, a JVM is able to execute the special format emitted by the compilers of these languages, the so-called Java bytecode. The programming languages that compile to Java bytecode achieve their portability across different platforms because their compilers does not translate programs directly to machine language, but to Java bytecode that, differently from machine language, is CPU- and OS-independent. It is sufficient to port a JVM implementation across different plat- forms, and automatically all the programs compiled to Java bytecode can be executed unchanged on all of them. The Java bytecode format is precisely documented in the Java Virtual Machine Specification (JVMS) books, that describe how a compliant JVM must execute a program in Java bytecode. The reference JVM implementation is Oracle’s Hotspot JVM, but there are many other ones, e.g., IBM’s OpenJ9 or aicas’ JamaicaVM. So JBSE is a JVM, and therefore it can be used as a drop-in replacement to Hotspot to execute Java (or Scala, Clojure, Groovy. ) software. Right? Well, not really. JBSE’s main purpose is to analyze, rather than execute, Java software. 2.1 Software analysis Let us face the reality: Too often software systems do not work as expected. There are many reasons why this happens, but the most cogent one is possibly that software systems quickly turn complex, and when they turn complex, they usually turn extremely complex. The Windows 10 operating system’s source code, for example, is about 50 millions of lines over 3.5 millions of files, and when checked out it occupies about 300 GB of disk space. Complexity in structure implies complexity in behavior, and unforeseeable behaviors are the main consequence, and the root cause of bugs. A possible way to dominate this complexity is to empower the software engineer with tools that help him or her with understanding how the system behaves. These tools perform what is commonly called software analysis and can be roughly classified into two categories: static and dynamic analysis tools. Static analysis tools extract information about a software system without executing it. The well known Findbugs, Checkstyle and PMD tools perform a kind of static analysis based on the idea of scanning a system’s source code in search for the occurrence of a number of predefined 3 jbse-manual Documentation, Release latest code patterns, each indicating the possible occurrence of a different kind of bug. Static analysis techniques usually require the availability of the source code and produce approximate answers, where false alarms and missed bugs are the norm, but their answers, when correct, can provide very general information on the correctness of the program. On converse, dynamic analysis tools gather information on the software under analysis by observing the effects of its execution. Testing is the quintessential dynamic analysis activity: It observes the effects of the execution of the system software when fed by a finite set of inputs, in search for the manifestations of software defects. Dynamic analyses are usually very precise, but bound to the (few) executions they are able to observe, they usually produce less general results than static analyses. For example, as observed by Dijkstra, testing alone cannot be used to assess the absence of any category of software bugs, while static analyses, in principle, may. JBSE performs a kind of analysis that is called symbolic execution, that is amenable both to verify the correctness of a program with respect to some desired properties expressed as assertions, and to generate test vectors for the program. When used for verification JBSE expects that you specify the verification properties of interest for your project as a set of assumptions and assertions. Assumptions specify the conditions that must be satisfied for an execution to be relevant. Preconditions are a typical form of assumptions, allowing e.g. to specify the range of the possible values for the program inputs. Assertions specify the conditions that must be satisfied for an execution to be correct. JBSE attempts to determine whether some input exists that satisfies all the assumptions and falsifies at least one assertion. In this regard JBSE is more similar in spirit, implementation and mode of use to tools like Symbolic PathFinder, Sireum/Kiasan and JNuke. 2.2 What is symbolic execution? If you do not know what “symbolic execution” is, then you may have a look at the corresponding Wikipedia article or to some textbook. But if you are really impatient, here is a very short tutorial. To explain what symbolic execution is we can consider that symbolic execution is to testing what symbolic equation solving is to numeric equation solving. Let us consider, for instance, the equation x2 − 2 · x + 1 = 0, of which we are asked to find its real solutions. This second degree equation is numeric, meaning that all its coefficients are numbers. According to the value of the discriminant ∆ the equation can have two real solutions (this happens when ∆ > 0), one real solution (when ∆ = 0) or no real solution (when ∆ < 0). In this case the equation has one real solution being ∆ = (−2)2 − 4 · 1 · 1 = 4 − 4 = 0. Conversely, the equation x2 − b · x + 1 = 0 is symbolic, because one of the coefficients b is not a number but a symbol, standing for an unknown numeric value ranging in a (possibly infinite) set of admissible values. If we assume that this set is the set of all the possible real numbers, then the discriminant of the second equation is ∆ = b2 − 4, for any real value of b. As with the numeric equations, to determine the solution of the symbolic equation we need to split cases based on the sign of the discriminant. But differently from our first example, where exactly one case holds, symbolic equation solving may require to follow more than one of them. Depending on the possible values of b our example symbolic equation may fall in one of three cases: If jbj > 2 the discriminant is greater than zero and the equation has two real solutions. If b = 2 or b = −2 the discriminant is zero and the equation has one real solution. Finally, if −2 < b < 2, the discriminant is less than zero and the equation has no real solutions. Since all the three subsets for b are nonempty any of the three cases may hold. As a consequence, the solution of a symbolic equation is usually expressed as a set of summaries. A summary associates a condition on the symbolic parameters with a corresponding possible result of the equation, where the result can be a number or anp expression 2 in the symbols. For ourp running example the solution produces as summaries jbj > 2 ! x = (b + b − 4)=2, jbj > 2 ! x = −(b + b2 − 4)=2, b = 2 ! x = 1, and b = −2 ! x = −1. Note that summaries overlap where a combination of parameters values (jbj > 2 in the previous case) yield multiple results, and that the union of the summaries does not span the whole domain for b, because some values for b yield no result. Symbolic execution is a program analysis technique that is based on performing the execution of a program with input values that may be symbols standing for sets of possible numeric (concrete) values. Consider for example the following Java program: package smalldemos.ifx; (continues on next page) 4 Chapter 2. Introduction jbse-manual Documentation, Release latest (continued from previous page) public class IfExample { boolean a, b; public void m(int x) { if (x>0){ a= true; } else { a= false; } if (x>0){ b= true; } else { b= false; } assert a== b; } } This program is the customary “double-if” example that is often used to illustrate how symbolic execution works.
Load more

Recommended publications
  • An OSEK/VDX-Based Multi-JVM for Automotive Appliances
    AN OSEK/VDX-BASED MULTI-JVM FOR AUTOMOTIVE APPLIANCES Christian Wawersich, Michael Stilkerich, Wolfgang Schr¨oder-Preikschat University of Erlangen-Nuremberg Distributed Systems and Operating Systems Erlangen, Germany E-Mail: [email protected], [email protected], [email protected] Abstract: The automotive industry has recent ambitions to integrate multiple applications from different micro controllers on a single, more powerful micro controller. The outcome of this integration process is the loss of the physical isolation and a more complex monolithic software. Memory protection mechanisms need to be provided that allow for a safe co-existence of heterogeneous software from different vendors on the same hardware, in order to prevent the spreading of an error to the other applications on the controller and leaving an unclear responsi- bility situation. With our prototype system KESO, we present a Java-based solution for ro- bust and safe embedded real-time systems that does not require any hardware protection mechanisms. Based on an OSEK/VDX operating system, we offer a familiar system creation process to developers of embedded software and also provide the key benefits of Java to the embedded world. To the best of our knowledge, we present the first Multi-JVM for OSEK/VDX operating systems. We report on our experiences in integrating Java and an em- bedded operating system with focus on the footprint and the real-time capabili- ties of the system. Keywords: Java, Embedded Real-Time Systems, Automotive, Isolation, KESO 1. INTRODUCTION Modern cars contain a multitude of micro controllers for a wide area of tasks, ranging from convenience features such as the supervision of the car’s audio system to safety relevant functions such as assisting the braking system of the car.
    [Show full text]
  • Secure Control Applications in Smart Homes and Buildings
    Die approbierte Originalversion dieser Dissertation ist in der Hauptbibliothek der Technischen Universität Wien aufgestellt und zugänglich. http://www.ub.tuwien.ac.at The approved original version of this thesis is available at the main library of the Vienna University of Technology. http://www.ub.tuwien.ac.at/eng Secure Control Applications in Smart Homes and Buildings DISSERTATION submitted in partial fulfillment of the requirements for the degree of Doktor der Technischen Wissenschaften by Mag. Dipl.-Ing. Friedrich Praus Registration Number 0025854 to the Faculty of Informatics at the Vienna University of Technology Advisor: Ao.Univ.Prof. Dipl.-Ing. Dr.techn. Wolfgang Kastner The dissertation has been reviewed by: Ao.Univ.Prof. Dipl.-Ing. Prof. Dr. Peter Palensky Dr.techn. Wolfgang Kastner Vienna, 1st October, 2015 Mag. Dipl.-Ing. Friedrich Praus Technische Universität Wien A-1040 Wien Karlsplatz 13 Tel. +43-1-58801-0 www.tuwien.ac.at Erklärung zur Verfassung der Arbeit Mag. Dipl.-Ing. Friedrich Praus Hallergasse 11/29, A-1110 Wien Hiermit erkläre ich, dass ich diese Arbeit selbständig verfasst habe, dass ich die verwen- deten Quellen und Hilfsmittel vollständig angegeben habe und dass ich die Stellen der Arbeit – einschließlich Tabellen, Karten und Abbildungen –, die anderen Werken oder dem Internet im Wortlaut oder dem Sinn nach entnommen sind, auf jeden Fall unter Angabe der Quelle als Entlehnung kenntlich gemacht habe. Wien, 1. Oktober 2015 Friedrich Praus v Kurzfassung Die zunehmende Integration von heterogenen Gebäudeautomationssystemen ermöglicht gesteigerten Komfort, Energieeffizienz, verbessertes Gebäudemanagement, Nachhaltig- keit sowie erweiterte Anwendungsgebiete, wie beispielsweise “Active Assisted Living” Szenarien. Diese Smart Homes und Gebäude sind heutzutage als dezentrale Systeme rea- lisiert, in denen eingebettete Geräte Prozessdaten über ein Netzwerk austauschen.
    [Show full text]
  • Android Cours 1 : Introduction `Aandroid / Android Studio
    Android Cours 1 : Introduction `aAndroid / Android Studio Damien MASSON [email protected] http://www.esiee.fr/~massond 21 f´evrier2017 R´ef´erences https://developer.android.com (Incontournable !) https://openclassrooms.com/courses/ creez-des-applications-pour-android/ Un tutoriel en fran¸caisassez complet et plut^ot`ajour... 2/52 Qu'est-ce qu'Android ? PME am´ericaine,Android Incorporated, cr´e´eeen 2003, rachet´eepar Google en 2005 OS lanc´een 2007 En 2015, Android est le syst`emed'exploitation mobile le plus utilis´edans le monde (>80%) 3/52 Qu'est-ce qu'Android ? Cinq couches distinctes : 1 le noyau Linux avec les pilotes ; 2 des biblioth`equeslogicielles telles que WebKit/Blink, OpenGL ES, SQLite ou FreeType ; 3 un environnement d'ex´ecutionet des biblioth`equespermettant d'ex´ecuterdes programmes pr´evuspour la plate-forme Java ; 4 un framework { kit de d´eveloppement d'applications ; 4/52 Android et la plateforme Java Jusqu'`asa version 4.4, Android comporte une machine virtuelle nomm´eeDalvik Le bytecode de Dalvik est diff´erentde celui de la machine virtuelle Java de Oracle (JVM) le processus de construction d'une application est diff´erent Code Java (.java) ! bytecode Java (.class/.jar) ! bytecode Dalvik (.dex) ! interpr´et´e L'ensemble de la biblioth`equestandard d'Android ressemble `a J2SE (Java Standard Edition) de la plateforme Java. La principale diff´erenceest que les biblioth`equesd'interface graphique AWT et Swing sont remplac´eespar des biblioth`equesd'Android. 5/52 Android Runtime (ART) A` partir de la version 5.0 (2014), l'environnement d'ex´ecution ART (Android RunTime) remplace la machine virtuelle Dalvik.
    [Show full text]
  • Jamaicavm 8.1 — User Manual
    JamaicaVM 8.1 — User Manual Java Technology for Critical Embedded Systems aicas GmbH 2 JamaicaVM 8.1 — User Manual: Java Technology for Critical Embedded Systems JamaicaVM 8.1, Release 1. Published May 31, 2017. c 2001–2017 aicas GmbH, Karlsruhe. All rights reserved. No licenses, expressed or implied, are granted with respect to any of the technology described in this publication. aicas GmbH retains all intellectual property rights associated with the technology described in this publication. This publication is intended to assist application developers to develop applications only for the Jamaica Virtual Machine. Every effort has been made to ensure that the information in this publication is accurate. aicas GmbH is not responsible for printing or clerical errors. Although the information herein is provided with good faith, the supplier gives neither warranty nor guarantee that the information is correct or that the results described are obtainable under end-user conditions. aicas GmbH phone +49 721 663 968-0 Emmy-Noether-Straße 9 fax +49 721 663 968-99 76131 Karlsruhe email [email protected] Germany web http://www.aicas.com aicas incorporated phone +1 203 359 5705 6 Landmark Square, Suite 400 Stamford CT 06901 email [email protected] USA web http://www.aicas.com aicas GmbH phone +33 1 4997 1762 9 Allee de l’Arche fax +33 1 4997 1700 92671 Paris La Defense email [email protected] France web http://www.aicas.com This product includes software developed by IAIK of Graz University of Technology. This software is based in part on the work of the Independent JPEG Group.
    [Show full text]
  • Partner Directory Wind River Partner Program
    PARTNER DIRECTORY WIND RIVER PARTNER PROGRAM The Internet of Things (IoT), cloud computing, and Network Functions Virtualization are but some of the market forces at play today. These forces impact Wind River® customers in markets ranging from aerospace and defense to consumer, networking to automotive, and industrial to medical. The Wind River® edge-to-cloud portfolio of products is ideally suited to address the emerging needs of IoT, from the secure and managed intelligent devices at the edge to the gateway, into the critical network infrastructure, and up into the cloud. Wind River offers cross-architecture support. We are proud to partner with leading companies across various industries to help our mutual customers ease integration challenges; shorten development times; and provide greater functionality to their devices, systems, and networks for building IoT. With more than 200 members and still growing, Wind River has one of the embedded software industry’s largest ecosystems to complement its comprehensive portfolio. Please use this guide as a resource to identify companies that can help with your development across markets. For updates, browse our online Partner Directory. 2 | Partner Program Guide MARKET FOCUS For an alphabetical listing of all members of the *Clavister ..................................................37 Wind River Partner Program, please see the Cloudera ...................................................37 Partner Index on page 139. *Dell ..........................................................45 *EnterpriseWeb
    [Show full text]
  • Actor-Oriented Programming for Resource Constrained Multiprocessor Networks on Chip
    Actor-Oriented Programming for Resource Constrained Multiprocessor Networks on Chip Gary J. Plumbridge PhD University of York Computer Science August 2015 for Ellie Abstract Multiprocessor Networks on Chip (MPNoCs) are an attractive architecture for inte- grated circuits as they can benefit from the improved performance of ever smaller tran- sistors but are not severely constrained by the poor performance of global on-chip wires. As the number of processors increases it becomes ever more expensive to provide co- herent shared memory but this is a foundational assumption of thread-level parallelism. Threaded models of concurrency cannot efficiently address architectures where shared memory is not coherent or does not exist. In this thesis an extended actor oriented programming model is proposed to en- able the design of complex and general purpose software for highly parallel and de- centralised multiprocessor architectures. This model requires the encapsulation of an execution context and state into isolated Machines which may only initiate communica- tion with one another via explicitly named channels. An emphasis on message passing and strong isolation of computation encourages application structures that are congru- ent with the nature of non-shared memory multiprocessors, and the model also avoids creating dependences on specific hardware topologies. A realisation of the model called Machine Java is presented to demonstrate the ap- plicability of the model to a general purpose programming language. Applications designed with this framework are shown to be capable of scaling to large numbers of processors and remain independent of the hardware targets. Through the use of an efficient compilation technique, Machine Java is demonstrated to be portable across sev- eral architectures and viable even in the highly constrained context of an FPGA hosted MPNoC.
    [Show full text]
  • Smart Dynamic Software Components Enabling Decision Support in Machine-To-Machine Networks
    IJCSI International Journal of Computer Science Issues, Vol. 10, Issue 1, No 3, January 2013 ISSN (Print): 1694-0784 | ISSN (Online): 1694-0814 www.IJCSI.org 540 Smart dynamic software components enabling decision support in Machine-to-machine networks Alexander Dannies1*, Javier Palafox-Albarrán1, Walter Lang1 and Reiner Jedermann1 1 Institute for Microsensors, -actuators and -systems, University of Bremen Bremen, Bremen, Germany technologies more ubiquitous, devices have to collect Abstract information from a high number of devices distributed in The future Internet of Things will be extended by machine-to- the environment. For such a detailed supervision CRN are machine communication technologies in order to include sensor rather disadvantageous for the following reasons: information. The overwhelming amount of data will require autonomous decision making processes which are directly Communication costs have to be kept as low as executed at the location where data is generated or measured. An possible. intelligent sensor system needs to be able to adapt to new parameters in its surrounding unknown at the time of deployment. Network protocols have to be optimized for In our paper we show that Java enables software updates on transmission of small packets of sensor data mobile devices and also that it is possible to run algorithms consuming as little energy as possible instead of required for decision making processes on wireless sensor enabling global communication. platforms based on Java. Keywords: Machine-to-Machine communication, Internet of In many applications, such as the monitoring Things, autonomous logistics, Java, dynamic updates, OSGi. inside large buildings or rural regions, the supervised area will not be fully covered by the CRN of an external operator.
    [Show full text]
  • Interrupt Handlers in Java
    Downloaded from orbit.dtu.dk on: Oct 06, 2021 Interrupt Handlers in Java Korsholm, Stephan; Schoeberl, Martin; Ravn, Anders P. Published in: Proceedings of the 11th IEEE International Symposium on Object/component/service-oriented Real-time distributed Computing (ISORC 2008) Link to article, DOI: 10.1109/ISORC.2008.68 Publication date: 2008 Document Version Early version, also known as pre-print Link back to DTU Orbit Citation (APA): Korsholm, S., Schoeberl, M., & Ravn, A. P. (2008). Interrupt Handlers in Java. In Proceedings of the 11th IEEE International Symposium on Object/component/service-oriented Real-time distributed Computing (ISORC 2008) (pp. 453-457) https://doi.org/10.1109/ISORC.2008.68 General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Interrupt Handlers in Java Stephan Korsholm Martin Schoeberl Department of Computer Science Institute of Computer Engineering Aalborg University DK-9220 Aalborg Vienna University of Technology, Austria [email protected] [email protected] Anders P.
    [Show full text]
  • Concurrent Compaction Using a Field Pinning Protocol
    Concurrent Compaction using a Field Pinning Protocol Erik Osterlund¨ Welf Lowe¨ Linnaeus University, Sweden Linnaeus University, Sweden [email protected] [email protected] Abstract objects and relocate them, i.e., perform compaction. Then Compaction of memory in long running systems has always the unused memory (garbage) is reclaimed. been important. The latency of compaction increases in to- We distinguish logical objects from their physical mem- day’s systems with high memory demands and large heaps. ory locations referred to as cells; a fragmented heap memory To deal with this problem, we present a lock-free protocol al- region is called from-space, a continuous heap memory re- gion is called to-space.1 lowing for copying concurrent with the application running, 2 which reduces the latencies of compaction radically. It pro- There are two different actors in GC. The garbage col- vides theoretical progress guarantees for copying and appli- lector(s) and the mutator(s). The garbage collector finds live cation threads without making it practically infeasible, with objects by scanning the stacks and globals for references to performance overheads of 15% on average. The algorithm root objects, identifies other live objects by computing the paves the way for a future lock-free Garbage Collector. transitive closure of these roots, and determines the con- demned set of potential objects for relocation. The garbage Categories and Subject Descriptors D.3.4 [Programming collector compacts memory by relocating live objects of the Languages]: Processors—memory management, garbage condemned set: it copies the payload of cells in from-space collection; D.1.3 [Programming Techniques]: Concurrent to cells in to-space and then remaps incoming references, Programming—parallel programming i.e., updates them to refer to the to-space cell.
    [Show full text]
  • Cooperative Framework for Open Real-Time Systems
    Departamento de Engenharia Informática Instituto Superior de Engenharia do Porto Cooperative Framework for Open Real-Time Systems Cláudio Roberto Ribeiro Maia Dissertação para a obtenção do Grau de Mestre em Engenharia Informática Área de especialização em Arquitectura, Sistemas e Redes Orientador Professor Doutor Luís Miguel Pinho Nogueira Júri Presidente: Professora Doutora Maria de Fátima Coutinho Rodrigues, Professora Coordenadora no Departamento de Engenharia Informática do Instituto Superior de Engenharia do Porto Vogais: Professor Doutor Alexandre Manuel Tavares Bragança, Professor Adjunto no Departamento de Engenharia Informática do Instituto Superior de Engenharia do Porto Professor Doutor Luís Miguel Pinho Nogueira, Professor Adjunto no Departamento de Engenharia Informática do Instituto Superior de Engenharia do Porto Porto, Fevereiro de 2011 ACKNOWLEDGEMENTS Since this project started back in October 2009, many people contributed by sharing experiences, guid- ance, knowledge and wisdom. In order to show my respect and gratitude to them, I would like to take this opportunity to do it. First of all, I would like to thank all the people at ISEP that in some way provided me with their support. More specifically, my school collegues for keeping me sane, the teachers for clarifying me with all sort of answers, the security guards for opening the doors during the night, the cleaning ladies for their warmful "Good mornings" and the remaining people to whom I have spoken and discussed about many different topics. I would also like to thank CISTER Research Centre for the opportunity of working in the CooperatES (Cooperative Embedded Systems) project (PTDC/EIA/71624/2006), which was the main driver to the MSc work presented in this document.
    [Show full text]
  • Java on Bare Metal with the Fiji VM
    Real Time Java on resource-constrained platforms with Fiji VM Filip Pizlo Lukasz Ziarek Jan Vitek Department of Computer Science, Purdue University, W. Lafayette, IN, 47909 Fiji Systems, LLC, Indianapolis, IN 46202. E-mail: {fil,luke,jan}@fiji-systems.com Abstract 3. A survey of limitations Java virtual machines face when tar- Real-time Java is quickly emerging as a platform for building geting hard real-time systems. We discuss our previous experi- safety-critical embedded systems. The real-time variants of Java, ence embedding Java virtual machines and identify six key goals including [8, 15], are attractive alternatives to Ada and C since state-of-the-art virtual machines should address to be better suited they provide a cleaner, simpler, and safer programming model. for hard real-time and mission critical application domains. Unfortunately, current real-time Java implementations have trouble 4. A concise description of the Fiji VM compiler and runtime scaling down to very hard real-time embedded settings, where system. We describe the unique features of the Fiji VM compiler memory is scarce and processing power is limited. In this paper, we and runtime system and their implementation. We address each of describe the architecture of the Fiji VM, which enables vanilla Java the six goals in the implementation and design of the Fiji VM. applications to run in very hard environments, including booting on bare hardware with only very rudimentary operating system 5. A performance comparison between the Fiji VM and state-of- support. We also show that our minimalistic approach delivers the-art, server-class Java VMs.
    [Show full text]
  • Efficient Compilation of .NET Programs for Embedded Systems
    Journal of Object Technology Published by AITO — Association Internationale pour les Technologies Objets, c JOT 2011 Online at http://www.jot.fm. Efficient Compilation of .NET Programs for Embedded Systems Olivier Sallenaveab Roland Ducournaub a. Cortus S.A., Montpellier, France http://www.cortus.com b. LIRMM — CNRS and Université Montpellier 2, France http://www.lirmm.fr Abstract Compiling under the closed-world assumption (CWA) has been shown to be an appropriate way for implementing object-oriented lan- guages such as Java on low-end embedded systems. In this paper, we ex- plore the implications of using whole program optimizations such as Rapid Type Analysis (RTA) and coloring on programs targeting the .Net infras- tructure. We extended RTA so that it takes into account .Net specific features such as (i) array covariance, a language feature also supported in Java, (ii) generics, whose specifications in .Net impacts type analysis and (iii) delegates, which encapsulate methods within objects. We also use an intraprocedural control flow analysis in addition to RTA . We eval- uated the optimizations that we implemented on programs written in C#. Preliminary results show a noticeable reduction of the code size, class hi- erarchy and polymorphism of the programs we optimize. Array covariance is safe in almost all cases, and some delegate calls can be implemented as direct calls. Keywords array covariance, closed-world assumption, delegate, late bind- ing, subtype test, type analysis 1 Introduction High-end embedded systems such as mobile phones have widely adopted object- oriented languages like Java. Object-oriented programming offers code reuse through inheritance and more reliable designs, which improves the productivity in software development.
    [Show full text]