DOCSLIB.ORG

AJVM – Java Virtual Machine Implemented in Actionscript 3.0

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
AJVM – Java Virtual Machine Implemented in Actionscript 3.0 Journal of Automation, Mobile Robotics & Intelligent Systems VOLUME 10, N° 1 2016 AJVM – Java Virtual Machine Implemented in ActionScript 3.0 Submitted: 5th January 2016; accepted: 2nd February 2016 Arkadiusz Janik, Jakub Krawczyk DOI: 10.14313/JAMRIS_1-2016/8 solution allowing to execute (in an isolated environ- ment) the whole OS and other software designed for Abstract: This paper describes the concept and implementation (VMWare Workstation or Oracle xVM VirtualBox). details of AJVM – state-of-the art Java Virtual Machine Thea specific interpreter platform is software due to capable hardware of executing virtualization bina- (JVM) implemented in ActionScript 3.0. Action Script ry, precompiled code which is an output of a built-in is an objective programming language that supports compilation to Java bytecode. In the presented solu- device [7]. In the further part of this paper the term tion there has been a novel idea utilized – to use the virtualcompiler machine defining will its be own used architecture to denote the as interpreter.of a virtual other Virtual Machine’s execution environment (Action- Script Virtual Machine) to build Java Virtual Machine. 1.2. Flash Platform and ActionScript 3.0 The subset of features specified in JVM Specification Adobe Flash technology (previously known as v.2 supported by AJVM has been chosen in a way which Macromedia Flash) is a multimedia platform en- enables the machine to be used in many practical ap- abling new features in web pages: animations, video plications both in the commercial context as well as in streaming, interactivity commonly used to imple- science. As the architecture of AJVM is modular, the ex- ment games, advertisements as well as more sophis- tension of its features in the future will not cause any ticated and complex applications. difficulties. The implementation of AJVM in ActionScript 3.0 which is executed by ActionScript Virtual Machine (Shockwave Flash Object). Usually there is a single (AVM) makes it possible to use Java code in applications Flash applications are published as SWF files written in ActionScript 3.0. It spawns many new oppor- libraries and multimedia resources. In Flash 5 the tunities considering that AVM is a part of FlashPlayer – conceptfile per application of actions introduced even though in itFlash may 4contain was extend many- commonly used multimedia player available in the form Action Script term was used of plugins for the majority of modern web browsers, in- in the context of a programming language [10, 11]. cluding mobile versions. Flashed and, 7 forwas the released first time, together with the second ver- sion of ActionScript programming language: such Keywords: JVM, Action Script, bytecode features as type-control (during compilation) and inheritance based on classes were introduced. Flash Players 9 was released with ActionScript 3.0 – the 1. Introduction - Traditional, commercial implementations of JVM port downgrade compatibility, there are two virtual Specification aim to increase the performance of machineslanguage wasin the redesigned player: AVM1 significantly (to support and, toAction sup- a Virtual Machine (VM). As a result VMs are usually Script 1.0 and 2.0) and AVM2 (to support Action- implemented in low level programming languages, Script 3.0) [14]. The number of new features have tightly integrated with Operating System (OS) and been introduced to the player including performance hardware (Just In Time compilers that compile by- tecode into native code of the hardware platform). OpenGL), type-control (during code compilation and The goal of AJVM is to execute Java applications in execution),optimization separation (hardware of acceleration class-based forand DirectX prototype- and a variety of computers equipped mainly with a web based inheritance, using packages, namespaces and browser, to increase code reusability by making it regular expressions, new bytecode format, support possible to use Java libraries in Flash applications and to provide convenient platform for end-users to To sum up: ActionScript 3.0 is object-based, im- observe and understand concepts behind JVM. On perativefor E4X format programing and others. language with strong type-con- top of that the solution extends Flash platform with trol, compiled to bytecode being executed on AVM2 new features: multi-threading, blocking operations, virtual machine, single-threaded (driven by events generic classes as well as a new concept of execut- triggered by Flash Player) so not supporting blocking ing bytecode. methods, with automatic memory management (Gar- bage Collector), not supporting generic classes, not 1.1. Basic Terms supporting anonymous classes. There are two major types of virtual machines: In the further part of the paper any references to emulators and interpreters [9]. The emulator is a Action Script will refer to Action Script 3.0. 58 Journal of Automation, Mobile Robotics & Intelligent Systems VOLUME 10, N° 1 2016 2. Related Work AminNes – Flash NES Emulator – Flash NES Emu- There are two major aspects of the contribution lator is an emulator of Nintendo Entertainment System of our work: Implementation of Java Virtual Machine in a non- 2KB video memory. The emulator supports MOS 6502 standard environment and– 8 bitsguarantees gaming theconsole highest equipped quality withof rendered 2kB RAM video. and Emulation of Java platform inside Flash Player. Flip8 – CHIP-8 Flash Emulator - In the opinion of the authors, there are no solu- tions other than AJVM that handle both: Action Script in 70s used to interpret programming– Flip8 language is an called emu and JVM. This makes AJVM a unique system capable of lator of CHIP-8. CHIP-8 is a virtual machine designed- emulating Java platform inside Flash Player. There are number of publications on the subject includingCHIP-8. It 35 used different to be operationsinstalled on [19]. a graphical calcu of non-standard JVMs including the ones mentioned lators. Flip8 is an emulator able to execute bytecode below: 3. Implementation of JVM in ActionScript 3.0 Jamiga – the goal of the project is to execute Java ActionScript Java Virtual Machine (AJVM) was applications on Amiga computers [16]. implemented in Action Script [13]. It implements JC – the property of the JVM is a novel approach to executing bytecode. All Java classes are translated JVM v.2.0. The sections included below present more - informationa subset of features on the architecture described in and the implementationspecification of piled to native code thus enabling performance simi- problems the authors of this article had to solve. laron-the-fly to traditional to source Just code In Time in C languageCompilers and (JITs) then [17]. com Squawk – implementation of JVM for Java ME (Mi- 3.1. Virtual Machine vs Standard Library cro Edition) for embedded systems and small, mobile The crucial part of the implementation of any devices. All elements, except for low-level modules sup- Java Virtual Machine is a standard library – the im- - plementation of core Java classes described by JVM plemented in Java (including Garbage Collector) [15]. Hello portingGNU I/O Classpath operations – Java and Standard OS specific Library code, distributwere im- Word Java application requires hundreds of core Java ed under GNU license providing a great base to build classesspecification to be present[4]. Even and execution loaded into of the VM. simplest The solution own JVMs [20]. described in the paper contains following elements in JOP - terms of a standard library: plementation of JVM with predictable execution time AJVM library – ActionScript 3.0 library contain- – Java Optimized Processor is a hardware im Flash or Flex projects. Flex is a set of components al- afor low embedded cost FPGA real-time (Field-Programmable systems. Due toGate the Array). small ing executable files of AJVM, ready to be used in any- size of the processor used, it can be implemented in be of more importance though slightly more expen- Silverlightlowing a developer [12]. to write RIA applications. It is be siveFor low than volume conventional systems, processors. the flexibility The ofprocessor an FPGA wascan ing ARTcompared standard to technologies library – suchan equivalent as XUL, JavaFX of Java or standard library included in any JVM distributions - sordesigned executes in VHDL bytecode programming directly, without language necessity (Very high to speed Hardware Description Language). The proces- native(such asimplementation JRE System Library of selected for JavaSE). methods A in standard the VM. Forlibrary the ispurpose specific of for AJVM VM implementationwe implemented as a itstandard expects (whichcompile is in-time consistent nor withto parse/interpret JVM –stack-based class VM files. rather Us thaning FPGA register-based) allows JOP to[21]. dynamically declare stack size based on GNU Classpath. Sable VM libraryAs the called authors ART focused (ActionScript on the selectedRuntime) features which ofis virtual machine, using state-of-the-art interpretation techniques. Its– goalsis a highly is to portablebe reasonably and efficient small, fast,Java standard library though it is possible to extend the implementationJVM, the ART is not in future. a complete implementation of the and compliant with the various specifications (JVM 3.2. High Level Overview of AJVM specification,2.1. Emulators JNI, of invocation Other Platforms interface, Implemented etc.) [18]. AJVM is available as an object created by the pro- in the Flash grammer’s code inside his/her Flash application (in Even though ActionScript 3.0 is relatively new lan- the similar way as for Jython interpreter for Python guage there have been several emulators implement- programming language). Consequently, the program- ed so far: mer’s code has a full control over AJVM. Moreover, FC64 – Flash Commodore 64 Emulator – FC64 is several isolated instances of AJVM within the single a low-level, fully functional emulator of Commodore Flash host application can be created. 64 allowing a user to execute applications designed - for Commodore 64 as well as to write code in BASIC ally the code of Flash host-application and the code programming language [22].
Load more

Recommended publications
  • Apache Harmony Project Tim Ellison Geir Magnusson Jr
    The Apache Harmony Project Tim Ellison Geir Magnusson Jr. Apache Harmony Project http://harmony.apache.org TS-7820 2007 JavaOneSM Conference | Session TS-7820 | Goal of This Talk In the next 45 minutes you will... Learn about the motivations, current status, and future plans of the Apache Harmony project 2007 JavaOneSM Conference | Session TS-7820 | 2 Agenda Project History Development Model Modularity VM Interface How Are We Doing? Relevance in the Age of OpenJDK Summary 2007 JavaOneSM Conference | Session TS-7820 | 3 Agenda Project History Development Model Modularity VM Interface How Are We Doing? Relevance in the Age of OpenJDK Summary 2007 JavaOneSM Conference | Session TS-7820 | 4 Apache Harmony In the Beginning May 2005—founded in the Apache Incubator Primary Goals 1. Compatible, independent implementation of Java™ Platform, Standard Edition (Java SE platform) under the Apache License 2. Community-developed, modular architecture allowing sharing and independent innovation 3. Protect IP rights of ecosystem 2007 JavaOneSM Conference | Session TS-7820 | 5 Apache Harmony Early history: 2005 Broad community discussion • Technical issues • Legal and IP issues • Project governance issues Goal: Consolidation and Consensus 2007 JavaOneSM Conference | Session TS-7820 | 6 Early History Early history: 2005/2006 Initial Code Contributions • Three Virtual machines ● JCHEVM, BootVM, DRLVM • Class Libraries ● Core classes, VM interface, test cases ● Security, beans, regex, Swing, AWT ● RMI and math 2007 JavaOneSM Conference | Session TS-7820 |
    [Show full text]
  • Openjdk – the Future of Open Source Java on GNU/Linux
    OpenJDK – The Future of Open Source Java on GNU/Linux Dalibor Topić Java F/OSS Ambassador Blog aggregated on http://planetjdk.org Java Implementations Become Open Source Java ME, Java SE, and Java EE 2 Why now? Maturity Java is everywhere Adoption F/OSS growing globally Innovation Faster progress through participation 3 Why GNU/Linux? Values Freedom as a core value Stack Free Software above and below the JVM Demand Increasing demand for Java integration 4 Who profits? Developers New markets, new possibilities Customers More innovations, reduced risk Sun Mindshare, anchoring Java in GNU/Linux 5 License + Classpath GPL v2 Exception • No proprietary forks (for SE, EE) • Popular & trusted • Programs can have license any license • Compatible with • Improvements GNU/Linux remain in the community • Fostering adoption • FSFs license for GNU Classpath 6 A Little Bit Of History Jun 1996: Work on gcj starts Nov 1996: Work on Kaffe starts Feb 1998: First GNU Classpath Release Mar 2000: GNU Classpath and libgcj merge Dec 2002: Eclipse runs on gcj/Classpath Oct 2003: Kaffe switches to GNU Classpath Feb 2004: First FOSDEM Java Libre track Apr 2004: Richard Stallman on the 'Java Trap' Jan 2005: OpenOffice.org runs on gcj Mai 2005: Work on Harmony starts 7 Sun & Open Source Java RIs Juni 2005: Java EE RI Glassfish goes Open Source Mai 2006: First Glassfish release Mai 2006: Java announced to go Open Source November 2006: Java ME RI PhoneME goes Open Source November 2006: Java SE RI Hotspot und Javac go Open Source Mai 2007: The rest of Java SE follows suit 8 Status: JavaOne, Mai 2007 OpenJDK can be fully built from source, 'mostly' Open Source 25,169 Source code files 894 (4%) Binary files (“plugs”) 1,885 (8%) Open Source, though not GPLv2 The rest is GPLv2 (+ CP exception) Sun couldn't release the 4% back then as free software.
    [Show full text]
  • Eclipse (Software) 1 Eclipse (Software)
    Eclipse (software) 1 Eclipse (software) Eclipse Screenshot of Eclipse 3.6 Developer(s) Free and open source software community Stable release 3.6.2 Helios / 25 February 2011 Preview release 3.7M6 / 10 March 2011 Development status Active Written in Java Operating system Cross-platform: Linux, Mac OS X, Solaris, Windows Platform Java SE, Standard Widget Toolkit Available in Multilingual Type Software development License Eclipse Public License Website [1] Eclipse is a multi-language software development environment comprising an integrated development environment (IDE) and an extensible plug-in system. It is written mostly in Java and can be used to develop applications in Java and, by means of various plug-ins, other programming languages including Ada, C, C++, COBOL, Perl, PHP, Python, Ruby (including Ruby on Rails framework), Scala, Clojure, and Scheme. The IDE is often called Eclipse ADT for Ada, Eclipse CDT for C/C++, Eclipse JDT for Java, and Eclipse PDT for PHP. The initial codebase originated from VisualAge.[2] In its default form it is meant for Java developers, consisting of the Java Development Tools (JDT). Users can extend its abilities by installing plug-ins written for the Eclipse software framework, such as development toolkits for other programming languages, and can write and contribute their own plug-in modules. Released under the terms of the Eclipse Public License, Eclipse is free and open source software. It was one of the first IDEs to run under GNU Classpath and it runs without issues under IcedTea. Eclipse (software) 2 Architecture Eclipse employs plug-ins in order to provide all of its functionality on top of (and including) the runtime system, in contrast to some other applications where functionality is typically hard coded.
    [Show full text]
  • Fedora Core, Java™ and You
    Fedora Core, Java™ and You Gary Benson Software Engineer What is Java? The word ªJavaº is used to describe three things: The Java programming language The Java virtual machine The Java platform To support Java applications Fedora needs all three. What Fedora uses: GCJ and ECJ GCJ is the core of Fedora©s Java support: GCJ includes gcj, a compiler for the Java programming language. GCJ also has a runtime and class library, collectively called libgcj. The class library is separately known as GNU Classpath. ECJ is the Eclipse Compiler for Java: GCJ©s compiler gcj is not used for ªtraditionalº Java compilation. More on that later... Why libgcj? There are many free Java Virtual machines: Cacao, IKVM, JamVM, Jikes RVM, Kaffe, libgcj, Sable VM, ... There are two main reasons Fedora uses libgcj: Availability on many platforms. Ability to use precompiled native code. GNU Classpath Free core class library for Java virtual machines and compilers. The JPackage Project A collection of some 1,600 Java software packages for Linux: Distribution-agnostic RPM packages. Both runtimes/development kits and applications. Segregation between free and non-free packages. All free packages built entirely from source. Multiple runtimes/development kits may be installed. Fedora includes: JPackage-compatible runtime and development kit packages. A whole bunch of applications. JPackage JOnAS Fedora©s Java Compilers gcj can operate in several modes: Java source (.java) to Java bytecode (.class) Java source (.java) to native machine code (.o) Java bytecode (.class, .jar) to native machine code (.o) In Fedora: ECJ compiles Java source to bytecode. gcj compiles that bytecode to native machine code.
    [Show full text]
  • Solution Brief JVM Performance Monitoring
    Solution Brief Monitoring the Health & Performance of Java Virtual Machines (JVM) Total Performance Visibility JVM: The Cornerstone of Java Enterprise Applications The Java Virtual Machine (JVM) forms the core of the Java application architecture. It plays the crucial role of interpreting and translating Java byte code into operations on the host platform. Since Java middleware (application servers such as Tomcat, JBoss EAP, JBoss AS, WildFly, WebSphere, and WebLogic) runs on the JVM, a performance issue at the JVM level has a major impact on business services supported by it. Monitoring of the JVM must be an integral part of any Java application performance monitoring strategy. IT Ops and DevOps teams use JVM Key Benefits performance metrics to troubleshoot server-side bottlenecks. Developers and architects can also benefit from JVM monitoring by uncovering code- Proactively detect and resolve level issues. Java application problems to ensure high service uptime and business continuity Key JVM Performance Questions to Answer Troubleshoot faster: Real-time • Is there any runaway thread hogging the CPU? Which line of code is it alerts pinpoint the exact line executing, in which class, and which method? of code that is impacting Java • Is the JVM heap and non-heap memory sized correctly? applications • Are there any out-of-memory-exceptions or memory leaks? In-depth analytics enable architects to optimize Java • When does garbage collection happen, and how much memory is applications to scale and support freed up each time? additional users • Are there any thread deadlocks happening that are causing Single pane of glass to monitor application processing to be hung? everything Java—from application server, JVM and database, all the way down to server and storage End-to-End JVM Monitoring with eG Enterprise infrastructure eG Enterprise is a comprehensive performance monitoring, diagnosis and reporting solution for Java application infrastructures.
    [Show full text]
  • FOSDEM 2006 – Saturday 25Th February (Part 1) 1/6
    FOSDEM 2006 – Saturday 25th February (part 1) 1/6 10:00 OpenGroupware ▼ Opening Talks Tutorials KDE openSUSE Embedded Mozilla Tcl/Tk 13:00 (Janson) (H2215/Ferrer) (H.1301) (H.1302) (H.1308) (H.1309) +GNUstep (H.2111) (AW1.105) 13:00 lunch break 13:00 Movitation, 13:00 Opening and GNUstep devtools: Goals and 13:15 13:15 introduction GORM, StepTalk Opportunities Axel Hecht Nicolas Roard Systems VoIP 13:30 DTrace S. Krause-Harder, SETR LiveCD 13:30 M. Loeffler (Janson) (Lameere) 13:45 Jon Haslam Hector Oron 13:45 Mozilla 14:00 14:00 Kubuntu openSUSE Build 14:00 Foundation CoreData Intro to Plan9 SER Service Intro 14:15 14:15 Jonathan 14:15 G. Markham Sašo Kiselkov Tcl/Tk Uriel M. Jan Janak A. Schroeter, 14:30 Pereira 14:30 Ridell C. Schumacher, Optimizing 14:30 Mozilla Clif Flynt A. Bauer 14:45 14:45 Linux kernel 14:45 Europe 15:00 15:00 Open SUSE Linux and apps 15:00 Tristan Nitot Web applicationsGUI for DTrace Asterisk M.Opdenacker 15:15 Jon Haslam Mark 15:15 Key Devroom Power Mngmt 15:15 SeaMonkey with SOPE ASIC 15:30 Spencer 15:30 Signing Timo Hoenig, Lock-free data 15:30 Project Marcus Mueller verification 15:45 15:45 Holger Macht exchange for 15:45 Robert Kaiser Karel Nijs Real-Time apps 16:00 16:00 SUSE Linux 16:00 Xen Speex Asterisk Marketing Peter Soetens Flock GNUstep on the Hecl: 10.2: 16:15 Ian Pratt J.-M. Valin 16:15 Mark KDE 16:15 Z. Braniecki Zaurus PDA scripting Quo vadis ? 16:30 16:30 Spencer Sebastian Alsa SoC layer16:30 Nicolaus Schaller for mobiles Kügler M.Loeffler,C.Thiel D.N.Welton 16:45 16:45 Liam Girdwood 16:45 Mozilla 17:00 Closing Talks (Janson) 17:00 17:00 Project BOF 17:15 17:15 17:15 FOSDEM Donators Return 17:30 17:30 17:45 17:45 17:30 FSF Europe Opening Talks (Janson) Hacker Rooms LPI Exam Sessions 10:00 FOSDEM Core Staff Welcome Speech Building H: H2213 Saturday 13:00-14:30 10:30 Keynote Building AW: AW1.117 (H2214) 15:00-16:30 Richard M.
    [Show full text]
  • A Study of Cache Performance in Java Virtual Machines, the University of Texas at Austin, 2002
    Cache Performance in Java Virtual Machines: A Study of Constituent Phases Anand S. Rajan, Juan Rubio and Lizy K. John Laboratory for Computer Architecture Department of Electrical & Computer Engineering The University of Texas at Austin (arajan, jrubio,[email protected]) Abstract This paper studies the cache performance of Java programs in the interpreted and just-in- time (JIT) modes by analyzing memory reference traces of the SPECjvm98 applications with the Latte JVM. Specifically, we study the cache performance of the different components of the JVM (class loader, the execution engine and the garbage collector). Poor data cache performance in JITs is caused by code installation, and the data write miss rate can be as high as 70% in the execution engine. In addition, this code installation also causes deterioration in performance of the instruction cache during execution of translated code. We also believe that there is considerable interference between data accesses of the garbage collector and that of the compiler-translator execution engine of the JIT mode. We observe that the miss percentages in the garbage collection phase are of the order of 60% for the JIT mode; we believe that interference between data accesses of the garbage collector and the JIT execution engine lead to further deterioration of the data cache performance wherever the contribution of the garbage collector is significant. We observe that an increase in cache sizes does not substantially improve performance in the case of data cache writes, which is identified to be the principal performance bottleneck in JITs. 1 1. Introduction Java[1] is a widely used programming language due to the machine independent nature of bytecodes.
    [Show full text]
  • WCET Analysis of Java Bytecode Featuring Common Execution Environments
    WCET Analysis of Java Bytecode Featuring Common Execution Environments Christian Frost, Casper Svenning Jensen, Kasper Søe Luckow, Bent Thomsen Department of Computer Science, Aalborg University Selma Lagerlöfs Vej 300 DK-9220, Aalborg East, Denmark {chrfrost,semadk,luckow,bt}@cs.aau.dk ABSTRACT 1. INTRODUCTION We present a novel tool for statically determining the Worst Java in its traditional form, has inherent issues that makes Case Execution Time (WCET) of Java Bytecode-based pro- it less suitable for development of hard real-time embedded grams called Tool for Execution Time Analysis of Java byte- systems such as the lack of the notion of a deadline and code (TetaJ). This tool differentiates itself from existing high-resolution real-time clocks. To accommodate these, a tools by separating the individual constituents of the execu- variety of initiatives such as the Real-Time Specification tion environment into independent components. The prime for Java (RTSJ) [23] and related profiles: Safety Critical benefit is that it can be used for execution environments Java (SCJ) [16] and Predictable Java (PJ) [9] have been featuring common embedded processors and software im- initiated. These specify certain alterations to the under- plementations of the JVM. TetaJ employs a model checking lying Java Virtual Machine (JVM) and various extensions approach for statically determining WCET where the Java through libraries that, when adhered to, creates a program- program, the JVM, and the hardware are modelled as Net- ming model that can be used for real-time systems devel- works of Timed Automata (NTA) and given as input to the opment in Java.
    [Show full text]
  • Hitachi Cloud Accelerator Platform Product Manager HCAP V 1
    HITACHI Inspire the Next 2535 Augustine Drive Santa Clara, CA 95054 USA Contact Information : Hitachi Cloud Accelerator Platform Product Manager HCAP v 1 . 5 . 1 Hitachi Vantara LLC 2535 Augustine Dr. Santa Clara CA 95054 Component Version License Modified 18F/domain-scan 20181130-snapshot-988de72b Public Domain Exact BSD 3-clause "New" or "Revised" a connector factory 0.0.9 Exact License BSD 3-clause "New" or "Revised" a connector for Pageant using JNA 0.0.9 Exact License BSD 3-clause "New" or "Revised" a connector for ssh-agent 0.0.9 Exact License a library to use jsch-agent-proxy with BSD 3-clause "New" or "Revised" 0.0.9 Exact sshj License Exact,Ma activesupport 5.2.1 MIT License nually Identified Activiti - BPMN Converter 6.0.0 Apache License 2.0 Exact Activiti - BPMN Model 6.0.0 Apache License 2.0 Exact Activiti - DMN API 6.0.0 Apache License 2.0 Exact Activiti - DMN Model 6.0.0 Apache License 2.0 Exact Activiti - Engine 6.0.0 Apache License 2.0 Exact Activiti - Form API 6.0.0 Apache License 2.0 Exact Activiti - Form Model 6.0.0 Apache License 2.0 Exact Activiti - Image Generator 6.0.0 Apache License 2.0 Exact Activiti - Process Validation 6.0.0 Apache License 2.0 Exact Addressable URI parser 2.5.2 Apache License 2.0 Exact Exact,Ma adzap/timeliness 0.3.8 MIT License nually Identified aggs-matrix-stats 5.5.1 Apache License 2.0 Exact agronholm/pythonfutures 3.3.0 3Delight License Exact ahoward's lockfile 2.1.3 Ruby License Exact Exact,Ma ahoward's systemu 2.6.5 Ruby License nually Identified GNU Lesser General Public License ai's
    [Show full text]
  • Contributing to Eclipse: a Case Study
    Contributing to Eclipse: A Case Study Henttonen Katja, Matinlassi Mari VTT Technical Research Centre of Finland P.O. Box 1100, 90571 Oulu, Finland {Katja.Henttonen, Mari.Matinlassi}@vtt.fi Abstract: Open source software has gained a lot of well•deserved attention during the last few years. Eclipse is one of the most successful open source communities providing an open development environment and an application lifecycle platform. The main aim of this paper is to describe a case study on contributing to the Eclipse open source community and report experiences. The most important experiences are related to building an architecture model repository tool as an Eclipse plug•in and starting a new community around it. 1 Introduction Open source software (OSS) has been growing its popularity among software developers, communities and media over a decade and lately also the research community has been active in studying the subject. Among the most successful open source projects, Eclipse (www.eclipse.org) is an open development platform and application framework for building software. The Eclipse community has distinguished itself in productivity and creativity [Ki05] and has developed new features that have evolved Eclipse towards a platform that is integrating not only tools but also applications and services [Gr05]. The new features also make Eclipse a strong force in the embedded market [Er06] [Kl05] and make the community even more international [La05]. There are several ways of contributing to open source communities, e.g. fixing bugs and providing new features. In this paper, contributing to Eclipse is considered as a twofold issue. On the one hand, a contribution, i.e.
    [Show full text]
  • Distro Notes This Document Was Revised on March 9, 2011
    Distro Notes This document was revised on March 9, 2011. Older versions can be discarded. 1. Overview. This document discusses a Linux distro that's under construction. Comments are welcome. The distro is portable; most versions run directly from pocket-size media (thumbdrives, 3" Mini-DVDs, etc.). It's useful for multimedia tasks, software development, Internet file or site downloads, office work, and system maintenance. Some versions also provide a large collection of games (including lightweight that even people who "don't play games" may find diverting). Target: This distro is aimed at UNIX and MS-Windows CLI developers, system administrators, multimedia hobbyists, and people with an interest in chess (there's 11 chess engines) and lightweight games in general. Desktop: There's a lightweight desktop. The desktop doesn't include GNOME or KDE eye candy (dancing icons, 3D workspaces, etc.) but it gets the job done and does support a few special features, including remote access and single-instance support. Windows clones: This distro resembles old versions of MS-Windows visually, it includes some MS-Windows work-alike programs, and it runs MS-Windows programs. However, it's not aimed at MS-Windows people. Former MS-Windows users should try PCLinuxOS and Ubuntu instead (these are polished Windows-style distros). That said, this distro offers somes advantages over Windows-style distros: it's faster, in some cases; it requires less memory (*); it includes tools, collections, and databases that are generally unavailable or poorly maintained elsewhere; and you can run it from a Flash device that fits on a keychain.
    [Show full text]
  • Java and C I CSE 351 Autumn 2016
    L26: JVM CSE351, Spring 2018 Java Virtual Machine CSE 351 Spring 2018 Model of a Computer “Showing the Weather” Pencil and Crayon on Paper Matai Feldacker-Grossman, Age 4 May 22, 2018 L26: JVM CSE351, Spring 2018 Roadmap C: Java: Memory & data Integers & floats car *c = malloc(sizeof(car)); Car c = new Car(); x86 assembly c->miles = 100; c.setMiles(100); c->gals = 17; c.setGals(17); Procedures & stacks float mpg = get_mpg(c); float mpg = Executables free(c); c.getMPG(); Arrays & structs Memory & caches Assembly get_mpg: Processes language: pushq %rbp Virtual memory movq %rsp, %rbp ... Memory allocation popq %rbp Java vs. C ret OS: Machine 0111010000011000 code: 100011010000010000000010 1000100111000010 110000011111101000011111 Computer system: 2 L26: JVM CSE351, Spring 2018 Implementing Programming Languages Many choices in how to implement programming models We’ve talked about compilation, can also interpret Interpreting languages has a long history . Lisp, an early programming language, was interpreted Interpreters are still in common use: . Python, Javascript, Ruby, Matlab, PHP, Perl, … Interpreter Your source code implementation Your source code Binary executable Interpreter binary Hardware Hardware 3 L26: JVM CSE351, Spring 2018 An Interpreter is a Program Execute (something close to) the source code directly Simpler/no compiler – less translation More transparent to debug – less translation Easier to run on different architectures – runs in a simulated environment that exists only inside the interpreter process . Just port the interpreter (program), not the program-intepreted Slower and harder to optimize 4 L26: JVM CSE351, Spring 2018 Interpreter vs. Compiler An aspect of a language implementation . A language can have multiple implementations . Some might be compilers and other interpreters “Compiled languages” vs.
    [Show full text]