INF 123: Software Architectures, Distributed Systems, and Interoperability

1
INF 123 Software Architectures, Distributed
Systems, and Interoperability

• Discussion Session
• Week 4 - Spring 2008
• Instructor Prof. Richard N. Taylor
• TA Rosalva Gallardo

2
Overview

• Questions about Assignment 1
• ArchStudio 4
• Hello World Demo using ArchStudio 4 and Myx.fw

3
Questions about Assignment 1

• How our answer for 2.2 should look like? Should I
  include code details?
• How many types of connector do we have for 2.3?
• Any other questions?
• gt Post your questions in the Noteboard and
  check it often

4
ArchStudio 4An Introductory Tutorial

• Slides adapted from Hazel Asuncion

5
Roadmap

• What is ArchStudio 4
• Concepts
• xADL 2.0
• Data Bindings
• Myx Architectural Style
• Toolset integrated with Eclipse
• Eclipse plug-in
• AIM Launcher
• ArchEdit
• Archipelago
• ArchLight
• Selector
• Type Wrangler
• Using ArchStudio
• Hello World Demo

6
What is ArchStudio 4?

• Architecture-centric IDE
• Open-source
• Eclipse plug-in
• Integrated tools for software architecture
• Modeling
• Visualization
• Analysis
• Implementation

Ref http//www.isr.uci.edu/projects/archstudio/
7
Just Another IDE?

• No, it complements existing IDEs like Eclipse
• Minimize architectural drift
• Architectural drift is the introduction of
  principal design decisions into a systems
  descriptive architecture that are not included
  in, encompassed by, or implied by the
  prescriptive architecture, but which do not
  violate any of the prescriptive architectures
  design decisions
• If not properly addressed, architectural drift
  will eventually result in architectural erosion.
  Taylor et al, 2009
• Built on its own architecture style

8
Concepts

• xADL 2.0
• Data Bindings
• Myx Architectural Style

9
xADL 2.0

• Architectural Description Language in XML
  developed by ISR at UCI
• This ADL is defined in a set of XML Schemas
• Modeling language behind ArchStudio
• Modular and highly extensible
• Core models
• Components (computation)
• Connectors (communication)
• Interfaces (the exposed entry and exit points for
  components and connectors)
• Configurations (topology)

Ref http//www.isr.uci.edu/projects/archstudio/xa
dl2.html http//www.ics.uci.edu/edashofy/papers
/icse2002-presentation.ppt http//www.isr.uci.edu
/projects/xarchuci/
10
xADL 2.0

• Tools can access the architecture description in
  xADL 2.0 via a common interface, the component
  xArchADT.
• Base xArch Instances Core
• Extensions
• Architecture structures and types
• Product Families versions, options, variants
• Implementation mappings architecture types to
  implementations

Ref http//www.ics.uci.edu/edashofy/papers/icse2
002-presentation.ppt
11
xADL 2.0 CM/Product Family Arch
Ref http//www.ics.uci.edu/edashofy/papers/icse2
002-presentation.ppt
12
xADL 2.0 Implementation Mapping
ArchStudio 4 currently supports mapping to Java
files
Ref http//www.ics.uci.edu/edashofy/papers/icse2
002-presentation.ppt
13
XML

• eXtensible Markup Language
• Means of representing structured data
• Looks like HTML but the tags are user-defined
• Schema
• Describe data in the XML doc
• The rules for the XML doc

Ref http//www.w3schools.com/xml/default.asp

14
xADL 2.0 Core Model
ltarchStructure id"archStructure90164"
type"typesArchStructure"gt ltdescriptiongtmainlt/d
escriptiongt ltcomponent id"componentffa805157"
type"typesComponent"gt ltdescriptiongtServerlt/d
escriptiongt ltinterface id"interfaceffa80123"
type"typesInterface"gt ltdescriptiongtgetRes
ourcelt/descriptiongt ltdirectiongtinlt/directio
ngt lt/interfacegt lt/componentgt ltcomponent
id"componentffa12852" type"typesComponent"gt
ltdescriptiongtClientlt/descriptiongt
ltinterface id"interfaceffa57518"
type"typesInterface"gt ltdescriptiongtgetReso
urcelt/descriptiongt ltdirectiongtoutlt/directio
ngt lt/interfacegt lt/componentgt ltconnector
id"connectorffa12435" type"typesConnector"gt
ltdescriptiongtHTTPlt/descriptiongt ltinterface
id"interfaceffa54685" type"typesInterface"gt
ltdescriptiongtgetResourcelt/descriptiongt
ltdirectiongtinlt/directiongt lt/interfacegt
ltinterface id"interfaceffa54686"
type"typesInterface"gt ltdescriptiongtgetReso
urcelt/descriptiongt ltdirectiongtoutlt/directio
ngt lt/interfacegt lt/connectorgt lt/archStructur
egt
Server
HTTP
Client
15
xADL 2.0 Components
Server
ltcomponent id"componentffa805157"
type"typesComponent"gt ltdescriptiongtServerlt/d
escriptiongt ltinterface id"interfaceffa80123"
type"typesInterface"gt ltdescriptiongtgetRes
ourcelt/descriptiongt ltdirectiongtinlt/directio
ngt lt/interfacegt lt/componentgt ltcomponent
id"componentffa12852" type"typesComponent"gt
ltdescriptiongtClientlt/descriptiongt
ltinterface id"interfaceffa57518"
type"typesInterface"gt ltdescriptiongtgetReso
urcelt/descriptiongt ltdirectiongtoutlt/directio
ngt lt/interfacegt lt/componentgt
HTTP
Client
16
xADL 2.0 Connector
Server
ltconnector id"connectorffa12435"
type"typesConnector"gt ltdescriptiongtHTTPlt/des
criptiongt ltinterface id"interfaceffa54685"
type"typesInterface"gt ltdescriptiongtgetReso
urcelt/descriptiongt ltdirectiongtinlt/direction
gt lt/interfacegt ltinterface
id"interfaceffa54686" type"typesInterface"gt
ltdescriptiongtgetResourcelt/descriptiongt
ltdirectiongtoutlt/directiongt lt/interfacegt
lt/connectorgt
HTTP
Client
17
xADL 2.0 Interfaces
ltcomponent id"componentffa805157"
type"typesComponent"gt ltdescriptiongtServerlt/d
escriptiongt ltinterface id"interfaceffa80123"
type"typesInterface"gt ltdescriptiongtgetRes
ourcelt/descriptiongt ltdirectiongtinlt/directio
ngt lt/interfacegt lt/componentgt ltcomponent
id"componentffa12852" type"typesComponent"gt
ltdescriptiongtClientlt/descriptiongt
ltinterface id"interfaceffa57518"
type"typesInterface"gt ltdescriptiongtgetReso
urcelt/descriptiongt ltdirectiongtoutlt/directio
ngt lt/interfacegt lt/componentgt ltconnector
id"connectorffa12435" type"typesConnector"gt
ltdescriptiongtHTTPlt/descriptiongt ltinterface
id"interfaceffa54685" type"typesInterface"gt
ltdescriptiongtgetResourcelt/descriptiongt
ltdirectiongtinlt/directiongt lt/interfacegt
ltinterface id"interfaceffa54686"
type"typesInterface"gt ltdescriptiongtgetReso
urcelt/descriptiongt ltdirectiongtoutlt/directio
ngt lt/interfacegt lt/connectorgt
Server
HTTP
Client
18
Data Bindings

• A set of Java classes that can be used to create
  and manipulate architecture descriptions
• Generated by Apigen tool, based on XML schemas
• Reduces the complexity of editing architecture
  descriptions by hiding the XML and providing
  constructs more familiar to architects
• Parses from and serializes to XML

• Data Binding API
• Components
• Connectors
• Interfaces
• Links
• Configurations
• etc.

• XML API (DOM, SAX)
• Elements
• Attributes
• Documents
• Namespaces

vs.
Ref http//www.ics.uci.edu/edashofy/papers/icse2
002-presentation.ppt
19
Data Binding Library
Ref Dashofy, E., Asuncion, H., et al.
ArchStudio 4 An Architecture-Based Meta-modeling
Environment. ICSE 2007 Demo Paper.
20
Myx Architecture Style

• Purpose
• Support building flexible, high performance
  tool-integrating environments
• Serve as a foundation for building environments
  in Eclipse
• Heritage
• Borrows most of key properties from C2 style
• System implementation currently supported in
  ArchStudio 4

Ref http//www.isr.uci.edu/projects/archstudio/my
x.html
21
Myx Architectural Style

• Rules
• Components are the loci of computation
• Connectors are the loci of communication
• Components communicate only through well-defined
  provided and required interfaces
• Components and connectors have two faces top
  and bottom
• Components interact through three distinct
  patterns
• Synchronous bottom-to-top procedure call
• Asynchronous top-to-bottom (notification)
  messaging
• Asynchronous bottom-to-top (request) messaging
• Components may only make assumptions about the
  services provided above them, and may make no
  assumptions about the services provided below
  them.
• Applications have at least one main thread of
  control. Additional threads may be created by
  components as necessary. Asynchronous connectors
  also have their own threads.
• Shared Memory

Ref http//www.isr.uci.edu/projects/archstudio/re
sources/myx-whitepaper.pdf
22
Myx Architectural Style

• Benefits
• Easy to reuse - components are relatively
  independent of each other
• Easy to reconfigure communication only via
  explicit interfaces
• Enables runtime modification through dynamic
  proxies and event pumps

23
Myx.fw Framework

• Difficult to adhere to the constraints of a style
  using an existing programming language
• Bridge the gap between Myx and Java myx.fw
• Component and Connectors implement IMyxBrick
  interface

Ref http//www.ics.uci.edu/edashofy/classes/211/
myx-assignment.ppt
24
Implementing a myx.fw component

• Components have main classes that implement
  IMyxBrick
• They may have as many auxiliary classes as you
  want
• The main class may just be a wrapper for services
  provided internally

AbstractMyxSimpleBrick
IMyxBrick
implements
extends
LunarLanderComponents
Ref http//www.ics.uci.edu/edashofy/classes/211/
myx-assignment.ppt
25
Implementing a myx.fw component

• Components have three main jobs
• Store data from the framework (IMyxBrickItems)
• Implement lifecycle methods (init, begin, end,
  destroy)
• Provide true objects for all provided interfaces

Ref http//www.ics.uci.edu/edashofy/classes/211/
myx-assignment.ppt
26
Component Jobs

• Store IMyxBrickItems from the framework
• The framework needs to store some data about the
  component along with the component
• Abstract base classes take care of this for you
• Implement lifecycle methods
• Called by the framework when the architecture is
  in particular states
• init() Brick is created
• begin() Brick is wired into the architecture and
  ready to start
• end() Brick is about to be unwired and shut down
• destroy() Brick is about to be dismissed

Ref http//www.ics.uci.edu/edashofy/classes/211/
myx-assignment.ppt
27
Component Jobs

• Provide true objects for each provided interface
• Each provided/required interface has a name
• The framework will occasionally ask a component
  give me the object that corresponds to this
  provided interface
• Likewise, a component may request, from the
  framework, the true object corresponding to one
  of its required interfaces

Ref http//www.ics.uci.edu/edashofy/classes/211/
myx-assignment.ppt
28
Toolset Integrated with Eclipse

• Eclipse plug-in
• ArchStudio Perspective
• AIM Launcher launch the system in development
  within ArchStudio
• ArchEdit
• Visualization
• Tree-view schema driven
• Indicate implementation mappings
• Archipelago
• Visualization and modeling
• Boxes and arrows
• ArchLight - analysis
• Selector product Families
• Type Wrangler consistency checks between types
  and instances

29
ArchStudio 4.0

• Built on its own tools and technologies
• Architecture specified in xADL 2.0
• Upon invocation
• Bootstrapper parses the ArchStudio xADL file
  using the Data Binding Library
• Bootstrapper steps through xADL file and
  instantiates the various components

30
ArchStudio Tools

• xArchADT Data Store
• Live integration between tools

Ref
31
Using ArchStudio

• Hello World Demo

32
Hello World Demo

• 1. Create Architecture
• 1.1 Create Structure
• 1.2 Create Types Set and Component Type
• 2. Add component
• 2.1 Edit description
• 2.2 Assign type to component
• 3. Map Architecture to Implementation
• 4. Write HelloWorld Java class
• 5. Move xml file to Java Project
• 6. Run Hello World

33
1. Create Architecture

• In Eclipse, go to ArchStudio Perspective
• Create a new project. File-gtNew-gtProject.
  General-gtProject. Next.
• Project Name HelloWorldProject. Finish

34
1. Create Architecture

• Right-click on the Project and select
  New-gtOtherArchStudio 4 -gt ArchStudio
  architecture Description
• File Name Architecture.xml. Finish.
• Open the xml file with Archipelago.

35
1.1 Create Structure

• On the Outline View, expand the root element.
  Right click on Structures. Select New Structure.
• Expand Structures. Right click on the new
  Structure and select Edit Description.
• New Description HelloWorld

36
1.2 Create Type Set and Component Type

• On the Outline View, select the root element.
  Right click on it. Select Create Type Set.
• Expand Types. Right click on Component Types and
  select New Component Type.
• Select the new Type. Right click on it and select
  Edit Description.
• New Description HelloWorldType

37
2. Add Component

• In the Outline View, double click on the
  HelloWorld structure
• Right click on the Archipelago View and Select
  New Component

38
2.1 Edit description

• Right click on the new component. Select Edit
  Description
• New Description HelloWorld

39
2.2 Assign type to component

• Select HelloWorldType in the Outline View. Drag
  it and drop it on the HelloWorld component.

40
3. Map Architecture to Implementation

• In the Navigator View, right click on the xml
  file. Open With-gtArchEdit
• In the Outline View, Expand Xarch, Arch Types,
  Component Type HelloWorldType. Right click on
  it. Select Promote to VariantComponentTypeImpl

41
3. Map Architecture to Implementation

• Similarly, right click on Component Type
  HelloWorld Type. Select Add Implementation.
• Right click on Implementation and select Promote
  to JavaImplementation
• Right click on Implementation and select Add Main
  Class

42
3. Map Architecture to Implementation

• Right click on Main Class and select Add
  JavaClassName
• Expand MainClass and double click on Java
  ClassName and enter HelloWorld as a value

43
4. Write Java Class

• Create Java Project. File-gtNew-gtJava Project.
• Project Name HelloWorld. Next.
• Click on Projects, Add.. Check edu.uci.isr.myx.fw.
  OK and Finish.

44
4. Write Java Class

• Right click on HelloWorld project and select
  New-gt Class
• Class Name Hello World. Finish.

45
4. Write Java Class

• Copy the following content in HelloWorld.java and
  Save the file
• import edu.uci.isr.myx.fw.AbstractMyxSimpleBrick
• import edu.uci.isr.myx.fw.IMyxName
• import edu.uci.isr.myx.fw.MyxUtils
• public class HelloWorld extends
  AbstractMyxSimpleBrick
• // category constructor
• public HelloWorld( )
• // category startup and cleanup
• public void init()
• public void begin()
• System.out.println("Hello world!")
• public void end()
• public void destroy()
• // override a required method
• public Object getServiceObject(IMyxName name)
• //Since we are not implementing an interface in
  this class

46
5. Move XML file to Java Project

• Create arch folder in HelloWorld/src
• Move (drag and drop)Architecture.xml from
  HelloWorldProject to HelloWorld/src/arch

47
6. Run Hello World

• In the Navigator View, right click on
  Architecture.xml, select Open With AIM Launcher
• In the Outline View, double click on HelloWorld
• Click on Instantiate

48
6. Run Hello World

• You should see the following output in the Console