CIS 212 Microcomputer Architecture Day 22

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CIS 212MicrocomputerArchitectureDay 22
Rhys Eric Rosholt
Gillet Hall - Room 304 718-960-8663 http//comet.l
ehman.cuny.edu/rosholt/ rhys.rosholt _at_
lehman.cuny.edu
Office Office Phone Web Site Email Address
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Reminder
Final ExaminationWednesday, December 16,
2009Gillet Hall Room 2251100 am to 100 pm28
Days from Today!Comprehensive / Open Book
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Chapter 10Application Development
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Chapter 10Application Development

• Chapter Outline
• The Application Development Process
• Programming Languages
• Compilation
• Link Editing
• Interpreters
• Focus - Java
• Symbolic Debugging
• Integrated Application Development Tools
• Focus Oracle JDeveloper
• Focus - Building the Next Generation of
  Application Software

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Programming Languages

• Instruct computer to perform a task
• Sometimes called code
• Programmer goals
• Make language easier for people to understand
• Develop languages and development approaches that
  require people to write fewer instructions to
  accomplish a task

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Programming Language Evolution
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Programming Languages

• Summary of capabilities of recent generations
• Instruction explosion
• Database access
• Support for GUIs
• Nonprocedural programming
• All but 1GL must be translated into CPU
  instructions prior to execution
• compilers
• interpreters
• hybrid translation systems

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Programming Language Characteristics
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First-Generation Languages

• Required programmers to remember binary codes
  that represented each CPU instruction and to
  specify all operands as binary numbers
• Tedious to program error-prone

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Second-Generation Languages

• Use mnemonics to represent variables (program
  instruction memory address) and labels (data item
  memory address)
• Easier to manipulate than binary numbers
  assembler translates program into binary CPU
  instructions
• Common in 1950s

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Third-Generation Languages

• Use mnemonics to represent instructions,
  variables, and labels
• Have degree of instruction explosion greater than
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• Translated with compilers, link editors, and
  interpreters
• Machine independent
• Developed before GUIs, database managers, and
  Internet

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Fourth-Generation Languages

• Majority were proprietary
• many were optional components of database
  management systems
• Most support mixture of procedural and
  nonprocedural instructions

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Equivalent Programs in SQL and C
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Fifth-Generation Languages

• Nonprocedural language suitable for developing
  software that mimics human intelligence
• Rule processor accepts a starting state as input
  and iteratively applies rules to achieve a
  solution
• First appeared in 1960s not widely used until
  1980s

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Object-Oriented Programming (OOP) Languages

• View data and programs as two parts of integrated
  whole (object)
• Promote reusability and portability of source
  code
• Uniquely suited to developing real-time programs
• Not clear successors to 5GLs neither
  nonprocedural nor exclusively used for developing
  artificial intelligence

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OOP Languages
Objects reside in a specific location, wait for
messages to arrive, and return a response.
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Scripting Languages

• Enable programmers to develop applications that
  do most of their work by calling other
  applications and system software
• Enable rapid assembly of application software by
  gluing together capabilities of other programs
• Evolved from 4GLs, though most now incorporate
  OOP concepts

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Programming Language Standards

• Set by ANSI and ISO
• Include definitions of
• Language syntax and grammar
• Machine behavior for each instruction or
  statement
• Test programs with expected warnings, errors, and
  execution behavior
• Guarantee program portability among operating
  systems and application programs

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Compilation

• Translates an entire source code file, building a
  symbol table and object code file as output

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Program Development
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Compiler

• Checks for syntax and other errors issues
  warning or error messages
• Updates internal tables that store information
  about data items and program components
• Generates CPU instructions or library calls to
  carry out the source code instruction

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Source Code Instruction Types

• Data declarations
• Data operations
• Control structures
• Function, procedure, or subroutine calls

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Data Declarations

• Define name and data type of program variables
• Stored in memory allocated by compiler

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Symbol Table
The compiler updates a symbol table to keep track
of data names, types, and assigned memory
addresses.
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Data Operations

• Instructions that update or compute a data value
• Translated by compiler into equivalent sequence
  of data movement and data transformation
  instructions for target CPU
• Compiler refers to entries in symbol table to
  determine source and destination memory addresses
  for data movement instructions

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Control Structures

• Source code instructions that control the
  execution of other source code instructions
• Common thread is transfer of control among CPU
  instructions

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Function Calls

• Named instruction sequences executed by call
  instructions
• Transfer control to the instruction following the
  call by executing a return instruction

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Implementing Call and Return Instructions

• Compiler generates CPU instructions to
• Pass input parameters to the function
• Transfer control to the function
• Execute CPU instructions within the function
• Pass output parameters back to the calling module
• Transfer control back to the calling module at
  the statement immediately following the function
  call statement

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Symbol Table
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CompilationJust The First Step

• source code
• translated by compiler into
• object code
• linked with library routines to make
• load module
• loaded into memory by operating system as
• runnable machine instructions

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Compiler

• 1. Checks for errors
• 2. Issues warnings and/or error messages
• 3. Builds and uses a Symbol Table as it works
• stores information about data items and program
  components
• 4. Generates CPU instructions and library calls
  to carry out the source code instructions
• 5. Creates an object code file as output

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Source Code Instruction Types

• Data declarations
• A data declaration creates an entry in the symbol
  table
• Data operations
• A data operation becomes a series of data
  transformation instructions
• Control structures
• A control structure becomes a series of control
  flow instructions
• Subprogram calls

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Symbol Table
The compiler updates a symbol table to keep track
of data names, types, and assigned memory
addresses.
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Subprogram Call and Return Operations

• Compiler generates CPU instructions to
• Pass input parameters to the function
• Transfer control to the function
• Execute CPU instructions within the function
• Pass output parameters back to the calling module
• Transfer control back to the calling module at
  the statement immediately following the function
  call statement

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Symbol Table
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Link Editing

• Statically links external reference calls in
  object code to library functions combines them
  into a single file containing executable code
• Can dynamically link external calls by statically
  linking them to an OS service function that loads
  and executes dynamic-link library (DLL) functions
  at run time
• Always used by interpreters

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Key Benefits of Link Editors in Program
Translation

• A single executable program can be constructed
  from multiple object code files compiled at
  different times
• A single compiler can generate executable
  programs that run under multiple operating systems

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Linking Separately CompiledFunctions into a
Single Program
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Dynamic and Static Linking

• Static linking
• Library and other subroutines cannot be changed
  once inserted into executable code
• Dynamic linking
• Performed during program loading or execution

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Advantages of Dynamicand Static Linking

• Dynamic
• Smaller application program executable files
• Flexibility
• Static
• Execution speed
• Improves reliability and predictability of
  executable programs

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Interpreters

• Interleave source code translation, link editing,
  and execution, one source code instruction at a
  time
• Advantage (vs. compilation)
• Provide flexibility to incorporate new or updated
  code into an application program (dynamic
  linking)
• Disadvantage (vs. compilation)
• Increase memory and CPU requirements during
  program execution

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Memory and CPU Resources Used During Program
Execution
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Java

• Object-oriented programming language and program
  execution environment
• Maximizes reliability of applications and
  reusability of existing code
• Has a standardized target machine language for
  Java interpreters and compilers
• Drawback Reduced execution speed due to use of
  interpreted byte codes and OS translation

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JavaHow Java and the JVMrelate to the CPU and
the OS
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Features of Java

• Provision of compilers and virtual machines at
  little or no cost
• Incorporation of JVMs into Web browsers
• Increasing development of application software
  that uses a Web browser as primary I/O device
• Ability of Java programs to execute on any
  combination of computer hardware and OS

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Symbolic Debugging

• Use of an automated tool for testing executable
  programs able to
• Trace calls to specific source code statements or
  subroutines
• Trace changes to variable contents
• Execute source code instructions one at a time
• Detect and report run-time errors to programmer

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Symbolic Debugger

• Uses symbol table, memory map, and source code
  files to trace memory addresses to specific
  source code statements and variables
• Inserts debugging checkpoints after each source
  code instruction program execution can be paused
• Debugging vs. production/distribution version
• Incorporated directly in most interpreters

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Application Development Tools
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Integrated Application Development Tools
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Programmers Workbench Components

• Smart program editor
• Compiler and/or interpreter
• Link editor and large library of classes or
  subroutines
• Interactive tool for prototyping and designing
  user interfaces
• Symbolic debugger
• Integrated window-oriented GUI

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CASE Tools

• Front-end CASE tools
• Support development of requirements and design
  models
• Back-end CASE tools
• Generate program source code from models

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Summary

• Software development process
• Programming languages
• Compilation and link editing
• Interpretation
• Symbolic debugging
• Application development tools

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Chapter Goals

• Describe the application development process and
  the role of methodologies, models, and tools
• Compare and contrast programming language
  generations
• Explain the function and operation of program
  translation software, including assemblers,
  compilers, and interpreters
• Describe link editing, and contrast static and
  dynamic linking
• Describe integrated application development
  software, including programmers workbenches and
  CASE tools

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Reminder
Final ExaminationWednesday, December 16,
2009Gillet Hall Room 2251100 am to 100 pm28
Days from Today!Comprehensive / Open Book
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Next ClassMondayNovember 23, 2009
Rhys Eric Rosholt
Gillet Hall - Room 304 718-960-8663 http//comet.l
ehman.cuny.edu/rosholt/ rhys.rosholt _at_
lehman.cuny.edu
Office Office Phone Web Site Email Address