Run-time Component memory analysis

Run-time Component memory analysis Project members: Gati Michael Johan Muskens Merijn de Jong Michel Chaudron 26 Sept 2003

Content • Project Introduction • (goals, idea and assumptions) • Problem analysis • Why use AspectC++ Approach • Analysis of AspectC++ • Modeling • Problems with AspectC++ • Current status of the project

Project Introduction Assumptions Goals Main Idea • Flexible and extendible design • Reusable extensions (implementation) • Investigate the use of aspect orientation • Validate the results of the tool with Chat application Main goal is to build a software tool to measure dynamic memory use of component based system

Project context & scope Project Introduction Robocop component Functional model Resource estimation model Software Tool Resource Measurement Source code model Document model

GoalsMain Idea Project Introduction Assumptions AC++ Dynamic memory information C++ Component Code Other Measurement Tool

Project Introduction GoalsMain Idea Assumptions Domain Linux development environment (G++/Ac++ compiler) C/C++ Implementation language Component design and development Aspect oriented programming (AspectC++) Mysql++ ( C++API) Assumptions &Constraints • Software tool should handle any generic c/c++ component • Software tool should be implemented in C/C++ under Linux environment

Chat Application Know the design and dynamic behaviour of the system Techniques used – function library modification Existing debugging tools Most tools analyze memory use by functions, call stack, block sizes Problem analysisExisting analysis work

Problem analysisChat application Idea • Relied on the knowledge of the component code Automatic instrumentation?

Transform CPU Unparsed C++ Parser C++’ Transform memory Compile Info Program Run Problem analysisTechniques of automatic instrumentation • Traditional way Extendibility Build multiple transforms (CPU, Memory ) Reuse the parser

Problem analysisTechniques of automatic instrumentation What is Aspect Oriented Programming? Goal of AOP -> separation of concerns Weaver takes the required input and process it into new program Aspect 1 Aspect2 Extendibility C++’ C++ Weaver A A Easy to add new Aspect B C Reusability B C Easy to reuse the code

Problem AnalysisProblems of Instrumentation techniques • Traditional way –parsing C++is difficult. • Aspect approach-alreadyexistsweaver for C++ -> but It is a prototype

What Profiling Aspect Extensibility Yes Yes High level of Abstraction/ Reusability No Yes Linux Platform Yes Yes Time of preparation Not feasible Feasible Build C++ parser Time of preparation - Feasible Aspect code Instrumentation Difficult Simple mechanism Why use AspectC++ Approach OPTIONS

Analysis of AspectC++Four Main questions • How to identify the patterns to instrument? • Which code to add to which pattern? • How to collect the reported data? • How to analyze the reported data?

Analysis of AspectC++How to identify the patterns to instrument? • Join points !! It is a place in the component code where an aspect code can interfere(function, a class, an attribute..) • Examples-join points for memory analysis

Analysis of AspectC++Which code to add to which pattern? We are interested in getting the following information • Size(allocated memory block) • Address of allocation • Address of deallocation • Time spent from allocation to deallocation • The name of the objects and class names

Analysis of AspectC++Which code to add to which pattern? advice code: You can specify when the join point should be called or executed by writing an advice code. Syntax: advice call (“joint point”):after(){ A} advice call (“joint point”):before(){ A} advice call (“joint point”):around(){ A} Join points can be combined with logical operators (||),(&&), or (!=)

Collecting data using AspectC++

Analysis of AspectC++ Example • Measure the size allocated by malloc() Advice call ("void * malloc (...)") && args (size): around (size_t size) { printf ("Memory size%ld: \n", size); tjp->proceed (); printf ("Pointer allocated: %p\n", *tjp->result ()); } Note: tjp==JoinPoint

Model 1-Mapping the measured data to different aggregation level Analysis: How to analyze data Application Total components Components Total classes/ component Classes Total objects /class Objects Each object

ModelingHow to analyze Model 2- ER- model – (Database)

C/C++ Input code Aspect code Ac++ weaving Other profiler C’/C’++ G. program g++ compiling C/C++Program Instrumentation Data Collection MYSQL server DB(3-tables) DB connector Data Retrieval tables graphs Analyzer Architecture What is not instrumented? Class names & object names Which data is collected? The 3 tables-> but thee are some problems of skipping rows Which analysis is displayed? Memory use over time

Problems of Aspect++ • Compiler problems • some files in the gcc 3.x header files cannot be parsed byac++ • But it works for g++ 2.9x- Take the headers from another machine and adapt the working environment for ac++ • Unable to instrument operators new & delete • Pre-processor • Use aspect to instruct where to put overloaded operators

Next plan • Implementation –> 1 Nov(25 Nov for improvement) • Technical problems- >5-Oct-2003 1. Get all data from program to database 2. Perform experiments on: ->Chat application with aspect code under g++2.9x ->Pre-processor • Extract tables from Db and make different analysis- 1 November • Writing report->20 -Jan-2004 • Modeling chapter ->architecture and design- 17-Oct-2003 • Implementation chapter -> 27 –Nov-2003 • Verification & validation->12-Dec-2003 • Management -> 20 Jan 2004

Run-time Component memory analysis