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SEAL Project Overview. ACAT03. 1-5 December, 2003 KEK. IX International Workshop on Advanced Computing and Analysis Techniques in Physics Research. Lorenzo Moneta/ CERN-EP on behalf of the SEAL team. Outline. Introduction Scope and motivation SEAL Work Packages Description
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SEAL Project Overview ACAT03 1-5 December, 2003 KEK IX International Workshop on Advanced Computing and Analysis Techniques in Physics Research Lorenzo Moneta/ CERN-EP on behalf of the SEAL team
Outline • Introduction • Scope and motivation • SEAL Work Packages • Description • Current status • Future plans and summary SEAL Project Overview
Project motivation • What is SEAL ? • project in LCG Application Area • started last year after BluePrint RTAG recommendations • common project on core tools and services • SEAL: Shared Environment for Applications at LHC • SEAL aims to • Provide the software infrastructure, basic frameworks, libraries and tools that are common among the LHC experiments • Select, integrate, develop and support foundation and utility class libraries • Develop a coherent set of basic framework services to facilitate the integration of LCG and non - LCG software • Do not re-invent the wheel • Try to use as much as possible of existing software • Develop/adapt/generalize to achieve necessary level of coherency SEAL Project Overview
Applications Reconstruction Framework Visualization Framework Simulation Framework OtherFrameworks . . . Basic Framework Foundation Libraries Optional Libraries Project scope • Foundation Class Libraries • Basic types (STL, Boost,…), utility libraries, system isolation libraries, domain specific foundation libraries • Mathematical Library • Basic mathematical functions, linear algebra, fitting and minimization libraries • Basic Framework Services • Component model, reflection, plug-in management, incident (event) management, distributed computing, grid services, scripting Software Structure SEAL Project Overview
Project Work Packages Not yet active SEAL Project Overview
Foundation and Utility Libraries • Inventory of existing C++ utilities (http://seal.cern.ch/components.html) • Recommended classes useful for LCG projects and experiments • Large number from Boost (open source project) • Support for Boost is provided (in contact with developers) • Develop in SEAL what is missing in STL and Boost • Have a set of low-level, fairly independent class libraries • 200 classes originated mainly from classlib (CMS) • Basic abstraction and foundation utilities classes • Timing utilities • Stream-oriented I/O, compression and decompression • High quality, efficient, well tested and documented library • Recommend best practice to LHC developers SEAL Project Overview
Plug-in Manager • Plug-in Management • Service in charge of managing, querying, [un]loading plug-ins • Low level plug-in management (no framework constraints) • Ability to create “module” libraries containing “plug-ins” • Ability to instantiate concrete implementations knowing the plug-in category and the concrete type • Caching information for fast loading • what modules contain • what kind of plug-ins exist and which categories • Imported from CMS IGuana • Basic concept: advanced object factory • Interfaces for object instantiation and plug-in provider • Dynamic loading completely orthogonal — and optional! SEAL Project Overview
Mathematical Libraries • GSL (Gnu Scientific Library) evaluation • Extensive comparison with NagC • Validation and test suite • Re-implementation of MINUIT in C++ • Prototype available with Migrad and Minos • Undergoing numerical and performance tests • Comparison tests with Fortran version (compatibility within errors) • Linear Algebra • Prototype wrapper around GSL matrices. • Comparison of various linear algebra packages (CLHEP, GSL, [u]CBLAS) • Participation in CLHEP project • Provide to experiments math and statistics libraries to be used in analysis, reconstruction and simulation. • support, consultancy, etc.. SEAL Project Overview
Object Dictionary • Adding “introspection/reflection” capabilities to C++ • Use for persistency and interactivity (e.g. Python) • Modern languages provide reflection inherently • In C++ reflection is very limited (RTTI) • The basic C++ concepts shall be supported • e.g. inheritance, methods, data members, accessibility, templates • Seal provides : • Reflection Builder and Reflection (API interface) packages • Dictionary generator to produce dict. source from C++ files • Uses gcc-xml + Python script • Dictionary for some standard packages (STL, CLHEP) • Used by POOL (persistency) SEAL Project Overview
Dictionary Generator • gcc-xml to parse header-files (extension to gcc ) • XML file generated with dictionary information • Python script to generate dictionary C++ code • use an additional XML file to customize class selection • Compiled and loaded at run-time to create dictionary • Provide meta information about the object to the user User .xml selection file lcgdict .xml gccxml par ser filter + exten gendict .h _dict.cpp ..Dict.so make (Python script) .h .h .h Reflection Libraries Clients #include files SEAL Project Overview
Framework Services • Motivation: • Allow LCG developers and users to write portable and modular code • Provide abstractions for modelling software systems • Component model definition • Basic Components • Set of “base classes” and interfaces needed to build more complex components • Provide standard functionality • instantiation, configuration, lifetime management, etc • Users (framework developers) should model their services using these proposed base classes • SEAL provide in addition a set of basic services implemented following the component model SEAL Project Overview
Application C1 C1 C2 C1 C5 C1 Svc1 Svc2 C3 C1 C4 C1 C1 C6 C1 C7 Svc1 C7 C1 SEAL Component Model • Hierarchy of bases classes • Components living in a Context • Services are Components providing their local Context • User classes inherit from Component or Services • Plug-in functionality for free Context Component Service SEAL Project Overview
Basic Common Framework Services • Application Service • Defines the top level Context • Defines initial set of Components to be loaded in the application • Message Service • Message composition, filtering and reporting • Configuration Service • Management of Component properties and loading configurations • Multiple backends foreseen: • Gaudi style options, .INI style, CMS style, XML, ... • Other services will come later: • Object Whiteboard (Transient Object repository) • Dictionary Service (Loading Dictionaries in the application) SEAL Project Overview
Scripting needed for Interactivity, Configuration, Rapid prototyping, Integration (Component bus), etc. Main scripting language : Python Define guidelines for developing Python bindings : Various tools available (Boost.Python, SWIG) Recommend solutions: Boost.Python LCG Dictionary EDG API PVSS XML Database GUI GUI Python shell math JPE PyROOT PyGaudi math Java Classes Root Classes Gaudi Framework Scripting Services SEAL Project Overview
Scripting Packages • PyLCGDict • Python extension module to the LCG dictionary • Provide access to C++ libraries from Python, “for free” • Automatically generates Python proxies for C++ objects using dictionary information • Everyone can create binding effortlessly • PyROOT • Python bindings for ROOT classes • access to ROOT functionality from Python • Binding using the ROOT dictionary (CINT) • Missing gateway ROOT -> Python SEAL Project Overview
Education/Documentation • Produce documentation • Reference documentation (generated with doxygen) • HowTo pages for the released elements • Plugin Manager, Dictionary generation, PyROOT, PyLCGDict, etc. • Release notes • Training material (tutorials) • Help developers incorporating SEAL into the LCG projects and the experiment frameworks • Python courses • Hands-on introduction course to Python programming • Very positive feedback received SEAL Project Overview
Software Process and QA • Design • Team design sessions • Prototypes using Pythons • Code Review • No formal code reviews • Coding done very often in pairs (XP style) • More than one developer knowledgeable for each package • Testing • More than 200 SEAL unit tests based on CppUnit • All are driven and run automatically by QmTest • Bug reporting and tracking • Savannah Portal (http://savannah.cern.ch/projects/seal) SEAL Project Overview
Future plans (1) • Foundation libraries (Plug-in Manager) • Follow Boost developments • Little development planned in SEAL (hash-maps) • MathLibs: • Produce inventory of mathematical functions • Evolve Minuit C++ into a final product • Linear Algebra studies • Generate dictionary library for Python and CINT • Dictionary: • Implementation of new reflection model • Overcome some existing limitations (typedef,…) • Converge to a common dictionary with CINT ? SEAL Project Overview
Future plans (2) • Framework: • Develop Whiteboard (object repository) and Dictionary service (loading of dictionary libraries on-demand) • Scripting : • PYLCGDict: • Migrate much of functional core from C++ to Python • Support more natural Python features (eg iterator protocol) • PyROOT: • Unify core with PyLCGDict • Develop gateway ROOT -> Python • Grid : • New LCG project (ARDA) is starting • Expect need to interface to some of the ARDA services • Documentation: • Produce tutorials for foundation classes, Boost, etc.. SEAL Project Overview
Summary • SEAL has delivered basic foundation, utility libraries and object dictionary • The main “client” have been POOL (persistency project) and PI • Plug-in manager is also used in CMS • Very positive feedback received for plug-in manager • Currently being integrated into experiments’ frameworks of LHCB (Gaudi) and ATLAS (ATHENA) • The first version of the Component Model and Framework services is available • Start integrating in POOL and the LHC experiments • Wait for feedback before developing more services • Scripting based on Python • Boost.Python and PyLCGDict recommended for Python bindings • PyLCGDict is used to provide bindings for classes of Physics Interfaces (PI) project SEAL Project Overview
Conclusions • http://seal.cern.ch/ Acknowledgments: Seal team members: R. Chytracek, J. Generowicz,W. Lavrijsen,M. Marino,P. Mato,S. Roiser,L. Tuura,M. Winkler SEAL Project Overview
Additional Slides SEAL Project Overview
LCG Application Domain Coverage SEAL Project Overview
PluginManager PluginCache * PluginFactoryBase ModuleBase * Module Library T PluginFactory PluginInfo Module ModuleDef * XXXFactory XXXInfo MyModuleDef Client Plug-in Manager Design • Originated from CMS Iguana SEAL Project Overview
NamespaceBuilder ItemBuilder ClassBuilder FieldBuilder MethodBuilder ReflectionBuilder Item PropertyList Namespace Class Field Method Reflection Reflection System • Reflection Builder: the loading interface • Reflection : the user API SEAL Project Overview
Other Clients: (python, GUI, etc.) LCG Object Dictionary: Usage . adl .h .xml Population ROOTCINT GCC - XML ADL/GOD CINT generated Dict generating code code in Conversion (1) LCG CINT Dict gateway LCG to CINT Dictionary Streamer Dict ROOT I/O (2) out Reflection SEAL Project Overview
ComponentFactory ComponentLoader Component Context Service MyComponent MyService Seal Component Model • Hierarchy of bases classes • Each Component lives in a Context • Contexts form their own hierarchy • Support for component look-up • A Service provides its own local Context • Components of a Service live in the scope defined by its own Context • User classes inherit from Component or Service • Plug-in functionality for free * 1 1 * SEAL Project Overview