1. SEAL Project Overview Lorenzo Moneta/ CERN-EP 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

2. Outline Introduction SEAL Work Packages Description Current status
Scope and motivation
SEAL Work Packages
Description
Current status
Future plans and summary
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

3. Project motivation What is SEAL ? SEAL aims to
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
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

4. Project scope Foundation Class Libraries Mathematical Library
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
Basic Framework
Foundation Libraries
Simulation Framework
Reconstruction Framework
Visualization Framework
Applications
. . .
Optional Libraries
Other Frameworks
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

5. Project Work Packages Foundation
Foundation and Utility Libraries and Plug-in Manager
MathLibs
Math Libraries Support and Coordination
Dictionary
LCG Object Dictionary
Framework
Component Model and Basic Framework services
Scripting
Scripting Services
Grid
Grid Services
Documentation
Education and Documentation
Not yet active
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

6. Foundation and Utility Libraries
Inventory of existing C++ utilities (
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
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

7. 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!
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

8. 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..
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

9. 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)
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

10. 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 .h
gccxml
par
ser
filter +
exten
gendict
_dict.cpp
..Dict.so
make .h
(Python script) .h .h
Reflection
Libraries
Clients
#include files
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

11. Framework Services Motivation: Component model definition
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
The current ideas
Give to the “users” (framework developers) a number pre-defined service base classes (from simple to more complex)
Developers should “model” their services using one of the proposed base classes
Standard functionality (instantiation, configuration, lifetime management, etc.) should be provided by these bases classes
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

12. SEAL Component Model Hierarchy of bases classes
Context
Application C1 C1 C2 C1 C5
Svc1
Svc2 C1 C3 C1 C4 C1 C6 C1 C7
Svc1 C1 C7
Component
Service
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
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

13. 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)
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

14. Scripting Services
Scripting needed for Interactivity, Configuration, Rapid prototyping, Integration (Component bus), etc.
Main scripting language :
Python
GUI
Python
math
shell
PyGaudi
Database
EDG API
XML
Gaudi
Frame work
PyROOT
Root
Classes
PVSS
JPE
Java
Define guidelines for developing Python bindings :
Various tools available (Boost.Python, SWIG)
Recommend solutions:
Boost.Python
LCG Dictionary
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

15. Scripting Packages PyLCGDict PyROOT
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
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

16. 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
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

17. 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 (
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

18. Future plans (1) Foundation libraries (Plug-in Manager) MathLibs:
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 ?
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

19. Future plans (2) Framework: Scripting : Grid : Documentation:
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..
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

20. 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
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

21. 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
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

22. Additional Slides
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

23. LCG Application Domain Coverage
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

24. Plug-in Manager Design
Originated from CMS Iguana
Module Library
PluginManager
PluginFactoryBase
PluginFactory T
PluginInfo
XXXFactory
XXXInfo
Module
ModuleDef
ModuleBase
MyModuleDef *
PluginCache
Client
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

25. Reflection System Reflection Builder: the loading interface
Reflection : the user API
PropertyList
Item
Method
Field
ItemBuilder
MethodBuilder
FieldBuilder
ClassBuilder
NamespaceBuilder
Reflection
ReflectionBuilder
Class
Namespace
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

26. LCG Object Dictionary: Usage.
adl .h
.xml
Population
ROOTCINT
GCC -
XML
ADL/GOD
CINT generated
Dict generating
code
code in
Conversion
(1)
LCG
Other
Clients:
(python, GUI, etc.)
CINT
LCG to CINT
Dict gateway
Dictionary
Streamer
Dict
ROOT I/O
(2)
out
Reflection
ACAT03, 1-5 Dec. 2003
SEAL Project Overview

27. 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
Component Factory
Component Loader
Component * 1
Service 1
Context *
MyComponent
MyService
ACAT03, 1-5 Dec. 2003
SEAL Project Overview