How cms-sw/cmssw works
CMSSW is a broad framework for event processing and scientific computing; the README provides only a brief introduction. This map focuses on the sampled runtime capabilities: framework services and events, random-state production, file storage, and a tracklet-matching component. The excerpts show some calls and registrations, but not the full event schedule or all plugin wiring, so unverified links are omitted or marked dashed.
Main entry points: StorageFactory.h Storage Factory · RandomEngineStateProducer.cc State Producer · XrdStorageMaker.cc XRootD Adapter · DCacheStorageMaker.cc DCache Adapter
Components 21
Framework Core
- Event API
FWCore/Framework/interface/Event.h - Parameter Sets
FWCore/ParameterSet/interface/ParameterSet.h - Message Logging
FWCore/MessageLogger/interface/MessageLogger.h - Service Access
FWCore/ServiceRegistry/interface/Service.h - Service Registry
FWCore/ServiceRegistry/interface/ServiceRegistry.h - Base Exceptions
FWCore/Utilities/interface/Exception.h - Framework Exceptions
FWCore/Utilities/interface/EDMException.h
Random State
- Random Service
FWCore/AbstractServices/interface/RandomNumberGenerator.h - State Producer
IOMC/RandomEngine/plugins/RandomEngineStateProducer.cc - Engine States
File Storage
- Storage Factory
FWStorage/StorageFactory/interface/StorageFactory.h - Storage API
FWStorage/StorageFactory/interface/Storage.h - Position Buffers
FWStorage/StorageFactory/interface/IOPosBuffer.h - Storage Maker
FWStorage/StorageFactory/interface/StorageMaker.h - Maker Registry
FWStorage/StorageFactory/interface/StorageMakerFactory.h - ROOT File Adapter
FWStorage/TFileAdaptor/src/TStorageFactoryFile.cc - XRootD Adapter
FWStorage/XrdAdaptor/plugins/XrdStorageMaker.cc - DCache Adapter
FWStorage/DCacheAdaptor/plugins/DCacheStorageMaker.cc
Tracklet Matching
- Match Engine
L1Trigger/TrackFindingTracklet/src/MatchEngineUnit.cc - Tracklet Settings
L1Trigger/TrackFindingTracklet/interface/Settings.h
Other components
- Event Processing
Connections 15
- Service Access → Service Registry: accesses
FWCore/ServiceRegistry/interface/Service.h - Framework Exceptions → Base Exceptions: extends
FWCore/Utilities/interface/EDMException.h - Event Processing → State Producer: runs
- State Producer → Random Service: reads state
IOMC/RandomEngine/plugins/RandomEngineStateProducer.cc - State Producer → Event API: puts products
IOMC/RandomEngine/plugins/RandomEngineStateProducer.cc - State Producer → Engine States: creates
IOMC/RandomEngine/plugins/RandomEngineStateProducer.cc - ROOT File Adapter → Storage Factory: opens via
FWStorage/TFileAdaptor/src/TStorageFactoryFile.cc - Storage Factory → Storage API: returns
- Storage API → Position Buffers: uses buffers
FWStorage/StorageFactory/interface/Storage.h - Storage Factory → Storage Maker: dispatches to
FWStorage/StorageFactory/interface/StorageFactory.h - XRootD Adapter → Storage Factory: reads hints
FWStorage/XrdAdaptor/plugins/XrdStorageMaker.cc - DCache Adapter → Storage Factory: reads hints
FWStorage/DCacheAdaptor/plugins/DCacheStorageMaker.cc - XRootD Adapter → Maker Registry: registers with
FWStorage/XrdAdaptor/plugins/XrdStorageMaker.cc - DCache Adapter → Maker Registry: registers with
FWStorage/DCacheAdaptor/plugins/DCacheStorageMaker.cc - Match Engine → Tracklet Settings: uses
L1Trigger/TrackFindingTracklet/src/MatchEngineUnit.cc