D Offline Reconstruction and Analysis Control Framework

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DØ Offline Reconstruction and Analysis Control
Framework

• J.Kowalkowski, H.Greenlee, Q.Li, S.Protopopescu,
  G.Watts, V.White, J.Yu

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DØ C Framework

• Set of well established interfaces from which
  reconstruction and analysis algorithms are built.
  
• Propagates events through a sets of algorithms in
  a well defined and established manner.
• The algorithm configuration and set is determined
  at program execution time.
• The framework hides many system related
  complexities from the user and the algorithm
  developer and allow for sharing of code for
  common or related tasks.

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Infrastructure

• RCP - Run Control Parameters
• Persistent part of algorithm
• Stored in database
• Event data identified by RCP set ID
• EDM - Event Data Model
• Framework
• Build/Configure/Run Algorithms
• IO_PACKAGES
• Event read/write packages
• DØOM - Object persistency package

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Qualities

• No coupling with external libaries
• Easy introduction of new algorithms
• Strong typing in event objects
• Independent GUI controls
• Flexible, run time configuration of
  reconstruction activities
• No need for user to write code to produce an
  executable with a custom configuration

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Concepts

• Algorithms (Package)
• Standard interface for configuration with RCP
• Common manipulation such as status reporting
• Defines a framework pluggable component
• Named event handlers (Interface)
• Algorithms register event handlers
• Handlers get invoked when the event occurs
• Factory
• Simple algorithm auto-registration mechanism
• Algorithm instances made by name at run time

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Event Processing

• Event Handlers and Work Queues
• Events generated by special Packages
• Placed on an event queue for processing
• Event contains type-code and an object
• Data Managers
• Events in queue dispatched to data managers
• Hold list of handlers (Interfaces instances)
• Controllers
• Event dispatcher, sequencer, state controller
• Queue and Package instances owner
• Can be nested to arbitrary depth.

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Example User Algorithm Class Definition
Class Algorithm public Package, Process, Tag,
RunInit public UserPackage(Context) UserPa
ckage() virtual Result processEvent(edmEvent
) virtual Result tagEvent(edmEvent) virtual
Result runInit(const RunNumber) virtual void
reinitialize(edmRCP) virtual void
statusReport() virtual void flush()
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Event Data Loop
read
ergenerate(Queue)
decide
ermakeDecision(Queue,Event)
CalrunInit(Run) ktrunInit(Run)
runInit
calprocessEvent(Event) jet3processEvent(Event) j
et5processEvent(Event) ktprocessEvent(Event)
process
PackageTypeinstance
EventReader EventWriteew CalRecocal ConeJetReco
jet3 ConeJetReco jet5 KTJetReco kt
calverifyEvent(Event) jet3verifyEvent(Event) jet
5verifyEvent(Event)
verify
write
ewoutput(Event)
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Event Handling Features

• No experiment or subsystem specific types
• New event types can be added by users without
  framework modifications
• Asynchronous and synchronous types
• Synchronous order can be determined at run time
• Event handlers and algorithm instances can be
  grouped by function and treated as a single unit

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Interactive Components

• Threaded model
• No built in interpreter or GUI
• Commander Abstraction
• configure algorithms and control event loop
• get reports from algorithms
• Messenger Abstraction
• catch and propagate errors and output to
  registered clients
• ORB
• manage client/server communications and remote
  framework interactions

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Simple Configuration Example
reco.rcp string PackageName Controller
string Flow "generator decide filter process
tag output" string Packages event_read hits
clustering id verify save" RCP event_read
ltreco readgt RCP hits ltreco hit_findergt RCP
clustering ltreco cluster_findergt RCP id
ltreco IDgt RCP verify ltreco verifygt RCP save
ltreco save_eventsgt
cluster_finder.rcp string PackageName
ClusterFinder double seed_threshold 2.3
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Algorithm View
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Interactive View
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Conclusion

• Algorithm abstraction (Package)
• Algorithm configuration system (RCP)
• Extensible event handling and dispatching system
  with C templates (Interface)
• Factory to create algorithms at run time
• Provisions for state machine behavior
• Separation of GUI and interactive components from
  reconstruction engine
• Independent threads for engine and GUI