1. Code&Semantic Observations
P.Hristov
Off-line Week
March 10, 2004
CERN

2. STEER Simulation classes Reconstruction classes IO classes
Generation of particles
Hits
Track references
Summable digits
Digits
AliSimulation
Reconstruction classes
Clusters/RecPoints
Tracks
Vertex
PID
ESD
AliReconstruction
IO classes
Loaders
AliStream
Classes, related to “conditions”
Geometry
Magnetic field
Configuration
Event headers
General/service classes
AliRun …
Obsolete classes?

3. STEER I
AliRun: delete gAlice->GetRunLoader(); delete gAlice; AliRunLoader rl = AliRunLoader::Open(“galice.root”); gAlice = rl->GetAliRun();
=> Something is wrong, we should instantiate AliRun only when it is needed, and can be initiated correctly. Do we need the global pointer gAlice?
Many shortcut methods can be removed
Obsolete parts of the code (Tree2Tree, etc.)
What should be the main function of AliRun?

4. STEER II AliModule & AliDetector AliMC & AliStack
Used in simulation & reconstruction => could we separate the two main use cases?
Do we need both?
What would be the relation with AliReconstructor class (see the talk of Thomas)?
AliMC & AliStack
Could AliMC be singleton which is not accessed via AliRun?
Could we make more clean distinction of responsibilities between AliMC and AliStack?
Could we avoid the mapping in AliStack?

5. STEER III: AliStream AliRunDigitizer AliRunDigitizer AliStream
galice.root
with sdigits
galice.root
AliRunLoader
galice.root
with sdigits
galice.root
with sdigits
sdigits
sdigits
sdigits
Do we really need this functionality?

6. STEER IV Could we fix the interfaces using pure virtual classes?
Missing base classes:
Calibration
Alignment
What else?
Could we revise the “dependences” (inheritance, usage, composition, aggregation, etc.)?

7. Tasks Features: Main issues: Conversion to tasks: only partially done
Recursive call of subtask tree via ExecuteTask/Exec/TTask::ExecuteTasks
Browsing & debugging
Main issues:
Access by name should be avoided
Object ownership: strict discipline in Add/CleanTasks/Clear needed
Conversion to tasks: only partially done

8. Tasks II Advantages Concerns How should we continue?
Uniform implementation of methods
Recursive behavior
Dynamic creation of task trees
Possibility to present/browse/debug
Concerns
More suitable for interactive jobs
Needs fully implemented task chains
Gives easy access by name => possible misusage
Simplicity: do we need this functionality?
How should we continue?

9. Pointers
Usage of pointers as data members: question of composition vs aggregation. If the object- data member has to be deleted in the destructor, one better uses it directly
Exceptions: if the size of (simple) container is variable or too big, use “new”
Root containers: set correctly object ownership
If you use pointers as data members, you must initialize them
Do not delete objects if you are not the owner
New/delete: avoid memory leaks

10. Pointers II
f->GetA()->GetB()->GetC()->Do(); usually occurs if the class responsibilities are not well defined
Could we improve such cases?
Transient pointers: do not forget to indicate by exclamation mark “//!” that given pointer should not be stored