AliRoot Core  3dc7879 (3dc7879)
HLT simulation in AliRoot


class  AliHLTSimulation

Detailed Description

This section describes the the simulation of the HLT in AliRoot.

General Remarks

HLT has a special role in the normal data flow of simulation and reconstruction. Since the HLT reconstruction and analysis runs on-line on the HLT farm, the raw data produced by HLT as a detector contains already reconstructed events. Consequently, the HLT response has to be simulated as well as the data of all other detectors. Since the detector data is needed, the HLT simulation is run at the end of AliSimulation. As a matter of fact, HLT always reconstructs data, HLT simulation means HLT reconstruction embedded into AliRoot.


The AliHLTSimulation class is the steering class called from AliSimulation. An instance of AliHLTSystem is used to run the chains defined by the available libraries or a AliHLTConfiguration configuration macro.

The libraries to be loaded can be specified as an option to AliSimulation.

AliSimulation sim;
See also
AliHLTSimulation for further details


The actual chains to be run depend on the HLT library modules which are loaded to the system. There is a default collection of libraries defined in AliHLTSystem::fgkHLTDefaultLibs. The default libraries are loaded if nothing else is specified. The libraries implement agents (AliHLTModuleAgent childs) describing the properties of a module.