Trigger Developers Guide

Introduction

This guide is intended for trigger algorithm developers in release 22 (“AthenaMT”). Information relevant for older releases (LHC Run 1&2) and other general topics can be found in the Trigger Developer TWiki pages.

Details on meetings and mailing lists can be found in the Trigger Software Upgrade TWiki.

The main tasks in migrating existing trigger code to AthenaMT are:

1. Migrate HLT::FexAlgo to a plain AthAlgorithm
2. Reading/writing of trigger features via get/attachFeature is replaced by a Read/WriteHandle
3. HLT::HypoAlg is replaced by one AthAlgorithm per group of chains (e.g. all electron chains) and one AlgTool per chain.
4. Monitoring histograms should be migrated to the new thread-friendly Monitored infrastructure

Relevant other documentation:

• Athena Multi Threading Tutorial, Sep 2017

Testing of code changes

Please see all details in the Trigger Validation section of this guide. A short summary of the information described there:

1. Run a test specific to your development while writing the code.
2. Run a minimal set of tests with larger coverage before submitting a MR with runTrigART.py -m -j4
3. Run unit tests for the packages you modified before submitting a MR with ctest -j4 in the build directory.

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