SimWatcher thread safe interface

[civanch]

PR description:

Technical updates replacing #36097 with less number of modifications.
Slightly modified interface to SimWatcher and SimProducer.
Old watchers should work in the same way in 1 thread jobs.
Added a possibility of thread safe SimWatchers or SimProducers.
Slightly improved debug printout.

No change in results are expected.

PR validation:

unit tests runs

if this PR is a backport please specify the original PR and why you need to backport that PR:

no

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-36229/26850

• This PR adds an extra 20KB to repository

[cmsbuild]

A new Pull Request was created by @civanch (Vladimir Ivantchenko) for master.

It involves the following packages:

• SimG4Core/Application (simulation)
• SimG4Core/Watcher (simulation)

@cmsbuild, @civanch, @mdhildreth can you please review it and eventually sign? Thanks.
@makortel, @cvuosalo, @rovere, @bsunanda, @fabiocos, @slomeo this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[civanch]

please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-270444/20725/summary.html
COMMIT: ed34236
CMSSW: CMSSW_12_2_X_2021-11-23-2300/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/36229/20725/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 42
• DQMHistoTests: Total histograms compared: 3247025
• DQMHistoTests: Total failures: 5
• DQMHistoTests: Total nulls: 1
• DQMHistoTests: Total successes: 3246997
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: -0.004 KiB( 41 files compared)
• DQMHistoSizes: changed ( 312.0 ): -0.004 KiB MessageLogger/Warnings
• Checked 177 log files, 37 edm output root files, 42 DQM output files
• TriggerResults: no differences found

[civanch]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[qliphy]

+1

[perrotta]

@civanch wfs 101 and 102 show the following fatal errors in the IBs, starting from CMSSW_12_2_X_2021-11-25-1100 when this PR was merged:

----- Begin Fatal Exception 25-Nov-2021 19:24:53 CET-----------------------
An exception of category 'Configuration' occurred while
   [0] Constructing the EventProcessor
   [1] Constructing module: class=OscarMTProducer label='g4SimHits'
Exception Message:
RunManagerMTWorker::createWatchers: Unable to use Watcher EcalSimHitsValidProducer if number of threads > 1
----- End Fatal Exception -------------------------------------------------

Could you please have a look and provide a fix?