Fix to prevent possible crashes if the prescale table changes during job

[apana]

Fix to prevent possible crashes in the L1TGlobalUtil code in CMSSW jobs where the prescale table is updated during the job. In the previous version this could sometimes cause an out-of-range exception.

[cmsbuild]

A new Pull Request was created by @apana (Leonard Apanasvich) for CMSSW_9_3_X.

It involves the following packages:

L1Trigger/L1TGlobal

@cmsbuild, @rekovic, @mulhearn can you please review it and eventually sign? Thanks.
@Martin-Grunewald, @kreczko this is something you requested to watch as well.
@davidlange6, @slava77 you are the release manager for this.

cms-bot commands are listed here

• Backported from Fix to prevent possible crashes if the prescale table changes during job #20503

[Martin-Grunewald]

@apana

Please also make a 94X PR - this is required first, then the backport PRs!

[Martin-Grunewald]

please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/22928/console Started: 2017/09/13 07:45

[cmsbuild]

+1
Tested at: dc75b66
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20487/22928/summary.html

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:
9fb6347
You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20487/22928/git-log-recent-commits
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20487/22928/git-merge-result

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-20487/22928/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 26
• DQMHistoTests: Total histograms compared: 2641982
• DQMHistoTests: Total failures: 194
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2641599
• DQMHistoTests: Total skipped: 189
• DQMHistoTests: Total Missing objects: 0
• Checked 107 log files, 14 edm output root files, 26 DQM output files

[apana]

@Martin-Grunewald

Hi Martin,

Thanks for the heads-up. I've made a PR to the cmssw master branch (CMSSW_9_4_X branch is closed for direct updates)

-Len

[rekovic]

+1

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_9_3_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_9_4_X is complete. This pull request will now be reviewed by the release team before it's merged. @davidlange6, @slava77, @smuzaffar (and backports should be raised in the release meeting by the corresponding L2)

[rekovic]

backport of #20503

[davidlange6]

+1