Fix race conditions in the PluginSystem

[Dr15Jones]

PR description:

• Use tbb::zero_allocator to be sure std::atomic is nullptr even before its constructor has finished
• Avoid having a temporary empty std::shared_ptr be placed in the map before being reset
• Be sure object is fully initialized before using it

PR validation:

Framework unit tests all pass.

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-32359/20203

• This PR adds an extra 20KB to repository

[cmsbuild]

A new Pull Request was created by @Dr15Jones (Chris Jones) for master.

It involves the following packages:

FWCore/PluginManager

@makortel, @smuzaffar, @cmsbuild, @Dr15Jones can you please review it and eventually sign? Thanks.
@makortel, @wddgit this is something you requested to watch as well.
@silviodonato, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[Dr15Jones]

please test

[cmsbuild]

The tests are being triggered in jenkins.

• CMSSW_11_3_X_2020-12-01-1100/slc7_amd64_gcc900: https://cmssdt.cern.ch/jenkins/job/ib-run-pr-tests/11234/console Started: 2020/12/01 19:59

[cmsbuild]

+1
Tested at: 82c4e10
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-d7019a/11234/summary.html
CMSSW: CMSSW_11_3_X_2020-12-01-1100
SCRAM_ARCH: slc7_amd64_gcc900

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:

• Run3-gex40 Add scenarios with modified tracker material budgets for the Run3 scenario #32300 @bsunanda: Run3-gex40 Add scenarios with modified tracker material budgets for the Run3 scenario
• Remove obsolete record SiPixelCPEGenericErrorParmRcd from frozen HLT GTs #32345 @christopheralanwest: Remove obsolete record SiPixelCPEGenericErrorParmRcd from frozen HLT GTs
• Remove GsfEleDEtaInSeedCut and GsfEleDPhiInCut #32327 @guitargeek: Remove GsfEleDEtaInSeedCut and GsfEleDPhiInCut
• migrate Alignment/TrackerAlignment to use esConsumes #32301 @mmusich: migrate Alignment/TrackerAlignment to use esConsumes
• New GEM-CSC LUT generator #32267 @dildick: New GEM-CSC LUT generator

You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-d7019a/11234/git-log-recent-commits
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-d7019a/11234/git-merge-result

[cmsbuild]

Comparison job queued.

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-d7019a/11234/summary.html

Comparison Summary:

• No significant changes to the logs found
• Reco comparison results: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 35
• DQMHistoTests: Total histograms compared: 2529593
• DQMHistoTests: Total failures: 7
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2529564
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 34 files compared)
• Checked 148 log files, 37 edm output root files, 35 DQM output files

[makortel]

+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. @silviodonato, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[qliphy]

+1