iox-#1575 Properly initialize ServiceRegistry in shared memory

[mossmaurice]

Pre-Review Checklist for the PR Author

1. Code follows the coding style of CONTRIBUTING.md
2. Tests follow the best practice for testing
3. Changelog updated in the unreleased section including API breaking changes
4. Branch follows the naming format (iox-123-this-is-a-branch)
5. Commits messages are according to this guideline
   • Commit messages have the issue ID (iox-#123 commit text)
   • Commit messages are signed (git commit -s)
   • Commit author matches Eclipse Contributor Agreement (and ECA is signed)
6. Update the PR title
   • Follow the same conventions as for commit messages
   • Link to the relevant issue
7. Relevant issues are linked
8. Add sensible notes for the reviewer
9. All checks have passed (except task-list-completed)
10. All touched (C/C++) source code files are added to ./clang-tidy-diff-scans.txt not done for posh
11. Assign PR to reviewer

Notes for Reviewer

• Fixes a bug, that would call vector::operator=(const vector&) on uninitialized data
  • No test was added as the false behavior relies on shared memory not being initialized, which can not be always reproduced (see below)

// Call stack before the bugfix

ServiceRegistry::operator=(const ServiceRegistry& rhs) (implicitly defined)
  |
   -- >  vector::operator=(const vector& rhs)
         |
         --> With certain compiler/compiler settings: vector::size() != 0, leading to false execution of copy assignment branch (at(i) = rhs.at(i))

// Call stack after the bugfix

ServiceRegistry::ServiceRegistry(const ServiceRegistry& rhs) (implicitly defined, ensures that all member variables are properly initialized)
  |
   -- >  vector::vector(const vector& rhs)
         |
         --> vector::operator=(const vector& rhs)
               |
               --> vector::size() == 0 is ensured, leading to correct execution of copy c'tor branch (emplace_back(rhs.at(i)))

Checklist for the PR Reviewer

• Commits are properly organized and messages are according to the guideline
• Code according to our coding style and naming conventions
• Unit tests have been written for new behavior
• Public API changes are documented via doxygen
• Copyright owner are updated in the changed files
• [ ] All touched (C/C++) source code files have been added to ./clang-tidy-diff-scans.txt
• PR title describes the changes

Post-review Checklist for the PR Author

1. All open points are addressed and tracked via issues

References

• Closes RouDi crash in publishServiceRegistry when assigning to unzeroized allocated chunk #1575

[codecov]

Codecov Report

Merging #1583 (47c7e96) into master (d2dd5b2) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1583      +/-   ##
==========================================
- Coverage   76.37%   76.36%   -0.02%     
==========================================
  Files         360      360              
  Lines       13865    13864       -1     
  Branches     1941     1941              
==========================================
- Hits        10590    10587       -3     
  Misses       2702     2702              
- Partials      573      575       +2     

Flag	Coverage Δ
unittests	76.00% <100.00%> (-0.02%)	⬇️
unittests_timing	15.57% <0.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
iceoryx_posh/source/roudi/port_manager.cpp	84.21% <100.00%> (-0.22%)	⬇️
iceoryx_hoofs/source/concurrent/loffli.cpp	88.57% <0.00%> (-2.86%)	⬇️

[dkroenke]

LGTM