Iox #33 implement uds with named pipes

[elfenpiff]

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. Branch follows the naming format (iox-#123-this-is-a-branch)
4. 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)
5. Update the PR title
   • Follow the same conventions as for commit messages
   • Link to the relevant issue
6. Relevant issues are linked
7. Add sensible notes for the reviewer
8. All checks have passed (except task-list-completed)
9. Assign PR to reviewer

Notes for Reviewer

It is important that you start your review with test_unix_domain_sockets.cpp - for no reasons.

The NamedPipe does not come with a unit test. The reason is that it is implemented so that it is compatible with IpcChannel which is in the end a message queue. This is far from perfect and has to be refactored - see issue #832
The IpcChannel tests suffices in this particular case.

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
• PR title describes the changes

Post-review Checklist for the PR Author

1. All open points are addressed and tracked via issues

References

• Closes TBD

[codecov]

Codecov Report

Merging #820 (48e33ae) into master (ea6ea66) will increase coverage by 0.13%.
The diff coverage is 83.52%.

@@            Coverage Diff             @@
##           master     #820      +/-   ##
==========================================
+ Coverage   75.01%   75.14%   +0.13%     
==========================================
  Files         328      330       +2     
  Lines       11705    11856     +151     
  Branches     1965     2001      +36     
==========================================
+ Hits         8780     8909     +129     
- Misses       2165     2179      +14     
- Partials      760      768       +8     

Flag	Coverage Δ
unittests	74.00% <83.52%> (+0.14%)	⬆️
unittests_timing	30.60% <19.31%> (-0.06%)	⬇️

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

Impacted Files	Coverage Δ
...eoryx_hoofs/include/iceoryx_hoofs/cxx/helplets.hpp	86.84% <ø> (ø)
...oofs/source/posix_wrapper/shared_memory_object.cpp	69.64% <ø> (ø)
...eoryx_posh/internal/runtime/ipc_interface_base.hpp	100.00% <ø> (ø)
iceoryx_posh/source/runtime/shared_memory_user.cpp	5.71% <0.00%> (ø)
iceoryx_posh/source/runtime/ipc_interface_base.cpp	59.30% <14.28%> (ø)
iceoryx_hoofs/source/posix_wrapper/named_pipe.cpp	83.33% <83.33%> (ø)
...fs/include/iceoryx_hoofs/internal/cxx/helplets.inl	93.47% <93.47%> (ø)
...oofs/include/iceoryx_hoofs/internal/cxx/string.inl	98.63% <100.00%> (-0.02%)	⬇️
..._hoofs/source/posix_wrapper/unix_domain_socket.cpp	62.38% <100.00%> (-0.33%)	⬇️
...fs/internal/posix_wrapper/shared_memory_object.hpp	66.66% <0.00%> (-33.34%)	⬇️
... and 2 more

[FerdinandSpitzschnueffler]

Not finished, but after reviewing the tests I have to consult the glory hypnotoad...

[elBoberido]

Reviewed everything but the actual named pipe implementation. This has to wait till tomorrow

[elBoberido]

The actual named pipe implementation is still not reviewed. Will do it after lunch

[elBoberido]

While I somehow understand the reasoning for this, I'm not quite sure if this is a good idea. It uses knowledge from a higher level to define something which is only used even more up in the stack. Maybe it's the lesser evil but I have to think a bit more about it.

[elBoberido]

Almost there, just a few minor issues left

[elBoberido]

Not required for this PR, but we need to get rid of this and use cxx::optional<IpcChannel> everywhere this is used

[FerdinandSpitzschnueffler]

they licked hypnotoad...