[CM] Improve memory allocation with buffer variables

[saikishor]

This PR tries to address the issue of memory allocation in the RT loop of the CM read, write, and update cycles

[codecov]

Codecov Report

Attention: Patch coverage is 97.91667% with 1 line in your changes missing coverage. Please review.

Project coverage is 89.34%. Comparing base (254b6e8) to head (74dcce2).

Files with missing lines	Patch %	Lines
.../include/controller_manager/controller_manager.hpp	93.33%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1801      +/-   ##
==========================================
- Coverage   89.34%   89.34%   -0.01%     
==========================================
  Files         139      139              
  Lines       15000    14984      -16     
  Branches     1291     1286       -5     
==========================================
- Hits        13402    13387      -15     
- Misses       1113     1114       +1     
+ Partials      485      483       -2     

Flag	Coverage Δ
unittests	89.34% <97.91%> (-0.01%)	⬇️

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

Files with missing lines	Coverage Δ
controller_manager/src/controller_manager.cpp	75.90% <100.00%> (-0.58%)	⬇️
.../include/controller_manager/controller_manager.hpp	96.87% <93.33%> (-3.13%)	⬇️

... and 6 files with indirect coverage changes

[fmauch]

This seems fair. Is there a reason that you went for a quite large number to reserve memory for?

[gavanderhoorn]

Question: would using an RT-safe memory allocator not be a more scalable approach?

[mergify]

This pull request is in conflict. Could you fix it @saikishor?

[saikishor]

This seems fair. Is there a reason that you went for a quite large number to reserve memory for?

Good question, the part of the vectors I can reduce it. For the part of the string, I think we will need it, when you have a large setup and it helps when concatenating strings

[saikishor]

Question: would using an RT-safe memory allocator not be a more scalable approach?

@gavanderhoorn Sure, I wanted to keep it simple and isolated, so it's easier for others. No big reason apart from that. Let me know what you think

[bmagyar]

Question: would using an RT-safe memory allocator not be a more scalable approach?

Do you have some pointers for us? (no pun intended! :D )

[saikishor]

@gavanderhoorn do you have any pointers to improve this approach?

[destogl]

Very nice!

[destogl]

It is a bit mix of concerns with concatenated_string but let's keep it and split if something else additional comes to the game.