MPI P4est parabolic 3D

[TJP-Karpowski]

MPI for 3D parabolic system on conforming and nonconforming P4est Mesh

The PR adds MPI support for the parabolic rhs for 3D P4est Meshes with AMR and load balancing.
The PR needs #2886, #2881, and #2888 to be merged first.

It already seems to work, and I'll add more information and testing once the previous ones are finalized.

Disclaimer

LLMs have been used to aid in the PR.

Funding Statement

This work has been funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project Number 237267381 – TRR 150.

[github-actions]

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Purpose and scope

• The PR has a single goal that is clear from the PR title and/or description.
• All code changes represent a single set of modifications that logically belong together.
• No more than 500 lines of code are changed or there is no obvious way to split the PR into multiple PRs.

Code quality

• The code can be understood easily.
• Newly introduced names for variables etc. are self-descriptive and consistent with existing naming conventions.
• There are no redundancies that can be removed by simple modularization/refactoring.
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Testing

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Performance

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Verification

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  are posted in the PR.

Created with ❤️ by the Trixi.jl community.

[codecov]

Codecov Report

❌ Patch coverage is 13.57143% with 605 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.39%. Comparing base (4c3bf99) to head (83c176e).

Files with missing lines	Patch %	Lines
...rc/solvers/dgsem_p4est/dg_2d_parabolic_parallel.jl	0.00%	310 Missing ⚠️
...rc/solvers/dgsem_p4est/dg_3d_parabolic_parallel.jl	0.00%	284 Missing ⚠️
src/callbacks_step/analysis_surface_integral_2d.jl	37.50%	5 Missing ⚠️
src/callbacks_step/amr.jl	0.00%	2 Missing ⚠️
src/solvers/dgsem/indicators.jl	93.33%	1 Missing ⚠️
src/solvers/dgsem_tree/indicators_1d.jl	95.00%	1 Missing ⚠️
src/solvers/dgsem_tree/indicators_2d.jl	93.33%	1 Missing ⚠️
src/solvers/dgsem_tree/indicators_3d.jl	93.33%	1 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (4c3bf99) and HEAD (83c176e). Click for more details.

HEAD has 2 uploads less than BASE

Flag	BASE (4c3bf99)	HEAD (83c176e)
unittests	27	25

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2894      +/-   ##
==========================================
- Coverage   97.09%   90.39%   -6.70%     
==========================================
  Files         609      614       +5     
  Lines       47484    48170     +686     
==========================================
- Hits        46102    43540    -2562     
- Misses       1382     4630    +3248     

Flag	Coverage Δ
unittests	90.39% <13.57%> (-6.70%)	⬇️

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