Advanced Streaming Extensions

This patch extends lbmpy's support for advanced streaming patterns. In particular, the Push-Collide-Stream, AA-Pattern and Esoteric Twist are considered.

• Boundary Handling: The LBM boundary implementations are overhauled completely. A new framework for defining and generating boundary kernels is introduced, which makes the symbolic definition independent of the streaming pattern. Boundaries can now be defined symbolically using the proxy fields f_out for accessing populations streaming out of a cell, and f_in for populations streaming in to a cell. Those are replaced during the code generation process according to the streaming pattern. The class BetweenTimestepsIndexing used herein can also be used to generate other kernels that run on the PDF-field in-between collision steps.

• Periodicity Handling: The build-in periodicity synchronization of pystencil's DataHandling does not work for advanced LBM streaming. The new class LBMPeriodicityHandling extends the SerialDataHandling to handle periodicity correctly.

• Utility: The patch introduces a few utility functions for the work with advanced streaming patterns.

.gitlab-ci.yml

@@ -99,22 +99,19 @@ pycodegen-integration:
   when: manual
   allow_failure: false
   script:
-    # run lbmpy long test pipeline
-    - export NUM_CORES=$(nproc --all)
-    - mkdir -p ~/.config/matplotlib
-    - echo "backend:template" > ~/.config/matplotlib/matplotlibrc
-    - pip install git+https://gitlab-ci-token:${CI_JOB_TOKEN}@i10git.cs.fau.de/pycodegen/pystencils.git@master#egg=pystencils
-    - py.test -v -n $NUM_CORES --cov-report html --cov-report term --cov=.
-    # change path to outside of lbmpy and call pip to set the environment variable right
-    - cd ..
-    - pip install -e lbmpy
-    # fetch pycodegen repository with waLberla as submodule and install waLBerla to run the integration tests
     - git clone https://gitlab-ci-token:${CI_JOB_TOKEN}@i10git.cs.fau.de/pycodegen/pycodegen.git
     - cd pycodegen
     - git submodule sync --recursive
     - git submodule update --init --recursive
     - git submodule foreach git fetch origin   # compare the latest master version!
     - git submodule foreach git reset --hard origin/master
+    - cd lbmpy
+    - git remote add test $CI_REPOSITORY_URL
+    - git fetch test
+    - git reset --hard $CI_COMMIT_SHA
+    - cd ..
+    - pip install -e pystencils/
+    - pip install -e lbmpy/
     - ./install_walberla.sh
     # build all integration tests
     - cd walberla/build/
@@ -123,6 +120,7 @@ pycodegen-integration:
     - make -j $NUM_CORES
     - cd ../UniformGridGenerated
     - make -j $NUM_CORES
+
   tags:
     - docker
     - cuda11