Fix init_prism centroid; make test-prism's parallel loops thread-safe - #81
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…aths Two related bugs surfaced by running the --enable-openmp test suite against test-prism, both pre-existing: 1) init_prism assigned prsm->centroid BEFORE the shift-to-o->center logic, then the shift only updated a local `centroid` variable. After construction, any prism whose center was modified ended up with prsm->centroid stale relative to the (shifted) vertices. 2) point_in_objectp, normal_to_object, and point_in_periodic_objectp each called geom_fix_object_ptr(&o) on every query. For prisms that path calls reinit_prism, which free()s + malloc()s shared per-prism arrays (vertices_p, vertices_top_p, ...). Under OpenMP the test was crashing with "malloc(): unaligned tcache chunk" / "free(): double free". This matches what PR NanoComp#75 already did for geom_get_bounding_box -- callers are now responsible for calling geom_fix_object_ptr after mutating o.center. test-prism: after the random-shift branch, call geom_fix_object_ptr on the block and prism once, single-threaded, before the parallel test loops run. Verified at OMP_NUM_THREADS = 1, 2, 4, 8, 16, 32, 64, 128, 166: all clean (0 point failures, 0 segment failures, no heap corruption). make check passes.
stevengj
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May 22, 2026
Per review feedback, point_in_objectp / normal_to_object / point_in_periodic_objectp are restored to their original behavior (call geom_fix_object_ptr internally) rather than being silently turned into thin aliases for the *_fixed_* variants. Their doc comments now state they are NOT thread-safe and direct concurrent callers at the *_fixed_* entry points. test-prism's parallel loops switched from point_in_objectp / normal_to_object to point_in_fixed_objectp / normal_to_fixed_object, which are pure reads and safe to call from multiple threads against an object that was fixed up once beforehand. Combined with the init_prism centroid fix in the previous commit, make check passes cleanly across OMP_NUM_THREADS = 1, 2, 4, 8, 16, 64, 166 (21 trials each: 0 point-inclusion failures, 0 segment failures, no heap-corruption signatures).
Luochenghuang
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The revised PR looks good to me. |
Luochenghuang
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May 29, 2026
Drops the macos-latest matrix entry per maintainer preference (less useful: project is primarily Linux-targeted, macOS runners cost more minutes, and the existing Travis macOS coverage didn't exercise anything Linux didn't). Adds --enable-openmp to the configure step and matrices the run on OMP_NUM_THREADS = 1 and 8. Both values share the same build; only the runtime thread count differs. This catches regressions in the parallel test paths (test-prism's #pragma omp parallel for loops in test_point_inclusion, test_normal_to_object, and test_line_segment_intersection) that a serial-only run wouldn't flag — same matrix philosophy used to validate the prism thread-safety work in PR NanoComp#75 / NanoComp#81.
Luochenghuang
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May 29, 2026
Drops the macos-latest matrix entry per maintainer preference (less useful: project is primarily Linux-targeted, macOS runners cost more minutes, and the existing Travis macOS coverage didn't exercise anything Linux didn't). Adds --enable-openmp to the configure step and matrices the run on OMP_NUM_THREADS = 1 and 8. Both values share the same build; only the runtime thread count differs. This catches regressions in the parallel test paths (test-prism's #pragma omp parallel for loops in test_point_inclusion, test_normal_to_object, and test_line_segment_intersection) that a serial-only run wouldn't flag — same matrix philosophy used to validate the prism thread-safety work in PR NanoComp#75 / NanoComp#81.
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* Migrate CI from Travis to GitHub Actions
Replaces the Travis configuration with an equivalent GitHub Actions
workflow at .github/workflows/ci.yml. Same matrix (ubuntu-latest +
macos-latest), same build pipeline (autogen.sh, make, make check,
make install), same on-failure log dump for utils/*.log.
Two minor modernizations:
- Switches the Ubuntu guile package from guile-2.0-dev to
guile-3.0-dev. guile-2.0 was dropped from Ubuntu after 20.04;
libctl already builds and runs against guile 3.0.
- macOS dependency install adds autoconf/automake/libtool explicitly
rather than relying on the runner image to provide them.
Workflow triggers on push to master, pull_request to master, and
manual workflow_dispatch. fail-fast disabled so a failure on one OS
doesn't cancel the other.
Also removes the Travis CI badge from README.md and replaces it with
a GitHub Actions badge pointing at the new workflow.
* CI: drop macOS, add OMP_NUM_THREADS matrix to exercise parallel tests
Drops the macos-latest matrix entry per maintainer preference (less
useful: project is primarily Linux-targeted, macOS runners cost more
minutes, and the existing Travis macOS coverage didn't exercise
anything Linux didn't).
Adds --enable-openmp to the configure step and matrices the run on
OMP_NUM_THREADS = 1 and 8. Both values share the same build; only
the runtime thread count differs. This catches regressions in the
parallel test paths (test-prism's #pragma omp parallel for loops in
test_point_inclusion, test_normal_to_object, and
test_line_segment_intersection) that a serial-only run wouldn't
flag — same matrix philosophy used to validate the prism
thread-safety work in PR #75 / #81.
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After #75 + #79,
test-prismwith--enable-openmpwas still failing atOMP_NUM_THREADS >= 2with heap corruption and intermittent point-inclusion mismatches. Two issues.1.
init_prismwritesprsm->centroidbefore the optional shiftThe line
prsm->centroid = centroid = ...happens before theelseblock that shifts bothverticesand the localcentroidto land ono->center. The shift only updates the local —prsm->centroidstays at the pre-shift value, while the vertex arrays reflect the shifted geometry. Block-vs-prism point-inclusion then disagrees on the difference between old and new placement.The pre-PR auto-fix in
point_in_objectpmasked this in serial code (the second call recomputedcentroidfrom the now-shifted vertices), but #79's parallel loop exposed it.Fix: move
prsm->centroid = centroid;to after the if/else. Idempotent in serial code too — not OpenMP-specific.2. test-prism's parallel loops were calling the thread-unsafe wrappers
point_in_objectp/normal_to_object/point_in_periodic_objectpcallgeom_fix_object_ptron every invocation, which for prisms doesfree/mallocon shared per-prism arrays. Two threads racing on the same prism corrupt the allocator — the original crash from #79.The wrappers are kept as-is (preserving API contract for callers that mutate object parameters between queries) but their doc comments now mark them as not thread-safe and direct concurrent callers at the
*_fixed_*variants.In test-prism:
test_point_inclusion: switch topoint_in_fixed_objectp.test_normal_to_object(disabled but still parallel): switch tonormal_to_fixed_object.run_unit_tests: callgeom_fix_object_ptronthe_blockandthe_prisminside theP_SHIFTblock, before the parallel loops run.Verification
make checkpasses. Three trials each atOMP_NUM_THREADS = 1, 2, 4, 8, 16, 64, 166: 21/21 clean (0/10000 points failed, 0/1000 segments failed, no heap-corruption signatures).