test prism rng testing#98
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The point/segment/normal tests call rand() inside OpenMP parallel loops. rand() uses global shared state, so even with a fixed seed the parallel execution order changes which iteration consumes which random value: failures weren't reproducible and varied between the omp=1 and omp=8 CI legs. Thread all random helpers through an 'unsigned *seed' and use rand_r(), with one seed per thread (seed[tid] = tid) passed as &seed[omp_get_thread_num()]. schedule(dynamic) -> schedule(static) fixes the iteration->thread mapping so the per-thread seeds actually yield reproducible results; the failure count is an integer reduction, so it's independent of thread combination order. The geometry calls still run in parallel, preserving thread-safety coverage. rand()/srand are removed; non-OpenMP builds get omp_get_* stubs.
stevengj
approved these changes
Jul 6, 2026
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Thread all random helpers through an
unsigned *seedand userand_r(), with one seed per thread (seed[tid] = tid) passed as&seed[omp_get_thread_num()]. schedule(dynamic) -> schedule(static) fixes the iteration->thread mapping so the per thread seeds actually yield reproducible results; the failure count is an integer reduction, so it's independent of thread combination order. The geometry calls still run in parallel, preserving thread-safety coverage.rand()/srandare removed; non-OpenMP builds getomp_get_*stubs.Closes #97