// RUN: %libomp-cxx-compile-and-run #include #include #include #include #include #include // AIX runs out of resource in 32-bit if 4*omp_get_max_threads() is more // than 64 threads with the default stack size. #if defined(_AIX) && !__LP64__ #define MAX_THREADS 64 #endif void dummy_root() { // omp_get_max_threads() will do middle initialization int nthreads = omp_get_max_threads(); std::this_thread::sleep_for(std::chrono::milliseconds(1000)); } int main(int argc, char *argv[]) { int N = std::min(std::max(std::max(32, 4 * omp_get_max_threads()), 4 * omp_get_num_procs()), std::numeric_limits::max()); #if defined(_AIX) && !__LP64__ if (N > MAX_THREADS) N = MAX_THREADS; #endif std::vector data(N); // Create a new thread to initialize the OpenMP RTL. The new thread will not // be taken as the "initial thread". std::thread root(dummy_root); #pragma omp parallel for num_threads(N) for (unsigned i = 0; i < N; ++i) { data[i] = i; } #pragma omp parallel for num_threads(N + 1) for (unsigned i = 0; i < N; ++i) { data[i] += i; } for (unsigned i = 0; i < N; ++i) { assert(data[i] == 2 * i); } root.join(); return 0; }