Bind TBB max threads num to OMP_NUM_THREADS environment variable value

Author: aobolensk

tasks/all/runner.cpp

@@ -1,4 +1,5 @@
 #include <gtest/gtest.h>
+#include <tbb/global_control.h>
 
 #include <boost/mpi/communicator.hpp>
 #include <boost/mpi/environment.hpp>
@@ -56,6 +57,21 @@ int main(int argc, char** argv) {
   boost::mpi::environment env(argc, argv);
   boost::mpi::communicator world;
 
+#ifdef _WIN32
+  size_t len;
+  char omp_env[100];
+  errno_t err = getenv_s(&len, omp_env, sizeof(omp_env), "OMP_NUM_THREADS");
+  if (err != 0 || len == 0) {
+    omp_env[0] = '\0';
+  }
+#else
+  const char* omp_env = std::getenv("OMP_NUM_THREADS");
+#endif
+  int num_threads = (omp_env != nullptr) ? std::atoi(omp_env) : 1;
+
+  // Limit the number of threads in TBB
+  tbb::global_control control(tbb::global_control::max_allowed_parallelism, num_threads);
+
   ::testing::InitGoogleTest(&argc, argv);
 
   auto& listeners = ::testing::UnitTest::GetInstance()->listeners();

tasks/tbb/runner.cpp

@@ -1,6 +1,22 @@
 #include <gtest/gtest.h>
+#include <tbb/global_control.h>
+
+int main(int argc, char** argv) {
+#ifdef _WIN32
+  size_t len;
+  char omp_env[100];
+  errno_t err = getenv_s(&len, omp_env, sizeof(omp_env), "OMP_NUM_THREADS");
+  if (err != 0 || len == 0) {
+    omp_env[0] = '\0';
+  }
+#else
+  const char* omp_env = std::getenv("OMP_NUM_THREADS");
+#endif
+  int num_threads = (omp_env != nullptr) ? std::atoi(omp_env) : 1;
+
+  // Limit the number of threads in TBB
+  tbb::global_control control(tbb::global_control::max_allowed_parallelism, num_threads);
 
-int main(int argc, char **argv) {
   ::testing::InitGoogleTest(&argc, argv);
   return RUN_ALL_TESTS();
 }