Initial commit.

Framework/external/embree/common/tasking/taskschedulertbb.cpp

@@ -0,0 +1,91 @@
+// Copyright 2009-2021 Intel Corporation
+// SPDX-License-Identifier: Apache-2.0
+
+#include "taskschedulertbb.h"
+
+namespace embree
+{
+  static bool g_tbb_threads_initialized = false;
+
+#if TBB_INTERFACE_VERSION >= 11005
+  static tbb::global_control* g_tbb_thread_control = nullptr;
+#else
+  static tbb::task_scheduler_init g_tbb_threads(tbb::task_scheduler_init::deferred);
+#endif
+
+  class TBBAffinity: public tbb::task_scheduler_observer
+  {
+  public:
+
+    void on_scheduler_entry( bool ) {
+      setAffinity(TaskScheduler::threadIndex());
+    }
+
+  } tbb_affinity;
+
+  void TaskScheduler::create(size_t numThreads, bool set_affinity, bool start_threads)
+  {
+    assert(numThreads);
+
+    /* first terminate threads in case we configured them */
+    if (g_tbb_threads_initialized) {
+#if TBB_INTERFACE_VERSION >= 11005
+      delete g_tbb_thread_control;
+      g_tbb_thread_control = nullptr;
+#else
+      g_tbb_threads.terminate();
+#endif
+      g_tbb_threads_initialized = false;
+    }
+
+    /* only set affinity if requested by the user */
+#if TBB_INTERFACE_VERSION >= 9000 // affinity not properly supported by older TBB versions
+    if (set_affinity)
+      tbb_affinity.observe(true);
+#endif
+
+    /* now either keep default settings or configure number of threads */
+    if (numThreads == std::numeric_limits<size_t>::max()) {
+      numThreads = threadCount();
+    }
+    else {
+      g_tbb_threads_initialized = true;
+      const size_t max_concurrency = threadCount();
+      if (numThreads > max_concurrency) numThreads = max_concurrency;
+#if TBB_INTERFACE_VERSION >= 11005
+      g_tbb_thread_control = new tbb::global_control(tbb::global_control::max_allowed_parallelism,numThreads);
+#else
+      g_tbb_threads.initialize(int(numThreads));
+#endif
+    }
+
+    /* start worker threads */
+    if (start_threads)
+    {
+      BarrierSys barrier(numThreads);
+      tbb::parallel_for(size_t(0), size_t(numThreads), size_t(1), [&] ( size_t i ) {
+          barrier.wait();
+        });
+    }
+  }
+
+  void TaskScheduler::destroy()
+  {
+#if TBB_INTERFACE_VERSION >= 9000 // affinity not properly supported by older TBB versions
+    // Stop observe to prevent calling on_scheduler_entry
+    // when static objects are already destroyed.
+    if (tbb_affinity.is_observing())
+      tbb_affinity.observe(false);
+#endif
+
+    if (g_tbb_threads_initialized) {
+#if TBB_INTERFACE_VERSION >= 11005
+      delete g_tbb_thread_control;
+      g_tbb_thread_control = nullptr;
+#else
+      g_tbb_threads.terminate();
+#endif
+      g_tbb_threads_initialized = false;
+    }
+  }
+}