Cycles: Add support of processor groups

Currently for windows only, this is an initial commit towards native
support of NUMA.

Current commit makes it so Cycles will use all logical processors on
Windows running on system with more than 64 threads.

Reviewers: juicyfruit, dingto, lukasstockner97, maiself, brecht

Subscribers: LazyDodo

Differential Revision: https://developer.blender.org/D2049

intern/cycles/util/util_thread.cpp

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2011-2016 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "util_thread.h"
+
+#include "util_system.h"
+#include "util_windows.h"
+
+CCL_NAMESPACE_BEGIN
+
+thread::thread(function<void(void)> run_cb, int group)
+  : run_cb_(run_cb),
+    joined_(false),
+	group_(group)
+{
+	pthread_create(&pthread_id_, NULL, run, (void*)this);
+}
+
+thread::~thread()
+{
+	if(!joined_) {
+		join();
+	}
+}
+
+void *thread::run(void *arg)
+{
+	thread *self = (thread*)(arg);
+	if(self->group_ != -1) {
+#ifdef _WIN32
+		HANDLE thread_handle = GetCurrentThread();
+		GROUP_AFFINITY group_affinity = { 0 };
+		int num_threads = system_cpu_group_thread_count(self->group_);
+		group_affinity.Group = self->group_;
+		group_affinity.Mask = (num_threads == 64)
+		                              ? -1
+		                              :  (1ull << num_threads) - 1;
+		if(SetThreadGroupAffinity(thread_handle, &group_affinity, NULL) == 0) {
+			fprintf(stderr, "Error setting thread affinity.\n");
+		}
+#endif
+	}
+	self->run_cb_();
+	return NULL;
+}
+
+bool thread::join()
+{
+	joined_ = true;
+	return pthread_join(pthread_id_, NULL) == 0;
+}
+
+CCL_NAMESPACE_END