initial commit, 4.5 stable

thirdparty/spirv-cross/include/spirv_cross/thread_group.hpp

@@ -0,0 +1,114 @@
+/*
+ * Copyright 2015-2017 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * 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.
+ */
+
+#ifndef SPIRV_CROSS_THREAD_GROUP_HPP
+#define SPIRV_CROSS_THREAD_GROUP_HPP
+
+#include <condition_variable>
+#include <mutex>
+#include <thread>
+
+namespace spirv_cross
+{
+template <typename T, unsigned Size>
+class ThreadGroup
+{
+public:
+	ThreadGroup(T *impl)
+	{
+		for (unsigned i = 0; i < Size; i++)
+			workers[i].start(&impl[i]);
+	}
+
+	void run()
+	{
+		for (auto &worker : workers)
+			worker.run();
+	}
+
+	void wait()
+	{
+		for (auto &worker : workers)
+			worker.wait();
+	}
+
+private:
+	struct Thread
+	{
+		enum State
+		{
+			Idle,
+			Running,
+			Dying
+		};
+		State state = Idle;
+
+		void start(T *impl)
+		{
+			worker = std::thread([impl, this] {
+				for (;;)
+				{
+					{
+						std::unique_lock<std::mutex> l{ lock };
+						cond.wait(l, [this] { return state != Idle; });
+						if (state == Dying)
+							break;
+					}
+
+					impl->main();
+
+					std::lock_guard<std::mutex> l{ lock };
+					state = Idle;
+					cond.notify_one();
+				}
+			});
+		}
+
+		void wait()
+		{
+			std::unique_lock<std::mutex> l{ lock };
+			cond.wait(l, [this] { return state == Idle; });
+		}
+
+		void run()
+		{
+			std::lock_guard<std::mutex> l{ lock };
+			state = Running;
+			cond.notify_one();
+		}
+
+		~Thread()
+		{
+			if (worker.joinable())
+			{
+				{
+					std::lock_guard<std::mutex> l{ lock };
+					state = Dying;
+					cond.notify_one();
+				}
+				worker.join();
+			}
+		}
+		std::thread worker;
+		std::condition_variable cond;
+		std::mutex lock;
+	};
+	Thread workers[Size];
+};
+}
+
+#endif