1 files changed, 158 insertions, 0 deletions
diff --git a/runtimes/neurun/core/src/exec/ParallelScheduler.h b/runtimes/neurun/core/src/exec/ParallelScheduler.h
new file mode 100644
index 000000000..9660478e8
--- /dev/null
+++ b/runtimes/neurun/core/src/exec/ParallelScheduler.h
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2019 Samsung Electronics Co., Ltd. All Rights Reserved
+ *
+ * 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 __NEURUN_EXEC_PARALLEL_SCHEDULER_H__
+#define __NEURUN_EXEC_PARALLEL_SCHEDULER_H__
+
+#include <unordered_map>
+#include <thread>
+#include <mutex>
+#include <condition_variable>
+#include <memory>
+#include <queue>
+#include <vector>
+#include <unordered_set>
+
+#include "exec/IFunction.h"
+#include "graph/BackendSet.h"
+
+namespace neurun
+{
+namespace exec
+{
+
+// TODO Extract this class to a separate file
+class WorkQueue
+{
+public:
+  enum class State
+  {
+    ONLINE,
+    FINISHING,
+    FORCE_FINISHING
+  };
+
+public:
+  /**
+   * @brief Create WorkQueue object
+   */
+  WorkQueue() = default;
+  /**
+   * @brief Destroy WorkQueue object
+   */
+  ~WorkQueue();
+  /**
+   * @brief Thread entry function
+   */
+  void operator()();
+  /**
+   * @brief Push the given Task to the job queue
+   *
+   * @param fn Function to be executed(a job)
+   */
+  void enqueue(std::unique_ptr<IFunction> &&fn);
+  /**
+   * @brief Flag as terminating so all the worker threads can terminate
+   */
+  void terminate();
+  /**
+   * @brief Flag as terminating so all the worker threads can terminate
+   */
+  void finish();
+  /**
+   * @brief Check if it has pending jobs. Even if this returns fals, WorkQueue threads may be still
+   * running
+   *
+   * @return true if the job queue not empty otherwise false
+   */
+  uint32_t numJobsInQueue();
+
+private:
+  State _state{State::ONLINE};
+  std::queue<std::unique_ptr<IFunction>> _functions;
+  std::mutex _mu;
+  std::condition_variable _cv;
+};
+
+// TODO Extract this class to a separate file
+class ThreadPool
+{
+public:
+  /**
+   * @brief Coustruct ThreadPool object
+   *
+   * @param num_threads Number of threads
+   */
+  ThreadPool(uint32_t num_threads = 1);
+  /**
+   * @brief Destroy ThreadPool object
+   */
+  ~ThreadPool();
+  /**
+   * @brief Enqueue a function
+   *
+   * @param fn A function to be queued
+   */
+  void enqueue(std::unique_ptr<IFunction> &&fn);
+  /**
+   * @brief Get number of jobs in worker's queue
+   *
+   * @return Number of jobs
+   */
+  uint32_t numJobsInQueue();
+
+  /**
+   * @brief Block until all jobs are finished
+   */
+  void finish();
+
+private:
+  void join();
+
+private:
+  WorkQueue _worker;
+  std::vector<std::thread> _threads;
+};
+
+class ParallelScheduler
+{
+public:
+  /**
+   * @brief Constructs ParallelScheduler object
+   *
+   * @param backends Backend set
+   */
+  ParallelScheduler(const graph::BackendSet &backends);
+  /**
+   * @brief Assign a task to the given backend
+   *
+   * @param[in] fn Function to be assigned
+   * @param[in] fn Target backend
+   */
+  void assign(std::unique_ptr<IFunction> &&fn, const backend::Backend *backend);
+  /**
+   * @brief Block until all jobs are finished
+   */
+  void finish();
+
+private:
+  std::unordered_map<const backend::Backend *, std::unique_ptr<ThreadPool>> _thread_pools;
+};
+
+} // namespace exec
+} // namespace neurun
+
+#endif // __NEURUN_EXEC_PARALLEL_SCHEDULER_H__