check in existing work

game/system/SystemThread.h

@@ -0,0 +1,89 @@
+/*!
+ * @file SystemThread.h
+ * Threads for the runtime.
+ */
+
+#ifndef RUNTIME_SYSTEMTHREAD_H
+#define RUNTIME_SYSTEMTHREAD_H
+
+#include <string>
+#include <functional>
+#include <pthread.h>
+#include <array>
+#include <mutex>
+#include <condition_variable>
+#include "Timer.h"
+
+
+constexpr int MAX_SYSTEM_THREADS = 16;
+
+class SystemThreadInterface;
+class SystemThreadManager;
+
+/*!
+ * Runs a function in a thread and provides a SystemThreadInterface to that function.
+ * Once the thread is ready, it should tell the interface with intitialization_complete().
+ * Thread functions should try to return when get_want_exit() returns true.
+ * Thread functions should also call report_perf_stats every now and then to update performance
+ * statistics.
+ */
+class SystemThread {
+public:
+  void start(std::function<void(SystemThreadInterface&)> f);
+  void join();
+  void stop();
+  SystemThread() = default;
+
+private:
+  friend class SystemThreadInterface;
+  friend class SystemThreadManager;
+  friend void* bootstrap_thread_func(void* thd);
+
+  std::string name = "invalid";
+  pthread_t thread;
+  SystemThreadManager* manager;
+  std::function<void(SystemThreadInterface &)> function;
+  bool initialization_complete = false;
+  std::mutex initialization_mutex;
+  std::condition_variable initialization_cv;
+  Timer stats_timer;
+  Timer stat_diff_timer;
+  double cpu_user = 0, cpu_kernel = 0;
+  uint64_t last_cpu_user = 0, last_cpu_kernel = 0;
+  uint64_t last_collection_nanoseconds = 0;
+  int id = -1;
+  bool want_exit = false;
+  bool running = false;
+};
+
+/*!
+ * The interface used by a thread in the runtime.
+ */
+class SystemThreadInterface {
+public:
+  SystemThreadInterface(SystemThread* p) : thread(*p) {
+
+  }
+  void initialization_complete();
+  void report_perf_stats();
+  bool get_want_exit() const;
+  void trigger_shutdown();
+private:
+  SystemThread& thread;
+};
+
+/*!
+ * A manager of all threads in the runtime.
+ */
+class SystemThreadManager {
+public:
+  SystemThread& create_thread(const std::string& name);
+  void print_stats();
+  void shutdown();
+  void join();
+private:
+  std::array<SystemThread, MAX_SYSTEM_THREADS> threads;
+  int thread_count = 0;
+};
+
+#endif //RUNTIME_SYSTEMTHREAD_H