Implement remote procedure calls.

src/RpcServer.h

@@ -0,0 +1,88 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. All Rights Reserved.                             */
+/* Open Source Software - may be modified and shared by FRC teams. The code   */
+/* must be accompanied by the FIRST BSD license file in the root directory of */
+/* the project.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#ifndef NT_RPCSERVER_H_
+#define NT_RPCSERVER_H_
+
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+#include <queue>
+#include <thread>
+#include <utility>
+#include <vector>
+
+#include "llvm/DenseMap.h"
+#include "atomic_static.h"
+#include "Message.h"
+#include "ntcore_cpp.h"
+
+namespace nt {
+
+class RpcServer {
+  friend class RpcServerTest;
+ public:
+  static RpcServer& GetInstance() {
+    ATOMIC_STATIC(RpcServer, instance);
+    return instance;
+  }
+  ~RpcServer();
+
+  typedef std::function<void(std::shared_ptr<Message>)> SendMsgFunc;
+
+  void Start();
+  void Stop();
+
+  bool active() const { return m_active; }
+
+  void ProcessRpc(StringRef name, std::shared_ptr<Message> msg,
+                  RpcCallback func, unsigned int conn_id,
+                  SendMsgFunc send_response);
+
+  bool PollRpc(bool blocking, RpcCallInfo* call_info);
+  void PostRpcResponse(unsigned int rpc_id, unsigned int call_uid,
+                       llvm::StringRef result);
+
+ private:
+  RpcServer();
+
+  void ThreadMain();
+
+  std::atomic_bool m_active;
+  std::atomic_bool m_terminating;
+
+  std::mutex m_mutex;
+  std::condition_variable m_call_cond, m_poll_cond;
+
+  struct RpcCall {
+    RpcCall(StringRef name_, std::shared_ptr<Message> msg_, RpcCallback func_,
+            unsigned int conn_id_, SendMsgFunc send_response_)
+        : name(name_),
+          msg(msg_),
+          func(func_),
+          conn_id(conn_id_),
+          send_response(send_response_) {}
+
+    std::string name;
+    std::shared_ptr<Message> msg;
+    RpcCallback func;
+    unsigned int conn_id;
+    SendMsgFunc send_response;
+  };
+  std::queue<RpcCall> m_call_queue, m_poll_queue;
+
+  llvm::DenseMap<std::pair<unsigned int, unsigned int>, SendMsgFunc>
+      m_response_map;
+
+  std::thread m_thread;
+
+  ATOMIC_STATIC_DECL(RpcServer)
+};
+
+}  // namespace nt
+
+#endif  // NT_RPCSERVER_H_