Add Dispatcher.

src/Dispatcher.cpp

@@ -0,0 +1,122 @@
+/*----------------------------------------------------------------------------*/
+/* 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.                                                               */
+/*----------------------------------------------------------------------------*/
+
+#include "Dispatcher.h"
+
+#include "tcpsockets/TCPAcceptor.h"
+#include "tcpsockets/TCPConnector.h"
+
+using namespace ntimpl;
+
+std::unique_ptr<Dispatcher> Dispatcher::m_instance;
+
+static NT_Type GetEntryType(unsigned int id) {
+  // TODO
+  return NT_UNASSIGNED;
+}
+
+Dispatcher::Dispatcher() : m_active(false) {}
+
+Dispatcher::~Dispatcher() { Stop(); }
+
+void Dispatcher::StartServer(const char* listen_address, unsigned int port) {
+  if (m_active) return;
+  m_active = true;
+  m_dispatch_thread = std::thread(&Dispatcher::DispatchThreadMain, this);
+  m_clientserver_thread =
+      std::thread(&Dispatcher::ServerThreadMain, this, listen_address, port);
+}
+
+void Dispatcher::StartClient(const char* server_name, unsigned int port) {
+  if (m_active) return;
+  m_active = true;
+  m_dispatch_thread = std::thread(&Dispatcher::DispatchThreadMain, this);
+  m_clientserver_thread =
+      std::thread(&Dispatcher::ClientThreadMain, this, server_name, port);
+}
+
+void Dispatcher::Stop() {
+  m_active = false;
+  if (m_dispatch_thread.joinable()) m_dispatch_thread.join();
+  if (m_clientserver_thread.joinable()) m_clientserver_thread.join();
+}
+
+void Dispatcher::SetUpdateRate(double interval) {
+  // TODO
+}
+
+void Dispatcher::SetIdentity(llvm::StringRef name) {
+  std::lock_guard<std::mutex> lock(m_user_mutex);
+  m_identity = name;
+}
+
+void Dispatcher::DispatchThreadMain() {
+  // TODO
+}
+
+void Dispatcher::ServerThreadMain(const char* listen_address,
+                                  unsigned int port) {
+  TCPAcceptor acceptor(static_cast<int>(port), listen_address);
+  if (acceptor.start() != 0) {
+    m_active = false;
+    return;
+  }
+  while (m_active) {
+    auto stream = acceptor.accept();
+    if (!stream) {
+      m_active = false;
+      break;
+    }
+    // add to connections list
+  }
+}
+
+void Dispatcher::ClientThreadMain(const char* server_name, unsigned int port) {
+  std::string self_id;
+  {
+    std::lock_guard<std::mutex> lock(m_user_mutex);
+    self_id = m_identity;
+  }
+  unsigned int proto_rev = 0x0300;
+  std::unique_ptr<NetworkConnection> conn;
+  while (m_active) {
+    // try to connect (with timeout)
+    auto stream = TCPConnector::connect(server_name, static_cast<int>(port), 1);
+    if (!stream) continue;  // keep retrying
+
+    conn.reset(new NetworkConnection(std::move(stream), GetEntryType));
+    conn->set_proto_rev(proto_rev);
+
+    // send client hello
+    conn->outgoing().push(
+        NetworkConnection::Outgoing{Message::ClientHello(self_id)});
+
+    // wait for response
+    auto resp = conn->incoming().pop();
+
+    if (resp->Is(Message::kProtoUnsup)) {
+      // reconnect with lower protocol (if possible)
+      if (proto_rev <= 0x0200) {
+        // no more options, abort (but keep trying to connect)
+        proto_rev = 0x0300;
+        continue;
+      }
+      proto_rev = 0x0200;
+      continue;
+    }
+
+    if (!resp->Is(Message::kServerHello)) {
+      // shouldn't happen; disconnect but keep trying to connect
+      proto_rev = 0x0300;
+      continue;
+    }
+
+    // add to connections list (the dispatcher thread will handle from here)
+
+    // block until told to reconnect
+  }
+}

src/Dispatcher.h

@@ -0,0 +1,69 @@
+/*----------------------------------------------------------------------------*/
+/* 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_DISPATCHER_H_
+#define NT_DISPATCHER_H_
+
+#include <atomic>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <vector>
+
+#include "llvm/StringRef.h"
+
+#include "NetworkConnection.h"
+
+namespace ntimpl {
+
+class Dispatcher {
+ public:
+  static Dispatcher& GetInstance() {
+    if (!m_instance) m_instance.reset(new Dispatcher);
+    return *m_instance;
+  }
+  ~Dispatcher();
+
+  void StartServer(const char* listen_address, unsigned int port);
+  void StartClient(const char* server_name, unsigned int port);
+  void Stop();
+  void SetUpdateRate(double interval);
+  void SetIdentity(llvm::StringRef name);
+
+  Dispatcher(const Dispatcher&) = delete;
+  Dispatcher& operator=(const Dispatcher&) = delete;
+
+ private:
+  Dispatcher();
+
+  void DispatchThreadMain();
+  void ServerThreadMain(const char* listen_address, unsigned int port);
+  void ClientThreadMain(const char* server_name, unsigned int port);
+
+  struct Connection {
+    enum State {
+    };
+    State state;
+    std::unique_ptr<NetworkConnection> conn;
+  };
+  std::thread m_dispatch_thread;
+  std::thread m_clientserver_thread;
+
+  // Mutex protected
+  std::vector<Connection> m_connections;
+  std::string m_identity;
+  std::mutex m_user_mutex;
+
+  std::atomic_bool m_active;
+  std::atomic_uint m_interval;
+
+  static std::unique_ptr<Dispatcher> m_instance;
+};
+
+}  // namespace ntimpl
+
+#endif  // NT_DISPATCHER_H_