setup timeout for tcp sockets

If we want to be able to stop the producer, we'll have to make sure,
it is not hanging inside the recv function because no new packages came in.

ur_rtde_driver/include/ur_rtde_driver/comm/producer.h

@@ -44,6 +44,10 @@ public:
 
   void setupProducer()
   {
+    timeval tv;
+    tv.tv_sec = 1;
+    tv.tv_usec = 0;
+    stream_.setReceiveTimeout(tv);
     stream_.connect();
   }
   void teardownProducer()

ur_rtde_driver/include/ur_rtde_driver/comm/tcp_socket.h

@@ -23,6 +23,7 @@
 #include <atomic>
 #include <mutex>
 #include <string>
+#include <memory>
 
 namespace ur_driver
 {
@@ -44,6 +45,7 @@ class TCPSocket
 private:
   std::atomic<int> socket_fd_;
   std::atomic<SocketState> state_;
+  std::unique_ptr<timeval> recv_timeout_;
 
 protected:
   virtual bool open(int socket_fd, struct sockaddr* address, size_t address_len)
@@ -111,6 +113,13 @@ public:
    * \brief Closes the connection to the socket.
    */
   void close();
+
+  /*!
+   * \brief Setup Receive timeout used for this socket.
+   *
+   * \param timeout Timeout used for setting things up
+   */
+  void setReceiveTimeout(const timeval& timeout);
 };
 }  // namespace comm
 }  // namespace ur_driver

ur_rtde_driver/src/comm/tcp_socket.cpp

@@ -44,6 +44,11 @@ void TCPSocket::setOptions(int socket_fd)
   int flag = 1;
   setsockopt(socket_fd, IPPROTO_TCP, TCP_NODELAY, &flag, sizeof(int));
   setsockopt(socket_fd, IPPROTO_TCP, TCP_QUICKACK, &flag, sizeof(int));
+
+  if (recv_timeout_ != nullptr)
+  {
+    setsockopt(socket_fd, SOL_SOCKET, SO_RCVTIMEO, recv_timeout_.get(), sizeof(timeval));
+  }
 }
 
 bool TCPSocket::setup(std::string& host, int port)
@@ -188,5 +193,16 @@ bool TCPSocket::write(const uint8_t* buf, const size_t buf_len, size_t& written)
 
   return true;
 }
+
+void TCPSocket::setReceiveTimeout(const timeval& timeout)
+{
+  recv_timeout_.reset(new timeval(timeout));
+
+  if (state_ == SocketState::Connected)
+  {
+    setOptions(socket_fd_);
+  }
+}
+
 }  // namespace comm
 }  // namespace ur_driver