[ros-users] Ros on Arm Hanging

[Cedric Pradalier]

Hi Daniel,

not sure if it is related, but when running ROS on the Gumstix Verdex, I 
had to increase the timeout in roslaunch/launch.py 
(_TIMEOUT_MASTER_START) from 10.0 seconds to 20.0 seconds. Maybe you're 
also affected by some timeout problems or race conditions that happen 
only on slow processors...

Best


On 07/01/2010 02:46 AM, Daniel Stonier wrote:
> Hi all,
>
> We're trying to get ros running on an armv6 core here and hitting a
> few issues. If anyone has any insight on how to go about tracking down
> the issues that would be great.
>
> Some general details about the problem:
>
> It's an armv6 core running a custom gentoo with cturtle. The example
> programs I have to test with are a simple client-server pair. The
> client pings the server with a timestamped rpc service request, the
> server too, timestamps and then sends a response. When the response is
> received by the client, it outputs and terminates.
>
> So it's pretty simple, no more than a few lines of code in server and
> client (I've added the code below). End result though, the server
> catches the request, at which point both client and server hang and
> server cpu % goes through the roof. Since the code is simple, I'm
> figuring it must be behind the scenes somewhere (maybe in the rosdep
> library builds or system configuration?)  I'm not sure how to track
> down the issue though - anyone have any ideas?
>
> Cheers,
> Daniel.
>
> ***************************** client.cpp *****************************
>
> class LatencyClient {
> public:
>      LatencyClient() :
>          client(node.serviceClient<  rpc_latency::ping_pong>("rpc_latency"))
>      {}
>      /**
>       * Latency benchmarking service request handler. This initiates
> the request and waits
>       * for the response. Handling is done in main().
>       * @return bool - success or failure of the request.
>       */
>      bool ping_pong() {
>          rpc_latency::ping_pong srv;
>          TimeStamp send_stamp;
>          TimeStamp final_stamp;
>
>          srv.request.ping_time = static_cast<double>(send_stamp.stamp());
>          if ( client.call(srv) ) {
>              final_stamp.stamp();
>              ROS_INFO("Send   Time : %lf", srv.response.pong_time -
> srv.request.ping_time);
>              ROS_INFO("Return Time : %lf",
> static_cast<double>(final_stamp) - srv.response.pong_time);
>              ROS_INFO("Round  Trip : %lf",
> static_cast<double>(final_stamp - send_stamp) );
>              return true;
>          } else {
>              ROS_ERROR("Failed to call service rpc_latency");
>              return false;
>          }
>      }
>
> private:
>      ros::NodeHandle node;
>      ros::ServiceClient client;
> };
>
> int main(int argc, char **argv) {
>      ros::init(argc, argv, "rpc_latency_client");
>
>      LatencyClient latency;
>      latency.ping_pong();
>      return 0;
> }
>
> ***************************** server.cpp *****************************
>
> class LatencyServer {
> public:
>      LatencyServer() :
>          service (node.advertiseService("rpc_latency",
> &LatencyServer::ping_pong, this))
>      {}
>
>      void spin() {
>          ros::spin();
>      }
>      bool ping_pong(rpc_latency::ping_pong::Request&request,
>                     rpc_latency::ping_pong::Response&response ) {
>          response.pong_time = timestamp.stamp();
>          ROS_INFO("TimeStamp: %lf", static_cast<double>(timestamp) );
>          return true;
>      }
>
> private:
>      TimeStamp timestamp;
>      ros::NodeHandle node;
>      ros::ServiceServer service;
> };
>
> int main(int argc, char **argv) {
>      ros::init(argc, argv, "rpc_latency_server");
>
>      LatencyServer latency_server;
>      latency_server.spin();
>      return 0;
> }
>
>
>
>    


-- 
Cedric - Specialising in cat herding
- http://www.asl.ethz.ch/people/cedricp
- http://www.skybotix.com