incorporating changes from #53

rclcpp/include/rclcpp/client.hpp

@@ -146,8 +146,12 @@ public:
     CallbackType cb)
   {
     int64_t sequence_number;
-    // TODO(wjwwood): Check the return code.
+    if (RMW_RET_OK != rmw_send_request(get_client_handle(), request.get(), &sequence_number)) {
-    rmw_send_request(get_client_handle(), request.get(), &sequence_number);
+      // *INDENT-OFF* (prevent uncrustify from making unecessary indents here)
+      throw std::runtime_error(
+        std::string("failed to send request: ") + rmw_get_error_string_safe());
+      // *INDENT-ON*
+    }
 
     SharedPromise call_promise = std::make_shared<Promise>();
     SharedFuture f(call_promise->get_future());

rclcpp/include/rclcpp/executor.hpp

@@ -162,8 +162,9 @@ protected:
         subscription->handle_message(message);
       }
     } else {
-      std::cout << "[rclcpp::error] take failed for subscription on topic: " <<
+      fprintf(stderr,
-        subscription->get_topic_name() << std::endl;
+        "[rclcpp::error] take failed for subscription on topic '%s': %s\n",
+        subscription->get_topic_name().c_str(), rmw_get_error_string_safe());
     }
   }
 
@@ -191,8 +192,9 @@ protected:
         service->handle_request(request_header, request);
       }
     } else {
-      std::cout << "[rclcpp::error] take failed for service on service: " <<
+      fprintf(stderr,
-        service->get_service_name() << std::endl;
+        "[rclcpp::error] take request failed for server of service '%s': %s\n",
+        service->get_service_name().c_str(), rmw_get_error_string_safe());
     }
   }
 
@@ -203,15 +205,19 @@ protected:
     std::shared_ptr<void> request_header = client->create_request_header();
     std::shared_ptr<void> response = client->create_response();
     bool taken = false;
-    rmw_take_response(
+    rmw_ret_t status = rmw_take_response(
       client->client_handle_,
       request_header.get(),
       response.get(),
       &taken);
+    if (status == RMW_RET_OK) {
       if (taken) {
         client->handle_response(request_header, response);
+      }
     } else {
-      std::cout << "[rclcpp::error] take failed for service on client" << std::endl;
+      fprintf(stderr,
+        "[rclcpp::error] take response failed for client of service '%s': %s\n",
+        client->get_service_name().c_str(), rmw_get_error_string_safe());
     }
   }
 

rclcpp/include/rclcpp/publisher.hpp

@@ -63,7 +63,13 @@ public:
   void
   publish(std::shared_ptr<MessageT> & msg)
   {
-    rmw_publish(publisher_handle_, msg.get());
+    rmw_ret_t status = rmw_publish(publisher_handle_, msg.get());
+    if (status != RMW_RET_OK) {
+      // *INDENT-OFF* (prevent uncrustify from making unecessary indents here)
+      throw std::runtime_error(
+        std::string("failed to publish message: ") + rmw_get_error_string_safe());
+      // *INDENT-ON*
+    }
   }
 
 private:

rclcpp/include/rclcpp/service.hpp

@@ -154,7 +154,13 @@ public:
     std::shared_ptr<rmw_request_id_t> & req_id,
     std::shared_ptr<typename ServiceT::Response> & response)
   {
-    rmw_send_response(get_service_handle(), req_id.get(), response.get());
+    rmw_ret_t status = rmw_send_response(get_service_handle(), req_id.get(), response.get());
+    if (status != RMW_RET_OK) {
+      // *INDENT-OFF* (prevent uncrustify from making unecessary indents here)
+      throw std::runtime_error(
+        std::string("failed to send response: ") + rmw_get_error_string_safe());
+      // *INDENT-ON*
+    }
   }
 
 private: