Do not crash Executor when send_response fails due to client failure. (…

…#2276)

* Do not crash Executor when send_response fails due to client failure.

Related to ros2/ros2#1253

It is not sane that a faulty client can crash our service Executor, as
discussed in the referred issue, if the client is not setup properly,
send_response may return RCL_RET_TIMEOUT, we should not throw an error
in this case.

Signed-off-by: Zang MingJie <zealot0630@gmail.com>

* Update rclcpp/include/rclcpp/service.hpp

Co-authored-by: Tomoya Fujita <Tomoya.Fujita@sony.com>
Signed-off-by: Zang MingJie <zealot0630@gmail.com>

* address review comments.

Signed-off-by: Tomoya Fujita <Tomoya.Fujita@sony.com>

---------

Signed-off-by: Zang MingJie <zealot0630@gmail.com>
Signed-off-by: Tomoya Fujita <Tomoya.Fujita@sony.com>
Co-authored-by: Zang MingJie <zealot0630@gmail.com>
(cherry picked from commit fbe8f28)

rclcpp/include/rclcpp/service.hpp

@@ -482,6 +482,14 @@ class Service
   {
     rcl_ret_t ret = rcl_send_response(get_service_handle().get(), &req_id, &response);
 
+    if (ret == RCL_RET_TIMEOUT) {
+      RCLCPP_WARN(
+        node_logger_.get_child("rclcpp"),
+        "failed to send response to %s (timeout): %s",
+        this->get_service_name(), rcl_get_error_string().str);
+      rcl_reset_error();
+      return;
+    }
     if (ret != RCL_RET_OK) {
       rclcpp::exceptions::throw_from_rcl_error(ret, "failed to send response");
     }