In Fast-RTPS PR was added check for subscribers count before publish service response and if it's equal 0 RMW_RET_ERROR is returned.
Application throws the unhandled exception RCLError.

Bug report

Required Info:

• Operating System:
  • Ubuntu 20.04
• Installation type:
  • binaries
• Version or commit hash:
  • Foxy latest release
• DDS implementation:
  • Fast-RTPS
• Client library (if applicable):
  • rclcpp

Steps to reproduce issue

Remove client while service callback is running

Expected behavior

No terminate.

Actual behavior

terminate called after throwing an instance of 'rclcpp::exceptions::RCLError'
what(): failed to send response: client will not receive response, at /tmp/binarydeb/ros-foxy-rmw-fastrtps-shared-cpp-1.2.0/src/rmw_response.cpp:124, at /tmp/binarydeb/ros-foxy-rcl-1.1.7/src/rcl/service.c:342

Additional information

With Cyclone DDS all works fine

Follow-ups

hidmic:

Hmm, yeah, rmw_fastrtps*_cpp and rmw_cyclonedds_cpp behavior differs. Missed it back then. Thanks for reporting @blacksoul000 !

RMW_RET_ERROR is too generic for upper layers to do anything about the situation. I'm not entirely sure RMW_RET_TIMEOUT is super appropriate either, but for Foxy we may not have a choice. CC @jacobperron.

blacksoul000

@hidmic any non-fault behavior will be good.

jacobperron:

Changing the return value to RMW_RET_TIMEOUT to make behavior between the RWM implementations sounds reasonable to me.