Bug report

Intra-process subscription count of Publisher is not updated in sync with the subscription count when intra-process communication is used.
When the get_subscription_count() method returns the updated count, get_intra_process_subscription_count() may not return the updated count yet. This behaviour causes the unit tests in test_publisher_subscription_count_api to fail occasionally.

Required Info:

• Operating System:
  • Ubuntu 16.04
• Installation type:
  • Source
• Version or commit hash:
  • 8743bcb
• DDS implementation:
  • Fast-RTPS
• Client library (if applicable):
  • rclcpp

Steps to reproduce issue

Repeat the unit test test_publisher_subscription_count_api until failure. Though this may be hard to reproduce locally, here's an instance of such a failure: https://ci.ros2.org/view/nightly/job/nightly_linux_repeated/1323/testReport/(root)/projectroot/test_publisher_subscription_count_api/

Above test logs shows that the equality conditions on get_subscription_count() are satisfied yet the conditions on get_intra_process_subscription_count() are not met.

Expected behavior

get_subscription_count() and get_intra_process_subscription_count() methods should be in sync when intra-process communication is used.

Actual behavior

The methods return different results.

Additional information