rclpy Add parallel callback test

Add parallel callback test

Open Flova opened this issue 3 years ago • 1 comments

Following up on the suggestion in #1039, this pull request adds a test case which checks if the parallel processing of callback is working when the reentrant callback group and the multithreaded executor are used. This behavior was broken recently, and the test should ensure that future regressions are noticed.

The test case is based on the reproduction example from #1039. I put it together with the callback group test cases, but we could put it somewhere else.