test_util GetTopics sporadically failing when using SHM monitoring only

[KerstinKeller]

Problem Description

On master, testcase GetTopics from the test suite test_util is sporadically failing when using SHM monitoring only.

Specifically, the map with publishers / subscribers is not empty after all publishers / subscribers have been destroyed.

##Investigation
Tracing the sample calls with the description gate show that when the testcase failes, subscribers and publishers are registered again after they have been unregistered.

    Register subscriber 
    Register subscriber 
    Register subscriber 
    Register publisher 
    Register publisher 
    Register publisher 
    Register publisher 
    Register subscriber 
    Register subscriber 
    Register subscriber 
    Register publisher 
    Register publisher 
    Register publisher 
    Register publisher 
    Unegister publisher 
    Unregister subscriber 
    Unregister subscriber 
    Unregister subscriber 
    Unegister publisher 
    Unegister publisher 
    Unegister publisher 
    Register subscriber 
    Register subscriber 
    Register subscriber 
    Register publisher 
    Register publisher 
    Register publisher 
    Register publisher 

How to reproduce

Run the test and enable shared_memory monitoring.

How did you get eCAL?

I don't know

Environment

eCAL System Information

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