How do I use the unit-test framework in parallel with shared Simulink data dictionaries?

How do I use the unit-test framework in parallel with shared Simulink data dictionaries? I'm calling "runInParallel" to perform some tests on Simulink models with a shared data dictionary, and the tests fail because the data dictionary cannot be accessed concurrently by all parallel workers.

Answer 1

[MathWorks Support Team]

The "runInParallel" function does not support all kinds of data access due to its multi-threaded nature. However, Simulink has the "Simulink.data.dictionary.setupWorkerCache" function which can be ran before the data dictionary is modified to ensure each parallel worker is only modifying their copy of the data dictionary.

To embed this function into the test suite, first create a TestRunnerPlugin that calls this function and then calls the superclass to run the actual tests. This way we ensure that the parallel pool has been initialized, the "setupWorkerCache" function called, and then the actual tests are ran. Save the below code in a file called "CacheSetupPlugin.m":

classdef CacheSetupPlugin < matlab.unittest.plugins.TestRunnerPlugin
    methods (Access = protected)
        %%overload the superclass' method
              function runTestSuite(plugin, pluginData)
                  Simulink.data.dictionary.setupWorkerCache

                    % Once setup is complete, invoke super class method to run the test suite
                    [e-mail](plugin, pluginData);

                    Simulink.data.dictionary.cleanupWorkerCache   
                end
      end
      methods (Hidden)
          function bool = supportsParallel(~) 
             bool = true; 
          end
      end
  end

Now run the test suite like so:

>> suite = matlab.unittest.TestSuite.fromClass(?testDataDictionaryInteractions)
>> runner = matlab.unittest.TestRunner.withTextOutput()
>> runner.addPlugin(CacheSetupPlugin)
>> result = runInParallel(runner,suite)

See the following links for added information:

https://www.mathworks.com/help/matlab/matlab_prog/create-custom-plugin.html

https://www.mathworks.com/help/matlab/matlab_prog/customizing-a-testrunner-with-plugins.html