[WIP] improve parameters support of the callbacks

[Thecave3]

• adaptation of parallelrunner.py to support all versions of Python
• minor bugs fixed

[pagmatt]

is this needed...?

[Thecave3]

probably not

[pagmatt]

this was taken from StackOverflow right? What about explaining with a few lines the reasoning behind this?

[Thecave3]

ThreadPool should share the memory with the main process, which is important to correctly use the callbacks.
The main difference between with Pool is that Pool spawn 5 independent processes (https://stackoverflow.com/questions/46045956/whats-the-difference-between-threadpool-vs-pool-in-the-multiprocessing-module).

[Thecave3]

At the current moment, I have included a simple test to check the effective working of the callback system, but I am having some issues since it cannot find the hash-example script.

Here is reported the full log of the execution:

(sem-py3.8) root@7c295de5c346:/workspace/sem# python -m pytest ./tests/test_utils.py
Getting and compiling ns-3...
=============================================================================================== test session starts ================================================================================================
platform linux -- Python 3.8.10, pytest-7.3.1, pluggy-1.0.0
rootdir: /workspace/sem
configfile: pyproject.toml
plugins: cov-4.0.0, xdist-3.2.1
collected 4 items

tests/test_utils.py ...F                                                                                                                                                                                     [100%]

===================================================================================================== FAILURES =====================================================================================================
__________________________________________________________________________________________________ test_callback ___________________________________________________________________________________________________

ns_3_compiled = '/tmp/pytest-of-root/pytest-11/test_callback0/ns-3-compiled'
config = {'campaign_dir': '/tmp/pytest-of-root/pytest-11/test_callback0/test_campaign', 'commit': '511132dd5cf9a691e40074113623fd6cff90ca61', 'params': {'dict': '/usr/share/dict/words', 'time': False}, 'script': 'hash-example'}
parameter_combination = OrderedDict([('dict', '/usr/share/dict/american-english'), ('time', False), ('RngRun', '0')])

    def test_callback(ns_3_compiled, config, parameter_combination):
        cb = TestCallback()
        n_runs = 10
        expected_output = 'Starting the simulations!\n' + f'Start single run!\nRun ended {0}\n' * n_runs + 'Simulations are over!\n'

>       campaign = CampaignManager.new(ns_3_compiled, config['script'], config['campaign_dir'], runner_type='SimulationRunner', overwrite=True,
                                           skip_configuration=True,
                                           check_repo=False
                                           #, optimized=True, max_parallel_processes=max_parallel_processes
                                           )

tests/test_utils.py:128:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
sem/manager.py:157: in new
    runner = CampaignManager.create_runner(ns_path, script,
sem/manager.py:260: in create_runner
    return locals().get(runner_type,
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

self = <sem.runner.SimulationRunner object at 0x7fd6864deeb0>, path = '/tmp/pytest-of-root/pytest-11/test_callback0/ns-3-compiled', script = 'hash-example', optimized = True, skip_configuration = True
max_parallel_processes = None

    def __init__(self, path, script, optimized=True, skip_configuration=False,
                 max_parallel_processes=None):
        """
        Initialization function.

        Args:
            path (str): absolute path to the ns-3 installation this Runner
                should lock on.
            script (str): ns-3 script that will be used by this Runner.
            optimized (bool): whether this Runner should build ns-3 with the
                optimized profile.
            skip_configuration (bool): whether to skip the configuration step,
                and only perform compilation.
        """

        # Save member variables
        self.path = path
        self.script = script
        self.optimized = optimized
        self.max_parallel_processes = max_parallel_processes

        if optimized:
            # For old ns-3 installations, the library is in build, while for
            # recent ns-3 installations it's in build/lib. Both paths are
            # thus required to support all versions of ns-3.
            library_path = "%s:%s" % (
                os.path.join(path, 'build/optimized'),
                os.path.join(path, 'build/optimized/lib'))
        else:
            library_path = "%s:%s" % (
                os.path.join(path, 'build/'),
                os.path.join(path, 'build/lib'))

        # We use both LD_ and DYLD_ to support Linux and Mac OS.
        self.environment = {
            'LD_LIBRARY_PATH': library_path,
            'DYLD_LIBRARY_PATH': library_path}

        # Configure and build ns-3
        self.configure_and_build(path, optimized=optimized,
                                 skip_configuration=skip_configuration)

        # ns-3's build status output is used to get the executable path for the
        # specified script.
        if os.path.exists(os.path.join(self.path, "ns3")):
            # In newer versions of ns-3 (3.36+), the name of the build status file is
            # platform-dependent
            build_status_fname = ".lock-ns3_%s_build" % sys.platform
            build_status_path = os.path.join(path, build_status_fname)
        else:
            build_status_fname = "build.py"
            if optimized:
                build_status_path = os.path.join(path,
                                                'build/optimized/build-status.py')
            else:
                build_status_path = os.path.join(path,
                                                'build/build-status.py')

        # By importing the file, we can naturally get the dictionary
        loader = importlib.machinery.SourceFileLoader(build_status_fname, build_status_path)
        mod = types.ModuleType(loader.name)
        loader.exec_module(mod)


        # Search is simple: we look for the script name in the program field.
        # Note that this could yield multiple matches, in case the script name
        # string is contained in another script's name.
        # matches contains [program, path] for each program matching the script
        matches = [{'name': program,
                    'path': os.path.abspath(os.path.join(path, program))} for
                   program in mod.ns3_runnable_programs if self.script
                   in program]

        if not matches:
>           raise ValueError("Cannot find %s script" % self.script)
E           ValueError: Cannot find hash-example script

sem/runner.py:100: ValueError
----------------------------------------------------------------------------------------------- Captured stderr call -----------------------------------------------------------------------------------------------
Building ns-3: 100%|██████████| 2/2 [00:00<00:00, 108.11file/s]
================================================================================================= warnings summary =================================================================================================
tests/test_utils.py:104
  /workspace/sem/tests/test_utils.py:104: PytestCollectionWarning: cannot collect test class 'TestCallback' because it has a __init__ constructor (from: tests/test_utils.py)
    class TestCallback(CallbackBase):

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
============================================================================================= short test summary info ==============================================================================================
FAILED tests/test_utils.py::test_callback - ValueError: Cannot find hash-example script
===================================================================================== 1 failed, 3 passed, 1 warning in 29.18s ======================================================================================
(sem-py3.8) root@7c295de5c346:/workspace/sem#