Exception handling or time out needed in the parallel mode

[krzysztofarendt]

When an exception happens in one of the threads, the main process waits indefinitely for its result. A timeout or exception handling should be implemented.

An example from one of the users of ModestPy:

Traceback (most recent call last):

  File "C:\Users\lucjsar\Documents\ModestPy\lucile_GBM_max_flows.py", line 151, in <module>
    estimates = session.estimate()

  File "C:\Users\lucjsar\Documents\ModestPy\modestpy\estimation.py", line 289, in estimate
    m_estimates = m_inst.estimate()

  File "C:\Users\lucjsar\Documents\ModestPy\modestpy\estim\ga_parallel\ga_parallel.py", line 315, in estimate
    workers=self.workers)

  File "C:\Users\lucjsar\AppData\Local\Continuum\anaconda3\lib\site-packages\modestga\ga.py", line 257, in minimize
    if pipes[i].poll(0.001):

  File "C:\Users\lucjsar\AppData\Local\Continuum\anaconda3\lib\multiprocessing\connection.py", line 257, in poll
    return self._poll(timeout)

 File "C:\Users\lucjsar\AppData\Local\Continuum\anaconda3\lib\multiprocessing\connection.py", line 330, in _poll
    return bool(wait([self], timeout))

  File "C:\Users\lucjsar\AppData\Local\Continuum\anaconda3\lib\multiprocessing\connection.py", line 868, in wait
    ready_handles = _exhaustive_wait(waithandle_to_obj.keys(), timeout)

  File "C:\Users\lucjsar\AppData\Local\Continuum\anaconda3\lib\multiprocessing\connection.py", line 800, in _exhaustive_wait
    res = _winapi.WaitForMultipleObjects(L, False, timeout)