bloomberg
Use proper timeout in `test_examples.py`
When the broker is slow to terminate, this test may fail. Rather than using sleep and polling whether the process has sucessfully terminated, as we’ve done in this test previously, we can instead use the timeout argument of Popen.communicate to wait for the broker to terminate.
This patch does two things: first, it increases the timeout after the broker has been terminated until we decide to kill the broker from 0.1 seconds to 2.0 seconds. This is still a short wait, but it gives a slow broker much more time to gracefully shut down. Second, it switches from sleep-and-poll to using the Popen.communicate function with a timeout to wait until the process has terminated. The exact idiom used in this patch is given in the documentation for this function; the double call to communicate is explained there by the note:
If the process does not terminate after timeout seconds, a
`TimeoutExpired` exception will be raised. Catching this
exception and retrying communication will not lose any output.
Because of this, the two calls to communicate are safe, and we only need the output of the latest call.
