==================
POP Release 21.0.0
==================

We are pleased to release POP 21.0.0.
This release makes it possible to fork a process involving a hub.


Pseudocode example of process forking:

.. code-block:: python

    import pop.hub
    import concurrent.futures

    # Create a hub
    hub = pop.hub.Hub()

    # Initialize the asyncio loop structures
    hub.pop.loop.create()
    # Replace the default executor, ThreadPoolExecutor, with a ProcessPoolExecutor
    hub.pop.loop.EXECUTOR = concurrent.futures.ProcessPoolExecutor()

    # Run the function in the executor by passing it and it's args to hub.pop.loop.wrap
    ret = hub.pop.loop.wrap(hub.my_sub.my_function, *my_func_args, **my_func_kwargs)
    # Await the return or run_until_complete in the loop
    hub.pop.Loop.run_until_complete(ret)


Functional example of process forking using a function not on the hub:

.. code-block:: python

    import pop.hub
    import concurrent.futures
    import os

    hub = pop.hub.Hub()
    hub.pop.loop.create()
    hub.pop.loop.EXECUTOR = concurrent.futures.ProcessPoolExecutor()

    # Run a function that is not on the hub in the executor.
    # Here we will use os.getpid() so that we can verify that the executor is forking
    ret = hub.pop.loop.wrap(os.getpid)

    forked_pid = hub.pop.Loop.run_until_complete(ret)

    # Get the pid of the parent process
    pid = os.getpid()

    # Verify that the two PIDs are different
    assert forked_pid != pid