CoreFoundation based selector and asyncio event loop

asyncio event loop

On macOS X, Cocoa uses an event loop to dispatch events (NSRunLoop, which is a wrapper around CFRunLoop).

Python's asyncio module uses an event loop too to handle asynchronous events. On macOS X, it's based on kqueue.

A thread can only use a single event loop, that's why it's not possible to use both Cocoa and asyncio on the same thread. This module implements an asyncio compatible event loop on top of CFRunLoop. Thus it's possible to use Cocoa in conjunction with asyncio. It uses internally PyObjC's runEventLoop or runConsoleEventLoop

Here is an example video of a simple Cocoa based GUI using asyncio and async/await to handle subprocesses and network calls:

The corresponding code is here: tests/gui/guidemo.py

Setup:

    loop = CoreFoundationEventLoop()
    asyncio.set_event_loop(loop)
    try:
        loop.run_forever()
    finally:
        loop.close()

CoreFoundationEventLoop's constructor's first argument is a boolean. True for a console app, False (default) for a GUI app. Additionnal arguments are then passed to PyObjCTools.AppHelper.runConsoleEventLoop or PyObjCTools.AppHelper.runEventLoop

selector

This module also provides a selector implementation based on CFRunLoop. But his selector isn't compatible with Cocoa GUIs

Installation

$ pip3 install corefoundationasyncio

This module depends on pyobjc

Contributing

Report issues here

Pull-requests welcome !

License