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diff --git a/examples/async/eratosthenes/doc/eratosthenes.rst b/examples/async/eratosthenes/doc/eratosthenes.rst index 494a94df3..56e9f391b 100644 --- a/examples/async/eratosthenes/doc/eratosthenes.rst +++ b/examples/async/eratosthenes/doc/eratosthenes.rst @@ -1,27 +1,21 @@ -Async examples -============== +Async "Eratosthenes" Example +============================ The Python language provides keywords for asynchronous operations, i.e., "async" to define coroutines or "await" to schedule asynchronous calls in the event loop (see `PEP 492 <https://peps.python.org/pep-0492/>`_). It is up to packages to implement an event loop, support for these keywords, and more. -The best-known package for this is `asyncio`. Since both an async package and -Qt itself work with event loops, special care must be taken to ensure that both -event loops work with each other. asyncio offers a function `stop` that allows -stopping an event loop without closing it. If it is called while a loop is -running through `run_forever`, the loop will run the current batch of callbacks -and then exit. New callbacks wil be scheduled the next time `run_forever` is -called. +The best-known package for this is `asyncio`. asyncio offers an API that allows +for the asyncio event loop to be replaced by a custom implementation. Such an +implementation is available with the `QtAsyncio` module. It is based on Qt and +uses Qt's event loop in the backend. -This approach is highly experimental and does not represent the state of the -art of integrating Qt with asyncio. Instead it should rather be regarded more -as a proof of concept to contrast asyncio with other async packages such as -`trio`, which offers a dedicated `low-level API +`trio` is another popular package that offers a dedicated `low-level API <https://trio.readthedocs.io/en/stable/reference-lowlevel.html>`_ for more -complicated use cases such as this. Specifically, there exists a function -`start_guest_run` that enables running the Trio event loop as a "guest" inside -another event loop - Qt's in our case. +complex use cases. Specifically, there exists a function `start_guest_run` that +enables running the Trio event loop as a "guest" inside another event loop - +Qt's in our case, standing in contrast to asyncio's approach. Based on this functionality, two examples for async usage with Qt have been implemented: `eratosthenes` and `minimal`: @@ -39,14 +33,6 @@ implemented: `eratosthenes` and `minimal`: boilerplate code is essential for an async program with Qt and offers a starting point for more complex programs. -Both examples feature: - -1. A window class. -2. An `AsyncHelper` class containing `start_guest_run` plus helpers and - callbacks necessary for its invocation. The entry point for the Trio/asyncio - guest run is provided as an argument from outside, which can be any async - function. - While `eratosthenes` offloads the asynchronous logic that will run in trio's/asyncio's event loop into a separate class, `minimal` demonstrates that async functions can be integrated into any class, including subclasses of Qt |